Oct 22, 2021 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Fri Oct 22 07:40:04 UTC 2021 (20211022 0730Z Day 3 shapefile | 20211022 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
ENHANCED 88,208 7,643,443 St. Louis, MO...Little Rock, AR...Springfield, MO...Columbia, MO...Fort Smith, AR...
SLIGHT 113,913 8,655,819 Memphis, TN...Kansas City, MO...Tulsa, OK...Overland Park, KS...Kansas City, KS...
MARGINAL 110,548 10,555,491 Dallas, TX...Plano, TX...Garland, TX...Shreveport, LA...Irving, TX...
Probabilistic Graphic
20211022 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
SIG SEVERE 48,403 4,826,956 St. Louis, MO...Springfield, MO...Columbia, MO...Fayetteville, AR...St. Charles, MO...
30 % 88,523 7,622,099 St. Louis, MO...Little Rock, AR...Springfield, MO...Columbia, MO...Fort Smith, AR...
15 % 114,218 8,764,323 Memphis, TN...Kansas City, MO...Tulsa, OK...Overland Park, KS...Kansas City, KS...
5 % 109,776 10,197,370 Dallas, TX...Plano, TX...Garland, TX...Shreveport, LA...Irving, TX...
   SPC AC 220740

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0240 AM CDT Fri Oct 22 2021

   Valid 241200Z - 251200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE MIDDLE
   MISSISSIPPI VALLEY REGION...

   ...SUMMARY...
   Severe storms with all hazards possible are expected over a portion
   of the middle Mississippi valley region Sunday afternoon and Sunday
   night. A few strong to severe storms are also possible over coastal
   Oregon.

   ...Eastern Kansas and Oklahoma into the middle Mississippi Valley
   region...

   A low-amplitude shortwave trough will move through KS and OK during
   the day, reaching the middle MS Valley later Sunday afternoon and
   evening. The attendant surface low will move from northeast KS
   during the morning into IL overnight. Trailing front will sweep
   across KS and OK into the MS Valley, reaching the TN and OH Valleys
   overnight. A warm front will extend east from the low and spread
   northward through the OH Valley.

   The pre-frontal warm sector is expected to become moderately
   unstable supported by the northward advection of low to mid 60s F
   dewpoints. Low clouds may accompany this moisture return, but some
   breaks should allow for pockets of diurnal heating of the boundary
   layer with MLCAPE from 1500-2000 J/kg MLCAPE. Low clouds and a
   modest cap may delay storm development until mid afternoon when
   storms should initiate along the cold front from eastern KS into
   eastern OK. Wind profiles with up to 50 kt effective bulk shear and
   sizeable low-level hodographs will support supercells. Storms may
   eventually evolve into lines during the evening as they continue
   through the MS and TN Valley regions. All severe hazards are
   possible including potential for significant severe weather.

   ...Coastal Oregon...

   A substantial upper trough will amplify as it approaches the west
   coast accompanied by cold air aloft and steep lapse rates. This will
   contribute to marginal surface-based instability, especially along
   coastal OR where vertical wind profiles with strong vertical shear
   will support a conditional threat for organized storms including
   low-topped supercells during the late afternoon into the evening.
   This region will continue to be monitored for a possible SLGT risk
   in later updates.

   ..Dial.. 10/22/2021

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