Aug 30, 2016 1300 UTC Day 1 Convective Outlook
Updated: Tue Aug 30 12:40:53 UTC 2016 (20160830 1300Z Day 1 shapefile | 20160830 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160830 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 25,461 101,787 Dickinson, ND...Williston, ND...Glendive, MT...Sidney, MT...
Probabilistic Tornado Graphic
20160830 1300 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20160830 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 15,087 59,366 Dickinson, ND...Glendive, MT...Sidney, MT...
Probabilistic Large Hail Graphic
20160830 1300 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 21,353 75,374 Williston, ND...Glendive, MT...Sidney, MT...
   SPC AC 301240

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0740 AM CDT TUE AUG 30 2016

   VALID 301300Z - 311200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS MT/ND BORDER AREA...

   ...SUMMARY...
   AN ISOLATED SEVERE STORM OR TWO IS POSSIBLE THIS EVENING ALONG THE
   MONTANA/NORTH DAKOTA BORDER AREA.

   ...SYNOPSIS...
   OUTSIDE OF STRONG MID-LEVEL FLOW ASSOCIATED WITH A COMPACT SHORTWAVE
   TROUGH NOW ENTERING NORTHERN CA...MODEST MID-LEVEL WESTERLIES WILL
   GENERALLY BE CONFINED TO THE GREAT LAKES REGION...WELL SOUTH OF A
   SHORTWAVE TROUGH MOVING ACROSS EXTREME NORTHERN ONTARIO TOWARDS
   JAMES BAY. GENERALLY WEAK SHEAR IS ANTICIPATED WHERE STORMS ARE MOST
   PROBABLE TODAY FROM THE MIDWEST TO CENTRAL/SOUTHERN GREAT PLAINS AND
   GULF COAST STATES. THIS SHOULD MINIMIZE ORGANIZED SEVERE POTENTIAL
   ACROSS MUCH OF THE CONUS EXCEPT FOR EASTERN MT/WESTERN ND.

   ...MT/ND BORDER AREA...
   A CONDITIONAL RISK FOR A HIGH-BASED SUPERCELL OR TWO SHOULD EXIST
   THIS EVENING WITH LOW PROBABILITY STORM DEVELOPMENT ALONG A
   QUASI-STATIONARY FRONT. IN SPITE OF BEING IN PROXIMITY TO THE
   MID-LEVEL RIDGE AXIS...GUIDANCE IS CONSISTENT IN STRENGTHENING
   LOW-LEVEL WINDS THIS EVENING. RESULTANT WAA MAY BE SUFFICIENT TO
   INITIATE ISOLATED STORMS BETWEEN 00-03Z. WHETHER THIS OCCURS IS
   UNCERTAIN AS ONLY A NARROW CORRIDOR OF MIDDLE 50S SURFACE DEW POINTS
   IS ANTICIPATED ALONG THE FRONT. SHOULD STORMS FORM...HIGH-LEVEL
   NORTHWESTERLIES WOULD BE SUFFICIENT TO YIELD ADEQUATE DEEP SHEAR
   THROUGH THE CLOUD-BEARING LAYER. IN CONJUNCTION WITH VERY STEEP
   MID-LEVEL LAPSE RATES...A RISK FOR ISOLATED SEVERE HAIL/WIND MAY
   DEVELOP.

   ..GRAMS/COHEN.. 08/30/2016

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z