May 22, 2020 1730 UTC Day 2 Convective Outlook
Updated: Fri May 22 17:32:02 UTC 2020 (20200522 1730Z Day 2 shapefile | 20200522 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20200522 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 181,683 1,615,335 Abilene, TX...Rapid City, SD...Grand Island, NE...Minot, ND...Kearney, NE...
MARGINAL 342,997 28,916,894 Chicago, IL...San Antonio, TX...Milwaukee, WI...Oklahoma City, OK...Omaha, NE...
Probabilistic Tornado Graphic
20200522 1730 UTC Day 2 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 2 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
2 % 104,726 13,656,882 Chicago, IL...Madison, WI...Aurora, IL...Rockford, IL...Naperville, IL...
Probabilistic Damaging Wind Graphic
20200522 1730 UTC Day 2 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 2 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 155,656 1,452,668 Abilene, TX...Rapid City, SD...Grand Island, NE...Kearney, NE...North Platte, NE...
5 % 357,739 28,800,850 New York, NY...Chicago, IL...Houston, TX...Philadelphia, PA...San Antonio, TX...
Probabilistic Large Hail Graphic
20200522 1730 UTC Day 2 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 2 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 36,742 241,130 Rapid City, SD...Scottsbluff, NE...Rapid Valley, SD...
15 % 153,409 1,070,011 Abilene, TX...Rapid City, SD...Minot, ND...North Platte, NE...Big Spring, TX...
5 % 317,956 22,442,282 New York, NY...Chicago, IL...Houston, TX...Philadelphia, PA...San Antonio, TX...
   SPC AC 221732

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1232 PM CDT Fri May 22 2020

   Valid 231200Z - 241200Z


   Severe thunderstorms producing damaging hail and wind are likely
   across parts of the Dakotas and Nebraska Saturday afternoon and
   evening. Scattered strong top severe storms are possible over much
   of west Texas. Isolated strong to marginally severe storms are
   possible over much of northern Illinois and into neighboring states.

   An upper trough will remain over much of the West, with an upper
   high over the Southeast. A weak shortwave trough will top the ridge
   over the Great Lakes region, with a warm front lifting north across

   To the west, a vast area of moisture and strong instability will
   exist over the Plains. Low pressure will develop over eastern CO,
   with a dryline from southwest KS into west TX. To the north, a
   surface/inverted trough will extend from central ND into eastern WY.
   The best area for large-scale lift will be near the northern
   boundaries, as a shortwave trough moves from WY into the Dakotas

   ...West TX into southwest OK...
   A large area of very strong instability will develop with heating,
   beneath weak southwest winds aloft. Mid to upper 60s dewpoints will
   be common east of the dryline from southwest KS into west TX, with
   relatively cool 500 mb temperatures of -11 to 12 C. Capping will be
   a primary concern regarding storm coverage on Saturday.
   Boundary-layer mixing near the dryline may initiate at least
   isolated storms capable of large hail and perhaps damaging winds
   should larger clusters form. Various models are uncertain regarding
   the best areas for initiation and ultimate coverage, but degree of
   instability supports a conditional Slight.

   ...NE/SD/ND region...
   Storms are expected to form relatively early in the day near the
   front, from the Black Hills into western ND. The early initiation as
   well as modest winds aloft suggest clusters of storms may quickly
   form, and possibly an MCS later in the day. Both damaging wind and
   large hail will be possible. 

   Farther south into western NE, eastern WY and northeast CO, wind
   profiles are more favorable for supercells, but capping will be a
   concern. Steep lapse rates as well as veering winds with height will
   conditionally favor supercells, perhaps with localized damaging hail
   and a brief tornado. 

   Storms will then proceed eastward across SD and NE overnight,
   supported by a 30-40 kt low level jet, with continued damaging wind

   ...Northern IL and surrounding areas...
   As the warm front lifts north, 1000-1500 J/kg MLCAPE is forecast to
   develop from eastern IA into IL. Wind profiles near the warm front
   show between 100-200 m2/s2 effective SRH, which when combined with
   the moist air mass may support a brief tornado. Storms are likely to
   initiation over eastern IA into northern IL, where heating will
   occur near the convergence zone, then translate east/northeast
   toward southern Lake Michigan. In addition, damaging wind gusts or
   marginal hail will be possible, depending on storm mode which may be
   mixed. A small Slight Risk is possible in later outlooks depending
   on expected storm coverage.

   ..Jewell.. 05/22/2020