SPC AC 231955
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0155 PM CST SAT DEC 23 2006
VALID 232000Z - 241200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SOUTH TEXAS THROUGH
EARLY TONIGHT...
...SOUTH TX...
EARLY AFTERNOON REGIONAL RADAR MOSAIC SHOWED AN EXTENSIVE AREA OF
PRECIPITATION WITH EMBEDDED CONVECTION EXTENDING FROM SW TX ESEWD
THROUGH SOUTH CENTRAL AND DEEP S TX. THE COMBINATION OF RICHER LOW
LEVEL MOISTURE INFLUX ACROSS S TX AND STRONGER LOW LEVEL WAA PER
STRENGTHENING SELY LLJ.../INDICATED BY SPECIAL 18Z BRO SOUNDING/...
ARE EXPECTED TO MAINTAIN GREATEST TSTM POTENTIAL OVER THIS REGION.
THIS TREND HAS BEEN EVIDENT THUS FAR WITH LIGHTNING DATA. SURFACE
MESOANALYSES SHOWED LEE CYCLOGENESIS OCCURRING OVER NERN MEXICO AS
STRONG LARGE SCALE ASCENT SPREADS DOWNSTREAM OF SEWD MOVING
MID/UPPER LEVEL LOW...NOW LOCATED OVER NRN MEXICO. IT APPEARS THAT
WARM SECTOR WITH SURFACE DEWPOINTS IN THE UPPER 60S TO NEAR 70 IS
BEGINNING TO MOVE INLAND OVER DEEP S TX...AS LOW LEVEL WINDS HAVE
SHIFTED TO S OF E. MODEST MID LEVEL LAPSE RATES /NEAR 6.5 C/KM/
ATOP THIS MOISTURE RETURN WILL CONTINUE TO SUPPORT MUCAPE VALUES OF
500 TO NEAR 1500 J/KG.
TSTMS ACROSS DEEP S TX SHOULD CONTINUE TO BECOME ROOTED AT OR NEAR
THE SURFACE...AS THE SURFACE LOW TRACKS NEWD THROUGH OR JUST S OF
THE U.S. BORDER INTO THE EVENING...BEFORE ENTERING THE WRN GULF
AROUND 24/06Z. STRENGTHENING DEEP LAYER SHEAR AND EFFECTIVE SRH
VALUES WITH THE APPROACH OF THE UPPER LOW SUGGEST A CONTINUED
TORNADO THREAT IN ADDITION TO DAMAGING WINDS IN THE VICINITY OF THE
SURFACE LOW TRACK.
MEANWHILE...EFFECTIVE BULK SHEAR AND MARGINAL ELEVATED INSTABILITY
ATOP COOLER AND MORE STABLE AIR MASS TO THE NORTH OF WARM SECTOR MAY
SUPPORT A FEW ROTATING STORMS WITH HAIL BEING THE PRIMARY THREAT
ACROSS THAT AREA.
..PETERS.. 12/23/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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