Major Hurricane Florence/Hurricane Warnings Hoisted SC/NC

Tropical Weather Discussions and Analysis
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

BULLETIN
Potential Tropical Cyclone Six Advisory Number 1
NWS National Hurricane Center Miami FL AL062018
1100 AM AST Thu Aug 30 2018

...TROPICAL STORM CONDITIONS EXPECTED OVER THE SOUTHERN CABO VERDE
ISLANDS ON FRIDAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...12.9N 18.4W
ABOUT 425 MI...680 KM ESE OF THE SOUTHERNMOST CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The government of the Cabo Verde Islands has issued a Tropical
Storm Warning for the southern islands of Santiago, Fogo and
Brava.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Santiago
* Fogo
* Brava

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

For storm information specific to your area, please monitor products
issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 AM AST (1500 UTC), the disturbance was centered near
latitude 12.9 North, longitude 18.4 West. The system is moving
toward the west near 12 mph (19 km/h), and this general motion
with a gradual turn toward the west-northwest is expected to
continue during the next few days. On the forecast track, the
disturbance is expected to move near or over the southern Cabo
Verde Islands on Friday.

Maximum sustained winds are near 30 mph (45 km/h) with higher gusts.
Some strengthening is forecast during the next 48 hours, and the
disturbance is expected to become a topical storm during the next
day or so.

Environmental conditions are favorable for the system to become a
tropical cyclone tonight or Friday.
* Formation chance through 48 hours...high...80 percent
* Formation chance through 5 days...high...90 percent

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL: The system could produce total rain accumulations
of 4 to 8 inches across the southern Cabo Verde Islands. These
rains could produce life-threatening flash floods.

WINDS: Tropical storm conditions are expected in the southern Cabo
Verde Islands on Friday.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 PM AST.
Next complete advisory at 500 PM AST.

$$
Forecaster Avila
Attachments
08302018 P TD 6 144600_5day_cone_no_line_and_wind.png
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Hurricane Florence Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL062018
835 AM AST Wed Sep 05 2018

...FLORENCE BECOMES A MAJOR HURRICANE...
...FIRST OF THE 2018 ATLANTIC HURRICANE SEASON...

Recent satellite imagery indicates that Florence is still
strengthening and is now a major hurricane. Maximum sustained
winds are estimated to be 120 mph (195 km/h). This increase in
intensity will be reflected in the forecast issued with the 1100 AM
AST (1500 UTC) advisory package.


SUMMARY OF 835 AM AST...1235 UTC...INFORMATION
---------------------------------------------------
LOCATION...21.7N 45.2W
ABOUT 1185 MI...1910 KM ENE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 1405 MI...2265 KM ESE OF BERMUDA
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...961 MB...28.38 INCHES

$$
Forecaster Berg/Rhome
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
TexasBreeze
Posts: 942
Joined: Sun Sep 26, 2010 4:46 pm
Location: NW Houston, TX
Contact:

Since developing close to Africa, the system has had modelling to be an eventual threat to the east coast. There have been some funky model tracks for it including large loops and southerly u-turns off the east coast!
User avatar
DoctorMu
Posts: 5648
Joined: Sun Jun 28, 2015 11:58 am
Location: College Station
Contact:

Euro and Canadian have Florence slamming into the NC coastline in a week. GFS not so much - so it's a lock! ;)

https://www.tropicaltidbits.com/analysi ... _us_30.png

https://www.tropicaltidbits.com/analysi ... p_us_8.png
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

TROPICAL STORM FLORENCE DISCUSSION NUMBER 32
NWS NATIONAL HURRICANE CENTER MIAMI FL AL062018
500 AM AST FRI SEP 07 2018

FLORENCE'S STRUCTURE CONTINUES TO BE NEGATIVELY AFFECTED BY STRONG
SOUTHWESTERLY SHEAR. CLOUD TOPS HAVE GENERALLY WARMED OVER THE
PAST 6 HOURS, AND RECENT MICROWAVE DATA SHOW THAT THE LOW-LEVEL
CIRCULATION CENTER OF FLORENCE IS DISPLACED NEARLY 20 NMI TO THE
SOUTHWEST OF THE MID-LEVEL CENTER. SATELLITE INTENSITY ESTIMATES
HAVE DECREASED SINCE LAST NIGHT, AND NOW SUPPORT AN INITIAL
INTENSITY OF 55 KT.

BASED ON GFS AND ECMWF SHIPS DIAGNOSTIC OUTPUT, THE SOUTHWESTERLY
SHEAR IS NEAR ITS PEAK NOW, AND SHOULD GRADUALLY DECREASE OVER THE
NEXT 24 TO 36 H. ALL OF THE INTENSITY GUIDANCE SHOWS LITTLE CHANGE
IN INTENSITY THROUGH THAT TIME. FROM 48 H ONWARD, A LOW SHEAR/WARM
SST ENVIRONMENT SHOULD ALLOW THE TROPICAL STORM TO RE-STRENGTHEN.
HOWEVER, THE EXTENT AND TIMING OF THE STRENGTHENING VARIES GREATLY
FROM MODEL TO MODEL, WITH THE DYNAMICAL MODELS GENERALLY SHOWING
MORE INTENSIFICATION, AND SOONER, THAN THE STATISTICAL MODELS. AS
HAS BEEN THE CASE FOR MOST OF FLORENCE'S EXISTENCE THUS FAR,
CONFIDENCE IN THE INTENSITY FORECAST, ESPECIALLY BEYOND 36 H, IS
LOW. THE NEW OFFICIAL FORECAST IS A LITTLE LOWER THAN THE PREVIOUS
ADVISORY FOR THE FIRST 48 H, BUT CLOSE TO IT AFTER THAT, AND LIES
BETWEEN THE MORE AGGRESSIVE HCCA AND LESS AGGRESSIVE IVCN CONSENSUS
AIDS.

NIGHTTIME PROXY-VIS AND EARLIER MICROWAVE IMAGERY INDICATE THAT
FLORENCE HAS TURNED WESTWARD, WITH AN ESTIMATED INITIAL MOTION OF
275/6 KT. MOST OF THE TRACK GUIDANCE HAS SHIFTED SLIGHTLY TOWARD THE
SOUTHWEST, SO THE NHC TRACK FORECAST HAS ALSO BEEN NUDGED IN THAT
DIRECTION. OVER THE NEXT 3 DAYS OF THE FORECAST, FLORENCE SHOULD BE
STEERED GENERALLY WESTWARD, AND THEN WEST-NORTHWESTWARD, BY A
MID-LEVEL RIDGE TO ITS NORTH. BY DAYS 4 AND 5, A DEVELOPING
MID-LATITUDE TROUGH COULD CREATE A WEAKNESS IN THIS RIDGE AND ALLOW
FLORENCE TO MOVE MORE TOWARD THE NORTHWEST, BUT THERE IS STILL
CONSIDERABLE UNCERTAINTY IN THE GLOBAL MODELS AND THEIR ENSEMBLES
REGARDING THE STRENGTH OF THE RIDGE AND IF THE AFOREMENTIONED TROUGH
WILL HAVE ANY NOTABLE IMPACT ON THE TRACK OF FLORENCE. THE NHC
FORECAST FOLLOWS HCCA VERY CLOSELY, AND IS ALSO NEAR THE MIDDLE OF
THE LARGE COMBINED ENVELOPE OF THE GFS, UKMET, AND ECMWF ENSEMBLES.

