Mesoscale Discussion 2221

Issued

Dec 15, 2007, 1:30 AM CST (07:30 UTC)

Expired

Dec 15, 2007, 3:00 AM CST

In force

90 min

Issued by

the Storm Prediction Center

The Houston radar (KHGX), 189 km from the middle of the area, began a volume at 07:30 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

000 
ACUS11 KWNS 150731
SWOMCD
SPC MCD 150730 
TXZ000-150900-

MESOSCALE DISCUSSION 2221
NWS STORM PREDICTION CENTER NORMAN OK
0130 AM CST SAT DEC 15 2007

AREAS AFFECTED...ECNTRL TX...UPR TX COAST

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 150730Z - 150900Z

THERE WILL BE A LOW PROBABILITY FOR AN ISOLD DMGG WIND GUST AND
LARGE HAIL ACROSS PORTIONS OF ECNTRL TX AND THE UPR TX COAST THROUGH
DAYBREAK.  

WATER VAPOR IMAGERY INDICATES THAT A WEAK IMPULSE HAS EJECTED NEWD
INTO AR AHEAD OF THE PARENT WAVE MOVING EWD ACROSS W TX.  THE FORMER
IMPULSE HELPED GENERATE THE WIDESPREAD...PRIMARILY ELEVATED TSTMS
LATE EVENING.  SRN END OF THE STORMS...NEAR PALESTINE AND NE OF
AUSTIN/ HAS INTENSIFIED AND WILL LIKELY CONTINUE ENEWD ACROSS ECNTRL
TX/UPR TX COAST DURING THE NEXT SVRL HRS. 

SFC LOW NEAR/NW OF BRYAN AT 06Z WILL DEVELOP NEWD TOWARD STRONGER
PRESSURE FALL AXIS OVER CNTRL AR THROUGH 12Z.  GULF BOUNDARY LAYER
WILL SUBSEQUENTLY SURGE NWD...REACHING A PALESTINE-JASPER LINE BY
DAWN.  THUS FAR...TSTMS APPEAR TO BE BASED JUST ABOVE THE SFC PER
RUC SOUNDINGS...BUT MAY ROOT CLOSER TO THE GROUND AS THE GULF AIR
MASS RETREATS INLAND.  PRESENCE OF STEEP MID-LVL LAPSE RATE
ENVIRONMENT...AS EVIDENCED BY UPSTREAM 00Z DRT RAOB...AND ABOUT 50
KTS OF EFFECTIVE SHEAR MAY RESULT IN STRONGER STORMS PRODUCING ISOLD
LARGE HAIL.  FURTHERMORE...CONVECTIVE MODE SHOULD TREND MOSTLY
LINEAR AS UPSTREAM IMPULSE TRANSLATES EWD WITH EMBEDDED SMALL SCALE
LEWPS EVOLVING.  THIS WILL INCREASE THE THREAT FOR ISOLD DMGG
WINDS...PARTICULARLY ALONG THE SRN END OF THE LINE.

..RACY.. 12/15/2007

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

ATTN...WFO...LCH...SHV...HGX...FWD...EWX...

31539640 32669552 32769512 32609468 32139429 31559401
31059399 30659412 30169470 29929543 29829603 29849721
29889745

Mesoscale Discussions in Texas, 2007Every mesoscale discussion in 2007

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.