Categorical Graphic
Probabilistic Tornado Graphic
Probabilistic Damaging Wind Graphic
Probabilistic Large Hail Graphic

   SPC AC 020559
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1159 PM CST SAT APR 01 2006
   
   VALID 021200Z - 031200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS EASTERN
   MISSOURI...SOUTHEAST IOWA...MUCH OF ILLINOIS...SOUTHWEST
   INDIANA...AND WESTERN KENTUCKY....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN FRINGES OF THE PLAINS
   TO THE APPALACHIANS...
   
   ...SYNOPSIS...
   MID-LEVEL SHORT-WAVE TROUGH IS FORECAST TO DEEPEN WHILE SHIFTING EWD
   FROM THE PLAINS ACROSS THE MS VALLEY AND INTO THE UPPER GREAT
   LAKES/OH AND TN VALLEYS THROUGH THE END OF THE PERIOD. A 70-PLUS KT
   H5 JET STREAK IS FORECAST TO ACCOMPANY THIS TROUGH...WITH THE CORE
   OF THIS JET EXPECTED FROM THE CENTRAL PLAINS EWD ACROSS THE
   OZARKS/MID MS VALLEY REGION AND INTO THE TN AND OH VALLEYS.
   
   AT THE SURFACE...LOW INITIALLY FORECAST OVER ERN NEB SHOULD DEEPEN
   AND MOVE ENEWD WITH TIME...EVENTUALLY REACHING LOWER MI AS A 990 MB
   CYCLONE.  WARM FRONT INITIALLY FORECAST TO EXTEND SEWD ACROSS MO
   INTO THE SERN U.S. SHOULD LIFT NEWD ACROSS THE TN AND OH VALLEYS
   WITH TIME...ALLOWING MOIST/UNSTABLE WARM SECTOR TO SPREAD ACROSS THE
   MID MS VALLEY REGION AHEAD OF COLD FRONT.  THIS COLD FRONT SHOULD
   CROSS MO DURING THROUGH THE AFTERNOON...AND THEN CONTINUE EWD ACROSS
   THE OH VALLEY REGION THROUGH THE OVERNIGHT HOURS.  TRAILING PORTION
   OF THE FRONT SHOULD SAG MORE SLOWLY SWD...LINGERING ACROSS AR AND TX
   THROUGH THE END OF THE PERIOD.
   
   ...MID MS/OH/TN VALLEYS...
   POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE APPEARS TO BE SETTING
   UP THIS PERIOD...CENTERED ON THE MID MS AND LOWER OH VALLEY REGION. 
   THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS
   THE MIDDLE AND LOWER MO VALLEY AHEAD OF APPROACHING UPPER TROUGH. 
   THIS CONVECTION SHOULD SHIFT EWD/NEWD INTO THE UPPER GREAT LAKES
   REGION THROUGH THE DAY.  THOUGH THIS INITIAL CONVECTION COMPLICATES
   THE FORECAST DUE TO ITS POTENTIAL EFFECTS ON AFTERNOON
   DESTABILIZATION...IT APPEARS ATTM THAT MOST OF THE CONVECTION SHOULD
   VACATE THE MID MS VALLEY REGION BY AFTERNOON...ALLOWING DAYTIME
   HEATING TO COMMENCE.  PRESUMING THIS OCCURS...1500 TO 2500 J/KG
   MEAN-LAYER CAPE SHOULD DEVELOP ACROSS THE WARM SECTOR...AIDED BY NWD
   ADVECTION OF LOW TO MID 60S DEWPOINTS BENEATH STEEPENING MID-LEVEL 
   LAPSE RATES.
   
   STORMS SHOULD REDEVELOP BY MID AFTERNOON -- LIKELY FROM SERN IA SWD
   ACROSS THE ERN HALF OF MO AHEAD OF ADVANCING COLD FRONT.  DEEP-LAYER
   WIND FIELD SHOULD BE QUITE STRONG ACROSS THIS REGION...AS POTENT
   MID-LEVEL JET SHIFTS EWD INTO THE REGION.  ALONG WITH FAVORABLE
   DEEP-LAYER SHEAR FOR SUPERCELLS...LOW-LEVEL SHEAR WILL ALSO BE
   STRONG -- PARTICULARLY FROM ERN IA SWD ACROSS ERN MO AND IL NEAR AND
   SE OF SURFACE LOW.  DEGREE OF LOW-LEVEL SHEAR ALONG WITH
   MOIST/MODERATELY-UNSTABLE AIRMASS SUGGESTS THAT SEVERAL TORNADOES
   WILL LIKELY OCCUR...A FEW OF WHICH COULD BE STRONG AND LONG-LIVED. 
   ADDITIONALLY...LARGE HAIL AND LOCALLY DAMAGING WINDS ARE ALSO
   EXPECTED.
   
   WITH TIME...STORMS SHOULD BECOME MORE LINEAR -- PARTICULARLY ACROSS
   THE OH VALLEY WHERE FLOW WILL BECOME MORE VEERED/UNIDIRECTIONAL WITH
   HEIGHT THROUGH THE EVENING.  GIVEN STRENGTH OF THE WIND FIELD...MORE
   ORGANIZED/WIDESPREAD DAMAGING WIND EVENT MAY EVOLVE/MOVE EWD ACROSS
   THIS REGION.  STORMS SHOULD CONTINUE THROUGH THE END OF THE
   PERIOD...WITH SEVERE THREAT EXTENDING AS FAR E AS THE CENTRAL
   APPALACHIANS BY 03/12Z.
   
   ..GOSS.. 04/02/2006
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z