SE TX / SW LA Discussion - Hot! Hot! Hot!

[Yankeegirl]

Glad I could help ya, Jen!! and yeah, what a bust in the weather department... It always does this when we have such a high chance of rain... we end up getting nuttin!!

[Yankeegirl]

And so it begins....

Flash Flood Watch

FLOOD WATCH
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
944 PM CDT THU JUL 26 2007

TXZ200-212>214-227-237-238-271045-
/O.EXB.KHGX.FF.A.0007.000000T0000Z-070727T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BRAZORIA-CHAMBERS-FORT BEND-GALVESTON-HARRIS-LIBERTY-WALLER-
INCLUDING THE CITIES OF...ALVIN...ANAHUAC...ANGLETON...
BROOKSHIRE...CLEVELAND...DAYTON...FREEPORT...FRIENDSWOOD...
GALVESTON...HEMPSTEAD...HOUSTON...HUMBLE...KATY...LAKE JACKSON...
LEAGUE CITY...LIBERTY...MISSOURI CITY...MONT BELVIEU...PASADENA...
PEARLAND...PRAIRIE VIEW...RICHMOND...ROSENBERG...SUGAR LAND...
TEXAS CITY...TOMBALL...WINNIE
944 PM CDT THU JUL 26 2007


...FLASH FLOOD WATCH IN EFFECT UNTIL 6 AM CDT FRIDAY...

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS EXPANDED
THE

* FLASH FLOOD WATCH TO INCLUDE A PORTION OF SOUTHEAST TEXAS...
INCLUDING THE FOLLOWING COUNTIES...BRAZORIA...CHAMBERS...FORT
BEND...GALVESTON...HARRIS...LIBERTY AND WALLER.

* UNTIL 6 AM CDT FRIDAY

* DEEP TROPICAL MOISTURE WILL STILL RESIDES OVER THE REGION. A
FAVORABLE UPPER LEVEL WIND PATTERN...AN APPROACHING UPPER LEVEL
DISTURBANCE FROM THE WEST AND A SURFACE BOUNDARY SITUATED ALONG
THE INTERSTATE 10 AND HIGHWAY 59 CORRIDOR WILL LEAD TO
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS OVERNIGHT.
THOUGH LOCALLY HEAVY RAIN IS POSSIBLE ACROSS THE ENTIRE WATCH
AREA...THE HEAVIEST WILL TEND TO ACCUMULATE ALONG THE MEANDERING
SURFACE BOUNDARY. EXPECT WIDESPREAD RAINFALL ACCUMULATIONS
AROUND 1 INCH OVERNIGHT...WITH LOCALIZED 4 INCH AMOUNTS
POSSIBLE WHERE ANY TRAINING HEAVY RAINS FOCUS ON THE SURFACE
BOUNDARY.

* BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS
OBSERVED...ACT QUICKLY. MOVE UP TO ESCAPE FLOOD WATERS. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED
QUICKLY. IF YOUR VEHICLE STALLS...ABANDON IT AND SEEK HIGHER
GROUND IMMEDIATELY. RAPIDLY RISING WATER MAY ENGULF YOUR VEHICLE
AND ITS OCCUPANTS AND SWEEP THEM AWAY. MOVE TO HIGHER GROUND.

THIS WATCH WILL LIKELY NEED TO BE EXTENDED AND OR RECONFIGURED
ON FRIDAY AS ADDITIONAL RAINFALL IS LIKELY.

$$

[Normandy]

Radar trends are not very good this morning, and the surface boundary is shown along the texas coastline per the NWS...Radar trends suggest rain is lifting north towards the Houston metro area VERY slowly, and it seems as if areas around and south of I-10 are going to get hammered by a very impressive widespread rain event. I'd widespread totals of maybe 1-2 inches with this first batch, as its slow movement northward should still allow nice totals despite its meager rainfall rates (around .5 per hour generally). Once this moves out, or as it does, convection should continue to refire along the boundary and train over the same areas again and again. And daytime heating will likely make rains more intense.
Id expect totals of around 3-4 inches widespread along the upper texas coast, and local totals approaching 8-10 along the boundary, where heavy rains will be focused.

Expect extreme flooding in some areas unfortunately.

[TexWx]

Seems like a weak low a little NE of Victoria?

That's not good.

[Normandy]

wouldnt worry much about it.

The big Low (the ULL) is wats really gonna cause us problems.

[KatDaddy]

I dont see much of a flood threat this morning as the heavy rains weaken.

[CajunMama]

Lots of rain moving up towards the lake charles area. I hope jagno doesn't get any flooding.

[jasons2k]

From Jeff:

NWS has issued a Flash Flood Watch until 700pm this evening.

Discussion:

Water vapor images clearly shows upper low stalled out over SW TX with good feed of moisture off the Gulf over the middle and upper TX coast. Surface reflection/vort lobe currently moving northward through Waller County was responsible for the morning heavy rainfall. Amounts averaged 2-3 inches over SE Harris Co. near the Bay and 1-2 inches over the NW part of the county. The heaviest rainfall has remained offshore this morning where convergent low level flow is noted.

