600
ACUS01 KWNS 141958
SWODY1
SPC AC 141955
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT WED MAY 14 2008
VALID 142000Z - 151200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A LARGE PART OF TX INTO
THE LWR MS VLY...
..TX/SRN OK EWD INTO THE SABINE RVR VLY
A MYRIAD OF OUTFLOW BOUNDARIES EXISTS IN WAKE OF THE NIGHTTIME
MCS/MCV NOW EXITING INTO THE LWR MS VLY. 19Z SFC ANALY PLACES ONE
BOUNDARY FROM NORTH OF BEAUMONT NWWD TO SOUTH OF WACO WHERE IT JOINS
WITH AN OUTFLOW ENHANCED COLD FRONT ARCING WWD FROM WACO TO NEAR SAN
ANGELO THEN INTO SERN NM. THE DRYLINE WAS BEGINNING TO MIX E OF THE
TRANSPECOS AND SHOULD REACH THE ERN PERMIAN BASIN AFTER 22Z.
THE AIR MASS S OF THE OUTFLOWS REMAINED MOIST AND UNSTABLE...AND
GIVEN PRESSURE FALLS INCREASING UPSTREAM AND A MODEST AMOUNT OF
INSOLATION N OF THE BOUNDARIES...AIR MASS SHOULD CONTINUE TO RECOVER
FROM THE WRN HILL COUNTRY/CONCHO VLY NWD INTO THE BIG COUNTRY/NCNTRL
TX LATE THIS AFTN/EARLY EVE...ROUGHLY UP TO I-20.
WATER VAPOR IMAGERY SHOWS THE UPR LOW SPINNING NEAR WINK. THE
FEATURE IS EXPECTED TO MOVE ACROSS NRN/CNTRL TX INTO OK OVERNIGHT
WITH ASSOCD H5 TEMPERATURES AROUND MINUS 18 DEG C. TSTMS HAVE
ALREADY FORMED OVER SERN NM AND ARE MOVING NEWD AHEAD OF THE LOW
INTO THE TX S PLAINS AND NRN PERMIAN BASIN WITH ISOLD SUPERCELLS
ALREADY NOTED...PRIMARILY ALONG THE SRN END OF THE LINE.
TSTMS WILL CONTINUE TO SPREAD ENEWD TOWARD CNTRL/SRN OK AND MUCH OF
NRN TX DURING THE PROGRESS OF THE EVENING. STRONGER SFC-BASED TSTMS
WILL FAVOR THE MORE ROBUST INSTABILITY ACROSS NWRN...NCNTRL AND
CNTRL TX...EFFECTIVELY DEVELOPING SEWD ALONG THE DRYLINE TOWARD THE
EDWARDS PLATEAU. MID-LEVEL LAPSE RATES WERE STILL QUITE STEEP AND
GIVEN INCREASINGLY SWLY FLOW ALONG BASE OF THE EJECTING UPR
LOW...VERTICAL SHEAR WILL BE SUPPORTIVE OF SUPERCELLS WITH VERY
LARGE HAIL THIS EVENING. THOUGH THE LOW-LEVEL SHEAR WILL PROBABLY
NOT BE TERRIBLY STRONG...PRESENCE OF THE OUTFLOW BOUNDARY AND AT
LEAST WEAK ESELY INFLOW INTO THE STORMS WILL BE FAVORABLE FOR ISOLD
TORNADOES...MAINLY ACROSS CNTRL AND PARTS OF NCNTRL TX ALONG/S OF
I-20. ACTIVITY WILL LIKELY BECOME MORE ELEVATED OVERNIGHT AS IT
HEADS TOWARD THE ARKLATEX/WRN LA. BUT...HAIL/GUSTY WINDS MAY STILL
ACCOMPANY NIGHTTIME STORMS.
MEANWHILE...ALTHOUGH MUCAPE WILL INCREASE A BIT N OF THE RED RIVER
INTO CNTRL/SRN OK THIS EVENING...THERE WILL LIKELY BE A SHARP NRN
EDGE TO THE SVR THREAT. ISOLD STG-SVR TSTMS WITH HAIL CANNOT BE
RULED OUT...ESPECIALLY ACROSS SRN OK. TO THE SOUTH...MID-LEVEL
HEIGHT FALLS WILL GRAZE THE NERN MEXICAN MOUNTAINS AND SCNTRL TX
OVERNIGHT. TSTMS THAT DEVELOP ALONG THE NRN COAHUILA MOUNTAINS AND
THE BIG BEND REGION MAY MAKE IT ACROSS THE RIO GRANDE AREAS VCNTY
DEL RIO WITH HAIL/HIGH WINDS. FARTHER S...CAP SHOULD HOLD STRONG
AND WITH STRONGER FORCING FOR ASCENT SPREADING N OF THE
REGION...LITTLE SUPPORT FOR SVR STORMS EXISTS ACROSS FAR S TX.
..LWR MS VLY
LEADING EDGE OF MORNING MCS HAS REGENERATED OVER SRN LA AND SRN MS
AMIDST AN AIR MASS CHARACTERIZED BY RICH GULF MOISTURE AND
TEMPERATURES IN THE MID-80S. MID-LEVEL LAPSE RATES AROUND 6.5 C/KM
AND H5 TEMPERATURES AOB MINUS 10 DEG C COINCIDENT WITH PWAT VALUES
1.75 INCHES WAS CONTRIBUTING TO VERY EFFICIENT RAIN MAKING STORMS.
FURTHERMORE...ADEQUATE 0-6KM SHEAR OF 30-40 KTS IS FAVORABLE FOR
SUPERCELL STRUCTURES. DMGG WIND GUSTS FROM STRONG PCPN LOADED
DOWNDRAFTS WILL BE THE PRIMARY THREAT...BUT ISOLD TORNADOES WILL BE
POSSIBLE...PRIMARILY ALONG UPDRAFTS THAT GROW STRONGLY VCNTY
RESIDUAL BOUNDARIES IN THE LOW LCL CONDITIONS.
..RACY.. 05/14/2008
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