Sep 21, 2019 1630 UTC Day 1 Convective Outlook
Updated: Sat Sep 21 16:14:11 UTC 2019 (20190921 1630Z Day 1 shapefile | 20190921 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20190921 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 87,247 5,198,293 Minneapolis, MN...St. Paul, MN...Des Moines, IA...Topeka, KS...Duluth, MN...
MARGINAL 322,164 16,740,447 Kansas City, MO...Omaha, NE...Wichita, KS...Lincoln, NE...Madison, WI...
Probabilistic Tornado Graphic
20190921 1630 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
5 % 33,643 1,202,630 Duluth, MN...St. Cloud, MN...Salina, KS...Superior, WI...Elk River, MN...
2 % 90,092 5,838,252 Kansas City, MO...Minneapolis, MN...St. Paul, MN...Des Moines, IA...Overland Park, KS...
Probabilistic Damaging Wind Graphic
20190921 1630 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
15 % 87,172 5,049,803 Minneapolis, MN...St. Paul, MN...Des Moines, IA...Topeka, KS...Duluth, MN...
5 % 323,254 17,149,930 Kansas City, MO...Omaha, NE...Wichita, KS...Lincoln, NE...Madison, WI...
Probabilistic Large Hail Graphic
20190921 1630 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
SIG SEVERE 26,316 497,047 Salina, KS...Manhattan, KS...Hays, KS...Junction City, KS...Great Bend, KS...
15 % 87,432 5,148,028 Minneapolis, MN...St. Paul, MN...Des Moines, IA...Topeka, KS...Duluth, MN...
5 % 239,572 10,172,377 Kansas City, MO...Omaha, NE...Wichita, KS...Lincoln, NE...Lubbock, TX...
   SPC AC 211614

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1114 AM CDT Sat Sep 21 2019

   Valid 211630Z - 221200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   MINNESOTA AND WISCONSIN...AND OVER PORTIONS OF THE CENTRAL PLAINS...

   ...SUMMARY...
   Large hail, damaging winds, and perhaps a couple of tornadoes are
   possible this afternoon/evening from Kansas to Iowa, and across
   parts of central Minnesota into northwest Wisconsin.

   ...MN/WI...
   Morning surface analysis shows a weak low over northwest MN, with a
   trailing cold front extending southward across the eastern Dakotas. 
   This front will move eastward today into central MN by
   mid-afternoon, where a combination of daytime heating and forcing
   associated with an upper trough tracking across the northern Plains
   will lead to the development of widely scattered thunderstorms.  12z
   model solutions are inconsistent on coverage of storms in this area,
   but forecast soundings suggest a conditional risk of rotating storms
   and the potential for hail and damaging wind in the strongest cells
   that form.  An isolated tornado or two is also possible, given the
   presence of remnant outflow boundaries and ample low-level moisture.
   Storms will move into central WI and weaken this evening.

   ...Central Plains...
   The aforementioned surface cold front extends southward into central
   NE/KS.  Strong heating is expected this afternoon ahead of the front
   from central/eastern KS into southeast NE, with MLCAPE values
   approaching 3000 J/kg.  Convective initiation is expected during the
   late afternoon over central KS.  Storms will build northeastward
   across the SLGT risk area during the evening, with the potential for
   large hail and damaging winds.  Shear profiles will promote initial
   supercell structures with a risk of very large hail.  Persistent
   clouds limit confidence in severe threat extending into
   central/eastern IA.

   ..Hart/Bentley.. 09/21/2019

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