KEY MESSAGES:

1. REGARDLESS OF FLORENCE'S EVENTUAL TRACK, LARGE SWELLS WILL BEGIN
TO AFFECT BERMUDA LATER TODAY AND PORTIONS OF THE U.S. EAST COAST
THIS WEEKEND, RESULTING IN LIFE-THREATENING SURF AND RIP CURRENTS.

2. THERE IS STILL VERY LARGE UNCERTAINTY IN FLORENCE'S TRACK
BEYOND DAY 5, AND IT IS TOO SOON TO DETERMINE WHAT, IF ANY, OTHER
IMPACTS FLORENCE COULD HAVE ON THE U.S. EAST COAST NEXT WEEK.

3. SINCE WE ARE NEAR THE PEAK OF HURRICANE SEASON, THIS IS A GOOD
TIME FOR EVERYONE WHO LIVES IN A HURRICANE-PRONE AREA TO ENSURE THEY
HAVE THEIR HURRICANE PLAN IN PLACE.

FORECAST POSITIONS AND MAX WINDS

INIT 07/0900Z 25.1N 50.7W 55 KT 65 MPH
12H 07/1800Z 25.1N 51.8W 55 KT 65 MPH
24H 08/0600Z 25.0N 53.2W 55 KT 65 MPH
36H 08/1800Z 25.0N 54.3W 60 KT 70 MPH
48H 09/0600Z 25.1N 55.4W 70 KT 80 MPH
72H 10/0600Z 26.2N 58.3W 95 KT 110 MPH
96H 11/0600Z 27.5N 63.5W 110 KT 125 MPH
120H 12/0600Z 30.0N 70.0W 110 KT 125 MPH

$$
FORECASTER ZELINSKY
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Tropical Storm Florence Discussion Number 36
NWS National Hurricane Center Miami FL AL062018
500 AM AST Sat Sep 08 2018

Although Florence remains a sheared tropical cyclone, satellite
imagery during the past 6 h also indicates that the shear has
started to abate somewhat, which has allowed the dense cirrus
canopy to build back over the previously exposed low-level
circulation center. Furthermore, deep convection with overshooting
cloud tops near -80C and an abundance of lightning activity have
developed very close to the center. Based on these data along with
Dvorak intensity estimates of T3.5/55 kt from TAFB and SAB, the
initial intensity has been raised to 55 kt.

The initial motion estimate is 265/8 kt. The mid-latitude flow
across CONUS and the northern Atlantic is forecast to flatten out
and become more zonal over the next 48 h or so, resulting in the
development of a narrow east-west oriented ridge along 35/36N
latitude. This large-scale feature is expected to steer Florence
in a general westward direction during that time. By days 3-5,
however, the flow across the central and western U.S. is forecast
to buckle and become more meridional as a deep mid-/upper-level
trough over the northeast Pacific pushes inland over the western
U.S., causing downstream ridging over the northeastern U.S. and
northwestern Atlantic. The global models agree on this general
change in the synoptic-scale flow pattern, but they differ
noticeably on where a downstream mid-/upper-level high pressure cell
takes up residence over the Atlantic either to the northwest or
northeast of Bermuda. The farther west/east the high develops will
determine how far west/east Florence will eventually move and
possibly affect the U.S. east coast beyond the 5-day forecast
period. The new official forecast track is close to the previous
advisory track through 48 h, and then was nudged a little to the
left or west of the previous track, which is close to the consensus
model TVCN and is north of the corrected-consensus models FSSE and
HCCA since the bulk of the NHC model guidance lies north of those
latter two models.

The upper-level environment is expected to improve to significantly
during the next 12 h and beyond with the current 20 kt of
southwesterly shear forecast to give way to shear of less than 10
kt. By 72 h and beyond, light shear from the southeast and east
along with the development of strong upper-level outflow jets to
the north of Florence is expected to create an environment that
favors significant and possibly even rapid strengthening. The new
NHC intensity forecast has been increased over the previous advisory
in anticipation of these very favorable dynamical conditions
developing, and now shows Florence becoming a hurricane by Sunday
and a major hurricane in 3 days, followed by additional
strengthening over the very warm Atlantic waters of at least 29 deg
C that are about 2 deg C above normal right now. The consensus
models IVCN and HCCA were closely followed, which are a little
below the FSSE model.

Key Messages:

1. Regardless of Florence's eventual track, large swells are
affecting Bermuda and will begin to affect portions of the U.S.
East Coast this weekend, resulting in life-threatening surf and rip
currents.

2. The risk of other direct impacts associated with Florence along
the U.S. East Coast next week has increased. However, there is
still very large uncertainty in model forecasts of Florence's track
beyond day 5, making it too soon to determine the exact location,
magnitude, and timing of these impacts. Interests near and along
the U.S. East Coast should monitor the progress of Florence through
the weekend and ensure they have their hurricane plans in place.

FORECAST POSITIONS AND MAX WINDS

INIT 08/0900Z 24.5N 54.2W 55 KT 65 MPH
12H 08/1800Z 24.6N 55.0W 60 KT 70 MPH
24H 09/0600Z 24.6N 56.0W 65 KT 75 MPH
36H 09/1800Z 24.6N 57.2W 75 KT 85 MPH
48H 10/0600Z 24.9N 59.0W 90 KT 105 MPH
72H 11/0600Z 26.0N 64.0W 105 KT 120 MPH
96H 12/0600Z 28.0N 70.2W 120 KT 140 MPH
120H 13/0600Z 30.9N 75.8W 125 KT 145 MPH

$$
Forecaster Stewart

Attachments
09082018 5 AM Florence 084758_5day_cone_no_line_and_wind.png
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

https://www.nhc.noaa.gov/#Florence
https://www.nhc.noaa.gov/refresh/graphi ... k#contents

Tropical Storm Florence Discussion Number 37
NWS National Hurricane Center Miami FL AL062018
1100 AM AST Sat Sep 08 2018

Code: Select all

Florence has undergone a dramatic structural evolution just within
the past 6 hours or so.  Vertical shear has decreased just enough
for the storm to take on a more symmetric shape, with convection
developing in a ring around the low-level center, and an elongated
band wrapping around to the northeastern part of the circulation.
The convection has waned a little bit in intensity, however, due to
the presence of dry air, and Dvorak estimates support maintaining
an initial intensity of 55 kt for now.  A NOAA P-3 aircraft is
approaching Florence now on a research mission and should provide
some useful data to better assess the storm's intensity.

Recent WindSat microwave data revealed that Florence has a
well-defined low-level ring in the 37-GHz channel, which tends to
be a harbinger of strengthening when environmental conditions are
favorable.  Since vertical shear is decreasing and should be 10 kt
or less by later today, and Florence is heading toward a deeper
pool of warm water over the southwestern Atlantic, a significant
phase of intensification is likely to begin by tonight, continuing
through Tuesday or Wednesday.  In fact, the official intensity
forecast explicitly shows rapid intensification occurring between
24 and 48 hours from now, and Florence is expected to become a
major hurricane by Monday.  The HFIP Corrected Consensus (HCCA) and
the Florida State Superensemble (FSSE), both of which tend to do
well in these scenarios, are both near the upper end of the guidance
suite, especially through day 3.  Even by days 4 and 5, the HWRF,
HMON, and ICON intensity consensus are near the top end of the
guidance, close to HCCA and FSSE.  Given the signals in the
environment, and the solutions provided by these models, the NHC
intensity forecast shows Florence reaching category 4 intensity by
day 3 and maintains that through the end of the forecast period.

