Helene/Cabo Verde Island Threat

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srainhoutx
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93L has a nice spin associated with it this morning and with its High (90%) chance for development and environmental conditions very favorable, I expect the NHC to Upgrade to a Tropical Depression later as it will impact the Cabo Verde Island over the weekend. It would take the name of Helene should it be upgraded later today.
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09062018 11Z 93L _msg4_x_vis2km_93LINVEST_25kts-1006mb-130N-167W_100pc.jpg
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srainhoutx
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BULLETIN
Potential Tropical Cyclone Eight Intermediate Advisory Number 1A
NWS National Hurricane Center Miami FL AL082018
200 PM AST Fri Sep 07 2018

...DISTURBANCE BECOMING BETTER ORGANIZED...
...TROPICAL STORM CONDITIONS AND HEAVY RAINFALL EXPECTED IN
PORTIONS OF THE CABO VERDE ISLANDS...


SUMMARY OF 200 PM AST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...13.2N 18.0W
ABOUT 440 MI...710 KM ESE OF THE SOUTHERNMOST CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Santiago, Fogo, and 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 200 PM AST (1800 UTC), the disturbance was centered near latitude
13.2 North, longitude 18.0 West. The system is moving toward the
west near 10 mph (17 km/h). A westward to west-northwestward motion
with a gradual increase in forward speed is expected during the next
72 hours. On the forecast track, the disturbance is expected to move
near the southern Cabo Verde Islands on Sunday.

Maximum sustained winds are near 35 mph (55 km/h) with higher
gusts. Satellite imagery indicates that the disturbance is becoming
better organized, and it is expected to become a tropical depression
or tropical storm later today.

Conditions are conducive for the disturbance to become a tropical
depression or tropical storm later today.
* Formation chance through 48 hours...high...near 100 percent
* Formation chance through 5 days... high...near 100 percent

The estimated minimum central pressure is 1004 mb (29.65 inches).


HAZARDS AFFECTING LAND
----------------------
WIND: Tropical storm conditions are expected to first reach the
warning area on Sunday.

RAINFALL: The disturbance is expected to produce total rain
accumulations of 3 to 5 inches, with maximum totals of 8 inches
across the southern Cabo Verde Islands. This rainfall may produce
life-threatening flash floods.


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

$$
Forecaster Beven

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

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srainhoutx
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TROPICAL STORM HELENE DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082018
1100 PM AST FRI SEP 07 2018

A VERY TIMELY ASCAT PASS INDICATED THAT THE WINDS ASSOCIATED WITH
THE DEPRESSION HAVE INCREASED TO 35 KT, AND ALSO THAT THE CENTER WAS
A LITTLE EAST OF THE LOCATION PREVIOUSLY INDICATED. THIS IS VERY
COMMON IN SYSTEMS DURING THE FORMATIVE STAGE. BASED ON THE ASCAT
DATA, THE SYSTEM HAS BEEN UPGRADED TO TROPICAL STORM HELENE, THE
EIGHTH NAMED STORM OF THE SEASON. THE SATELLITE PRESENTATION HAS
ALSO IMPROVED DURING THE PAST SEVERAL HOURS, AND NOW THE CYCLONE HAS
LARGE CYCLONICALLY CURVED CONVECTIVE BANDS TO THE SOUTH OF THE
CENTER. THE OUTFLOW IS FAIR IN ALL QUADRANTS.

HELENE WILL BE MOVING OVER WARM WATERS AND WITHIN AN ENVIRONMENT
OF LIGHT SHEAR THROUGH THE NEXT 3 TO 4 DAYS, AND MOST OF THE
GUIDANCE RESPONDS TO THAT ENVIRONMENT BY GRADUALLY STRENGTHENING THE
CYCLONE. THE NHC FORECAST FOLLOWS THE TREND OF THE INTENSITY
CONSENSUS, AND BRINGS HELENE TO HURRICANE INTENSITY IN ABOUT 3 DAYS.

CURRENTLY, HELENE IS EMBEDDED WITHIN A SOUTHWEST MONSOON-TYPE FLOW,
AND IS MOVING TOWARD THE WEST AT ABOUT 9 OR 10 KNOTS. HOWEVER, AS
THE CYCLONE MOVES AWAY FROM THE AFRICAN COAST, IT WILL BECOME
STEERED BY THE EASTERLY FLOW AROUND THE SUBTROPICAL RIDGE AND SHOULD
THEN INCREASE IN FORWARD SPEED. MOST OF THE TRACK MODELS ARE IN
EXTREMELY GOOD AGREEMENT, AT LEAST FOR THE NEXT 3 DAYS WHEN THE
CONFIDENCE IN THE FORECAST IS HIGH. AT THE LONG RANGE, A MID-LEVEL
TROUGH IS EXPECTED TO DEVELOP OVER THE CENTRAL ATLANTIC, FORCING THE
CYCLONE TO TURN MORE TO THE NORTHWEST AND EVEN NORTH LATER ON. THE
NHC FORECAST IS IN THE MIDDLE OF THE GUIDANCE ENVELOPE AND BASICALLY
ON TOP OF THE CORRECTED CONSENSUS HCCA.


FORECAST POSITIONS AND MAX WINDS

INIT 08/0300Z 13.6N 18.5W 35 KT 40 MPH
12H 08/1200Z 13.8N 19.9W 35 KT 40 MPH
24H 09/0000Z 14.3N 22.3W 40 KT 45 MPH
36H 09/1200Z 14.8N 25.0W 50 KT 60 MPH
48H 10/0000Z 15.4N 28.0W 55 KT 65 MPH
72H 11/0000Z 17.0N 33.9W 65 KT 75 MPH
96H 12/0000Z 18.5N 39.0W 65 KT 75 MPH
120H 13/0000Z 20.5N 42.5W 60 KT 70 MPH

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

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