SPC issues slight risk of severe wx for South/Southeast Tx

[jasons2k]

wow...it is up to 88F at IAH, and 87F at Tomball. These current numbers exceed the forecasted highs by 2-3F. Also...dewpoints remain the upper 60s under variably changing skies. We are certaintly primed for severe weather today!

Well yes and no. We certainly have the surface heating, but the cap has been a little stonger than was anticipated and convergence along the front & low level shear are almost non-existent. Maybe some hailers and some strong gusts but it doesn't look like a very violent or widespread event.

[Johnny]

Yep, some nice gusty winds with some isolated hailers is what I'm thinking also. This will more than likely turn into a good rain event than a severe weather event.

[Johnny]

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 249
NWS STORM PREDICTION CENTER NORMAN OK
305 PM CDT TUE APR 25 2006

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

TEXAS
COASTAL WATERS

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 305 PM UNTIL
1000 PM CDT.

HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES WEST
NORTHWEST OF LAREDO TEXAS TO 40 MILES NORTHEAST OF HOUSTON TEXAS.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 31025.

[Extremeweatherguy]

wow...it is up to 88F at IAH, and 87F at Tomball. These current numbers exceed the forecasted highs by 2-3F. Also...dewpoints remain the upper 60s under variably changing skies. We are certaintly primed for severe weather today!

Well yes and no. We certainly have the surface heating, but the cap has been a little stonger than was anticipated and convergence along the front & low level shear are almost non-existent. Maybe some hailers and some strong gusts but it doesn't look like a very violent or widespread event.

According to the NWS...the cap is close to breaking across most of the area. Either way though, I agree that hail and wind will be the main threats. The hail could get quite large though...up to 2.5"+ in a few storms.

[Extremeweatherguy]

From the SPC:

...S TX...

THE CAP CONTINUES TO WEAKEN WITHIN PRE-FRONTAL WARM SECTOR ACROSS S
TX WHERE THE ATMOSPHERE HAS BECOME MODERATELY UNSTABLE WITH MLCAPE
AROUND 2500 J/KG. STORMS ARE EXPECTED TO DEVELOP IN VICINITY OF THE
FRONT WITHIN THE NEXT COUPLE HOURS OR SO AND SUBSEQUENTLY SPREAD
SEWD. DEEP LAYER VERTICAL SHEAR FROM 35 TO 40 KT IS SUFFICIENT FOR
SOME STORMS TO TAKE ON SUPERCELL STRUCTURES. THE STRONG
INSTABILITY...STEEP MID LEVEL LAPSE RATES AND POTENTIAL FOR UPDRAFT
ROTATION WILL SUPPORT THE THREAT OF VERY LARGE HAIL. SOME STORMS MAY
EVENTUALLY MERGE INTO CLUSTERS WITH AN INCREASING THREAT FOR
DAMAGING WIND GUSTS.

[Extremeweatherguy]

I know that the front has already reached college station (but not yet Brenham)...but does anyone know how fast this thing is moving? If storms don't start firing soon...then our window of opportunity may shut quickly.

[Johnny]

I think the front is going to start slowing down big time very soon and stay in the area for the rest of this evening and into tonight. It will move offshore in the morning/early afternoon tomorrow.

[Extremeweatherguy]

looks like a few svr. storms have fired SW and SE of Dallas...but nothing down here yet. I predict that we will see it just like OK did yesterday. West of OKC it was very quite for most of the day and then POP, a line of supercells seemed to have come out of no where by the evening.

[Johnny]

Storms should start popping up anytime now. I've been stuck in the office and haven't even looked out a window today. I'll be leaving here shortly and I'm sure I'll see some towers building up. At least I hope so.

[Extremeweatherguy]

Storms should start popping up anytime now. I've been stuck in the office and haven't even looked out a window today. I'll be leaving here shortly and I'm sure I'll see some towers building up. At least I hope so.

Yeah I was just outside and it seems to be HOT, HUMID and partly cloudy with some towering cumulus visible around the area...just no T-storms yet.

[Extremeweatherguy]

I think the front is going to start slowing down big time very soon and stay in the area for the rest of this evening and into tonight. It will move offshore in the morning/early afternoon tomorrow.

Just noticed that the front has cleared Brenham (not getting NW winds gusting to 18mph)...and at Tomball the winds just turned NW at 3mph.

[jasons2k]

Been in meetings for awhile and just now catching-up again. Things should start popping soon (hopefully).

[Johnny]

The weather station I'm looking at has winds out of the NNW in Brenham gusting to 18 mph also. BUT it also says the dewpoint is 73 degrees and the humidity is up to 74%?

[Yankeegirl]

Severe thunderstrom watch till 10 pm here.... Nice, its still sunny here...
Severe Thunderstorm Watch

SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 249
NWS STORM PREDICTION CENTER NORMAN OK
403 PM CDT TUE APR 25 2006

SEVERE THUNDERSTORM WATCH 249 REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR THE FOLLOWING LOCATIONS

TXC007-013-015-025-039-057-071-089-123-127-131-149-157-163-167-
175-177-201-239-249-255-273-283-285-291-297-311-321-323-339-355-
373-391-407-409-455-469-471-473-479-481-493-507-260300-
/O.CON.KWNS.SV.A.0249.000000T0000Z-060426T0300Z/

TX
. TEXAS COUNTIES INCLUDED ARE

ARANSAS ATASCOSA AUSTIN
BEE BRAZORIA CALHOUN
CHAMBERS COLORADO DEWITT
DIMMIT DUVAL FAYETTE
FORT BEND FRIO GALVESTON
GOLIAD GONZALES HARRIS
JACKSON JIM WELLS KARNES
KLEBERG LA SALLE LAVACA
LIBERTY LIVE OAK MCMULLEN
MATAGORDA MAVERICK MONTGOMERY
NUECES POLK REFUGIO
SAN JACINTO SAN PATRICIO TRINITY
VICTORIA WALKER WALLER
WEBB WHARTON WILSON
ZAVALA

[Yankeegirl]

They have also upped our rain chances tonight from 60% to 70%.... Nice!!!

[Extremeweatherguy]

looks like an isolated cell is forming west of corpus...this could be the start. Currently in NW Houston it is partly cloudy..in the lower 90s (in my backyard) and there is little to no wind.

ALSO: The front has dropped Brenham down to 79F and the dewpoint has dropped to 70F there. The good news, however, is that many severe storms are popping to the south of Dallas (which is well behind the front and where temps. are/were in the 60s with dewpoints near 61F). My thoughts are:

If you are ahead or near the front: Highest risk of Severe weather

If you are just behind the front: Decent shot at Severe weather

If you are over 2 hours behind the front: "Ok" chance of severe weather

[Extremeweatherguy]

still no activity...

[jasons2k]

Looking at my GRLevel 3 loops, it *looks* like the surface front stretches along this approximate line:

Trinity/Polk County line to the Montgomery/Walker County line @ I-45 to the NW tip of Montgomery County to the Austin/Colorado County line @ I-10.

Still waiting.......

[jasons2k]

A blip in Dewitt County...

[Extremeweatherguy]

there are some very impressive storms down to our SW right now with 2-3 tornado warnings out and it is as hot and humid as can be up here in Houston. When will we the storms!? I have been waiting for 3 hours so far.