Florence's longer-term motion is 265/6 kt.  The cyclone appears to
be slowing down as was expected, and this type of motion is likely
to continue for the next 24-36 hours.  In fact, the track guidance
has slowed down during this period, and the updated NHC track
forecast is a little slower than the previous one.  After 36 hours,
the most notable change in the models was a northeastward shift in
the 06Z GFS.  However, that run appears to be an outlier from the
rest of the dynamical models, and its trend opposes the slight
westward shift noted in the HCCA and FSSE aids.  The updated NHC
track forecast is therefore very close to or slightly west of the
previous forecast on days 4 and 5.  The exact path of Florence as it
approaches the southeastern U.S. coastline will depend heavily on
the position and strength of the blocking high pressure that is
expected to develop north of Bermuda and extend westward over the
eastern U.S., and so far there has not been much more clarity on
those important details.

Key Messages:

1. Florence is forecast to be a dangerous major hurricane near the
southeast U.S. coast by late next week, and the risk of direct
impacts continues to increase. However, given the uncertainty in
track and intensity forecasts at those time ranges, it's too soon to
determine the exact timing, location, and magnitude of those
impacts.

2. Interests along the U.S. East Coast, particularly from north
Florida through North Carolina, should closely monitor the progress
of Florence, ensure they have their hurricane plan in place, and
follow any advice given by local officials.

3. Large swells are affecting Bermuda and will begin to affect
portions of the U.S. East Coast this weekend, resulting in
life-threatening surf and rip currents.

FORECAST POSITIONS AND MAX WINDS

INIT  08/1500Z 24.5N  54.3W   55 KT  65 MPH
 12H  09/0000Z 24.6N  55.0W   60 KT  70 MPH
 24H  09/1200Z 24.6N  56.1W   70 KT  80 MPH
 36H  10/0000Z 24.8N  57.5W   85 KT 100 MPH
 48H  10/1200Z 25.1N  59.3W  100 KT 115 MPH
 72H  11/1200Z 26.3N  64.9W  115 KT 130 MPH
 96H  12/1200Z 28.5N  71.5W  125 KT 145 MPH
120H  13/1200Z 31.5N  77.0W  120 KT 140 MPH

$$
Forecaster Berg
[/i]
Last edited by unome on Tue Sep 11, 2018 8:52 am, edited 1 time in total.
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Tropical Storm Florence Discussion Number 38
NWS National Hurricane Center Miami FL AL062018
500 PM AST Sat Sep 08 2018

A NOAA P3 aircraft conducted a research mission several hours ago
in Florence and measured SFMR surface winds of around 60 kt and
winds up to 65 kt at a flight level of 8000 feet. Velocities of
65-70 kt at 500 meters were also measured by the Doppler radar on
the plane. Based on these data, the initial wind speed is raised to
60 kt. Dropsonde data also showed that the central pressure was
down to 989 mb.

Florence is slowly recovering from the dry air its circulation
ingested while it was under the influence of strong shear.
Convection in the outer bands is relatively thin but is deeper and
more persistent near the center. Now that the shear has decreased
and the warm waters ahead of Florence reach deeper into the ocean,
continued strengthening is anticipated. In fact, the official
forecast continues to show a period of rapid intensification, now
beginning 12-24 hours, with Florence reaching major hurricane
intensity between 36-48 hours. One fly in the ointment is that the
SHIPS diagnostics are keeping mid-level relative humidities around
the cyclone around 50 percent, which isn't particularly moist, but
I'm going to assume that Florence will be able to scour out the dry
air within its circulation in the coming days. The HCCA model and
the ICON intensity consensus support maintaining a forecast peak
intensity of 125 kt in 4 days or so, so no significant changes were
made from the previous forecast. Regardless of the specifics of
the other models--some of which are higher and some of which are
lower--Florence is expected to be a powerful major hurricane on
days 3 through 5 as it moves across the southwestern Atlantic Ocean.

Florence is creeping westward (270 degrees) at 4 kt, trapped
between high pressure to its northeast and southwest. A different
blocking ridge is expected to develop north and northeast of
Bermuda over the next few days, causing Florence to accelerate
toward the west-northwest and northwest between days 3-5. There
have been some notable shifts in the model guidance on this cycle,
with the ECMWF model swinging to the northeast closer to the GFS,
and the HWRF model swinging farther south along the southern edge
of the guidance envelope. Despite this change in the deterministic
ECMWF run, its individual ensemble members are still showing a
significant spread of solutions from just north of the Bahamas to
offshore the coast of North Carolina by day 5. Because of this
spread, the updated NHC track forecast largely maintains
continuity and remains close to the TVCN multi-model consensus.
And despite the ECMWF's shift, this track prediction remains north
of the HCCA and FSSE solutions.

Key Messages:

1. Florence is forecast to be a dangerous major hurricane near the
southeast U.S. coast by late next week, and the risk of direct
impacts continues to increase. However, given the uncertainty in
track and intensity forecasts at those time ranges, it's too soon to
determine the exact timing, location, and magnitude of those
impacts.

2. Interests along the U.S. East Coast, particularly from north
Florida through North Carolina, should closely monitor the progress
of Florence, ensure they have their hurricane plan in place, and
follow any advice given by local officials.

3. Large swells affecting Bermuda and portions of the U.S. East
Coast will continue into next week. These swells will result in
life-threatening surf and rip currents.


FORECAST POSITIONS AND MAX WINDS

INIT 08/2100Z 24.6N 54.7W 60 KT 70 MPH
12H 09/0600Z 24.6N 55.4W 70 KT 80 MPH
24H 09/1800Z 24.7N 56.6W 80 KT 90 MPH
36H 10/0600Z 25.0N 58.3W 95 KT 110 MPH
48H 10/1800Z 25.4N 60.5W 110 KT 125 MPH
72H 11/1800Z 26.9N 66.4W 120 KT 140 MPH
96H 12/1800Z 29.5N 72.5W 125 KT 145 MPH
120H 13/1800Z 32.5N 77.0W 120 KT 140 MPH

$$
Forecaster Berg
Attachments
09082018 5 PM Florence 204611_5day_cone_no_line_and_wind.png
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

our peeps on the east coast are paying close attention to Florence, as is the Navy in Norfolk, VA (https://www.cnic.navy.mil/regions/cnrma ... rfolk.html https://www.facebook.com/pg/NavalStationNorfolk)

11:00 AM AST Sun Sep 9
Location: 24.4°N 56.3°W
Moving: W at 6 mph
Min pressure: 984 mb
Max sustained: 75 mph


https://www.nhc.noaa.gov/nhc_at1.xml
https://www.nhc.noaa.gov/#Florence
https://www.nhc.noaa.gov/refresh/graphi ... k#contents

Image

Image

Hurricane Florence Discussion Number 41
NWS National Hurricane Center Miami FL AL062018
1100 AM AST Sun Sep 09 2018

Satellite images indicate that Florence is strengthening. Deep convection has intensified in the central dense overcast, with hints of a ragged eye in the latest GOES-16 visible channel. The NOAA Hurricane Hunters just flew through the eye, finding 70 kt winds at flight-level and 66 kt from the SFMR. This data confirms that Florence has become a hurricane again, and the initial wind speed is set to 65 kt. The aircraft also found that the minimum pressure has decreased to 984 mb.

Overnight microwave data and the Hurricane Hunter vortex message show that a mostly complete eyewall has formed with Florence. In combination with low vertical wind shear and progressively warmer waters near 29C, this structure is a blueprint for rapid intensification. Almost all of the intensity guidance is showing at least one period of rapid strengthening during the next few days, which is rather rare. The NHC wind speed forecast is raised in the first couple of days following the guidance trend, then is very similar to the previous one. All indications are that Florence will be an extremely dangerous Category 4 hurricane while it moves over the western Atlantic toward the southeastern United States.

