SPC AC 232005
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0305 PM CDT WED MAY 23 2007
VALID 232000Z - 241200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SRN KS...NW OK
AND THE TX PANHANDLE...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE GREAT
PLAINS AND UPPER MIDWEST...
...SRN AND CNTRL PLAINS...
AN UPPER-LEVEL TROUGH OVER THE FOUR CORNERS REGION IS EVIDENT ON
WATER VAPOR IMAGERY AND THIS FEATURE WILL MOVE EWD TOWARD THE SRN
PLAINS LATE THIS AFTERNOON. 19Z SFC ANALYSIS SHOWS A FRONTAL
BOUNDARY LOCATED FROM NEAR TOPEKA KS EXTENDING SWWD TO NEAR GAGE OK.
A CAPPING INVERSION HAS WEAKENED ACROSS THE CNTRL PLAINS AND THE
CONVECTIVE LINE WILL LIKELY BECOME UNIFORM OVER THE CNTRL PLAINS BY
EARLY EVENING. THUNDERSTORMS SHOULD ALSO INITIATE IN THE TX
PANHANDLE AND IN WRN OK AS THE CAPPING INVERSION WEAKENS LATE THIS
AFTERNOON. STRONG INSTABILITY...INCREASING VERTICAL SHEAR AND A
STRENGTHENING LOW-LEVEL JET WILL CREATE FAVORABLE THERMODYNAMIC AND
SHEAR PROFILES FOR WIDESPREAD SEVERE THUNDERSTORMS ACROSS THE
MODERATE RISK AREA.
LATEST OBJECTIVE ANALYSIS SHOWS A BROAD MID-LEVEL JET LOCATED FROM
NRN NM EXTENDING NEWD ACROSS SE CO AND WRN KS. THIS BAND OF STRONG
MID-LEVEL FLOW IS CREATING 0-6 KM SHEAR VALUES IN THE 40 TO 50 KT
RANGE ALONG THE FRONTAL BOUNDARY AS SHOWN ON REGIONAL PROFILERS.
THIS COMBINED WITH MLCAPE VALUES OF 2000 TO 3000 J/KG WILL BE
SUFFICIENT FOR SUPERCELLS. THE SUPERCELL THREAT SHOULD BE GREATEST
ACROSS THE TX PANHANDLE WHERE INITIATION WILL BE LATER AND STORM
COVERAGE SHOULD BE MORE SCATTERED IN NATURE. AS THE LOW-LEVEL JET
INCREASES THROUGH EARLY EVENING...A FEW TORNADOES AND VERY LARGE
HAIL WILL BE POSSIBLE WITH THE MOST INTENSE STORMS. AN ENHANCED
TORNADO THEAT MAY DEVELOP ACROSS THE NRN TX PANHANDLE...NW OK AND SW
KS EARLY THIS EVENING AS THE LOW-LEVEL JET INTENSIFIES. A FEW
SUPERCELLS MAY ALSO DEVELOP ALONG THE BOUNDARY IN KS. OTHERWISE...A
MULTICELL THREAT WILL EXIST FURTHER NORTHEAST ALONG THE BOUNDARY
ACROSS CNTRL KS...NE KS AND SW IA WHERE AN LINEAR MCS IS DEVELOPING
ATTM. FRONTAL FORCING AND UNIDIRECTIONAL WINDS JUST ABOVE THE SFC
ARE LIKELY CONTRIBUTING TO THE DEVELOPMENT OF THIS LINEAR MCS. LARGE
HAIL AND ISOLATED WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGER
CELLS IN THE LINE THROUGH MUCH OF THE EVENING.
...UPPER MIDWEST...
AN UPPER-LEVEL LOW EVIDENT ON WATER VAPOR IMAGERY OVER WRN ND WILL
CONTINUE TO LIFT NWD LATE THIS AFTERNOON. AT THE SFC...A COLD FRONT
IS LOCATED ACROSS WRN MN AND WRN IA. THUNDERSTORMS ARE DEVELOPING
EAST OF THE FRONTAL BOUNDARY ACROSS WRN IA...SERN MN AND NW WI. THIS
ACTIVITY IS DEVELOPING ALONG THE WRN EDGE OF AN AXIS OF MODERATE
INSTABILITY WITH MLCAPE VALUES AROUND 1000 J/KG AN A REGION OF
LOW-LEVEL CONVERGENCE. FOR THIS REASON...THUNDERSTORM COVERAGE
SHOULD CONTINUE TO INCREASE LATE THIS AFTERNOON WITH MCS DEVELOPMENT
POSSIBLE ACROSS THE REGION THROUGH EARLY EVENING.
IN ADDITION...A MID-LEVEL JET WAS LOCATED ACROSS THE ERN DAKOTAS
WITH THE EDGE OF STRONGER MID-LEVEL FLOW LOCATED OVER CNTRL MN AND
NW IA. AS A RESULT...MODERATE VERTICAL SHEAR PROFILES ARE PRESENT
MAINLY FROM THE FRONT NWWD. THIS SHOULD BE SUFFICIENT FOR AN
ISOLATED SUPERCELL THREAT ESPECIALLY IN THE STRONGER DEEP LAYER
SHEAR NEAR THE FRONTAL BOUNDARY. ALTHOUGH AN ISOLATED TORNADO THREAT
WILL REMAIN POSSIBLE...THE MAIN THREATS SHOULD BE LARGE HAIL AND
ISOLATED WIND DAMAGE.
..BROYLES.. 05/23/2007
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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