April Weather Discussion.

[Ptarmigan]

Activity is picking up. The Sun is out and it is quite warm and humid. I think severe weather will be likely.

[wxdata]

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
720 PM CDT FRI APR 23 2010

TXC041-240029-
/O.CAN.KHGX.TO.W.0005.000000T0000Z-100424T0030Z/
BRAZOS TX-
720 PM CDT FRI APR 23 2010

...THE TORNADO WARNING FOR BRAZOS COUNTY IS CANCELLED...
THE THUNDERSTORM WHICH PROMPTED THE TORNADO HAS WEAKENED OR MOVED OUT
OF THE AREA.

[srainhoutx]

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
720 PM CDT FRI APR 23 2010

TXC313-240030-
/O.CON.KHGX.TO.W.0005.000000T0000Z-100424T0030Z/
MADISON TX-
720 PM CDT FRI APR 23 2010

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR MADISON
COUNTY...

AT 714 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
TORNADO. THIS TORNADO WAS LOCATED NEAR NORMANGEE...OR 13 MILES WEST
OF MADISONVILLE...AND MOVING EAST AT 35 MPH.

* THE TORNADO WILL IMPACT AREAS NEAR AND SOUTH OF NORMANGEE. THE WARNING
MAY BE EXTENDED.

[wxdata]

HGX: Unverified/Non-NWS Report -- from David Douglas (via spotternetwork.org) @ 07:23 PM CDT -- (S) Rotating Wall Cloud -- -- Spotter is 3 miles SSW of Cross Roads, TX (Madison county) [31.037/-95.940] -- (SN#5259)

[wxdata]

Update from San Antonio's NWS for central and south Texas
-

"Just wanted to give everyone a quick overview of what to expect tonight. The northeast escarpment counties have broken enough of the cap to produce isolated thunderstorms while the rest of the area remains capped off. Will expect current activity to die off after sunset due to the loss of heating. This will create a brief lull in the activity until a cold front moves through the area around midnight. With the increased moisture return and additional forcing provided by the front, you can expect more organized convection to impact the I-35 and southeast counties. Anticipating hail and high wind to be the primary threat."

[wxdata]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
731 PM CDT FRI APR 23 2010

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHWESTERN HOUSTON COUNTY IN SOUTHEAST TEXAS...
NORTHERN MADISON COUNTY IN SOUTHEAST TEXAS...

* UNTIL 815 PM CDT

* AT 725 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 25
MILES WEST OF AUSTONIO...OR 10 MILES NORTHWEST OF MADISONVILLE...
NEAR NORMANGEE AND MOVING EAST AT 30 MPH.

* LOCATIONS IN THE SEVERE THUNDERSTORM WARNING INCLUDE BUT ARE NOT
LIMITED TO MIDWAY..

[wxdata]

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
736 PM CDT FRI APR 23 2010


...THE TORNADO WARNING FOR MADISON COUNTY HAS BEEN ALLOWED TO
EXPIRE...

A TORNADO WATCH IS IN EFFECT UNTIL 2 AM FOR THE WARNED AREA. RADAR
INDICATES THE ROTATION WITH THE STORM HAS WEAKENED. ALSO A SPOTTER IN
THE AREA REPORTED A WALL CLOUD HAD DISSIPATED. THEREFORE THE WARNING
WAS ALLOWED TO EXPIRE. A SEVERE THUNDERSTORM WARNING WAS ISSUED FOR
PORTIONS OF THE WARNED AREA...AS THE THREAT FOR LARGE HAIL CONTINUES.

[wxdata]

Storm Spotter: rotating wall cloud northwest of Crocket

[wxdata]

Way, away, but interesting:

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
747 PM CDT FRI APR 23 2010

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* TORNADO WARNING FOR...
NORTHERN HOUSTON COUNTY IN SOUTHEAST TEXAS...

* UNTIL 815 PM CDT

* AT 743 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO THIS TORNADO
WAS LOCATED NEAR LATEXO... MOVING EAST AT 30 MPH.

* LOCATIONS IN THE TORNADO WARNING INCLUDE BUT ARE NOT LIMITED TO
KENNARD.

[wxdata]

Maybe a hint of a hook echo north of Crockett (although radar beam is 15,000 ft above the surface as this distance..

[wxdata]

Spotter: wall cloud down to the trees in above storm.

[srainhoutx]

[wxdata]

MESOSCALE DISCUSSION 0358
NWS STORM PREDICTION CENTER NORMAN OK
0757 PM CDT FRI APR 23 2010

AREAS AFFECTED...CENTRAL-SOUTH CENTRAL TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 240057Z - 240200Z

NEW WATCHES WILL LIKELY BE NEEDED THIS EVENING ACROSS NORTH CENTRAL
TO SOUTH CENTRAL TX. THE WATCH FARTHER N SHOULD BE A SEVERE TSTM
WATCH...WHILE A TORNADO WATCH MAY BE NEEDED INTO SOUTH CENTRAL TX TO
THE SW OF WW 82.