Air mass has likely been worked over by morning convection and will take a few hours to recover. Lift associated with N moving meso low will weaken with time. Should see some clearing to the SW of the area shortly pushing temps. toward the trigger temps. and likely starting the whole convective process over again. Have noted that storm motions S and SW of metro Houston have really slowed in the past few hours and this is of some concern…as the fast storms motions this morning and yesterday have helped reduce higher rainfall totals. Not sure how much development we will see this afternoon as dry slot on water vapor rotates in from the SW…we shall see.

Saturday:
Similar pattern in place tomorrow as today with 2.2-2.4 inch PWS and strongly divergent upper air pattern. Slug of moisture off the LA coast may push more west on Saturday as upper high begins to build in from the east. Will once again have to go with 70-80% coverage on Saturday.

Rain chances should begin to come down starting Sunday as ridging attempts to build in from the east allowing modest drying. Will still be plenty of moisture for daily afternoon storms, but coverage should be reduced.

Historical Note:
July has been an extremely wet month across the state following a record wet June. Below are the current rainfall amounts for selected cities and their normal July rainfall. The Victoria and Corpus amounts are incredible.

Victoria: 18.71 inches (2.50 normal)
Corpus Christi: 18.05 inches (1.66 normal)
IAH: 9.13 inches (2.70 normal) 7th wettest July on record
Galveston: 7.51 inches (2.90 normal)
San Antonio: 11.06 inches (1.67 normal)

A look back at history does reveal a surprising fact. The top 5 wettest July’s at IAH were in the following years:

1. 1900
2. 1942
3. 1943
4. 1961
5. 1955

Interestingly tropical cyclones impacted the TX in 4 out of the 5 above years after a very wet July.

1900 --- Great Galveston Hurricane (cat 4)
1942 --- Galveston (cat 1), Matagorda Bay (cat 1)
1943 --- Galveston (cat 2)
1961 --- Hurricane Carla, Matagorda Bay (cat 4)
1995 --- None

IAH is .25 of an inch away from becoming the 6th wettest July on record and 5.67 inches away from the wettest July on record.

[southerngale]

NWS LCH issued a Flood Watch for us in Southeast Texas. It's been raining for a while now.

FLOOD WATCH
NATIONAL WEATHER SERVICE LAKE CHARLES LA
507 AM CDT FRI JUL 27 2007

...SHOWERS AND THUNDERSTORMS WILL PREVAIL FOR TODAY AND SATURDAY...

.A GULF (OR INSTABILITY) FRONT IS SLOWLY MOVING INLAND. THIS
FRONTAL SYSTEM WILL FOCUS DEEP MOISTURE ACROSS THE GOLDEN
TRIANGLE...RESULTING IN WIDESPREAD SHOWERS AND THUNDERSTORMS. THIS
NORTHWARD DRIFTING INSTABILITY FRONT WILL REACH A LINE FROM CONROE
TEXAS TO GULFPORT MISSISSIPPI BY SATURDAY MORNING.

TXZ201-215-216-271800-
/O.NEW.KLCH.FF.A.0005.070727T1007Z-070727T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HARDIN-JEFFERSON-ORANGE-
INCLUDING THE CITIES OF...LUMBERTON...BEAUMONT/PORT ARTHUR...
ORANGE
507 AM CDT FRI JUL 27 2007

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS AFTERNOON...

THE NATIONAL WEATHER SERVICE IN LAKE CHARLES HAS ISSUED A

* FLASH FLOOD WATCH FOR A PORTION OF SOUTHEAST TEXAS...INCLUDING
THE FOLLOWING AREAS...HARDIN...JEFFERSON AND ORANGE.

* THROUGH THIS AFTERNOON

* THE COMBINATION OF DEEP MOISTURE...A SURFACE BOUNDARY...AND
FAVORABLE DYNAMICS ALOFT WILL GENERATE WIDESPREAD SHOWERS AND
THUNDERSTORMS TODAY. MEAN AREAL RAINFALL TOTALS ACROSS THE
GOLDEN TRIANGLE WILL BE AROUND 2 INCHES. LOCAL RAINFALL TOTALS
FROM 3 TO 5 INCHES ARE POSSIBLE IN THE STRONGER RAINBANDS.

* A FLASH FLOOD WATCH MEANS RAPIDLY RISING WATER OR FLOODING IS
POSSIBLE WITHIN THE WATCH AREA. IF YOU ARE IN THE WATCH
AREA...CHECK PREPAREDNESS REQUIREMENTS...KEEP INFORMED...AND BE
READY FOR QUICK ACTION IF FLASH FLOODING IS OBSERVED OR IF A
WARNING IS ISSUED.

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

[Extremeweatherguy]

it feels very tropical out there this morning. The temperature is cool with very fast low clouds overhead and I am getting a persistant light breeze out of the east. It Kind of reminds me of how it would feel if a tropical depression was making landfall along the coast right now.

I have also received close to 0.70" of rain this morning (most of it in the storm around 5-6am).

