Jun 23, 2009 1300 UTC Day 1 Convective Outlook
Updated: Tue Jun 23 12:53:25 UTC 2009
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20090623 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20090623 1300 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20090623 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20090623 1300 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 231249
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0749 AM CDT TUE JUN 23 2009
   
   VALID 231300Z - 241200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL HI PLNS/MID MO
   VLY TO THE UPR MS VLY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE FL
   PENINSULA...
   
   ...SYNOPSIS...
   UPR RDG WILL CONTINUE TO BUILD SLOWLY W FROM THE CNTRL/SRN PLNS INTO
   THE SRN RCKYS THIS PERIOD AS ELONGATED UPR LOW PERSISTS OFF THE E
   CST.  SPLIT FLOW PATTERN IN THE WEST WILL BECOME BETTER DEFINED AS
   THE WLYS INCREASE ACROSS THE PACIFIC NW/S CNTRL CANADA...NORTH OF
   LOW NOW IN THE PROCESS OF CLOSING OFF THE CA CST. LEAD DISTURBANCE
   IN THE WLY JET...NOW OVER ERN MT...SHOULD CONTINUE ENE INTO WRN
   ONTARIO BY THIS EVE AS WEAKER UPSTREAM IMPULSE IN BC REACHES SRN SK.
   
   AT THE SFC...COLD FRONT ASSOCIATED WITH MT IMPULSE WILL MOVE
   GENERALLY SE ACROSS THE NRN HALF OF THE PLNS AND THE UPR MS VLY/UPR
   GRT LKS THROUGH THE PERIOD.  THE BOUNDARY WILL PROVIDE A FOCUS FOR
   STORMS...ESPECIALLY THIS AFTN/TONIGHT.
   
   ...CNTRL HI PLNS/MID MO VLY TO UPR MS VLY...
   LONG-LIVED MCS NOW OVER NE NEB/CNTRL AND SE SD SHOULD CONTINUE
   GENERALLY ENE THROUGH LATE THIS MORNING.  IT IS UNCERTAIN ATTM
   WHETHER OR NOT SYSTEM WILL INDEED WEAKEN BY THAT TIME AS IT IS ABOUT
   TO ENTER A REGION OF ENHANCED SFC-BASED INSTABILITY CENTERED OVER NE
   NEB AND NRN IA...WHERE SFC HEATING WILL BE UNINHIBITED.  IN
   ADDITION...A MODEST SLY LLJ WILL CONTINUE ACROSS REGION...LIKELY
   ASSOCIATED WITH ENTRANCE REGION OF PASSING NRN STREAM UPR VORT /REF
   MCD 1284/.
   
   AT ANY RATE...GIVEN THE DEGREE OF EXPECTED DIURNAL DESTABILIZATION
   /SBCAPE AOA 3000 J PER KG/...HI PWS...AND PRESENCE OF WEAK TO
   MODERATE WSWLY SHEAR ON NRN FRINGE OF UPR RDG..POTENTIAL WILL
   EXIST FOR DMGG WIND/MARGINALLY SVR HAIL AS SYSTEM TURNS AND/OR
   REDEVELOPS A BIT S OF E AND MOVES INTO NW IA.
   
   FARTHER W AND N...AIRMASS ALSO WILL DESTABILIZE ALONG/AHEAD OF COLD
   FRONT EXTENDING FROM NRN MN SW INTO WRN NEB/NE CO.  UPLIFT ALONG
   FRONT...AND ANY BOUNDARIES LEFT FROM OVERNIGHT MCS...SHOULD SUPPORT
   SCTD STORM DEVELOPMENT BY MID TO LATE AFTN.  THIS ACTIVITY MAY FOCUS
   PRIMARILY OVER NRN/CNTRL MN...WHERE LARGE SCALE UVV WILL EXIST CLOSE
   TO UPR JET...AND IN WRN NEB/ERN WY/NE CO...WHERE LOW LVL UPSLOPE
   FLOW WILL FOSTER DEVELOPMENT.
   
   WHILE NOT PARTICULARLY STRONG...VEERING FLOW WITH HEIGHT SHOULD BE
   SUFFICIENT FOR ORGANIZED/ROTATING STORMS IN THE CNTRL HI PLNS. 
   THESE MAY YIELD LARGE HAIL...DMGG WINDS AND POSSIBLY A BRIEF TORNADO
   OR TWO.  STRONGER...DEEP UNIDIRECTIONAL WSW FLOW WILL BE PRESENT TO
   FOSTER POSSIBLE SMALL BOWING STRUCTURES WITH WIND/HAIL IN MN.
   
   THE STORMS IN THE CNTRL HI PLNS MAY LINGER INTO THE EVE AND MERGE
   INTO A SMALL CLUSTER OR TWO OF STRONG/POSSIBLY SVR STORMS TONIGHT AS
   LLJ STRENGTHENS OVER REGION. A BRANCH OF THE LOW LVL FLOW SHOULD
   ALSO VEER EWD ACROSS IA.  THIS MAY SUPPORT LONGEVITY OF ANY CLUSTER
   LEFT OVER THAT STATE FROM EARLIER IN THE DAY.  WEAKER SHEAR AND
   DIURNAL STABILIZATION SHOULD...HOWEVER...YIELD A GRADUALLY
   DIMINISHING SEVERE THREAT.
   
   ...FL PENINSULA...
   TSTMS EXPECTED TO INCREASE IN COVERAGE AND STRENGTH OVER WRN AND SRN
   PARTS OF THE FL PENINSULA AS SFC HEATING FURTHER DESTABILIZES AXIS
   OF CONFLUENCE ORIENTED ROUGHLY PARALLEL TO THE PENINSULA.  SATELLITE
   LOOPS SUGGEST THAT MUCH OF FL WILL REMAIN IN REGION OF UVV/UPR
   DIVERGENCE THROUGH AT LEAST MIDDAY.  COUPLED WITH MODERATE DEEP
   UNIDIRECTIONAL NLY FLOW...HI PWS...AND VERY WARM SFC TEMPERATURES IN
   AREAS NOT AFFECTED BY EARLIER STORMS...SETUP MAY SUPPORT UPSCALE
   DEVELOPMENT INTO ORGANIZED CLUSTERS.  FORWARD-PROPAGATING
   SEGMENTS/STORM MERGERS COULD YIELD DMGG WINDS AND POSSIBLY A BRIEF
   TORNADO THROUGH LATE AFTN.
   
   ...AL/GA...
   SCTD DIURNALLY-ENHANCED TSTMS LIKELY WILL EXTEND UPSTREAM FROM FL
   ACTIVITY INTO PARTS OF GA AND AL...ALONG NRN EXTENSION OF SAME
   CONFLUENCE AXIS AFFECTING FL.  WHILE CONVERGENCE AND UVV ARE
   EXPECTED TO BE WEAKER IN THIS REGION RELATIVE TO POINTS S...
   MOIST/UNSTABLE ENVIRONMENT AND MODEST DEEP NLY FLOW ON WRN FRINGE OF
   OFFSHORE LOW WILL MAINTAIN A LOW PROBABILISTIC THREAT FOR LOCALLY
   STRONG/SVR STORMS/STORM CLUSTERS THROUGH EARLY EVE.
   
   ..CORFIDI/GRAMS.. 06/23/2009
   
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