SURFACE ANALYSES SHOWED A WEAK BOUNDARY EXTENDING FROM VICINITY OF
DRT NEWD TO THE ARKLATEX INTO WRN AR WITH TSTMS EXTENDING SWWD ALONG
THIS BOUNDARY TO TRAVIS COUNTY WHERE A STORM PRODUCED 1 INCH
DIAMETER HAIL AT 2328Z. VISIBLE SATELLITE IMAGERY SHOWED ADDITIONAL
CU/TCU DEVELOPING SWWD FROM TRAVIS COUNTY. THIS BOUNDARY MARKS THE
WRN EXTENT OF GREATER LOW LEVEL MOISTURE MEANWHILE...A SECOND
BOUNDARY WAS LOCATED FARTHER W AND EXTENDED FROM NW TX /20 W SPS/ TO
NEAR SJT TO THE TX BIG BEND REGION. AN EXTENSIVE CLOUD BAND
EXTENDED SWWD FROM THIS LATTER BOUNDARY...LIKELY INDICATIVE OF THE
STRONG FORCING FOR ASCENT AND HEIGHT FALLS SPREADING EWD AHEAD OF A
MORE VIGOROUS SHORTWAVE TROUGH... CURRENTLY LOCATED OVER NRN
CHIHUAHUA/FAR SW TX. THIS ASCENT AND SECOND SURFACE BOUNDARY WILL
MOVE EWD THIS EVENING...EVENTUALLY MERGING WITH/OVERTAKING THE
BOUNDARY FARTHER E. STEEP MID LEVEL LAPSE RATES SPREADING EWD ATOP
THE MOIST BOUNDARY LAYER WILL AID IN MAINTAINING MODERATE
INSTABILITY.

THE TRAVIS COUNTY STORM AND TCU EXTENDING SWWD MAY BE UNDER THE
INFLUENCE OF THE LEADING EDGE OF ASCENT WITH THE APPROACHING SW TX
TROUGH. ADDITIONAL STORMS SHOULD DEVELOP ACROSS SOUTH CENTRAL TX
INTO THE EARLY EVENING...WITH THE LIKELIHOOD FOR EVEN MORE ROBUST
UPDRAFTS AS THE TROUGH MOVES INTO THIS REGION. STRENGTHENING SWLY
MID LEVEL WINDS WILL MAINTAIN EFFECTIVE BULK SHEAR IN EXCESS OF 50
KT FOR ORGANIZED STORMS. ALTHOUGH LOW LEVEL WINDS /SFC-1 KM/ ARE
RELATIVELY WEAK AT THIS TIME ACROSS SOUTH CENTRAL TX...AN EXPECTED
INCREASE SLY WINDS VEERING AND ALSO INCREASING WITH HEIGHT WILL
SUPPORT A THREAT FOR TORNADOES AND DAMAGING WINDS AS THE TROUGH
SWEEPS EWD LATER THIS EVENING/ TONIGHT. UNTIL THEN...HAIL AND
STRONG WIND GUSTS SHOULD BE THE PRIMARY THREAT FOR THE NEXT FEW
HOURS /UNTIL ABOUT MID EVENING/.

[wxdata]

8pm update from the Storm Prediction Center-

"AS UPPER PERTURBATION EJECTS EWD THEN NEWD OVER
SWRN THROUGH N-CENTRAL TX OVERNIGHT...FRONT WILL RESUME SEWD MOTION
ACROSS S TX AND MIDDLE TX COAST...REACHING TO NEAR SHV AND FSM BY
END OF PERIOD. "



http://www.spc.noaa.gov/products/outloo ... _0100.html

[srainhoutx]

Rather large extentsion W with that Slight Risk area.

[wxdata]

New showers/storm redeveloping from Wichita Falls to Brownwood

[wxdata]

Lake Charles 0z sounding:

Station identifier: LCH
Station number: 72240
Observation time: 100423/1200
Station latitude: 30.11
Station longitude: -93.21
Station elevation: 10.0
Showalter index: -6.50
Lifted index: -6.62
SWEAT index: 577.09
K index: 12.70
Cross totals index: 28.30
Vertical totals index: 28.30
Totals totals index: 56.60
Convective Available Potential Energy: 777.98
CAPE using virtual temperature: 868.79
Convective Inhibition: -9.15
CINS using virtual temperature: -10.56
Level of Free Convection: 857.05
LFCT using virtual temperature: 856.89
Bulk Richardson Number: 7.89
Bulk Richardson Number using CAPV: 8.81

[srainhoutx]

Lake Charles 0z sounding:

Station identifier: LCH
Station number: 72240
Observation time: 100423/1200
Station latitude: 30.11
Station longitude: -93.21
Station elevation: 10.0
Showalter index: -6.50
Lifted index: -6.62
SWEAT index: 577.09
K index: 12.70
Cross totals index: 28.30
Vertical totals index: 28.30
Totals totals index: 56.60
Convective Available Potential Energy: 777.98
CAPE using virtual temperature: 868.79
Convective Inhibition: -9.15
CINS using virtual temperature: -10.56
Level of Free Convection: 857.05
LFCT using virtual temperature: 856.89
Bulk Richardson Number: 7.89
Bulk Richardson Number using CAPV: 8.81

Interesting read for those not familiar with Bulk Richardson Number (BRN)...

http://www.theweatherprediction.com/habyhints/315/

[Houstonkid]

Lake Charles 0z sounding:

Can you decipher for us non-weather folks?

Still a cap?

[wxdata]

yes, still a cap (at least at Lake Charles.)