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

   SPC AC 141616
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1116 AM CDT WED JUL 14 2010
   
   VALID 141630Z - 151200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS TODAY AND TONIGHT ACROSS SERN
   MN...NERN IA AND MUCH OF WI...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER GREAT LAKES AND
   UPPER MS VALLEY SWWD INTO THE CNTRL HIGH PLAINS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PART OF THE CO FRONT
   RANGE...
   
   ...UPPER GREAT LAKES/UPPER MIDWEST...
   
   STRONG/SEVERE MCS IS IN PROGRESS THIS MORNING OVER NWRN WI WITH MORE
   DISCRETE STORM DEVELOPMENT OBSERVED OVER SRN MN/NERN IA.  SURFACE
   AND UPPER-AIR ANALYSES SUGGEST THAT THIS ACTIVITY IS OCCURRING
   WITHIN A ZONE OF STRONG WAA ALONG THE NOSE OF A 40-45 KT LLJ...AND
   GENERALLY STRADDLING A WARM FRONT EXTENDING FROM LOW PRESSURE OVER
   E-CNTRL SD ENEWD INTO CNTRL WI.  12Z OBSERVED SOUNDINGS SHOW THE
   PRESENCE OF STEEP MIDLEVEL LAPSE RATES /ASSOCIATED WITH AN EML/ 
   ATOP A MOIST BOUNDARY LAYER /I.E. 100 MB MEAN MIXING RATIO IN EXCESS
   OF 18 G PER KG AT MPX/.  WHEN COUPLED WITH DAYTIME HEATING...AIR
   MASS WILL BECOME MODERATE TO STRONGLY UNSTABLE BY AFTERNOON WITH
   MLCAPE RANGING FROM 1000-2000 J/KG AHEAD OF ONGOING MCS OVER
   NRN/CNTRL WI...TO AS HIGH AS 3500-4500 J/KG FARTHER S ACROSS IA.
   
   CAPPING ASSOCIATED WITH EML WILL GRADUALLY BE ERODED THROUGH THE DAY
   OWING TO LARGE-SCALE FORCING ASSOCIATED WITH UPSTREAM
   TROUGH...STRONG STORM AND MESOSCALE COLD POOLS AND FRONTAL
   CONVERGENCE.  THESE PROCESSES SHOULD ALLOW INITIAL STORMS TO BECOME
   FULLY SURFACE-BASED WHILE AT THE SAME TIME PERMITTING SUBSEQUENT
   STORM DEVELOPMENT FARTHER S ACROSS SRN MN...CNTRL/SRN WI AND IA. 
   EXPECT A COMBINATION OF FORWARD-PROPAGATING QLCS AND SUPERCELL MODES
   TO CO-EXIST WITH THE THREAT FOR CORRIDORS OF DAMAGING WIND
   GUSTS...LARGE HAIL AND TORNADOES /SOME POSSIBLY STRONG/. 
   CURRENTLY...IT APPEARS THE GREATEST THREAT FOR SIGNIFICANT TORNADOES
   WILL EXIST ACROSS SRN MN INTO W-CNTRL OR SWRN WI LATER TODAY. 
   HERE...LATEST MODEL GUIDANCE INDICATES THAT THE HIGHEST LIKELIHOOD
   FOR MORE DISCRETE STORM MODES WILL COINCIDE WITH STRONG INSTABILITY
   AND MORE THAN SUFFICIENT LOW AND DEEP-LAYER SHEAR.
   
   EXPECT THE THREAT FOR MAINLY LARGE HAIL AND DAMAGING WIND GUSTS TO
   CONTINUE OVERNIGHT ACROSS PARTS OF IA...SRN WI INTO IL IN
   CONJUNCTION WITH ONE OR MULTIPLE MCS/S.
   
   ...MID MO VALLEY INTO CNTRL HIGH PLAINS...
   
   ISOLATED TO SCATTERED TSTMS ARE ONGOING THIS MORNING FROM CNTRL NEB
   INTO ERN SD IN ASSOCIATION WITH A WELL-DEFINED SHORT WAVE TROUGH
   PROGRESSING EWD THROUGH THE DAKOTAS AND WRN NEB.  12Z OBSERVED
   SOUNDINGS SUGGEST THAT THIS ACTIVITY IS LIKELY SITUATED ABOVE THE
   STRONG CAP CENTERED IN THE 800-850 MB LAYER.  GIVEN THE PRESENCE OF
   THE STEEP LAPSE RATES AND MODEST CLOUD-BEARING SHEAR...SOME HAIL
   WILL BE POSSIBLE WITH THE STRONGER STORMS.
   
   SURFACE-BASED TSTM DEVELOPMENT WILL BECOME INCREASINGLY LIKELY ALONG
   THE COLD FRONT BY MID/LATE AFTERNOON FROM ERN NEB/WRN IA SWWD INTO
   WRN KS AS THE COMBINATION OF STRONG HEATING AND FORCING ASSOCIATED
   WITH SRN EXTENSION OF ABOVE-MENTIONED SHORT WAVE TROUGH
   PROGRESSIVELY OVERSPREAD THE REGION.  AMBIENT...PRE-FRONTAL AIR MASS
   WILL BE HOT AND QUITE MOIST WITH DEWPOINTS IN THE MID/UPPER 70S F. 
   WHEN COUPLED WITH THE STEEP MIDLEVEL LAPSE RATES...ENVIRONMENT IS
   EXPECTED TO BECOME STRONGLY TO EXTREMELY UNSTABLE WITH MLCAPE
   RANGING FROM 4000-5500 J/KG OVER THE MID MO VALLEY...TO 2000-3000
   J/KG ACROSS WRN KS.  WHILE LOW AND DEEP-LAYER SHEAR WILL NOT BE AS
   STRONG AS THAT OVER THE UPPER MIDWEST...IT WILL BE SUFFICIENT TO
   SUPPORT SUPERCELLS CAPABLE OF LARGE HAIL...DAMAGING WINDS AND
   PERHAPS A FEW TORNADOES...GIVEN THE DEGREE OF INSTABILITY.
   
   ...CHEYENNE RIDGE INTO CO FRONT RANGE...
   
   THE COMBINATION OF STEEP LAPSE RATES AND RESIDUAL BOUNDARY LAYER
   DEWPOINTS IN THE 40S TO LOWER 50S F WITHIN POST-FRONTAL UPSLOPE
   REGIME WILL YIELD POCKETS OF MODEST INSTABILITY BY AFTERNOON WITH
   MLCAPE OF 500-1500 J/KG.  ISOLATED STORM DEVELOPMENT WILL BE
   POSSIBLE THROUGH THE LATTER HALF OF THE DIURNAL HEATING CYCLE WITH
   FORECAST WIND PROFILES SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE
   HAIL AND LOCALLY STRONG WIND GUSTS.
   
   ..MEAD/JEWELL.. 07/14/2010
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z