Apr 27, 2024 1630 UTC Day 1 Convective Outlook
Updated: Sat Apr 27 16:25:57 UTC 2024 (20240427 1630Z Day 1 shapefile | 20240427 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20240427 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MODERATE 71,046 4,763,886 Oklahoma City, OK...Tulsa, OK...Wichita, KS...Norman, OK...Wichita Falls, TX...
ENHANCED 119,815 11,553,376 Dallas, TX...Fort Worth, TX...Kansas City, MO...Arlington, TX...Plano, TX...
SLIGHT 221,399 21,962,587 Chicago, IL...Milwaukee, WI...Omaha, NE...Madison, WI...Grand Rapids, MI...
MARGINAL 156,984 16,413,975 San Antonio, TX...Austin, TX...St. Louis, MO...Fort Wayne, IN...Lansing, MI...
Probabilistic Tornado Graphic
20240427 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
SIG SEVERE 144,283 14,107,590 Dallas, TX...Fort Worth, TX...Oklahoma City, OK...Kansas City, MO...Tulsa, OK...
15 % 70,831 4,761,997 Oklahoma City, OK...Tulsa, OK...Wichita, KS...Norman, OK...Wichita Falls, TX...
10 % 73,555 9,324,472 Dallas, TX...Fort Worth, TX...Kansas City, MO...Arlington, TX...Plano, TX...
5 % 127,197 6,097,842 Lincoln, NE...Des Moines, IA...Springfield, MO...Mesquite, TX...Waco, TX...
2 % 176,438 21,716,341 Chicago, IL...San Antonio, TX...Austin, TX...Milwaukee, WI...Omaha, NE...
Probabilistic Damaging Wind Graphic
20240427 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
SIG SEVERE 83,243 10,949,742 Dallas, TX...Fort Worth, TX...Oklahoma City, OK...Tulsa, OK...Arlington, TX...
30 % 151,008 15,313,938 Dallas, TX...Fort Worth, TX...Oklahoma City, OK...Kansas City, MO...Tulsa, OK...
15 % 244,079 22,636,681 Chicago, IL...Milwaukee, WI...Omaha, NE...Lincoln, NE...Madison, WI...
5 % 165,931 16,445,556 San Antonio, TX...Austin, TX...St. Louis, MO...Fort Wayne, IN...Lansing, MI...
Probabilistic Large Hail Graphic
20240427 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 238,174 16,227,054 Dallas, TX...Fort Worth, TX...Oklahoma City, OK...Kansas City, MO...Tulsa, OK...
45 % 67,765 4,544,242 Oklahoma City, OK...Tulsa, OK...Wichita, KS...Norman, OK...Wichita Falls, TX...
30 % 123,072 12,185,779 Dallas, TX...Fort Worth, TX...Kansas City, MO...Arlington, TX...Plano, TX...
15 % 198,709 14,905,080 Milwaukee, WI...Omaha, NE...Madison, WI...Grand Rapids, MI...Aurora, IL...
5 % 162,662 21,185,417 Chicago, IL...San Antonio, TX...Austin, TX...Naperville, IL...Joliet, IL...
   SPC AC 271625

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1125 AM CDT Sat Apr 27 2024

   Valid 271630Z - 281200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
   AND EVENING ACROSS PORTIONS OF SOUTHERN KANSAS...MUCH OF
   OKLAHOMA...AND NORTHWEST TEXAS....

   ...SUMMARY...
   Severe thunderstorms are likely today and tonight across the
   southern and central Plains into the lower to mid Missouri Valley.
   The most numerous/intense storms are expected from north Texas into
   Oklahoma and southeast Kansas, where strong tornadoes, very large
   hail of 2-3 inches in diameter and damaging winds of 60-80 mph are
   all possible.

   ...A regional outbreak of severe thunderstorms is forecast for this
   afternoon and evening across parts of KS/OK.  Very large hail and
   strong tornadoes are possible..

   ...OK/northwest TX/south-central KS...
   Water vapor imagery shows the main upper trough is still back over
   southern AZ, with a rapidly ejecting mid/upper level jet streak
   nosing into OK/TX.  This lead feature has aided in the development
   of severe storms this morning over parts of west TX/OK.  Storms will
   develop northeastward through the afternoon into central KS, despite
   an expansive anvil shield from the morning convection.  These storms
   will pose a risk of very large hail and a few tornadoes through the
   afternoon and early evening.

   Farther south, the air mass across much of central/western OK and
   northwest TX continues to warm/destabilize as temperatures rise
   through the mid/upper 70s - eliminating CINH.  Only weak upper
   forcing through the afternoon will result in chaotic development of
   discrete supercells in a very strongly sheared and very unstable
   environment.  Forecast soundings show very steep mid-level lapse
   rates, ample low-level moisture, and strong/increasing shear
   profiles through the day.  Details of timing and location are
   nebulous, but those storms that develop will pose a risk of very
   large hail and strong and possibly long-track tornadoes.  The
   stronger large-scale forcing will arrive around/after dark, with a
   greater eastward surge of storms across central OK expected.  This
   activity may organize upscale in bowing segments will an increasing
   risk of damaging winds along with hail and tornadoes into southeast
   KS and northeast OK tonight.

   ...Southeast CO into northern KS...
   A rather strong surface boundary extends from southeast CO across
   much of northern KS.  Relatively strong heating along this boundary
   and moderate instability will lead to scattered thunderstorm
   development by mid-afternoon along the entire corridor.  Steep
   mid-level lapse rates, strong deep-layer shear, and favorable
   low-level wind profiles in vicinity of the boundary will pose a risk
   of very large hail and a few tornadoes through the afternoon and
   early evening.  This activity is expected to build eastward this
   evening along the same boundary into parts of southern IA/northern
   MO, with a continued risk of large hail along with an increasing
   threat of damaging winds.

   ..Hart/Jewell.. 04/27/2024

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