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

   SPC AC 240600
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0100 AM CDT THU AUG 24 2006
   
   VALID 241200Z - 251200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF ERN SD THROUGH
   CNTRL AND SRN MN AND EXTREME NRN IA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE NRN AND
   CNTRL PLAINS THROUGH THE UPPER MS VALLEY AREA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE OH VALLEY
   THROUGH MID ATLANTIC AND NERN U.S....
   
   ...SYNOPSIS...
   
   STRONG SHORTWAVE TROUGH OVER THE NRN ROCKY MOUNTAIN REGION WILL MOVE
   EWD INTO THE NRN PLAINS AND UPPER MS VALLEY THIS PERIOD...RESULTING
   IN LEE CYCLOGENESIS AND DEAMPLIFICATION OF SHORTWAVE RIDGE. A MORE
   SUBTLE LEAD VORT MAX CURRENTLY OVER SRN MT WILL MOVE EWD IN ADVANCE
   OF THE MAIN UPPER TROUGH. A COLD FRONT WILL ACCOMPANY THE SHORTWAVE
   TROUGH INTO THE NRN PLAINS. BY EARLY THURSDAY THE FRONT WILL EXTEND
   FROM ERN MT SWWD THROUGH ERN WY. THIS BOUNDARY ALONG WITH DEVELOPING
   LEE CYCLONE WILL ADVANCE EWD THROUGH THE DAKOTAS DURING THE DAY. A 
   QUASISTATIONARY FRONT WILL EXTEND FROM THE LOW OVER SD EWD THROUGH
   SRN MN AND SRN WI.
   
   
   ...NRN PLAINS THROUGH UPPER MS VALLEY AREA...
   
   RESERVOIR OF UNTAPPED INSTABILITY WILL PERSIST OVER PORTIONS OF SD
   INTO SRN MN GENERALLY NEAR AND S OF E-W FRONT. BOUNDARY LAYER IN
   WARM SECTOR WILL MOST LIKELY REMAIN CAPPED BY A STRONG EML MUCH OF
   THE DAY. STORMS MAY BE ONGOING EARLY THURSDAY N OF FRONT MOSTLY
   ACROSS ND AS FORCING FOR ASCENT ACCOMPANYING LEAD SHORTWAVE TROUGH
   INCREASES. DOWNSTREAM FROM THIS ACTIVITY AND ESPECIALLY S OF E-W
   FRONT FROM CNTRL AND ERN SD INTO SRN MN...THE ATMOSPHERE SHOULD
   BECOME VERY UNSTABLE AS SURFACE HEATING COMMENCES. STORMS MAY
   INITIALLY INTENSIFY ALONG EWD ADVANCING COLD FRONT. STRONG LINEAR
   FORCING ENHANCED BY DEEP LAYER ASCENT ACCOMPANYING EWD ADVANCING
   SHORTWAVE TROUGH MAY RESULT IN ACTIVITY EVOLVING INTO A LINEAR MCS.
   HOWEVER...SOME SUPERCELL STRUCTURES WILL BE POSSIBLE ESPECIALLY
   ALONG SRN END OF THE LINE. DAMAGING WIND AND LARGE HAIL WILL BE THE
   MAIN THREATS...BUT AN ISOLATED TORNADO OR TWO WILL ALSO BE POSSIBLE
   WITH ANY SUPERCELL MODES WITHIN THE LINE.
   
   FARTHER EAST...ASCENT ASSOCIATED WITH LEAD SHORTWAVE TROUGH AND A
   BRANCH OF THE LOW LEVEL JET E OF SURFACE LOW WILL MAINTAIN FORCING
   FOR ASCENT ALONG AND N OF THE E-W STATIONARY FRONT. POTENTIAL WILL
   EXIST FOR STORMS TO DEVELOP NEAR AND JUST N OF THE BOUNDARY AS THE
   CAP WEAKENS DURING THE AFTERNOON. ESELY LOW LEVEL FLOW NEAR FRONT
   VEERING TO WSWLY AND INCREASING TO 40+ KT AT 6 KM WILL CONTRIBUTE TO
   FAVORABLE LOW LEVEL AND DEEP LAYER SHEAR PROFILES FOR SUPERCELLS
   WITH LOW LEVEL MESOCYCLONES. VERY LARGE HAIL AND A FEW TORNADOES
   WILL BE POSSIBLE WITH ANY DISCRETE SUPERCELLS THAT DEVELOP NEAR THIS
   BOUNDARY. OVERNIGHT...STORMS MAY EVOLVE INTO ONE OR MORE MCSS AS THE
   LOW LEVEL JET INCREASES WITH A CONTINUING THREAT FOR MAINLY DAMAGING
   WIND AND LARGE HAIL FROM THE UPPER MS VALLEY INTO PARTS OF THE GREAT
   LAKES.
   
   ...OH VALLEY THROUGH MID ATLANTIC AND NERN STATES...
   
   STORMS MAY STILL BE IN PROGRESS IN WARM ADVECTION REGIME FROM PARTS
   OF SRN LOWER MI INTO NRN OH EARLY THURSDAY. POTENTIAL WILL EXIST FOR
   SOME OF THIS ACTIVITY TO BECOME SURFACE BASED AS THE DOWNSTREAM
   ATMOSPHERE DESTABILIZES. PRIMARY THREAT WILL BE DAMAGING WIND AS
   ACTIVITY ADVANCES ESEWD. OTHER STORMS MAY DEVELOP DOWNSTREAM OVER
   PARTS OF THE MID ATLANTIC AS THE ATMOSPHERE DESTABILIZES AND AS VORT
   MAX ROTATES SEWD THROUGH BASE OF UPPER TROUGH. BOUNDARY LAYER FLOW
   WILL BE RATHER WEAK...BUT DEEP LAYER VERTICAL SHEAR WILL BE
   SUFFICIENT FOR UPDRAFT ROTATION. POOR MID LEVEL LAPSE RATES AND
   MODEST INSTABILITY WILL LIMIT OVERALL HAIL POTENTIAL. HOWEVER...THE
   STRONGER STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED DAMAGING
   WIND GUSTS.
   
   ..DIAL/GUYER.. 08/24/2006
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z