Nov 23, 2009 1730 UTC Day 2 Convective Outlook
Updated: Mon Nov 23 17:32:46 UTC 2009
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20091123 1730 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20091123 1730 UTC Day Probabilitic Graphic
Probability Legend Image
   SPC AC 231730
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1130 AM CST MON NOV 23 2009
   
   VALID 241200Z - 251200Z
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   SERIES OF PROGRESSIVE SHORTWAVES WILL HELP TO SHIFT SYNOPTIC
   TROUGHING EWD FROM HIGH PLAINS TOWARD MS VALLEY REGION THROUGH DAY-2
   PERIOD.  STG SHORTWAVE TROUGH -- NOW ANALYZED OVER FRONT/LARAMIE/BIG
   HORN RANGES OF CO/WY -- IS FCST TO STRENGTHEN WITH 500 MB CLOSED LOW
   DEVELOPING OVERNIGHT DAY-1 OVER KS.  THIS LOW SHOULD MOVE ENEWD FROM
   NRN MO TOWARD SRN LM AND WEAKEN SOMEWHAT DAY-2...AS UPSTREAM
   PERTURBATION APCHS/INTENSIFIES.  LATTER TROUGH -- NOW EVIDENT IN
   MOISTURE CHANNEL IMAGERY APCHG BC COAST -- IS FCST TO MOVE THROUGH
   LARGE SCALE RIDGE POSITION OVER WRN CANADA DAY-1...THEN TURN SEWD
   ACROSS SWRN PORTIONS OF PRAIRIE PROVINCES AND NRN U.S. HIGH PLAINS
   DAY-2.  BY 25/12Z...THIS FEATURE SHOULD EVOLVE INTO CLOSED CYCLONE
   WITHIN 500-300 MB LAYER...OVER ERN DAKOTAS AND WRN MN...WITH
   POSITIVELY TILTED TROUGH SWWD ACROSS NEB.
   
   AT SFC...LOW NOW EVIDENT OVER SWRN KS IS EXPECTED TO MOVE NEWD ALONG
   BAROCLINIC ZONE TO VICINITY STJ BY START OF PERIOD...THEN DEEPEN
   SLIGHTLY AND BECOME MORE CLOSELY COLLOCATED WITH LEADING MID-UPPER
   PERTURBATION INVOF SRN LM.  TRAILING COLD FRONT WILL MOVE EWD ACROSS
   LOWER-MID MS VALLEY...AND SEWD FROM TX/LA ACROSS NWRN GULF. 
   MEANWHILE...OLDER FRONTAL ZONE ACROSS CENTRAL/SRN FL PENINSULA IS
   EXPECTED TO DECELERATE...BECOMING MORE DIFFUSE WITH TIME THROUGHOUT
   PERIOD. 
   
   ...S TX...
   ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE...BEGINNING AT START
   OF PERIOD AS CARRY-OVER FROM POTENTIAL DISCUSSED IN DAY-1 OUTLOOK. 
   REGIME SHOULD BE CHARACTERIZED BY STG LOW LEVEL WAA AND MOISTURE
   TRANSPORT...WHICH WILL COMBINE WITH POCKETS OF ENHANCED SFC HEATING
   TO DESTABILIZE PREFRONTAL BOUNDARY LAYER THROUGH MUCH OF AFTERNOON. 
   AS PREFRONTAL SFC DEW POINTS UPPER 60S F BECOME MORE COMMON...MLCAPE
   MAY RISE INTO 2000-2500 J/KG RANGE IN AREAS OF RELATIVELY SUSTAINED
   CLOUD BREAKS.  FRONTAL LIFT IMPINGING ON THIS ALREADY WEAKLY CAPPED
   AIR MASS SHOULD BOOST CONVECTIVE COVERAGE INTO SCATTERED-NUMEROUS
   RANGES AS FRONT MOVES SWD/SEWD OVER THIS REGION.  MAJOR LIMITING
   FACTOR FOR ANY ORGANIZED SVR POTENTIAL WILL BE LACK OF SHEAR...WITH
   WEAK LOW-MID LEVEL WINDS LIMITING BOTH HODOGRAPH SIZE AND BULK WIND
   DIFFERENCE THROUGH DEEP-LAYER SAMPLES. 
   
   ...NRN MO TO WI/IL BORDER REGION...
   WIDELY SCATTERED AND SHALLOW TSTMS ARE POSSIBLE IN ZONE OF STRONG
   DEEP-LAYER ASCENT...STEEPENING LOW-MID LEVEL LAPSE RATES
   SUFFICIENTLY TO SUPPORT RELATIVELY UNCAPPED AND MRGL BUOYANCY. 
   MODIFIED FCST SOUNDINGS SUGGEST LOW LEVEL FRONTOGENETIC/CYCLOGENETIC
   FORCING AND WEAK CINH WILL SUPPORT MLCAPE UP TO ABOUT 250 J/KG AND
   MUCAPE APCHG 500 J/KG FOR REASONABLY PROGGED SFC TEMPS 50S F AND DEW
   POINTS UPPER 40S.  LACK OF MORE ROBUST SHEAR...LOW LEVEL THETAE AND
   CAPE PRECLUDE SVR THREAT.
   
   ...CENTRAL/SRN FL...
   ISOLATED TO WIDELY SCATTERED TSTMS WILL BE POSSIBLE WITHIN LOW-LEVEL
   BAROCLINIC ZONE ACROSS THIS REGION...SUPPORTED BY WEAK FRONTAL
   ASCENT...DIURNAL HEATING...AND SFC DEW POINTS UPPER 60S/LOW 70S F. 
   50-80 KT UPPER-LEVEL WINDS BENEATH SRN FRINGE OF SUBTROPICAL JET
   BRANCH MAY AID IN STORM ORGANIZATION...ESPECIALLY INVOF E COAST
   WHERE SLY AND ELY FLOW COMPONENTS MAY AID IN SHEAR THROUGH
   CLOUD-BEARING LAYER.  HOWEVER...SVR POTENTIAL APPEARS TOO
   MRGL/CONDITIONAL FOR AOA 5-PERCENT PROBABILITIES ATTM.
   
   ..EDWARDS.. 11/23/2009
   
   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z