Florence continues moving slowly westward, caught between a pair of mid-level ridges over the Atlantic Ocean. A very strong ridge is forecast to build over the northwestern Atlantic during the next few days, which should steer Florence west-northwestward at a much faster forward speed. By Wednesday, the hurricane should turn northwestward, and slow down somewhat due to another ridge forming over the Ohio Valley. It is interesting to note that while the ensemble means from the ECMWF and UKMET are west of the NHC forecast, the strongest members are on the right side of their ensemble envelope. Thus, the new NHC track forecast is very similar to the previous one, and continues to lie between the corrected consensus and consensus aids. The Ohio Valley ridge is concerning because Florence could stop moving pretty quickly around day 5, potentially leading to a serious heavy rain episode and inland flood hazard.

Key Messages:

1. There is an increasing risk of two life-threatening impacts from Florence: storm surge at the coast and freshwater flooding from a prolonged heavy rainfall event inland. While it is too soon to determine the exact timing, location, and magnitude of these impacts, interests at the coast and inland from South Carolina into the mid-Atlantic region should closely monitor the progress of Florence, ensure they have their hurricane plan in place, and follow any advice given by local officials.


FORECAST POSITIONS AND MAX WINDS

INIT 09/1500Z 24.4N 56.3W 65 KT 75 MPH
12H 10/0000Z 24.5N 57.4W 80 KT 90 MPH
24H 10/1200Z 24.9N 59.3W 95 KT 110 MPH
36H 11/0000Z 25.6N 61.7W 105 KT 120 MPH
48H 11/1200Z 26.4N 64.5W 120 KT 140 MPH
72H 12/1200Z 29.0N 70.8W 125 KT 145 MPH
96H 13/1200Z 32.2N 75.8W 120 KT 140 MPH
120H 14/1200Z 35.0N 78.5W 85 KT 100 MPH...INLAND

$$
Forecaster Blake
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

https://www.nhc.noaa.gov/#Florence
https://www.nhc.noaa.gov/refresh/graphi ... k#contents

11:00 PM AST Sun Sep 9
Location: 24.6°N 57.7°W
Moving: W at 7 mph
Min pressure: 974 mb
Max sustained: 90 mph

Code: Select all

663 
WTNT41 KNHC 100248
TCDAT1

Hurricane Florence Discussion Number  43
NWS National Hurricane Center Miami FL       AL062018
1100 PM AST Sun Sep 09 2018

Florence's satellite appearance has continued to improve quite
markedly since the previous advisory. An eye was evident in GOES-16
high-resolution infrared imagery and other channels between
2300-0000 UTC, but it became cloud covered immediately thereafter
due to a strong burst of deep convection in the southern and eastern
eyewall where cloud tops colder than -80C and an abundance of
lightning activity was observed. Since that time, the CDO has
expanded and become more circular, outflow has increased and become
more symmetrical, and an eye has begun to re-appear. The initial
intensity has been increased to 80 kt for this advisory based on a
subjective Dvorak intensity estimate of T4.5/77 kt from SAB and NHC
objective intensity estimates ranging from 77 kt to 87 kt.

The initial motion estimate is 280/06 kt. Once again, there is no
significant change to the previous forecast track or synoptic
reasoning. The models appear to be getting better dialed in on both
the location and strength of the developing blocking ridge in the
vicinity of Bermuda during the next 4 days as the mid-latitude flow
amplifies across the CONUS and the northwestern Atlantic. In fact,
the global models are now in very good agreement on forecasting
Florence's upper-level mass outflow being deposited to the north and
east of the hurricane, which will act to further strengthen the
blocking ridge and help to drive the hurricane northwestward toward
the southeastern U.S. coastal region. The new NHC model guidance is
even more tightly packed about the previous forecast track, with
less than a 90 n mi cross-track spread at 72 h and less than 120 n
mi spread at 96 h, just prior to expected landfall. Therefore, the
new official advisory track is essentially just an update and
extension of the previous forecast, and lies between the nearly
juxtaposed HCCA and FSSE corrected consensus track models.

Now that Florence has developed an inner-core ring of deep
convection, which has insulated the eye from intrusions of dry air,
rapid intensification appears likely to begin soon and continue for
the next 36 hours or so due to the expected very low vertical wind
shear conditions, dual outflow jet pattern that will be developing,
and very warm SSTs of 29-29.5 deg C beneath the hurricane. The most
favorable combination of the aforementioned factors will occur in
about 48 h, and that's when Florence is likely to achieve its
maximum intensity.  After 72 hours, the wind shear is expected to
increase to around 10-15 kt from the south or southwest, and the
dual outflow pattern is forecast to change to only a single poleward
outflow pattern. This slight degradation in the upper-level
environment, along with slightly cooler SSTs, is expected to result
in a gradual weakening of the powerful cyclone. However, Florence is
still forecast to be near category-4 strength when the dangerous
hurricane makes landfall. The official intensity forecast is an
average of the intensity forecast from the corrected consensus
models HCCA and FSSE, with the latter explicitly forecasting a peak
intensity of 134 kt in 72 hours. It is also worth noting that the
model guidance is also significantly increasing the size of
Florence's wind field over the next few days, and the official
forecast reflects this trend.

The NOAA G-IV jet will conduct another synoptic surveillance
mission early Monday morning in support of the 1200 UTC model
cycle, and these flights will continue through Tuesday. In addition,
upper-air stations across portions of the central and eastern U.S.
are conducting special 0600 UTC and 1800 UTC radiosonde launches to
collect extra data for the numerical models. Hopefully these data
will help improve the track and intensity forecasts.

Key Messages:

1. There is an increasing risk of two life-threatening impacts from
Florence: storm surge at the coast and freshwater flooding from a
prolonged heavy rainfall event inland. While it is too soon to
determine the exact timing, location, and magnitude of these
impacts, interests at the coast and inland from South Carolina into
the mid-Atlantic region should closely monitor the progress of
Florence, ensure they have their hurricane plan in place, and follow
any advice given by local officials.

2. Large swells affecting Bermuda and portions of the U.S. East
Coast will continue this week.  These swells will result in
life-threatening surf and rip currents.


FORECAST POSITIONS AND MAX WINDS

INIT  10/0300Z 24.6N  57.7W   80 KT  90 MPH
 12H  10/1200Z 24.9N  59.1W   90 KT 105 MPH
 24H  11/0000Z 25.6N  61.5W  105 KT 120 MPH
 36H  11/1200Z 26.5N  64.4W  120 KT 140 MPH
 48H  12/0000Z 27.8N  67.6W  130 KT 150 MPH
 72H  13/0000Z 31.2N  73.6W  130 KT 150 MPH
 96H  14/0000Z 34.0N  77.5W  120 KT 140 MPH
120H  15/0000Z 35.2N  79.0W   55 KT  65 MPH...INLAND

$$
Forecaster Stewart

Code: Select all

296 
FONT11 KNHC 100248
PWSAT1

HURRICANE FLORENCE WIND SPEED PROBABILITIES NUMBER  43              
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL062018               
0300 UTC MON SEP 10 2018                                            

AT 0300Z THE CENTER OF HURRICANE FLORENCE WAS LOCATED NEAR LATITUDE 
24.6 NORTH...LONGITUDE 57.7 WEST WITH MAXIMUM SUSTAINED WINDS NEAR  
80 KTS...90 MPH...150 KM/H.                                         

Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH)                  
   ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME      
   EASTERN  DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME      
   CENTRAL  DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME      

WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS                 

CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST     
   ...34 KT (39 MPH... 63 KM/H)...                                  
   ...50 KT (58 MPH... 93 KM/H)...                                  
   ...64 KT (74 MPH...119 KM/H)...                                  
FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS               

PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE               
    OP  IS THE PROBABILITY OF THE EVENT BEGINNING DURING            
        AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY)               
   (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN           
        00Z MON AND THE FORECAST HOUR (CUMULATIVE PROBABILITY)      

PROBABILITIES ARE GIVEN IN PERCENT                                  
X INDICATES PROBABILITIES LESS THAN 1 PERCENT                       
PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN
THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT.             
PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY              
64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT.                 


  - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - -   

               FROM    FROM    FROM    FROM    FROM    FROM    FROM 
  TIME       00Z MON 12Z MON 00Z TUE 12Z TUE 00Z WED 00Z THU 00Z FRI
PERIODS         TO      TO      TO      TO      TO      TO      TO  
             12Z MON 00Z TUE 12Z TUE 00Z WED 00Z THU 00Z FRI 00Z SAT

FORECAST HOUR    (12)   (24)    (36)    (48)    (72)    (96)   (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
LOCATION       KT                                                   

ISLIP NY       34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

NYC JFK AIRPRT 34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

NYC CNTRL PARK 34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

NEWARK NJ      34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

TRENTON NJ     34  X   X( X)   X( X)   X( X)   X( X)   2( 2)   5( 7)

NWS EARLE NJ   34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   4( 5)

ALLENTOWN PA   34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   5( 6)

PHILADELPHIA   34  X   X( X)   X( X)   X( X)   X( X)   3( 3)   7(10)

ATLANTIC CITY  34  X   X( X)   X( X)   X( X)   X( X)   5( 5)   6(11)

BALTIMORE MD   34  X   X( X)   X( X)   X( X)   X( X)   8( 8)  12(20)
BALTIMORE MD   50  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

DOVER DE       34  X   X( X)   X( X)   X( X)   X( X)   8( 8)  10(18)
DOVER DE       50  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

ANNAPOLIS MD   34  X   X( X)   X( X)   X( X)   X( X)  10(10)  13(23)
ANNAPOLIS MD   50  X   X( X)   X( X)   X( X)   X( X)   1( 1)   3( 4)
ANNAPOLIS MD   64  X   X( X)   X( X)   X( X)   X( X)   X( X)   1( 1)

WASHINGTON DC  34  X   X( X)   X( X)   X( X)   X( X)  11(11)  15(26)
WASHINGTON DC  50  X   X( X)   X( X)   X( X)   X( X)   1( 1)   3( 4)
WASHINGTON DC  64  X   X( X)   X( X)   X( X)   X( X)   X( X)   1( 1)

CAPE HENLOPEN  34  X   X( X)   X( X)   X( X)   X( X)  12(12)   8(20)
CAPE HENLOPEN  50  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)
CAPE HENLOPEN  64  X   X( X)   X( X)   X( X)   X( X)   X( X)   1( 1)

OCEAN CITY MD  34  X   X( X)   X( X)   X( X)   X( X)  16(16)  11(27)
OCEAN CITY MD  50  X   X( X)   X( X)   X( X)   X( X)   2( 2)   3( 5)
OCEAN CITY MD  64  X   X( X)   X( X)   X( X)   X( X)   1( 1)   1( 2)

PAX RIVER NAS  34  X   X( X)   X( X)   X( X)   X( X)  18(18)  16(34)
PAX RIVER NAS  50  X   X( X)   X( X)   X( X)   X( X)   2( 2)   4( 6)
PAX RIVER NAS  64  X   X( X)   X( X)   X( X)   X( X)   1( 1)   1( 2)

WALLOPS CDA    34  X   X( X)   X( X)   X( X)   X( X)  19(19)  13(32)
WALLOPS CDA    50  X   X( X)   X( X)   X( X)   X( X)   3( 3)   3( 6)
WALLOPS CDA    64  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

CHARLOTTESVIL  34  X   X( X)   X( X)   X( X)   X( X)  20(20)  25(45)
CHARLOTTESVIL  50  X   X( X)   X( X)   X( X)   X( X)   1( 1)   9(10)
CHARLOTTESVIL  64  X   X( X)   X( X)   X( X)   X( X)   X( X)   3( 3)

RICHMOND VA    34  X   X( X)   X( X)   X( X)   X( X)  28(28)  24(52)
RICHMOND VA    50  X   X( X)   X( X)   X( X)   X( X)   6( 6)  11(17)
RICHMOND VA    64  X   X( X)   X( X)   X( X)   X( X)   1( 1)   6( 7)

DANVILLE VA    34  X   X( X)   X( X)   X( X)   X( X)  34(34)  36(70)
DANVILLE VA    50  X   X( X)   X( X)   X( X)   X( X)   8( 8)  22(30)
DANVILLE VA    64  X   X( X)   X( X)   X( X)   X( X)   2( 2)   7( 9)

NORFOLK NAS    34  X   X( X)   X( X)   X( X)   X( X)  35(35)  19(54)
NORFOLK NAS    50  X   X( X)   X( X)   X( X)   X( X)  10(10)   9(19)
NORFOLK NAS    64  X   X( X)   X( X)   X( X)   X( X)   3( 3)   6( 9)

NORFOLK VA     34  X   X( X)   X( X)   X( X)   X( X)  36(36)  19(55)
NORFOLK VA     50  X   X( X)   X( X)   X( X)   X( X)  11(11)   8(19)
NORFOLK VA     64  X   X( X)   X( X)   X( X)   X( X)   4( 4)   5( 9)

OCEANA NAS VA  34  X   X( X)   X( X)   X( X)   1( 1)  36(37)  19(56)
OCEANA NAS VA  50  X   X( X)   X( X)   X( X)   X( X)  11(11)   8(19)
OCEANA NAS VA  64  X   X( X)   X( X)   X( X)   X( X)   4( 4)   5( 9)

ELIZABETH CTY  34  X   X( X)   X( X)   X( X)   1( 1)  47(48)  19(67)
ELIZABETH CTY  50  X   X( X)   X( X)   X( X)   X( X)  19(19)  10(29)
ELIZABETH CTY  64  X   X( X)   X( X)   X( X)   X( X)   8( 8)   6(14)

GREENSBORO NC  34  X   X( X)   X( X)   X( X)   X( X)  34(34)  36(70)
GREENSBORO NC  50  X   X( X)   X( X)   X( X)   X( X)   8( 8)  22(30)
GREENSBORO NC  64  X   X( X)   X( X)   X( X)   X( X)   2( 2)   8(10)

RALEIGH NC     34  X   X( X)   X( X)   X( X)   X( X)  48(48)  33(81)
RALEIGH NC     50  X   X( X)   X( X)   X( X)   X( X)  20(20)  28(48)
RALEIGH NC     64  X   X( X)   X( X)   X( X)   X( X)   7( 7)  18(25)

ROCKY MT NC    34  X   X( X)   X( X)   X( X)   X( X)  54(54)  28(82)
ROCKY MT NC    50  X   X( X)   X( X)   X( X)   X( X)  27(27)  23(50)
ROCKY MT NC    64  X   X( X)   X( X)   X( X)   X( X)  12(12)  15(27)

