[MCD] SWOMCD

Fri Apr 21 06:14:45 UTC 2006

ACUS11 KWNS 210612
SWOMCD
SPC MCD 210612 
TXZ000-210815-

MESOSCALE DISCUSSION 0597
NWS STORM PREDICTION CENTER NORMAN OK
0112 AM CDT FRI APR 21 2006

AREAS AFFECTED...PORTIONS CENTRAL/S-CENTRAL TX.

CONCERNING...SEVERE THUNDERSTORM WATCH 230...

VALID 210612Z - 210815Z

TSTMS CONTINUE TO INCREASE IN COVERAGE ACROSS PORTIONS
CENTRAL/S-CENTRAL TX -- FROM NERN HILL COUNTRY W ACT...SWWD ACROSS
HILL COUNTRY AND LOWLANDS NE DRT.  ALTHOUGH ANY OF THIS ACTIVITY MAY
PRODUCE HAIL AS IT MOVES EWD AND SEWD INTO MORE UNSTABLE
INFLOW...MAIN SEVERE POTENTIAL WILL BE CONCENTRATED ACROSS AREA
BETWEEN AUS-COT...INCLUDING SAT.  WW 230 IS THEREFORE REQUIRED.

SFC MESOANALYSIS INDICATES QUASISTATIONARY BAROCLINIC ZONE FROM
ABOUT 20 S DRT....ENEWD THROUGH HDO...SAT...IAH.  THIS BOUNDARY HAS
BEEN REINFORCED BY OUTFLOWS FROM EARLIER CONVECTION.  CONVECTION
DEVELOPING/INCREASING IN COVERAGE TO ITS N DOES NOT APPEAR TO BE
SFC-BASED...GIVEN STATIC STABILITY APPARENT NEAR SFC IN MODIFIED
RAOBS AND RUC FCST SOUNDINGS.  HOWEVER...COMBINATION OF STEEP
MIDLEVEL LAPSE RATES -- APPARENT ON 00Z DRT RAOB -- AND LOW LEVEL
WAA/MOIST ADVECTION ATOP STABLE LAYER -- CONTRIBUTES TO FAVORABLE
BUOYANCY.  ELEVATED MUCAPES 1000-1500 J/KG ARE EVIDENT WITHIN ABOUT
70-90 NM OF BOUNDARY...DECREASING GRADUALLY FARTHER NWD OVER CENTRAL
TX.  EFFECTIVE SHEAR VECTOR SPEEDS OF 40-60 KT SUGGEST SOME
POTENTIAL FOR SUPERCELL STRUCTURES...ESPECIALLY OVER S-CENTRAL TX
VICINITY SAT...WHICH WOULD ENHANCE LARGE HAIL POTENTIAL.  TSTMS
MOVING ALONG AND S OF BOUNDARY WILL BE NEARLY SFC-BASED...AND MAY
PRODUCE DAMAGING WIND AS WELL.

..EDWARDS.. 04/21/2006

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...HGX...FWD...CRP...EWX...SJT...

29100080 29900037 30429949 31079837 30999775 30609688
30339662 29839657 29029698 28519861 28000001 28140006
28250026 28480035 28670048 28930062 29060065 

WWWW