[JenBayles]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
957 AM CDT FRI JUL 27 2007

.UPDATE...
STILL SOME UNCERTAINTY WITH TODAYS FORECAST BUT FEEL IT IS BEST TO
MAINTAIN THE FLOOD WATCH THIS AFTERNOON. 250 MB ANALYSIS SHOWS
UPPER LEVEL WINDS REMAIN STRONGLY DIVERGENT AND WITH THE UPPER
LEVEL SYSTEM REMAINING IN PLACE OVER WEST TEXAS...FEEL DIVERGENCE
WILL REMAIN OVER EAST TEXAS. PW`S STILL AOA 2 INCHES WITH 850 MB
DEW PTS BETWEEN 14-16C. 700 MB MOISTURE IS STILL PLENTIFUL AS CRP
SOUNDING SHOW 7C. AT 14Z...A SURFACE LOW WAS JUST EAST OF
MATAGORDA BAY WITH A TROF EXTENDING NE ALONG THE UPPER COAST AND
SOUTH OVER THE WESTERN GULF. A WEAK 850 MB TROF WAS ALSO NOTED
ALONG THE COAST. 12Z SOUNDINGS SHOW CONVECTIVE TEMPS BETWEEN 82-84
DEGREES SO IT WON`T TAKE MUCH HEATING TO GET THINGS TO REDEVELOP
INLAND THIS AFTERNOON.

THE UNCERTAINTY IS REGARD TO THE MCS OVER THE GULF. THERE IS THE
POSSIBILITY THAT THIS SYSTEM HAS STOLEN THE THUNDER (SO TO SPEAK)
WRT TO CONVECTIVE DEVELOPMENT INLAND. THE 12Z NAM/RUC AND 00Z CAN
ALL SUPPORT NEW DEVELOPMENT ALONG AND JUST INLAND FROM THE COAST.
WITH SUCH ABUNDANT MOISTURE AND INSTABILITY IN PLACE AND THE
GROUNDS SO SATURATED...FEEL IT IS BEST TO MAINTAIN CURRENT FLOOD
WATCH. DUE TO CLOUD COVER...HAVE TRIMMED TEMPS LOWER ALONG THE
COAST.

[KatDaddy]

I hear ya EWG. Very tropical feel with fast moving scuds.

[jasons2k]

Yep, and on the visibles it actually looks like it does when a sheared, weak depression is making landfall.

[Extremeweatherguy]

also, there is a 1012mb surface low just to our south. So basically, this is as close to a depression as you can get without it actually being called a depression...

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

I wonder if this could possibly become one if it moved back over the GOM?

**according to wind reports..the center of the low is currently south of Houston/Galveston (which are both seeing east winds) and east of Victoria and Palacious (both seeing north winds). So this is very close to the water right now.**

[Extremeweatherguy]

This is an interesting TWO:

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1130 AM EDT FRI JUL 27 2007

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A WEAK AREA OF LOW PRESSURE NEAR THE UPPER TEXAS COAST IS PRODUCING
SHOWERS AND THUNDERSTORMS OVER THE NORTHWESTERN GULF OF MEXICO.
THE LOW IS EXPECTED TO MOVE INLAND OVER THE NEXT DAY OR SO AND
SIGNIFICANT DEVELOPMENT IS NOT EXPECTED. HOWEVER THE SYSTEM WILL
PRODUCE LOCALLY HEAVY RAINFALL OVER PORTIONS OF SOUTHEASTERN TEXAS
AND SOUTHERN LOUISIANA. SEE STATEMENTS FROM LOCAL NATIONAL WEATHER
SERVICE FORECAST OFFICES FOR ADDITIONAL INFORMATION.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

Seems like they have at least left the door open for a possible weak development if this were to remain over the water (which it looks like it is trying to do ATM).

[southerngale]

They've been saying that... not sure it really means much.

It's been raining steadily here for hours, but it's not that heavy. We've received several inches of rain, but as far as a flood threat... I'm not so sure. We've had much heavier rain than this recently, with street flooding, etc. when there was no Flood Watch. I guess we'll see, but at this time, I'm not worried.

[Normandy]

Interestingly this surface Low has seemed to become a more dominant feature in regards to producing the core rains....and luckily for us its just offshore and keeping the rains just offshore with it. I didn't expect the low to become this strong....with that being said, I still expect a heavy rain even as the atmosphere begins to destabilize. But it probably won't be as severe as I thought. So far ive gotten about 1.50 inches.

[Houstonia]

When I checked the current conditions on wunderground.com about an hour ago, the pressures in Houston were rising.

They are falling now.

But doesn't it look like the majority of the rain will affect Beaumont/SE LA to y'all? It looks like a swirl to me with the majority of the storm in the NE quadrant.

[Extremeweatherguy]

ATM, the rain will mostly affect Beaumont/SE LA..however, this could change later today. The center of the low is near Matagorda bay, and if temperatures can rise then I wouldn't be surprised to see more storms fire right around it later on this afternoon.

[jasons2k]

IMO this is looking like a heavy rain event for tonight. A low-level tropical low almost stationary W/SW of Houston and flow right off the GOM. You can see the first bands setting-up now.