[MCD] SWOMCD

Tue Apr 18 23:17:32 UTC 2006

ACUS11 KWNS 182315
SWOMCD
SPC MCD 182314 
ARZ000-LAZ000-TXZ000-OKZ000-190115-

MESOSCALE DISCUSSION 0547
NWS STORM PREDICTION CENTER NORMAN OK
0614 PM CDT TUE APR 18 2006

AREAS AFFECTED...FAR SERN OK...NERN TX...SWRN AR AND NWRN LA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 182314Z - 190115Z

NON-SURFACE BASED CONVECTION HAS DEVELOPED RECENTLY OVER NERN TX
BENEATH HIGH CLOUD COVER. IT IS UNCERTAIN ATTM WHETHER CONVECTION
CAN BECOME SURFACE BASED IN THE NEXT HR OR TWO BEFORE INCREASING
BOUNDARY LAYER INHIBITION OCCURS. AREA WILL BE MONITORED FOR A
POSSIBLE WW.

RECENT SFC OBS FROM DFW HAD BKN150 AND WEBCAMS IN THE DFW AREA
SUGGEST THAT A MID LEVEL ACCAS BAND WITH SOME VIRGA WAS MOVING
ACROSS THE REGION IN ASSOCIATION WITH MID/HIGH LEVEL SPEED MAX.
SUFFICIENT MID LEVEL MOISTENING HAS LIKELY OCCURRED WITH THIS
VIRGA/ACCAS TO ALLOW FOR ELEVATED CONVECTION TO DEVELOP OVER NERN
TX. SURFACE OBSERVATIONS OVER THE ARKLATEX REGION AHEAD OF THIS
CONVECTION...MODIFIED FOR 21Z RUC FORECAST SOUNDINGS...SUGGEST THAT
AROUND 100 J/KG OF MLCINH REMAINS. GIVEN RECENT OBSERVED CELL MOTION
ON RADAR...IT APPEARS CONVECTION REMAINS NON-SURFACE BASED. THIS
BEING SAID...IT REMAINS POSSIBLE THAT SUFFICIENT EVAPORATIVE COOLING
MIGHT OCCUR IN THE NEXT HR OR TWO /WHILE THE BOUNDARY LAYER HAS THE
LEAST CINH/ THAT THIS CONVECTION COULD STILL BECOME SURFACE BASED.
MODERATE INSTABILITY /MLCAPES AROUND 2000 J/KG / AND SUFFICIENT
SHEAR WILL ALLOW FOR A SVR WIND/HAIL THREAT IF STORMS DO BECOME
SURFACE BASED.

..CROSBIE.. 04/18/2006

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

ATTN...WFO...LZK...SHV...FWD...

33999438 33519537 32949517 32589459 32469384 32969293
33899262 

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