[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 281804
SWOMCD
SPC MCD 281804 
OKZ000-TXZ000-281930-

MESOSCALE DISCUSSION 0679
NWS STORM PREDICTION CENTER NORMAN OK
0104 PM CDT FRI APR 28 2006

AREAS AFFECTED...N CNTRL TX THRU S CNTRL/SE OK

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 281804Z - 281930Z

TRENDS ARE BEING MONITORED FOR THE POSSIBILITY OF AN ADDITIONAL WW
EAST OF WW 256.

WHILE SURFACE-BASED CONVECTIVE INITIATION APPEARS UNDERWAY ALONG DRY
LINE...SOUTHEAST OF LUBBOCK THROUGH AREAS EAST/SOUTHEAST OF 
MIDLAND...AN INCREASE IN CONVECTIVE DEVELOPMENT IS ALSO ONGOING 
NORTH OF THE TEXAS HILL COUNTRY INTO AREAS NEAR/WEST OF DALLAS/FORT
WORTH. THIS APPEARS BASED ABOVE AT LEAST SHALLOW NEAR SURFACE
INVERSION LAYER...IN ASSOCIATION WITH BROADER AREA OF ISENTROPIC
ASCENT... DOWNSTREAM OF SOUTHERN PLATEAU CLOSED LOW.  THIS FORCING
WILL SPREAD NORTHEASTWARD ACROSS THE RED RIVER VALLEY THROUGH THE
20-21Z TIME FRAME...AS UPPER SYSTEM SHIFTS INTO THE SOUTHERN
ROCKIES.

STEEP MID-LEVEL LAPSE RATES ARE CONTRIBUTING TO MOST UNSTABLE CAPE
ON THE ORDER OF 1000 J/KG OVER A FAIRLY BROAD AREA OF THE SOUTHERN
PLAINS.  THIS WILL SUPPORT RISK OF LARGE HAIL IN STRONGEST
CELLS...THOUGH INCREASINGLY WIDESPREAD NATURE OF CONVECTION MAY TEND
TO MITIGATE THREAT MOST AREAS NORTH/EAST OF DALLAS/FORT WORTH. BEST
HAIL POTENTIAL SEEMS LIKELY TO REMAIN CONFINED TO AREAS WEST OF THE
METROPLEX INTO THE EDWARDS PLATEAU...IN CLOSER PROXIMITY STEEPENING
LOW-LEVEL LAPSE RATES.

..KERR.. 04/28/2006

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

ATTN...WFO...SHV...TSA...FWD...OUN...EWX...SJT...

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