August 2017: Looking Back at Harvey 5 Year Later

[mckinne63]

We are getting in on some of the rain action in Stafford today! We missed out here the last few days. Hearing rumblings of thunder.

[srainhoutx]

Special Weather Statement
National Weather Service Houston/Galveston TX
1226 PM CDT SAT AUG 5 2017

Harris TX-Fort Bend TX-
1226 PM CDT SAT AUG 5 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN FORT BEND AND
SOUTHWESTERN HARRIS COUNTIES UNTIL 100 PM CDT...

At 1226 PM CDT, Doppler radar was tracking a strong thunderstorm over
northern Sugar Land, moving northeast at 15 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Sugar Land, Missouri City, Stafford, Bellaire, West University Place,
Richmond, Hunters Creek Village, Bunker Hill Village, Piney Point
Village, Town West, Pecan Grove, Greenway / Upper Kirby Area,
Eldridge / West Oaks, Spring Branch West, First Colony, Addicks Park
Ten, Spring Valley, Mission Bend, Afton Oaks / River Oaks Area and
Neartown / Montrose.

[srainhoutx]

We are getting a nice thundershower here in NW Harris County. Meanwhile, 90L continues to organize and the NHC has raised the chances for Tropical Development. Personally I believe the chances should have been higher with reports of near Tropical Storm strength already being indicated within the squalls. That would require Pre Tropical Cyclone Advisories and we remember how confusing that was with Cindy.

Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 PM EDT Sat Aug 5 2017 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: 1. Showers and thunderstorms associated with a strong tropical wave located over the central Caribbean Sea are beginning to show some signs of organization, and satellite wind data indicate that the wave is producing a small area of winds that are just below tropical storm force. Additional development of this system is possible while it moves west-northwestward at 10 to 15 mph, and a tropical depression or tropical storm could form over the northwestern Caribbean Sea before it reaches the Yucatan peninsula late Monday or Tuesday. Even if formation does not occur before the system reaches the Yucatan peninsula, a tropical depression or tropical storm could form over the Bay of Campeche during the middle part of next week. Development would likely not occur if the system moves inland over Central America and southeastern Mexico and does not re-emerge over water. An Air Force Reserve reconnaissance aircraft is scheduled to investigate this system tomorrow afternoon, if necessary. Interests along the coasts of Honduras, Belize, and the Yucatan peninsula of Mexico should monitor the progress of this disturbance. * Formation chance through 48 hours...medium...40 percent. * Formation chance through 5 days...medium...60 percent. 2. Disorganized showers and thunderstorms continue in association with an elongated area of low pressure that extends more than a thousand miles southwest of the Cabo Verde Islands. Although this system has failed to consolidate so far, environmental conditions appear conducive enough to support some development while this system moves west-northwestward across the tropical Atlantic Ocean at about 15 mph. * Formation chance through 48 hours...low...30 percent. * Formation chance through 5 days...medium...50 percent. Forecaster Berg

[Rip76]

Man we've had a lot of Mexico riders the last few years.

[srainhoutx]

TropicsWatch‏ @TropicsWatch · 45m45 minutes ago
Our Disturbance 23 (#90L) is looking like a wave that's in the process of developing an LLC. I'd say development chances 90%+.

08052017 TropicsWatch DGfgF13UAAA4JLK.jpg

[DoctorMu]

Mike Ventrice of WSI via Twitter allows us to visually see the various 51 individual members of the ECMWF EPS. Clearly The Mexico Gulf Coast is the most likely scenario for eventual landfall, but you cane see a few members keep the system over water a little longer and into South Texas.

08052017 00Z EC EPS Members DGdm0LAUIAADtzO.jpg

Michael Ventrice‏Verified account @MJVentrice · 2h2 hours ago
Invest 99L losing steam in the recent ECMWF EPS run- 90L still likely to spin up into a tropical storm over the Bay of Campeche.

That's a consensus.

[davidiowx]

Mike Ventrice of WSI via Twitter allows us to visually see the various 51 individual members of the ECMWF EPS. Clearly The Mexico Gulf Coast is the most likely scenario for eventual landfall, but you cane see a few members keep the system over water a little longer and into South Texas.

08052017 00Z EC EPS Members DGdm0LAUIAADtzO.jpg

Michael Ventrice‏Verified account @MJVentrice · 2h2 hours ago
Invest 99L losing steam in the recent ECMWF EPS run- 90L still likely to spin up into a tropical storm over the Bay of Campeche.

