[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 201821
SWOMCD
SPC MCD 201821 
TXZ000-201945-

MESOSCALE DISCUSSION 0582
NWS STORM PREDICTION CENTER NORMAN OK
0121 PM CDT THU APR 20 2006

AREAS AFFECTED...PARTS OF WRN AND CNTRL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 219...220...

VALID 201821Z - 201945Z

HAIL THREAT WILL CONTINUE ACROSS WW AREAS ANOTHER COUPLE OF HOURS
...BUT MAXIMUM HAIL SIZES MAY BEGIN TO DECREASE AS ACTIVITY DEVELOPS
TOWARD NORTH CENTRAL/NORTHEAST TEXAS.  NEW WWS NORTH/EAST OF 219/220
MAY NOT BE NEEDED.  DRY LINE ACROSS SOUTHWEST TEXAS WILL BE
MONITORED FOR POSSIBILITY OF INCREASING SEVERE THREAT LATER THIS
AFTERNOON.

PRIMARY SOUTHERN BRANCH SHORT WAVE TROUGH IS NOW CROSSING THE
SOUTHERN ROCKIES...BUT WEAKER DOWNSTREAM IMPULSE APPEARS TO HAVE
LIFTED THROUGH THE TEXAS BIG BEND/PECOS VALLEY REGION. MID/UPPER
FORCING WITH THIS FEATURE SEEMS LIKELY TO SPREAD NORTHEAST OF THE
EDWARDS PLATEAU AND HILL COUNTRY BETWEEN NOW AND 21Z...ACCOMPANIED
BY STRONGER CONVECTIVE DEVELOPMENT.  MODELS SUGGEST...HOWEVER...THAT
THE LOW-LEVEL JET WILL REMAIN DIRECTED NORTHWESTWARD THROUGH THE
LOWER RIO GRANDE VALLEY INTO THE PECOS VALLEY. WITH LOSS OF BETTER
MOIST INFLOW...ONGOING CONVECTION SEEMS LIKELY TO BECOME
INCREASINGLY ELEVATED AS IT PROGRESSES DEEPER INTO CENTRAL
TEXAS...AND WEAKER CAPE MAY MITIGATE LARGE HAIL THREAT.

AS CONVECTION LIFTS NORTHWARD...MOIST BOUNDARY LAYER WILL BEGIN TO
WARM FROM SOUTH CENTRAL TEXAS INTO THE TRANSPECOS REGION...AND
SURFACE FRONT MAY REDEVELOP NORTHWARD...CLOSER TO MIDLAND/JUNCTION
AND AUSTIN.  HOWEVER...STRENGTHENING CAP MAY INHIBIT FURTHER
CONVECTIVE DEVELOPMENT UNTIL FORCING WITH UPSTREAM SHORT WAVE BEGINS
TO INTERACT WITH DRY LINE ACROSS SOUTHWEST TEXAS LATER THIS
AFTERNOON.

..KERR.. 04/20/2006

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

ATTN...WFO...SHV...HGX...FWD...EWX...SJT...LUB...MAF...

32360261 33090168 33209964 33309800 33309667 32549541
31029570 30119771 29829870 30310038 30690162 30210198
29910221 30040266 31350285 

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