Severe Weather in SE Texas for Friday 4/22

[ticka1]

Jeff - what are you thoughts on the severe weather potential for us here in SE Texas? I am hearing that we could have severe storms coming through tomorrow afternoon and evening - and then I hear that the severe event will not happen.

[sparky]

Well i know for TN MS AL GA it might get interesting we are in a moderate risk. From what i have read all day not gonna be a big tornado event mostly straight line winds and large hail.

[sparky]

Apr-22-2005 0600 UTC Day 1 Convective Outlook
Updated: Fri Apr 22 06:04:10 UTC 2005



SIGNIFICANT NUMBER OF SEVERE STORMS ARE EXPECTED OVER A LARGE
REGION OF THE MIDWEST AND SOUTH DURING THE DAY TODAY. VERY LARGE
HAIL... WIDESPREAD DAMAGING WINDS... AND TORNADOES... ARE ALL
POSSIBLE AS AN INTENSIFYING STORM SYSTEM AND COLD FRONT SWEEP EAST
ACROSS PARTS OF ILLINOIS... INDIANA... OHIO... KENTUCKY...
TENNESSEE... EASTERN MISSISSIPPI... ALABAMA... GEORGIA... AND SMALL
AREAS OF NORTH AND SOUTH CAROLINA... AS WELL AS THE FLORIDA
PANHANDLE.

...LA WWD TO SERN TX...
SCATTERED SEVERE STORMS ARE POSSIBLE AS FRONTAL CIRCULATION SPREADS
ACROSS THESE AREAS COINCIDENT WITH STRONG DIURNAL DESTABILIZATION.
NWLY MID LEVEL FLOW OF 40KT ATOP WEAK LOW LEVEL FLOW WILL CONTRIBUTE
TO SUFFICIENT SHEAR FOR A COUPLE OF SUPERCELLS OR SUSTAINED UPDRAFTS
CAPABLE OF LARGE HAIL AND DAMAGING DOWNDRAFTS...AND PERHAPS AN
ISOLATED TORNADO.

http://www.spc.noaa.gov/products/outlook/day1otlk.html#topimage
for probabilities and detailed discussion.

Looks to be active across ohio valley and mid south all the way to me. been a while since i have been at a 15% for tornadoes will be interesting to see how this unfolds.

[jeffl]

Tough forecast for this afternoon and evening with regards to severe weather potential over SE TX. Main thrust of the event will be over the central and SE Gulf states.

Cold front currently moving through north TX as noted by 30 and 40 degree dewpoints clashing with 60 and near 70 degree dewpoints. Low level inflow has all but collapsed overnight as strong surface low pressure over NE moves on into the Midwest. Air mass over SE TX is moist and unstable with 1500 J/kg of CAPE on the AM soundings.

Strong surface heating should commence by midday as low level clouds break up. Forecasted highs in the mid to upper 80's will support a very unstable atmosphere by mid afternoon as the front reaches our northern counties. CAPES are progged to reach into the 3000 J/kg range and although shear and low level inflow will be weak the high instability will compensate.

Expect storms to develop along the front from N of College Station to N of Lufkin in the 100-300pm time frame and move southward. Heating and lift along the boundary should break the cap and release the built up surface energy. Storms will go quickly severe with large hail and downburst (dry layer at 750 to 630 mb) being the main threats. An isolated tornado cannot be ruled out given a SSW storm motion into a SSW low level inflow field or roughly 180 degrees of low level turning from inflow to updraft base. Storms may remain scattered in nature as they drop southward reaching the HOU area around 600pm and the coast by 900-1100pm. They could also form into a squall line or MCS as suggested by the ETA and GFS, although these systems typically need more low level inflow than we currently have. Either way some will see an active afternoon and some may get no rain at all.

Will watch with interest.

[sparky]

MESOSCALE DISCUSSION 0651
NWS STORM PREDICTION CENTER NORMAN OK
1106 AM CDT FRI APR 22 2005

AREAS AFFECTED...ERN TX...WRN/CENTRAL LA...AND WRN/CENTRAL MS

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 221606Z - 221800Z

SEVERE THUNDERSTORM THREAT IS EXPECTED TO INCREASE THROUGH THIS
AFTERNOON ACROSS ERN TX...WRN/CENTRAL LA...AND WRN/CENTRAL MS. WW
WILL LIKELY BE NEEDED SOON.

AT 1550Z...ISOLATED THUNDERSTORMS CONTINUE ALONG SURFACE COLD FRONT
RED RIVER PARISH LA WSWWD TO ANDERSON COUNTY TX. FRONT SHOULD
CONTINUE TO MOVE SEWD ACROSS THE DISCUSSION AREA THIS AFTERNOON.
SURFACE HEATING COMBINED WITH MID 60S BOUNDARY LAYER DEWPOINTS WILL
LEAD TO MLCAPE VALUES 1500-2500 J/KG. AXIS OF STEEP LOW-MID LEVEL
LAPSE RATES ALONG FRONT SHOULD LEAD TO INCREASING CONVECTIVE
COVERAGE AS CIN CONTINUES TO DECREASE. DEEP LAYER FLOW IS PRIMARILY
PARALLEL TO FRONT...SUGGESTING A BROKEN LINE OF STORMS WITH EMBEDDED
SEVERE/LONG-LIVED CORES CONTAINING LARGE HAIL AND ISOLATED DAMAGING
WINDS. CONVECTIVE COVERAGE SHOULD ALSO BE AIDED BY STRONG 500-300MB
DIVERGENCE BETWEEN SWRN U.S. RIDGE AND CYCLONIC FLOW AROUND THE
UPPER LOW CENTERED ACROSS MO. AS COVERAGE OF STORMS INCREASES...WW
WILL LIKELY BE REQUIRED BY 17Z.

..BANACOS.. 04/22/2005


ATTN...WFO...JAN...LIX...LCH...SHV...HGX...FWD...E WX...