That's a consensus.

Way to early to call any model runs a consensus. A center reformation would change a lot of things. It sure has gotten its act together today.

[DoctorMu]

Mike Ventrice of WSI via Twitter allows us to visually see the various 51 individual members of the ECMWF EPS. Clearly The Mexico Gulf Coast is the most likely scenario for eventual landfall, but you cane see a few members keep the system over water a little longer and into South Texas.

08052017 00Z EC EPS Members DGdm0LAUIAADtzO.jpg

Michael Ventrice‏Verified account @MJVentrice · 2h2 hours ago
Invest 99L losing steam in the recent ECMWF EPS run- 90L still likely to spin up into a tropical storm over the Bay of Campeche.

That's a consensus.

Way to early to call any model runs a consensus. A center reformation would change a lot of things. It sure has gotten its act together today.

You mean "accurate." It's a "consensus," by definition because multiple models say the same thing - unusually bunched. It does not mean the vast majority will be correct. There's no irony emoticon.

Having said that chances are that a ridge will move into mid to east Texas block northward movement. We'll see.

[srainhoutx]

It looks like a relatively quiet day ahead for SE Texas with some mid level capping I place that likely will inhibit thunderstorm development. There is a possibility that areas to our SW along Matagorda, Jackson and Wharton Counties my have a better chance for some storms to fire off later today.

Up North near the Red River across portions of Oklahoma and North Texas, Rain chances continue to look active as a stalled boundary and more organized Convection is possible from various shortwaves rippling along that boundary. One of those shortwaves may increase our local chances rain wise on Monday into Tuesday as it passes overhead of SE Texas. The boundary across the Southern Plains extending toward the SE and Mid Atlantic States looks very active for rainfall with the possibility of some flooding issues across Oklahoma into the Dallas/Ft Worth Metroplex and on East over the next 7 Days.

The attachment 08062017 09Z 7 Day QPF p168i.gif is no longer available

Now for 90L in the Western Caribbean Sea. Convection is still attempting to consolidate and the NHC has cancelled the RECON Mission schedule for this afternoon. There is a High Chance that we will have Franklin sometime tomorrow as it nears the Gulf of Honduras and the Yucatan Peninsula. Odds of Tropical Cyclone Genesis increased rather dramatically overnight after the Hurricane Models began running at 12Z yesterday adding further forecasting assistance the NHC. An Air Force C-130 is scheduled to fly down from Biloxi and investigate tomorrow. The model guidance continues favor a track that would move potential TS or Hurricane Franklin into the Mexican Gulf Coast from Veracruz to Tampico. The Best track guidance suggests the disturbance gained about 1 degree of latitude now located somewhere near 15N and 81W, or a couple of Hundred miles East of the Guatemala/Honduras Border. MIMIC suggests vorticity or low level spin has increased suggesting a broad low level circulation is beginning to form. While the general track idea has not changed, I always urge caution when using those spaghetti track plots until a storm actually forms. Environmental Conditions ahead of 90L continue to improve and look very favorable for Tropical Development, particularly in the NW Caribbean Sea near the Yucatan Peninsula, the Bay of Campeche and the Western Gulf of Mexico. I would continue to monitor possible future Franklin because of where it is headed due to being close to our backyard and for any unexpected curveballs that may come our way and until it's inland and gone...

[srainhoutx]

Michael Ventrice‏Verified account @MJVentrice · 15m15 minutes ago
Growing support for #90L to reach Hurricane intensity later this week, putting Mexico at a higher risk for a landfalling hurricane.

[Rip76]

It looks like a relatively quiet day ahead for SE Texas with some mid level capping I place that likely will inhibit thunderstorm development. There is a possibility that areas to our SW along Matagorda, Jackson and Wharton Counties my have a better chance for some storms to fire off later today.

Looks like it may be our area today. (SE Texas/Houston)

Looking out at these towers building, I just sat and thought about 2009-2013(ish), where we didn't see many storms at all.
It was so strange.

[mckinne63]

We had a brief shower late morning here in Stafford. Skies are looking very cloudy and gloomy. It looks like it is missing a good chance to rain!

[Texaspirate11]

NHC will be initiating advisories by 5 PM EDT on Potential Tropical Cyclone Seven, located over the northwestern Caribbean Sea.

[srainhoutx]

Getting our second thunderstorm of the day in NW Harris County.

The National Hurricane Center will begin issuing Advisories for TD 7 at 5:00 PM EDT.

