Sep 1, 2014 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Mon Sep 1 07:16:21 UTC 2014 (20140901 0730Z Day 3 shapefile | 20140901 0730Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
0730 UTC Day 3 Outlook Graphic
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Graphic
20140901 0730 UTC Day Probabilitic 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.
Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 205,153 7,579,781 Minneapolis, MN...St. Paul, MN...Sioux Falls, SD...Rochester, MN...Fargo, ND...
   SPC AC 010716

   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0216 AM CDT MON SEP 01 2014

   VALID 031200Z - 041200Z

   ...NO SVR TSTM AREAS FORECAST...

   ...SUMMARY...
   ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THE UPPER
   MISSISSIPPI VALLEY AND NORTHERN PLAINS.

   ...UPPER MS VALLEY/NRN PLAINS...

   WEAK MID-LEVEL HEIGHT RISES ARE EXPECTED ACROSS THE UPPER MS VALLEY
   WEDNESDAY...WELL AHEAD OF SHORT-WAVE TROUGH THAT SHOULD PROGRESS
   INTO ERN MT BY THE END OF THE PERIOD.  BENEATH WEAK SHORT-WAVE
   RIDGING...BOUNDARY LAYER MOISTURE IS EXPECTED TO ADVANCE NWD ACROSS
   THE MO VALLEY INTO ERN SD/SRN MN WHERE LOWER 70S SFC DEW POINTS
   SHOULD BE IN PLACE BY LATE AFTERNOON.  IN THE ABSENCE OF SIGNIFICANT
   LARGE SCALE FORCING...DIABATIC HEATING AND WEAK LOW LEVEL WARM
   ADVECTION WILL PROVE INSTRUMENTAL IN CONVECTION THAT EVOLVES ACROSS
   THIS REGION.  LATEST NAM/GFS DEVELOP SCT PRECIPITATION WITHIN THE
   WARM ADVECTION ZONE ACROSS THE UPPER MS VALLEY.  IT/S NOT CLEAR
   WHERE THIS ACTIVITY WILL BE ROOTED AND UPDRAFTS COULD BE ELEVATED
   RATHER THAN INGESTING HIGHER QUALITY BOUNDARY LAYER PARCELS.  EVEN
   SO...THERE IS SOME CONCERN ROBUST UPDRAFTS WILL EVOLVE AS FORECAST
   SOUNDINGS EXHIBIT VEERING WIND PROFILES WITH HEIGHT AND SUFFICIENT
   BULK SHEAR FOR SUPERCELLS.  HAVE INTRODUCED 5 PERCENT SEVERE PROBS
   TO ACCOUNT FOR THIS UNCERTAINTY.  IF IT BECOMES MORE CLEAR WARM
   ADVECTION CONVECTION WILL ROOT INTO HIGH MOISTURE AIRMASS THEN
   SEVERE PROBS WILL BE RAISED ACCORDINGLY.

   FARTHER WEST...DIFLUENT HIGH-LEVEL FLOW WILL SPREAD ACROSS THE NRN
   HIGH PLAINS OF MT INTO THE WRN DAKOTAS BY 04/00Z.  UVV SHOULD
   INCREASE ACROSS THIS REGION AFTER DARK AND THE PROSPECT FOR SCT
   CONVECTION SHOULD INCREASE ALONG COLD FRONT DURING THE LATTER HALF
   OF THE PERIOD.  ONE NEGATIVE FOR ORGANIZED SEVERE ACROSS THIS REGION
   IS THE LIMITED LOW-LEVEL MOISTURE.  DESPITE THE ELY BOUNDARY LAYER
   FLOW IT APPEARS MOISTURE/INSTABILITY SUFFICIENT FOR STRONG UPDRAFTS
   MAY STRUGGLE TO ADVECT INTO ND PRIOR TO FRONTAL PASSAGE.

   ..DARROW.. 09/01/2014

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z