SPC AC 241722
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1222 PM CDT MON AUG 24 2009
VALID 251200Z - 261200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
LATE SUMMER PATTERN WILL PERSIST INTO MIDWEEK WITH FASTER MIDLEVEL
FLOW PRIMARILY NORTH OF THE U.S. BORDER WITH CANADA. SHORT WAVE
TROUGH...CURRENTLY ACROSS MT AND WITHIN THE FASTER NRN STREAM
FLOW...WILL TRACK EWD FROM THE UPPER GREAT LAKES ON TUESDAY.
STRONGER HEIGHT FALLS WITH THIS SYSTEM WILL REMAIN IN CANADA WHILE A
WEAK TRAILING COLD FRONT SETTLES SWD ACROSS THE CENTRAL PLAINS. THIS
SYSTEM...ALONG WITH WEAKER AND SLOWER-MOVING DISTURBANCES EMANATING
FROM THE LOWER LATITUDES...WILL ACT TO DAMPEN THE UPPER RIDGE NOW
SITUATED ACROSS THE GREAT PLAINS AND MIDWEST.
...CENTRAL PLAINS...
LATEST MODEL GUIDANCE DEPICTS POTENTIAL FOR SCATTERED CONVECTION TO
BE ONGOING NEAR WEAK COLD FRONT FROM MN SWWD ACROSS IA/NEB EARLY
TUESDAY MORNING. STRONGER DEEP-LAYER ASCENT ACROSS THE FRONTAL ZONE
WILL BE LACKING AS THE PRIMARY SHORT WAVE TROUGH ASSOCIATED WITH
THIS BOUNDARY TRACKS EWD AWAY FROM THESE AREAS. HOWEVER...DIURNAL
HEATING AND MOISTURE ADVECTION NEAR THE FRONTAL ZONE WILL CONTRIBUTE
TO AREAS OF STRONG DESTABILIZATION AND AN INCREASING CHANCE OF
ADDITIONAL TSTM DEVELOPMENT THROUGH THE AFTERNOON. MOIST
POST-FRONTAL UPSLOPE FLOW MAY ALSO ENHANCE CONVECTIVE POTENTIAL
ACROSS PARTS OF ERN CO AND NEB.
FROM THE FRONT RANGE ENEWD ALONG/NEAR THE FRONT TO IA...WEAK LOW
LEVEL ELY FLOW WILL BE TOPPED BY GENERALLY WEAK WLY FLOW ALOFT. THIS
WILL RESULT IN DEEP-LAYER SHEAR PROFILES TOO MARGINAL FOR MORE
ORGANIZED CONVECTION. IN ADDITION...WARMER AIR ALOFT WILL CONTRIBUTE
TO CONSIDERABLE CONVECTIVE INHIBITION...ESPECIALLY EAST OF THE FRONT
RANGE. IT IS POSSIBLE THAT SLOW-MOVING SWRN U.S. UPPER
VORT/SHORTWAVE COULD AID TSTM DEVELOPMENT/PERSISTENCE ACROSS CO AND
ADJACENT AREAS OF KS THROUGH THE LATTER HALF OF THE PERIOD BUT AREAL
COVERAGE OF SEVERE FROM THIS POTENTIAL MCS APPEARS LOW ATTM.
WHILE ISOLATED DAMAGING WIND GUSTS AND PERHAPS MARGINALLY SEVERE
HAIL EVENTS MAY OCCUR IN THIS REGIME...IT IS TOO EARLY TO DELINEATE
A HIGHER PROBABILITY SEVERE AREA.
...ELSEWHERE...
SCATTERED THUNDERSTORMS WILL ONCE AGAIN DEVELOP ACROSS MUCH OF THE
SWRN U.S. ALONG AN AXIS FROM NRN MEXICO...ERN AZ/WRN NM INTO THE
CNTRL ROCKIES.
OTHER SCATTERED THUNDERSTORMS SHOULD BE CONCENTRATED ALONG THE FL
PENINSULA WHERE WEAK VERTICAL SHEAR AND MARGINAL LAPSE RATES SHOULD
SUPPORT PRIMARILY PULSE-TYPE SUB-SEVERE THUNDERSTORMS.
..CARBIN.. 08/24/2009
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z
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