[srainhoutx]

Potential Tropical Cyclone Seven Discussion Number 1
NWS National Hurricane Center Miami FL AL072017
500 PM EDT Sun Aug 06 2017

Surface and scatterometer data indicate that the broad area of
low pressure over the northwestern Caribbean Sea still lacks a
well-defined center of circulation. However, this system is
likely to become a tropical storm before reaching the coast of the
Yucatan Peninsula late tomorrow, and advisories are being initiated
to enable the issuance of a tropical storm warning and watch for
Yucatan and Belize respectively. The scatterometer pass and NOAA
data buoy observations indicate that the maximum winds are near
30 kt. The disturbance has been experiencing westerly vertical
shear due to a nearby upper-level low and this has been inhibiting
development. Global model predictions show that this low will soon
dissipate and an upper-level anticyclone will become established
over the area. Therefore, strengthening is likely with the main
impediment being interaction with land. The official intensity
forecast is a little above the model consensus. It should be
noted that the system could become a hurricane between 72 and 96
hours, i.e. prior to reaching the Gulf coast of Mexico.

Since the center lacks definition, the initial location and motion
are quite uncertain, and my best guess for the current motion is
290/10. The steering pattern for the disturbance/tropical cyclone
is expected to be fairly straightforward and persistent for the
next few days. A general west-northwestward track is expected to
continue until landfall in mainland Mexico. The official track
forecast is generally a blend of the latest GFS and ECMWF solutions.

FORECAST POSITIONS AND MAX WINDS

INIT 06/2100Z 15.6N 82.0W 30 KT 35 MPH...POTENTIAL TROP CYCLONE
12H 07/0600Z 16.6N 83.6W 35 KT 40 MPH...TROPICAL CYCLONE
24H 07/1800Z 18.0N 85.9W 45 KT 50 MPH
36H 08/0600Z 19.0N 88.0W 45 KT 50 MPH...INLAND
48H 08/1800Z 19.9N 90.1W 35 KT 40 MPH...INLAND
72H 09/1800Z 21.0N 93.8W 60 KT 70 MPH...OVER WATER
96H 10/1800Z 21.2N 97.8W 60 KT 70 MPH...INLAND
120H 11/1800Z...DISSIPATED

$$
Forecaster Pasch

[srainhoutx]

Sunday evening briefing from Jeff:


Looking at the upper air pattern across TX this afternoon…one could wonder if it is October or August.

An upper level trough across the central US has resulted in another rare summer cold front dropping into TX. The front currently extends from SE OK to SE NM with numerous thunderstorms having formed along the boundary this afternoon over N/NC/ and WC TX. Pretty rare to see such rainfall over the heart of TX in early August and the WPC forecast of widespread soaking rainfall tonight-Tuesday over a large part of the state. Locally the air mass has been very moist today and a weak short wave moving up the TX coast resulted in a couple of rounds of thunderstorms mainly along and SE of US 59. Actually have a weak low level jet in place over the state feeding into the frontal boundary to our NW which is helping to supply a rich feed of Gulf moisture.

Global and meso scale models are in fairly good agreement with the thunderstorms currently over NC TX gradually growing upscale into a slow southward moving MCS tonight which will be approaching our N/NW counties toward sunrise on Monday. Given the numerous activity to our NW, another short wave approaching, and NW flow aloft to help move the activity southward all appear favorable for this complex to reach SE TX Monday morning. Air mass will continue to be very moist with low level feed off the Gulf keeping PWS of 2.1-2.3 inches into Tuesday. Meso and high resolution guidance shows the complex weakening as it enters SE TX Monday morning, but a southward moving outflow boundary will likely continue southward helping to set off additional storms by mid to late morning. Will keep with the thinking of the heaviest rainfall and most organized activity N of HWY 105 where 1-3 inches widespread will be possible (rare for August without a tropical system). South of HWY 105 totals could still certainly reach 1-3 inches, but the activity may be more isolated and scattered than widespread.

Actual front will sag into the area late Monday and Tuesday. This could keep activity going well into the evening hours on Monday depending on exactly how the morning activity evolves. Think the boundary will only help to destabilize the air mass and add a surface focus on Tuesday which looks to be another wet day.

Rainfall amounts over the next 48 hours could approach 3-5 inches over the area with isolated higher amounts. Storm motions should be 10-15kts, but cell training could help pile totals and that coupled with deep moisture will likely result in hourly rainfall rates of 2-3 inches under the strongest cells. Street flooding will likely be the main threat, although WPC has placed those locations north of HWY 105 in a slight risk for flash flooding late tonight and Monday.