CAPE HATTERAS  34  X   X( X)   X( X)   X( X)  12(12)  63(75)   7(82)
CAPE HATTERAS  50  X   X( X)   X( X)   X( X)   1( 1)  37(38)   6(44)
CAPE HATTERAS  64  X   X( X)   X( X)   X( X)   X( X)  19(19)   4(23)

FAYETTEVILLE   34  X   X( X)   X( X)   X( X)   1( 1)  59(60)  25(85)
FAYETTEVILLE   50  X   X( X)   X( X)   X( X)   X( X)  32(32)  27(59)
FAYETTEVILLE   64  X   X( X)   X( X)   X( X)   X( X)  16(16)  19(35)

CHARLOTTE NC   34  X   X( X)   X( X)   X( X)   X( X)  28(28)  29(57)
CHARLOTTE NC   50  X   X( X)   X( X)   X( X)   X( X)   4( 4)  18(22)
CHARLOTTE NC   64  X   X( X)   X( X)   X( X)   X( X)   1( 1)   6( 7)

CHERRY PT NC   34  X   X( X)   X( X)   X( X)   3( 3)  70(73)  15(88)
CHERRY PT NC   50  X   X( X)   X( X)   X( X)   X( X)  47(47)  16(63)
CHERRY PT NC   64  X   X( X)   X( X)   X( X)   X( X)  26(26)  13(39)

NEW RIVER NC   34  X   X( X)   X( X)   X( X)  13(13)  74(87)   6(93)
NEW RIVER NC   50  X   X( X)   X( X)   X( X)   1( 1)  56(57)   9(66)
NEW RIVER NC   64  X   X( X)   X( X)   X( X)   X( X)  34(34)   9(43)

MOREHEAD CITY  34  X   X( X)   X( X)   X( X)  11(11)  76(87)   6(93)
MOREHEAD CITY  50  X   X( X)   X( X)   X( X)   1( 1)  57(58)  10(68)
MOREHEAD CITY  64  X   X( X)   X( X)   X( X)   X( X)  36(36)  10(46)

SURF CITY NC   34  X   X( X)   X( X)   X( X)   3( 3)  74(77)  13(90)
SURF CITY NC   50  X   X( X)   X( X)   X( X)   X( X)  51(51)  17(68)
SURF CITY NC   64  X   X( X)   X( X)   X( X)   X( X)  33(33)  15(48)

WILMINGTON NC  34  X   X( X)   X( X)   X( X)   2( 2)  72(74)  15(89)
WILMINGTON NC  50  X   X( X)   X( X)   X( X)   X( X)  49(49)  19(68)
WILMINGTON NC  64  X   X( X)   X( X)   X( X)   X( X)  29(29)  16(45)

BALD HEAD ISL  34  X   X( X)   X( X)   X( X)   7( 7)  76(83)   7(90)
BALD HEAD ISL  50  X   X( X)   X( X)   X( X)   1( 1)  55(56)  13(69)
BALD HEAD ISL  64  X   X( X)   X( X)   X( X)   X( X)  36(36)  12(48)

FLORENCE SC    34  X   X( X)   X( X)   X( X)   X( X)  47(47)  25(72)
FLORENCE SC    50  X   X( X)   X( X)   X( X)   X( X)  20(20)  19(39)
FLORENCE SC    64  X   X( X)   X( X)   X( X)   X( X)  10(10)  13(23)

COLUMBIA SC    34  X   X( X)   X( X)   X( X)   X( X)  27(27)  23(50)
COLUMBIA SC    50  X   X( X)   X( X)   X( X)   X( X)   7( 7)  12(19)
COLUMBIA SC    64  X   X( X)   X( X)   X( X)   X( X)   2( 2)   6( 8)

LITTLE RIVER   34  X   X( X)   X( X)   X( X)   2( 2)  64(66)  17(83)
LITTLE RIVER   50  X   X( X)   X( X)   X( X)   X( X)  38(38)  19(57)
LITTLE RIVER   64  X   X( X)   X( X)   X( X)   X( X)  22(22)  13(35)

MYRTLE BEACH   34  X   X( X)   X( X)   X( X)   3( 3)  68(71)  10(81)
MYRTLE BEACH   50  X   X( X)   X( X)   X( X)   X( X)  38(38)  13(51)
MYRTLE BEACH   64  X   X( X)   X( X)   X( X)   X( X)  21(21)  11(32)

GEORGETOWN SC  34  X   X( X)   X( X)   X( X)   1( 1)  49(50)  18(68)
GEORGETOWN SC  50  X   X( X)   X( X)   X( X)   X( X)  24(24)  14(38)
GEORGETOWN SC  64  X   X( X)   X( X)   X( X)   X( X)  12(12)  10(22)

CHARLESTON SC  34  X   X( X)   X( X)   X( X)   1( 1)  33(34)  16(50)
CHARLESTON SC  50  X   X( X)   X( X)   X( X)   X( X)  12(12)  10(22)
CHARLESTON SC  64  X   X( X)   X( X)   X( X)   X( X)   6( 6)   5(11)

BEAUFORT MCAS  34  X   X( X)   X( X)   X( X)   X( X)  22(22)  14(36)
BEAUFORT MCAS  50  X   X( X)   X( X)   X( X)   X( X)   6( 6)   7(13)
BEAUFORT MCAS  64  X   X( X)   X( X)   X( X)   X( X)   2( 2)   4( 6)

ATLANTA GA     34  X   X( X)   X( X)   X( X)   X( X)   3( 3)   7(10)

AUGUSTA GA     34  X   X( X)   X( X)   X( X)   X( X)  15(15)  16(31)
AUGUSTA GA     50  X   X( X)   X( X)   X( X)   X( X)   2( 2)   5( 7)
AUGUSTA GA     64  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

SAVANNAH GA    34  X   X( X)   X( X)   X( X)   X( X)  14(14)  13(27)
SAVANNAH GA    50  X   X( X)   X( X)   X( X)   X( X)   3( 3)   4( 7)
SAVANNAH GA    64  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

KINGS BAY GA   34  X   X( X)   X( X)   X( X)   X( X)   6( 6)   6(12)

WAYCROSS GA    34  X   X( X)   X( X)   X( X)   X( X)   5( 5)   6(11)

MAYPORT NS FL  34  X   X( X)   X( X)   X( X)   X( X)   7( 7)   5(12)

JACKSONVILLE   34  X   X( X)   X( X)   X( X)   X( X)   4( 4)   5( 9)

GAINESVILLE FL 34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)

DAYTONA BEACH  34  X   X( X)   X( X)   X( X)   X( X)   2( 2)   1( 3)

COLUMBUS GA    34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   4( 5)

BERMUDA        34  X   X( X)   X( X)   2( 2)   2( 4)   X( 4)   X( 4)

$$                                                                  
FORECASTER STEWART                                                  
User avatar
Rip76
Posts: 1787
Joined: Mon Feb 15, 2010 12:38 am
Location: The Woodlands
Contact:

Wow...

down to 945
130kt FL in NE eyewall
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

Rip76 wrote:Wow...

down to 945
130kt FL in NE eyewall
yup, a cat 4 now - should take out the "Possible" in thread title
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

unome wrote:
Rip76 wrote:Wow...

down to 945
130kt FL in NE eyewall
yup, a cat 4 now - should take out the "Possible" in thread title
Updated Topic to include Major Hurricane and change to Likely. It's a typical busy Monday work wise for me... ;)
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

srainhoutx wrote:Updated Topic to include Major Hurricane and change to Likely. It's a typical busy Monday work wise for me... ;)
thank you, as always :)
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

a post from Chris Hollis of Tropical Atlantic.com , images of recon with IR satellite, stunning

https://canetalk.com/2018/09/1536605407 ... 6109.shtml

more recon options: http://hurricanecity.com/recon/ (they mirror Tropical Atlantic.com to reduce strain on their server)
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Florence has completed an Eye Wall Replacement Cycle with a much larger eye of about 50 miles wide. This should lead to a much larger storm and allow for re intensification throughout the day.

