Severe Threat TX

[jeff]

Active more typical May period shaping up for the southern plains starting this evening.

Strong upper level trough over the W US will eject into the plains late today with a secondary vort max over NW Mexico currently swinging across TX tonight and Sunday. Low level moisture is increasing as surface pressures fall in the lee of the Rockies. Low to mid 60 degree dewpoints will spread inland into N TX and NW TX today with near 70 degree dewpoints along the coast by early Sunday (PWS rising to near 1.5-1.7 in).

Forecast models minus the dry GFS support thunderstorm develop tonight over central and SW TX into NW TX ahead of the dryline and ahead of the eastward moving short wave over NW Mexico. Models and SPC agree with upscale development into an MCS driven by favorable 250mb upper air venting, good low level inflow, and favorable low to mid level shear. 1000-500 mb thickness lines support a MCS track generally toward the E and ENE from SC TX through early Sunday morning.

Sunday:

MCS should be ongoing along I-35 Sunday morning. Air mass over E TX will be moist and unstable with CAPES forecast near 2500 J/kg, LI's near -6, and favorable low level shear. Diurnal heating effects suggest the MCS may weaken in the morning and then regenerate along and S of a well defined MVC by early afternoon. Location and track of MVC will be detrimental in convective evolution Sunday across SE and E TX. Additionally, since this will be a mesoscale driven event it is not out of the question that the MCS sweeps off the coast Sunday morning with no development Sunday evening. Future guidance this afternoon should help determine the extent and severity of the overnight thunderstorm complex and shed light on potential developments Sunday.

Main severe weather threats will be damaging winds and large hail.

[TexasStooge]

Code: Select all

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FORT WORTH TX
250 AM CDT SAT MAY 7 2005

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-072100-
ANDERSON-BELL-BOSQUE-COLLIN-COMANCHE-COOKE-CORYELL-DALLAS-DELTA-
DENTON-EASTLAND-ELLIS-ERATH-FALLS-FANNIN-FREESTONE-GRAYSON-HAMILTON-
HENDERSON-HILL-HOOD-HOPKINS-HUNT-JACK-JOHNSON-KAUFMAN-LAMAR-LAMPASAS-
LEON-LIMESTONE-MCLENNAN-MILAM-MILLS-MONTAGUE-NAVARRO-PALO PINTO-
PARKER-RAINS-ROBERTSON-ROCKWALL-SOMERVELL-STEPHENS-TARRANT-VAN ZANDT-
WISE-YOUNG-
250 AM CDT SAT MAY 7 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEST OF A JACKSBORO TO
MINERAL WELLS... STEPHENVILLE... LAMPASAS LINE THIS AFTERNOON... AND
ACROSS ALL OF NORTH TEXAS TONIGHT. THE MAIN THREAT WILL BE LARGE HAIL
AND DAMAGING WINDS... HOWEVER ISOLATED TORNADOS WILL BE POSSIBLE FROM
THE STRONGER SUPERCELL TYPE THUNDERSTORMS DURING THE  AFTERNOON AND
EVENING HOURS.

.DAYS TWO THROUGH SEVEN...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS ALL OF NORTH
TEXAS SUNDAY.  LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY
THREAT ON SUNDAY.

THERE WILL BE A CHANCE OF THUNDERSTORMS THROUGHOUT NORTH TEXAS
MONDAY... ALSO WEST OF A GAINESVILLE TO GRANBURY AND LAMPASAS LINE ON
WEDNESDAY... AND ACROSS ALL OF NORTH TEXAS THURSDAY AND FRIDAY.  AN
ISOLATED SEVERE THUNDERSTORM IS POSSIBLE DURING THE AFTERNOON OR
EVENING HOURS ON ANY ONE OF THESE DAYS... BUT WIDESPREAD SEVERE
WEATHER IS NOT EXPECTED.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUESTED WEST OF A JACKSBORO...
STEPHENVILLE... LAMPASAS LINE BY LATE AFTERNOON... AND ACROSS
ALL OF NORTH TEXAS TONIGHT.

[Yankeegirl]

All I know is that it is reallllly humid out there today!

[PTrackerLA]

We could REALLY use the rain. Jeff, what do you think about rain chances for us here in Louisiana? According to NWS it sounds like we have a slightly better chance of rain Monday.

[jeff]

We could REALLY use the rain. Jeff, what do you think about rain chances for us here in Louisiana? According to NWS it sounds like we have a slightly better chance of rain Monday.

S LA would have better chances Monday for sure, however those chances are only 30/40%. Ridge to your E will only give very little ground so what comes out of TX Sunday and early Monday will likley fall apart as it moves eastward into the ridge.

[Yankeegirl]

The weather channel has us for a 70%chance of Strong Storms here tomorrow afternoon.... Not that I watch the weather channel...

[chadtm80]

http://www.storm2k.nhcwx.com/hw3.php?st ... pp=0&key=0

[jeff]

Weakening MCS now pushing into EC TX along well defined bow. Outflow boundary extends WSW from bow apex to N of San Antonio. Additional short wave energy over NE Mexico will move into C and SC TX today with additional thunderstorm development. Dry line is across far W TX and air mass recovery over C TX is underway given clear skies and return of S winds.

Thunderstorms will continue to fire along the stalling outflow boundary roughly along and north of I-10 awaiting the next short wave. The AM CRP sounding was capped around 700mb so the southward extent of the activity is in question.

