Jun 6, 2008 1300 UTC Day 1 Convective Outlook
Updated: Fri Jun 6 12:55:13 UTC 2008
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20080606 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20080606 1300 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20080606 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20080606 1300 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 061251
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0751 AM CDT FRI JUN 06 2008
   
   VALID 061300Z - 071200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO EARLY TONIGHT FROM
   THE UPPER GREAT LAKES TO THE MID MS VALLEY...
   
   ...SYNOPSIS...
   RECENT PRESSURE TENDENCIES SUGGEST THAT THE DEEP SURFACE CYCLONE
   /985 MB/ OVER NE SD/SE ND WILL CONTINUE TO LIFT NWD TOWARD MANITOBA
   IN ADVANCE OF A STRONG MID LEVEL TROUGH OVER ERN SD/SW MN/WRN IA. 
   THIS WILL RESULT IN THE WARM FRONT LIFTING NWD ACROSS MN/WI/MI
   TODAY...WHILE A TRAILING COLD FRONT MOVES EWD ACROSS IA/MN TO WI. 
   MEANWHILE...THE REMNANTS OF A PRE-FRONTAL SQUALL LINE SHOULD
   CONTINUE TO WEAKEN THIS MORNING ACROSS CENTRAL/ERN WI AND
   CENTRAL/NRN IL.
   
   ...WI/WRN UPPER MI THIS AFTERNOON...
   THE OVERNIGHT PRE-FRONTAL CONVECTION REDUCED BOUNDARY LAYER MOISTURE
   ACROSS IA/SRN MN...WHERE DEWPOINTS ARE NOW GENERALLY IN THE LOW-MID
   60S.  SURFACE HEATING AND THIS RESIDUAL MOISTURE IN ADVANCE OF THE
   COLD FRONT MAY SUPPORT DEVELOPMENT OF A FEW STORMS ALONG THE FRONT
   THIS AFTERNOON ACROSS WI AND WRN UPPER MI.  EFFECTIVE BULK SHEAR AOA
   50 KT AND MLCAPE OF 500-1500 J/KG WILL BE SUFFICIENT FOR ORGANIZED
   STORMS CAPABLE OF PRODUCING DAMAGING WINDS AND PERHAPS AN ISOLATED
   TORNADO.  HOWEVER...BACKING MID LEVEL FLOW IN CONJUNCTION WITH THE
   MID LEVEL WAVE WILL RESULT IN HODOGRAPH STRUCTURES THAT ARE LESS
   THAN IDEAL FOR SUPERCELLS.
   
   ...LOWER MI/INDIANA/IL THIS AFTERNOON/EVENING...
   THE BOUNDARY ASSOCIATED WITH THE PRE-FRONTAL CONVECTION COULD
   PERSIST LONG ENOUGH TODAY TO PROVIDE A FOCUS FOR ADDITIONAL
   THUNDERSTORM DEVELOPMENT THIS AFTERNOON FROM WRN LOWER MI TO NW
   INDIANA...AND SRN IL.  DESPITE MID LEVEL LAPSE RATES NO GREATER THAN
   6.5 C/KM...BOUNDARY LAYER DEWPOINTS OF 68-70 F AND SURFACE
   TEMPERATURES IN THE 80S WILL CONTRIBUTE TO AFTERNOON MLCAPE VALUES
   OF 1500-2500 J/KG.
   
   THE LLJ WILL WEAKEN AND LIFT NWD FROM THE MID MS VALLEY TO THE UPPER
   GREAT LAKES BY AFTERNOON AS THE PRIMARY SYNOPTIC CYCLONE MOVES NWD
   INTO CANADA.  LOW-LEVEL SHEAR WILL STILL REMAIN MODEST IN THE WARM
   SECTOR THROUGH THE AFTERNOON...AND BULK SHEAR THROUGH THE MID LEVELS
   WILL BE SUFFICIENT FOR BOTH SUPERCELLS AND BOWING LINE SEGMENTS. 
   DAMAGING WINDS AND A COUPLE OF TORNADOES WILL BE POSSIBLE THIS
   AFTERNOON/EVENING...AS WELL AS MARGINALLY SEVERE HAIL.
   
   ...SRN MO/NW AR/NE OK TODAY THROUGH TONIGHT...
   THE OUTFLOW BOUNDARY WITH THE OVERNIGHT CONVECTION HAS BECOME
   DIFFUSE ACROSS THIS AREA...WHILE THE REMNANT DRYLINE IS ALREADY
   STALLING ACROSS CENTRAL OK.  A CONTINUED INFLUX OF RICH LOW-LEVEL
   MOISTURE FROM THE S...DAYTIME HEATING...AND THE RIGHT ENTRANCE
   REGION OF THE MID-UPPER JET WILL SUPPORT WIDELY SCATTERED
   THUNDERSTORMS THROUGH ABOUT MID AFTERNOON ACROSS THE SRN MO AREA. 
   THUNDERSTORM DEVELOPMENT FARTHER W INTO ERN OK IS MORE QUESTIONABLE
   GIVEN THE WARMER MID LEVEL TEMPERATURES AND HEIGHT RISES EXPECTED IN
   THE WAKE OF THE DEPARTING MID LEVEL TROUGH BY MIDDAY.  VERTICAL
   SHEAR WILL BE STRONG ENOUGH FOR SUPERCELLS...PRIOR TO THE WEAKENING
   OF MID-UPPER FLOW WITH THE DEPARTURE OF THE PLAINS SHORTWAVE TROUGH.
    DAMAGING WINDS...LARGE HAIL...AND A TORNADO OR TWO WILL BE THE MAIN
   THREATS.
   
   OVERNIGHT...A LOW-LEVEL WAA REGIME WILL DEVELOP IN RESPONSE TO LEE
   CYCLOGENESIS DOWNSTREAM FROM THE NEXT TROUGH DIGGING TOWARD THE
   INTERMOUNTAIN WEST.  THIS WILL LIKELY SHIFT THE FOCUS FOR
   THUNDERSTORM DEVELOPMENT NWD ACROSS MO...WITH AREAS TO THE W
   EXPECTED TO REMAIN CAPPED.
   
   ...NRN HIGH PLAINS THIS AFTERNOON/EVENING...
   A MID LEVEL SHORTWAVE TROUGH OVER THE INTERIOR PAC NW WILL PROGRESS
   EWD OVER THE NRN ROCKIES TO THE NRN HIGH PLAINS BY TONIGHT. 
   RESIDUAL MOISTURE IN THE WAKE OF THE NRN PLAINS CYCLONE...ALONG WITH
   STEEP LOW-MID LEVEL LAPSE RATES WITH DAYTIME HEATING...COULD SUPPORT
   A FEW LOW-TOPPED STORMS WITH HAIL/GUSTY WINDS BY LATE AFTERNOON NEAR
   THE MT/SD/WY BORDER.
   
   ..THOMPSON/CROSBIE.. 06/06/2008
   
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