Upper level ridge will begin to build over the area Wednesday helping to keep PTC #7 (likely TS Franklin by then) south of the TX coast. This should also help to reduce rain chances back toward climo with 30% afternoon storms along the seabreeze. Appears moisture associated with the Bay of Campeche tropical system (possibly near hurricane intensity by Wednesday) will contract around the center and remain well south of our area.

Upper ridging appears unable to gain a good foothold…so after a few “hot” and “dry” days Thursday-Saturday another weakness develops in the ridge over TX and Gulf moisture comes surging back into the region by next Sunday with rain chances once again increasing.

48hr Forecasted Rainfall Amounts:

[brooksgarner]

Brooks here:

wg8dlm5-1.GIF

Waiting for Franklin to form... No threat to Houston, according to every computer model I can conjure, thanks to the steering currents around that subtropical ridge centered over the Bahamas.

potential_7.png

See you at 10pm on KHOU...

[brooksgarner]

Capture.JPG

Good evening guys... I'm tracking the chance for morning rain/storms tomorrow, if a thunderstorm complex south of Dallas survives its trip 190 miles southeast... HRRR says yes.

5987d13a64f72685453794.gif

[Texaspirate11]

HGX NWS DISCO TONIGHT

Despite the buzz on social media, sharknado threat for Southeast
Texas will be nil tonight.

[srainhoutx]

MESOSCALE PRECIPITATION DISCUSSION 0640 NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 223 AM EDT MON AUG 07 2017 AREAS AFFECTED...CENTRAL TX CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE VALID 070622Z - 071222Z SUMMARY...SHOWERS AND THUNDERSTORMS ARE EXPANDING IN COVERAGE ACROSS CENTRAL TX. HOURLY RAIN TOTALS UP TO 2.5" AND LOCAL AMOUNTS TO 5" ARE POSSIBLE. DISCUSSION...A WEST-NORTHWEST/EAST- SOUTHEAST ORIENTED BAND OF THUNDERSTORMS IS TRYING TO FORM ACROSS CENTRAL TX, MOVING EAST-SOUTHEAST AT ~15 KTS, WHICH HAS SHOWN SOME BROADENING IN THE COLD CLOUD TOPS ON NON-OPERATIONAL GOES-16 INFRARED IMAGERY. THIS IS OCCURRING NORTH OF WHAT HAS BEEN A PROGRESSIVE OUTFLOW BOUNDARY WHICH IS LOCATED SOUTH OF SAN ANGELO. INFLOW AT 850 HPA IS INCREASING IN THIS AREA, NOW UP TO 20 KTS PER THE DEL RIO TX VAD WIND PROFILE. EFFECTIVE BULK SHEAR IS ~20 KTS. PRECIPITABLE WATER VALUES OF 1.6-2.1" EXIST IN THIS AREA PER GPS VALUES. RAP GUIDANCE SHOWS A SLOWING OF THE SOUTHWARD MOVEMENT OF THE OUTFLOW BOUNDARY AS THE INFLOW AT 850 HPA INCREASES TOWARDS 35 KTS AND BEGINS TO VEER. AS IT MOVES INTO SOUTHEAST TX, THE RAINFALL/ THUNDERSTORM BAND COULD BROADEN AS IT ENCOUNTERS 79F DEWPOINTS NORTHWEST OF HOUSTON TX. FORWARD PROPAGATION VECTORS SUGGEST THAT THE BOUNDARY SHOULD TRY TO PROGRESS SOUTH-SOUTHEAST AT 10-15 KTS, WHICH SHOULD LIMIT OVERALL TOTALS. SOME BACKBUILDING AND EASTWARD PROGRESSION IS EXPECTED WITH TIME. THE GUIDANCE THAT APPEARS TO BE CAPTURING THIS ACTIVITY THE BEST RIGHT NOW IS THE 00Z WRF NSSL, WHICH SHOWS LOCAL MAXIMA OF 5-6", WHICH COULD BE A TOUCH HIGH. HOURLY RAIN TOTALS UP TO 2.5" ARE POSSIBLE WHERE CELLS TRAIN OR MERGE ALONG WITH LOCAL MAXIMA AROUND 5" OVER THE NEXT SEVERAL HOURS, WHICH COULD EXCEED THE HIGH FLASH FLOOD GUIDANCE VALUES IN THE REGION. ROTH ATTN...WFO...EWX...FWD...HGX...SJT...