Image
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

https://www.nhc.noaa.gov/#Florence
https://www.nhc.noaa.gov/refresh/graphi ... e#contents

Code: Select all

WTNT31 KNHC 112040
TCPAT1

BULLETIN
Hurricane Florence Advisory Number  50
NWS National Hurricane Center Miami FL       AL062018
500 PM AST Tue Sep 11 2018

...DANGEROUS FLORENCE EXPECTED TO BRING LIFE-THREATENING STORM
SURGE AND RAINFALL TO PORTIONS OF THE CAROLINAS AND MID-ATLANTIC...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...27.5N 67.1W
ABOUT 360 MI...580 KM SSW OF BERMUDA
ABOUT 785 MI...1260 KM ESE OF CAPE FEAR NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...140 MPH...220 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...945 MB...27.91 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

A Storm Surge Warning has been issued from South Santee
River, South Carolina, to Duck, North Carolina, and the Albemarle
and Pamlico Sounds, including the Neuse and Pamlico Rivers.

A Hurricane Warning has been issued from South Santee
River, South Carolina, to Duck, North Carolina, and the Albemarle
and Pamlico Sounds.

A Tropical Storm Watch has been issued from north of the North
Carolina/Virginia border to Cape Charles Light, Virginia, and for
the Chesapeake Bay south of New Point Comfort.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* South Santee River South Carolina to Duck North Carolina
* Albemarle and Pamlico Sounds, including the Neuse and Pamlico
Rivers

A Storm Surge Watch is in effect for...
* Edisto Beach South Carolina to South Santee River South Carolina
* North of Duck North Carolina to the North Carolina/Virginia border

A Hurricane Warning is in effect for...
* South Santee River South Carolina to Duck North Carolina
* Albemarle and Pamlico Sounds

A Hurricane Watch is in effect for...
* Edisto Beach South Carolina to South Santee River South Carolina
* North of Duck North Carolina to the North Carolina/Virginia border

A Tropical Storm Watch is in effect for...
* North of the North Carolina/Virginia border to Cape Charles Light
Virginia
* Chesapeake Bay south of New Point Comfort

Interests elsewhere in the southeastern and mid-Atlantic states
should monitor the progress of Florence.  Additional watches and
warnings may be required tonight or Wednesday.

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.  This is a life-threatening situation.  Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions.  Promptly follow evacuation and other
instructions from local officials.

A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area.  A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous.  Preparations to protect life and property should be
rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.  A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM AST (2100 UTC), the center of the eye of Hurricane
Florence was located by satellite near latitude 27.5 North,
longitude 67.1 West. Florence is moving toward the west-northwest
near 17 mph (28 km/h). A motion toward the west-northwest and
northwest is expected through early Thursday. Florence is expected
to slow down considerably by late Thursday into Friday. On the
forecast track, the center of Florence will move over the
southwestern Atlantic Ocean between Bermuda and the Bahamas through
Wednesday, and approach the coast of North Carolina or South
Carolina in the hurricane warning area on Thursday and Friday.

Maximum sustained winds have increased to near 140 mph (220 km/h)
with higher gusts.  Florence is a category 4 hurricane on the
Saffir-Simpson Hurricane Wind Scale.  Further strengthening is
forecast tonight and Wednesday.  While some weakening is expected on
Thursday, Florence is forecast to be an extremely dangerous major
hurricane through landfall.

Hurricane-force winds extend outward up to 60 miles (95 km) from the
center and tropical-storm-force winds extend outward up to 175 miles
(280 km).

The estimated minimum central pressure is 945 mb (27.91 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE:  The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline.  The water has the
potential to reach the following heights above ground if peak surge
occurs at the time of high tide...

Cape Fear to Cape Lookout, including the Neuse and Pamlico
Rivers...9-13 ft
North Myrtle Beach to Cape Fear...6-9 ft
Cape Lookout to Ocracoke Inlet...6-9 ft
South Santee River to North Myrtle Beach...4-6 ft
Ocracoke Inlet to North Carolina/Virginia Border...4-6 ft
Edisto Beach to South Santee River...2-4 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
destructive waves.  Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances.  For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

RAINFALL: Florence is expected to produce total rainfall
accumulations of 15 to 25 inches with isolated maximum amounts of
35 inches near the storm's track over portions of the Carolinas and
Mid-Atlantic States from late this week into early next week. This
rainfall would produce catastrophic flash flooding and significant
river flooding.

WIND:  Hurricane conditions are expected to reach the coast within
the hurricane warning area on Friday.  Winds are expected to first
reach tropical storm strength on Thursday, making outside
preparations difficult or dangerous.  Preparations to protect life
and property should be rushed to completion.

SURF:  Swells generated by Florence are affecting Bermuda and
portions of the U.S. East Coast.  These swells are likely to cause
life-threatening surf and rip current conditions.  Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM AST.
Next complete advisory at 1100 PM AST.

$$
Forecaster Stewart

Code: Select all

Hurricane Florence Discussion Number  50
NWS National Hurricane Center Miami FL       AL062018
500 PM AST Tue Sep 11 2018

Microwave satellite data indicate that Florence completed a full
eyewall replacement cycle (ERC) a few hours ago, and recent visible
and infrared imagery suggests that the eye has contracted slightly.
Outflow continues to expand in all quadrants, and the outflow jets
to the northwest and east have become better defined. Satellite
intensity estimates from TAFB, SAB, and UW-CIMSS ADT are all
T6.0/115 kt, and recent NHC objective intensity estimates are
T6.2/120 kt. Given that the eye has mostly cleared out and has also
warmed to near 19 deg C, the initial intensity has been bumped
upward to 120 kt, which could be conservative. All of the wind radii
had to be expanded/increased based on a blend of the earlier
reconnaissance data and a 1430 UTC ASCAT scatterometer pass.

The initial motion estimate is now 300/15 kt. There remains no
significant to the previous track forecast or reasoning. Overall,
the global and regional models have done a good job capturing the
evolving synoptic- scale flow pattern across CONUS, with an
amplifying trough moving onshore the the northwestern U.S. coast,
which is inducing downstream ridging across the northeastern U.S.
and the northwestern Atlantic Ocean. Water vapor imagery indicates
that the blocking high pressure northwest of Bermuda is continuing
to build and shift slowly eastward. The 12Z GFS model made a
significant shift to the west, the UKMET made a shift to the east,
and the ECMWF track has remained basically unchanged through 72
hours. As a result the consensus models have made only minor track
shifts to the west. What is noticeable is that all of the global and
regional models are indicating that the steering currents will
collapse by 72 h when Florence is approaching the southeast U.S.
coast. The weak steering currents are expected to continue through
the weekend, which makes the forecast track on days 3-5 quite
uncertain. The latest NHC forecast track is very similar to the
previous two advisory tracks, and lies the middle of the guidance
envelope between the consensus models TVCA to the north and the HCCA
and FSSE models to the south.

