Categorical Graphic
Probabilistic Graphic
Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.

   SPC AC 291721
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1221 PM CDT FRI JUL 29 2011
   
   VALID 301200Z - 311200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE ERN
   DAKOTAS...MN AND NWRN WI...
   
   ..SYNOPSIS...
   SHORTWAVE TROUGHS WILL PROGRESS EWD THROUGH THE WLY/S...SITUATED
   ACROSS SRN CANADA/NRN US BORDER. ONE WAVE WILL MOVE EAST OF NEW
   ENGLAND...WHILE ANOTHER SHIFTS THROUGH SRN CANADA INTO ONTARIO...
   AND BEGINS AMPLIFYING AS THE UPPER RIDGE BUILDS NWD OVER THE
   ROCKIES/PLAIN STATES. AT THE SURFACE A COLD FRONT WILL MOVE SEWD
   ACROSS THE NRN PLAINS AND IS FORECAST TO EXTEND FROM NWRN MN INTO
   CENTRAL SD BY LATE AFTERNOON. ALSO...A DISSIPATING FRONT...
   ASSOCIATED WITH EXITING NEW ENGLAND TROUGH...WILL EXTEND FROM 
   NEAR THE VA/NC BORDER WWD INTO FAR SRN KS.
   
   ...ERN DAKOTAS...MN AND NWRN WI...
   ALTHOUGH OPERATIONAL MODELS SUGGEST OVERNIGHT CONVECTION MAY BE
   LOCATED ACROSS PORTIONS OF NERN ND/NWRN MN IN THE MORNING...STORM
   SCALE MODELS KEEP CONVECTION NORTH OF THE BORDER. ASSUMING THIS 
   HAPPENS...A MORE CLEAR SETUP FOR CONVECTION TO DEVELOP ALONG THE
   FRONT WILL BE IN PLACE SATURDAY AFTERNOON. AHEAD OF THE FRONT... SLY
   WINDS WILL ADVECT AT LEAST UPPER 60 DEWPOINTS ACROSS THE SLIGHT RISK
   AREA. THESE DEWPOINTS ...ALONG WITH HEATING AND STEEP MID LEVEL
   LAPSE RATES...SHOULD YIELD MLCAPES AOA 3000 J/KG. DESPITE STRONGER
   FORCING BEING IN CANADA...FRONTAL CONVERGENCE AND COOLING IN THE
   500-700 MB LAYER SHOULD HELP BREAK CAP AND INITIATE STORMS. MID
   LEVEL FLOW AT 30-50 KT...WITH STRONGER WINDS IN MN...WILL SUPPORT
   EFFECTIVE SHEAR IN THE 35-45 KT RANGE... WHICH FAVORS A MIX OF
   MULTICELL AND SUPERCELLS. THE THERMODYNAMIC PROFILES APPEAR
   FAVORABLE FOR SUPERCELLS TO PRODUCE VERY LARGE HAIL...SO A
   SIGNIFICANT AREA HAS BEEN ADDED TO THE GRAPHIC. OTHERWISE...HAIL AND
   DAMAGING WINDS WILL BE THE MAIN THREAT...THOUGH TORNADOES ALSO
   APPEAR POSSIBLE ACROSS NRN/CENTRAL MN DUE TO STRONGER LOW/DEEP LAYER
   SHEAR. THE STORMS ARE EXPECTED TO SPREAD EWD DURING THE EVENING
   THROUGH MN AND POSSIBLY NWRN WI. ALTHOUGH THE FORCING IN SD WILL BE
   WEAKER WITH A STRONGER CAP...SEVERE STORMS ARE EXPECTED TO BACKBUILD
   SWD ALONG THE FRONT DURING THE EVENING.
   
   ...MID ATLANTIC STATES WWD INTO THE CENTRAL/SRN PLAINS...
   GIVEN WEAK FRONTAL CONVERGENCE AND A MOIST BOUNDARY LAYER...A FEW
   POCKETS OF THUNDERSTORMS ARE LIKELY DURING THE AFTERNOON...
   ESPECIALLY ACROSS THE MID MS AND TN VALLEYS WHERE SOUNDINGS WILL BE
   MORE MOIST VERTICALLY. SHEAR WILL BE WEAK...BUT TEMPERATURES IN THE
   90S PLUS PW VALUES ABOVE 2 INCHES MIGHT SUPPORT A FEW STRONG
   DOWNBURSTS.
   
   ...SRN TX...
   REMNANTS OF DON ARE FORECAST BY THE NHC TO MOVE INLAND TONIGHT
   ACROSS FAR SRN TX AND CONTINUE WWD INTO NRN MEXICO BY LATE SATURDAY.
   WHILE THE SYSTEM IS LIKELY TO BE DOWNGRADED TO A DEPRESSION DURING
   THE DAY...IF SOME HEATING OCCURS ON THE PERIPHERY OF THE
   CIRCULATION...ENOUGH SHEAR SHOULD EXIST FOR ORGANIZED STORMS...WITH
   AN ISOLATED TORNADO OR WIND GUST POSSIBLE.
   
   ..IMY.. 07/29/2011
   
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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z