Aug 9, 2020 0100 UTC Day 1 Convective Outlook
Updated: Sun Aug 9 00:41:41 UTC 2020 (20200809 0100Z Day 1 shapefile | 20200809 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20200809 0100 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 22,602 153,753 Mitchell, SD...Huron, SD...Madison, SD...
SLIGHT 90,921 4,325,668 Minneapolis, MN...St. Paul, MN...Sioux Falls, SD...Bloomington, MN...Plymouth, MN...
MARGINAL 156,341 6,389,907 Omaha, NE...Lincoln, NE...Madison, WI...Rochester, MN...Duluth, MN...
Probabilistic Tornado Graphic
20200809 0100 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
2 % 89,421 1,288,677 Sioux Falls, SD...St. Cloud, MN...North Platte, NE...Watertown, SD...Willmar, MN...
Probabilistic Damaging Wind Graphic
20200809 0100 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
SIG SEVERE 39,051 288,131 North Platte, NE...Watertown, SD...Brookings, SD...Mitchell, SD...Huron, SD...
30 % 22,602 153,753 Mitchell, SD...Huron, SD...Madison, SD...
15 % 90,929 4,328,355 Minneapolis, MN...St. Paul, MN...Sioux Falls, SD...Bloomington, MN...Plymouth, MN...
5 % 156,160 6,373,421 Omaha, NE...Lincoln, NE...Madison, WI...Rochester, MN...Duluth, MN...
Probabilistic Large Hail Graphic
20200809 0100 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
15 % 60,349 356,678 North Platte, NE...Watertown, SD...Brookings, SD...Mitchell, SD...Huron, SD...
5 % 166,578 7,070,405 Minneapolis, MN...St. Paul, MN...Sioux Falls, SD...Duluth, MN...Sioux City, IA...
   SPC AC 090041

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0741 PM CDT Sat Aug 08 2020

   Valid 090100Z - 091200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NE
   TO SOUTHEAST SD...

   ...SUMMARY...
   Severe thunderstorms with a risk for large hail and severe wind
   gusts are developing across parts of western and central Nebraska
   this evening. This activity may evolve into a severe wind-producing
   MCS and expand northeastward across southern to eastern South Dakota
   into southwest Minnesota later tonight.

   ...Nebraska to Minnesota...

   Earlier thoughts regarding the possible evolution of a
   wind-producing MCS appear to be on track. Over the last few hours
   convection has gradually matured as it spread across eastern WY into
   western SD/northwest NE Panhandle. Southern flank of this activity
   has a bow-type structure that recently produced 72kt wind gust at
   CDR. With the synoptic front draped from eastern SD into northeast
   CO, easterly low-level inflow is noted north of boundary ahead of
   this maturing MCS. While LLJ is not particularly noteworthy, the air
   mass is quite unstable downstream with MLCAPE values of 4000-5000
   J/kg. 00z sounding from LBF is sampling the western edge of this
   higher buoyancy with 3500 J/KG MLCAPE, but only 20kt of sfc-6km bulk
   shear. Even so, observed wind fields appear adequate for a
   long-lived MCS that should track along the SD/NE border region.
   Additionally, new robust convection is gradually increasing along
   the surface front over southwest NE, with towering cu field
   extending northeast toward ONL. This activity should continue to
   deepen and a secondary corridor of focused severe convection is
   expected, as currently depicted by latest ENH risk. Severe storms
   should propagate toward southwest MN late tonight.

   ..Darrow.. 08/09/2020

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z