Aug 28, 2015 2000 UTC Day 1 Convective Outlook
Updated: Fri Aug 28 20:05:54 UTC 2015 (20150828 2000Z Day 1 shapefile | 20150828 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150828 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 22,867 237,608 Hibbing, MN...Bemidji, MN...
Probabilistic Tornado Graphic
20150828 2000 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
20150828 2000 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 % 22,791 236,447 Hibbing, MN...Bemidji, MN...
Probabilistic Large Hail Graphic
20150828 2000 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 % 22,711 236,626 Hibbing, MN...Bemidji, MN...
   SPC AC 282005

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0305 PM CDT FRI AUG 28 2015

   VALID 282000Z - 291200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS NRN MN...

   ...SUMMARY...
   ISOLATED STORMS WITH LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE
   LATE THIS AFTERNOON AND EVENING ACROSS NORTHERN MINNESOTA.  OTHER
   STRONG STORMS WITH GUSTY WINDS COULD OCCUR THIS AFTERNOON ACROSS
   SOUTH GEORGIA AND NORTH FLORIDA...AND FROM NORTHEAST KANSAS INTO
   NORTHWEST MISSOURI AND SOUTHEAST IOWA.

   ...DISCUSSION...
   CURRENT FORECAST REASONING APPEARS TO REMAIN VALID...WITH ONLY MINOR
   LINE TWEAKS APPEARING NECESSARY ATTM.  THE BIGGEST CHANGE THIS
   FORECAST WILL BE TO SHIFT THE WRN FRINGE OF THE 5%/MRGL RISK AREA
   EWD OUT OF ND...AS CAPPING APPEARS LIKELY TO HINDER STORM
   DEVELOPMENT THIS AFTERNOON/EVENING ACROSS THIS REGION.

   ..GOSS.. 08/28/2015

   .PREV DISCUSSION... /ISSUED 1130 AM CDT FRI AUG 28 2015/

   ...SYNOPSIS...
   SLOW EWD PROGRESSION OF A MIDLEVEL TROUGH OVER IA IS
   EXPECTED...LARGELY IN RESPONSE TO HEIGHT RISES OVER THE NRN PLAINS
   WHICH WILL OCCUR DOWNSTREAM FROM ANOTHER PRONOUNCED SHORTWAVE TROUGH
   THAT WILL APPROACH THE PAC NW COAST SAT MORNING.

   ...ERN ND/NRN MN THIS AFTERNOON/EVENING...
   MORNING CONVECTION WITH AN INITIAL SPEED MAX HAS WEAKENED OVER THE
   PAST COUPLE OF HOURS.  ADDITIONAL STORM DEVELOPMENT WILL BE POSSIBLE
   LATE THIS AFTERNOON/EVENING ALONG A WEAK SURFACE TROUGH FROM ERN ND
   INTO NW MN AS AFTERNOON SURFACE HEATING/MIXING WEAKENS CONVECTIVE
   INHIBITION...AND A WEAK UPSTREAM SPEED MAX APPROACHES FROM SRN
   SASKATCHEWAN.  STEEP LAPSE RATE PROFILES AND BOUNDARY LAYER
   DEWPOINTS NEAR 60 F WITH MIXING WILL CONTRIBUTE TO MLCAPE AOA 2000
   J/KG...WITH DEEP-LAYER VERTICAL SHEAR THAT WILL BE SUFFICIENT FOR
   ORGANIZED MULTICELL CLUSTERS AND PERHAPS MARGINAL SUPERCELL
   STRUCTURES.  ISOLATED LARGE HAIL AND DAMAGING OUTFLOW GUSTS WILL BE
   POSSIBLE FOR A FEW HOURS LATE THIS AFTERNOON INTO THIS EVENING.

   ...N FL/S GA THIS AFTERNOON...
   A MIDLEVEL LOW OVER THE N CENTRAL GULF OF MEXICO WILL MOVE
   LITTLE...WITH A PLUME OF TROPICAL MOISTURE PERSISTING TO THE E OF
   THE TROUGH OVER S GA/FL.  SCATTERED THUNDERSTORMS ARE EXPECTED
   THROUGH THE AFTERNOON ALONG LOCAL SEA BREEZE CIRCULATIONS AND A
   RESIDUAL FRONT.  MODIFIED 12Z SOUNDINGS SUPPORT AFTERNOON MLCAPE
   NEAR 2500 J/KG ACROSS N FL/S GA...WHERE THERE WILL ALSO BE SOME
   POTENTIAL FOR STRONG DOWNDRAFTS AND OUTFLOW WINDS GIVEN
   PRECIPITATION LOADING IN AN ENVIRONMENT WITH DCAPE NEAR 1200 J/KG. 
   STILL...COVERAGE OF STRONG STORMS IS IN QUESTION...AND WILL NOT ADD
   A 5% WIND AREA IN THIS UPDATE.  

   ...NE KS/NW MO/SW IA THIS AFTERNOON...
   PERSISTENT CLOUDS/RAIN IN THE WAA ZONE WITH THE IA SHORTWAVE TROUGH
   HAVE REDUCED LAPSE RATES AND WILL LIMIT THE STRONGER SURFACE HEATING
   TO A NARROW CORRIDOR FROM NE KS INTO SE NEB/NW MO/SW IA THIS
   AFTERNOON.  THE HAIL AND DOWNBURST RISKS WITH ADDITIONAL STORM
   DEVELOPMENT ALONG THE SURFACE COLD FRONT LATER THIS AFTERNOON WILL
   BE TEMPERED BY THE POOR LAPSE RATES...AND BUOYANCY SHOULD REMAIN
   LIMITED WHERE VERTICAL SHEAR WILL BE STRONGER IN THE WAA ZONE OVER
   IA.  THUS...WILL NOT ADD ANY PROBABILITIES IN THIS UPDATE...BUT THIS
   AREA WILL CONTINUE TO BE MONITORED THROUGH THE AFTERNOON.

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z