Oct 1, 2016 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Sat Oct 1 07:23:08 UTC 2016 (20161001 0730Z Day 3 shapefile | 20161001 0730Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
0730 UTC Day 3 Outlook Graphic
Day 3 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 94,496 415,396 Rapid City, SD...North Platte, NE...Dickinson, ND...Spearfish, SD...Rapid Valley, SD...
Probabilistic Graphic
20161001 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.
Day 3 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 96,625 437,893 Rapid City, SD...North Platte, NE...Dickinson, ND...Pierre, SD...Williston, ND...
   SPC AC 010723

   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0223 AM CDT SAT OCT 01 2016

   VALID 031200Z - 041200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM THE NEB SANDHILLS
   NORTHWARD INTO THE NORTHERN PLAINS...

   ...SUMMARY...
   ISOLATED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE OVER PARTS OF
   WESTERN NEBRASKA NORTHWARD INTO SOUTHEASTERN MONTANA AND THE WESTERN
   DAKOTAS MONDAY AFTERNOON AND EVENING.

   ...SYNOPSIS...
   A VIGOROUS MID-LEVEL DISTURBANCE WILL ROTATE THROUGH THE BASE OF A
   LARGER-SCALE WESTERN U.S. TROUGH AND MOVE FROM UT INTO SOUTHEASTERN
   MT DURING THE DAY AND EVOLVE INTO A CLOSED H5 LOW.  A STRONG
   CYCLONIC FLOW REGIME WILL ENCOMPASS MUCH OF THE SOUTHWESTERN U.S.
   INTO THE GREAT PLAINS.  IN THE LOW LEVELS...A COLD FRONT WILL EXTEND
   SOUTHWARD FROM A DEEPENING SURFACE LOW OVER EASTERN MT/WESTERN ND.  

   ...WESTERN NEB NORTHWARD INTO THE DAKOTAS AND SOUTHEASTERN MT...
   STRONG LOW-LEVEL SOUTHERLY FLOW ONGOING EARLY MONDAY OVER THE
   CENTRAL AND NORTHERN PLAINS WILL BE MAINTAINED AS AN 80-KT H5 SPEED
   MAX APPROACHES AND ASSOCIATED HEIGHT FALLS /IN EXCESS OF 60 M PER 12
   HR/ OVERSPREAD THE REGION.  MODELS SHOW A NARROW CORRIDOR OF MID TO
   POSSIBLY UPPER 50S DEWPOINTS FROM THE SANDHILLS NORTHWARD INTO THE
   WESTERN DAKOTAS WHICH WILL LIKELY CONTRIBUTE TO WEAK-MODERATE
   BUOYANCY 250-1250 J/KG MLCAPE.  A CAPPING INVERSION WILL BECOME MORE
   PROMINENT WITH SOUTHWARD EXTENT AND LIKELY DELAY --IN SOME CASES ACT
   TO INHIBIT-- STORM DEVELOPMENT DURING THE AFTERNOON/EARLY EVENING. 
   NONETHELESS...IT APPEARS ISOLATED TO SCATTERED THUNDERSTORMS WILL
   DEVELOP INITIALLY NEAR THE SURFACE LOW AND BOUNDARY.  FORECAST
   SOUNDINGS SHOW STRENGTHENING AND VEERING WIND PROFILES WITH HEIGHT
   SUPPORTING THE RISK FOR ORGANIZED STORM STRUCTURES.  LESSENING
   INSTABILITY AFTER DARK WILL LIKELY LEAD TO A WEAKENING IN STORMS AS
   A STRONG LOW-LEVEL WAA REGIME SHIFTS EASTWARD AND STRENGTHENS OVER
   THE CENTRAL AND NORTH-CENTRAL PLAINS DURING THE OVERNIGHT HOURS.

   ..SMITH.. 10/01/2016

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