SPC AC 231945
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0145 PM CST MON NOV 23 2009
VALID 232000Z - 241200Z
...NO SVR TSTM AREAS FORECAST...
--- UPDATES ---
1630Z GEN TSTM LINES APPEAR TO REMAIN VALID BASED ON OBSERVATIONAL
TRENDS AND LIMITED UPDATES IN PROGNOSTIC GUIDANCE SINCE. AS
SUCH...NO SUBSTANTIAL ADJUSTMENTS CAN BE JUSTIFIED ATTM...AND SVR
POTENTIAL STILL APPEARS TOO SMALL/CONDITIONAL EVERYWHERE FOR AOA
5-PERCENT PROBABILITIES.
..EDWARDS.. 11/23/2009
.PREV DISCUSSION... /ISSUED 1023 AM CST MON NOV 23 2009/
...SYNOPSIS...
THE MAIN BELT OF THE WLYS WILL REMAIN OVER CANADA THIS PERIOD. IN
THE WEAKER SRN BRANCH...AMPLIFYING DISTURBANCE NOW OVER THE CNTRL
RCKYS SHOULD EVOLVE INTO A CLOSED LOW THAT SHOULD REACH NE KS BY 12Z
TUE. DOWNSTREAM IN THE SAME BRANCH OF FLOW...IMPULSE NOW OVER W TN
EXPECTED TO CONTINUE ENE INTO SW VA THIS EVE...AND OFF THE NJ CST
EARLY TUE.
AT THE SFC...COLD FRONT/LOW ASSOCIATED WITH RCKYS SYSTEM WILL BECOME
BETTER DEFINED THROUGH THE PERIOD...WITH SUBSTANTIAL ASCENT EXPECTED
OVER THE CNTRL PLNS/LWR MO VLY LATER TONIGHT/EARLY TUE. FARTHER
E...WEAK FRONT AND ASSOCIATED CIRCULATION CENTERS WILL LINGER OFF
THE NC CST TODAY. THE CIRCULATIONS LIKELY WILL EVOLVE INTO SINGLE
LOW OFF THE DELMARVA CST TONIGHT/EARLY TUE AS TN UPR SYSTEM
APPROACHES REGION.
...CNTRL PLNS/LWR MO VLY...
MID LVL LAPSE RATES WILL STEEPEN LATE THIS AFTN THROUGH TONIGHT
OVER PARTS OF KS/NEB...DOWNSTREAM FROM AMPLIFYING CNTRL RCKYS
TROUGH. MOISTURE WILL REMAIN LIMITED. BUT COMBINATION OF
STEEPENING LAPSE RATES WITH STRONG DCVA/WAA MAY SUPPORT SCTD AREAS
OF WEAK TSTMS TONIGHT/EARLY TUE FROM CNTRL KS INTO ERN NEB/NW MO AND
WRN IA.
...ERN U.S...
ISOLD TO WDLY SCTD TSTMS SHOULD PERSIST INVOF FRONT/LOW LVL
CIRCULATION CENTERS E OF THE NC OUTER BANKS. CURRENT CONDITIONS
/WITH NELY SFC WINDS AT HATTERAS/...AND LOW AMPLITUDE NATURE OF
UPSTREAM DISTURBANCE...SUGGEST THAT WARM SECTOR AIR MASS...AND ANY
ASSOCIATED POTENTIAL FOR SFC-BASED STORMS/SVR WEATHER...WILL REMAIN
OFFSHORE.
FARTHER S...WEAKENING FRONT STALLED OVER CNTRL FL...LOOSELY TIED TO
SYSTEM OFF THE NC CST...MAY PROVIDE SUFFICIENT LOW LVL CONVERGENCE
TO SUPPORT A FEW DIURNAL TSTMS IN MOIST/MODESTLY UNSTABLE
AIR...WHERE MLCAPE COULD REACH 1500 J/KG.
...SRN/CNTRL TX...
SLY FLOW/MOISTURE TRANSPORT WILL INCREASE OVER SRN/ERN TX
TONIGHT/EARLY TUE AS AMPLIFYING SYSTEM REACHES THE CNTRL PLNS.
GRADUAL REMOVAL OF EXISTING CIN...AND UPLIFT ALONG SFC COLD
FRONT...MAY SUPPORT ISOLD STORM DEVELOPMENT LATE IN THE PERIOD.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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