By early afternoon new thunderstorms should develop along the outflow boundary and across SW TX as the next short wave ejects ENE across the state. Dry line across W TX will also become active as strong surface heating works on a moist air mass. Convective developments over SC, and SE TX may drive inland convection along the dry line as low level inflow may be limited should thunderstorms really get going closer to the coast. If development near the coast is minimal, and the C TX air mass does recover then severe thunderstorms will be possible along the dry line this evening and tonight as suggested by the RUC and ETA.

Meso scale nature of the event is causing forecasting havoc with respect to timing and movement.

[jeff]

Tornado Watch issued for SE and SC TX through 700pm.

Stalling outflow boundary from morning MCS currently extends from Longview to downtown Houston to N of San Antonio. Convection continues to develop along the boundary where 850mb flow is perpendicular. Cells continue to develop and lift northward becoming elevated above the meso high/cold pool.

Surface based activity is developing over SC TX where capping is weakening and large scale ascent is approaching from Mexican short wave. Cluster near KSAT will likley move E along and just south of stalled outflow boundary where air mass is unstable with 3000 J/kg of CAPE and LI's around -7. Additional thunderstorms will develop across SC TX and the coastal bend as cap weakens with a tornado threat. Evolution of KSAT cluster may be into a long lived bow echo sweeping E to ESE along the I-10 corridor.

NOTE: wake low wind event is winding down over the DFW area after significant high winds earlier this morning. Gust to 63 mph were recorded with widespread 40-50mph winds for 1-2 hours this morning. Surface gradient is relaxing as wake low is weakening.

If a well defined bow echo does develop over SC and SE TX another wake low wind event will be possible during the early to mid evening hours along the track of the MVC.

[chadtm80]

TORNADO WATCH
Issue Date: 1144 AM CDT SUN MAY 08 2005
Expiration: 700 PM CDT SUN MAY 08 2005

TORNADO WATCH 231 IS IN EFFECT UNTIL 700 PM CDT FOR THE
FOLLOWING LOCATIONS
TXC013-015-019-021-025-029-039-055-057-071-089-091-123-127-149-
157-163-167-175-177-187-201-209-239-255-259-265-283-285-291-297-
311-321-323-325-385-391-463-469-473-481-493-507-090000-
/O.NEW.KWNS.TO.A.0231.050508T1650Z-050509T0000Z/
TX
. TEXAS COUNTIES INCLUDED ARE
ATASCOSA AUSTIN BANDERA
BASTROP BEE BEXAR
BRAZORIA CALDWELL CALHOUN
CHAMBERS COLORADO COMAL
DEWITT DIMMIT FAYETTE
FORT BEND FRIO GALVESTON
GOLIAD GONZALES GUADALUPE
HARRIS HAYS JACKSON
KARNES KENDALL KERR
LAVACA LA SALLE LIBERTY
LIVE OAK MATAGORDA MAVERICK
MCMULLEN MEDINA REAL
REFUGIO UVALDE VICTORIA
WALLER WHARTON WILSON
ZAVALA
$$



http://www.storm2k.nhcwx.com/hw3.php?st ... pp=0&key=0

[PTrackerLA]

Looks like SE Texas will be receiving some much needed heavy rains this evening. Not sure if they were forecasting this much precip over there so hopefully that means our rain chances are increasing as well.

[JenBayles]

Got some hail in West Houston around 3:00 - 1/2 to minimal 1". I'm loving this rain!

[PTrackerLA]

Congrats on the rain Jen, looks like we'll get in on the action tomorrow! Let's all hope for a good soaking so we can prevent a drought from developing and plus I'm tired of watering the grass!

[Yankeegirl]

We are getting slammed out here in West Harris County! Seems like its training over the area... Its Great!

[KatDaddy]

Here it comes. Expect 60MPH winds and torriental rains from Houston south to Galveston over the next 1-2hours.

[Roxy]

Barely a drop yet here in CL. But I see it coming!

We need it, we put 'weed and feed' out in anticipation!!!

[PTrackerLA]

Radar estimates are 1"-3" of rain around the Houston metro, hopefully yall didn't have any severe weather. It remains to be seen whether this MCS can make it on into south Louisiana and the NWS seems to think it will die out after sunset but hopefully it will put a big dent in the high pressure allowing storms to refire over us tomorrow.

[jeff]

Wake low winds playing havoc with the power. 3rd attempt at a post.

Strong wake low moving off the upper TX coast with sustained 30-40mph winds with gust up to 50mph across Harris County into the coastal areas.

Rainfall finally winding down after impressive amounts and lots of urban flooding. I-10 main lanes were impassable earlier near 610W loop. ALERT gage at Spring Branch and Bingle recorded 1.77 inches in 15 minutes and 2.17 in 30 mintues.

Widespread 1-3 inches fell north of I-10 with 4-6 inches west of Columbus. A couple of more inches over NC Harris and water would have been in homes. Thankfully the ground was dry and the bayous were able to handle the rapid run-off.

NOTE KHGX 88D was hit by lightening and has been having operation problems since the strike, also one report of a person struck by lightening in Fort Bend Co.

Air mass is worked over and complex near and NW of Austin will have a hard time getting in here given our stable low levels. Air mass will begin to recover over night as SE winds return.

For those that wanted rain, we just deleted our 8 week dry spell in 6 hours. As usual too much of a good thing too fast.

[Rainband]

Stay safe

[vbhoutex]

I-10 is still shut down at I-610. They are working to clear it. Atill 134,000 in the metro area without power. My son stayed on the East side of town tonight instead of trying to make it home throught the water. My rain guage only registered 0.63", but I think it is not working right since everything else around us got at least 2" and our streets were flooded for a couple of hours. Golfball sized hail reported in Texas City. Definitely a rough day weather wise.