During the next 24 hours or so, Florence is expected to remain in a
very favorable environment consisting of low shear near 5 kt, an
expanding upper-level outflow pattern, and above-average SSTs of
29.0-29.5 deg C, which should result in additional strengthening.
By 48 h, the decreasing forward speed along with the large
inner-core wind field should induce some upwelling and gradual
weakening. Although the GFS- and ECMWF-based SHIPS intensity models
are indicating an increase in the southwesterly shear to near 20 kt,
this could be due to the SHIPS model capturing Florence's own
strong outflow from the GFS and ECMWF model fields. Despite the
weakening shown at 72 hours, Florence is still expected to remain a
dangerous hurricane through landfall. After Florence moves inland,
the slow forward speed of less than 5 kt should cause a rapid spin
down and weakening of the hurricane's circulation. The new NHC
intensity forecast is a little above the highest guidance based on
the aforementioned very favorable synoptic outflow pattern, and to
maintain continuity with the previous forecast.

Key Messages:

1. A life-threatening storm surge is now highly likely along
portions of the coastlines of South Carolina and North Carolina, and
a Storm Surge Warning is in effect for a portion of this area. All
interests from South Carolina into the mid-Atlantic region should
ensure they have their hurricane plan in place and follow any advice
given by local officials.

2. Life-threatening, catastrophic flash flooding and significant
river flooding is likely over portions of the Carolinas and
Mid-Atlantic states from late this week into early next week, as
Florence is expected to slow down as it approaches the coast and
moves inland.

3. Damaging hurricane-force winds are likely along portions of the
coasts of South Carolina and North Carolina, and a Hurricane Warning
has been issued for a part of this area.  Damaging winds could also
spread well inland into portions of the Carolinas and Virginia.

4. Large swells affecting Bermuda and portions of the U.S. East
Coast will continue this week, resulting in life-threatening surf
and rip currents.

FORECAST POSITIONS AND MAX WINDS

INIT  11/2100Z 27.5N  67.1W  120 KT 140 MPH
 12H  12/0600Z 28.7N  69.3W  130 KT 150 MPH
 24H  12/1800Z 30.4N  72.1W  135 KT 155 MPH
 36H  13/0600Z 32.1N  74.5W  130 KT 150 MPH
 48H  13/1800Z 33.4N  76.2W  120 KT 140 MPH
 72H  14/1800Z 34.5N  77.7W  100 KT 115 MPH...NEAR THE COAST
 96H  15/1800Z 35.0N  78.8W   40 KT  45 MPH...INLAND
120H  16/1800Z 35.7N  81.7W   25 KT  30 MPH...INLAND

$$
Forecaster Stewart
BlueJay
Posts: 938
Joined: Tue Mar 04, 2014 10:47 am
Location: Alden Bridge-The Woodlands, Texas
Contact:

My cousin is a resident of Wilmington NC. She is a recent transplant from Wisconsin. She advised our family earlier today that she now knows that Florence is serious because Walmart will be closed today at 6 pm until further notice. I hope my cousin and everyone has taken this storm seriously and has/is prepared the best possible.

God speed to all of those who are faced with dealing with Florence.
unome
Posts: 3059
Joined: Fri Feb 12, 2010 6:11 pm

https://www.nhc.noaa.gov/#Florence

Code: Select all

BULLETIN
Hurricane Florence Intermediate Advisory Number 50A
NWS National Hurricane Center Miami FL       AL062018
800 PM AST Tue Sep 11 2018

...DANGEROUS FLORENCE HEADED FOR THE U.S. EAST COAST...
...EXPECTED TO BRING LIFE-THREATENING STORM SURGE AND RAINFALL TO
PORTIONS OF THE CAROLINAS AND MID-ATLANTIC STATES...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...28.0N 67.9W
ABOUT 350 MI...565 KM SSW OF BERMUDA
ABOUT 725 MI...1165 KM ESE OF CAPE FEAR NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...140 MPH...220 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...945 MB...27.91 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* South Santee River South Carolina to Duck North Carolina
* Albemarle and Pamlico Sounds, including the Neuse and Pamlico
Rivers

A Storm Surge Watch is in effect for...
* Edisto Beach South Carolina to South Santee River South Carolina
* North of Duck North Carolina to the North Carolina/Virginia border

A Hurricane Warning is in effect for...
* South Santee River South Carolina to Duck North Carolina
* Albemarle and Pamlico Sounds

A Hurricane Watch is in effect for...
* Edisto Beach South Carolina to South Santee River South Carolina
* North of Duck North Carolina to the North Carolina/Virginia border

A Tropical Storm Watch is in effect for...
* North of the North Carolina/Virginia border to Cape Charles Light
Virginia
* Chesapeake Bay south of New Point Comfort

Interests elsewhere in the southeastern and mid-Atlantic states
should monitor the progress of Florence.  Additional watches and
warnings may be required tonight or Wednesday.

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a
depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.  This is a life-threatening situation.  Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions.  Promptly follow evacuation and other
instructions from local officials.

A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area.  A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous.  Preparations to protect life and property should be
rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.  A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.


DISCUSSION AND OUTLOOK
----------------------
At 800 PM AST (0000 UTC), the eye of Hurricane Florence was located
by satellite near latitude 28.0 North, longitude 67.9 West.
Florence is moving toward the west-northwest near 17 mph (28 km/h).
A motion toward the west-northwest and northwest is expected through
early Thursday.  Florence is expected to slow down considerably by
late Thursday into Friday.  On the forecast track, the center of
Florence will move over the southwestern Atlantic Ocean between
Bermuda and the Bahamas through Wednesday, and approach the coast of
North Carolina or South Carolina in the hurricane warning area on
Thursday and Friday.

Maximum sustained winds are near 140 mph (220 km/h) with higher
gusts.  Florence is a category 4 hurricane on the Saffir-Simpson
Hurricane Wind Scale.  Strengthening is forecast tonight and
Wednesday.  While some weakening is expected on Thursday, Florence
is forecast to be an extremely dangerous major hurricane through
landfall.

Hurricane-force winds extend outward up to 60 miles (95 km) from
the center and tropical-storm-force winds extend outward up to 175
miles (280 km).

The estimated minimum central pressure is 945 mb (27.91 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE:  The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline.  The water has the
potential to reach the following heights above ground if peak surge
occurs at the time of high tide...

Cape Fear to Cape Lookout, including the Neuse and Pamlico
Rivers...9-13 ft
North Myrtle Beach to Cape Fear...6-9 ft
Cape Lookout to Ocracoke Inlet...6-9 ft
South Santee River to North Myrtle Beach...4-6 ft
Ocracoke Inlet to North Carolina/Virginia Border...4-6 ft
Edisto Beach to South Santee River...2-4 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
destructive waves.  Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances.  For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

RAINFALL: Florence is expected to produce total rainfall
accumulations of 15 to 25 inches with isolated maximum amounts of
35 inches near the storm's track over portions of the Carolinas and
Mid-Atlantic States from late this week into early next week.  This
rainfall would produce catastrophic flash flooding and significant
river flooding.

WIND:  Hurricane conditions are expected to reach the coast within
the hurricane warning area on Friday.  Winds are expected to first
reach tropical storm strength on Thursday, making outside
preparations difficult or dangerous.  Preparations to protect life
and property should be rushed to completion.

SURF:  Swells generated by Florence are affecting Bermuda and
portions of the U.S. East Coast.  These swells are likely to cause
life-threatening surf and rip current conditions.  Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM AST.

$$
Forecaster Pasch
Post Reply
  • Information
  • Who is online

    Users browsing this forum: No registered users and 19 guests