San Antonio, TX...Corpus Christi, TX...Montgomery, AL...Little Rock, AR...Springfield, MO...
Probabilistic Tornado 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 %
85,573
5,098,329
Baton Rouge, LA...Shreveport, LA...Lafayette, LA...Wichita Falls, TX...Lawton, OK...
2 %
180,175
24,251,281
Houston, TX...Dallas, TX...Austin, TX...Fort Worth, TX...Oklahoma City, OK...
Probabilistic Damaging Wind 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
30 %
77,593
5,298,290
Oklahoma City, OK...Baton Rouge, LA...Lafayette, LA...Norman, OK...Wichita Falls, TX...
San Antonio, TX...Austin, TX...Fort Worth, TX...Montgomery, AL...Little Rock, AR...
Probabilistic Large Hail 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
63,440
10,669,559
Dallas, TX...Austin, TX...Fort Worth, TX...Oklahoma City, OK...Arlington, TX...
30 %
12,115
443,089
Wichita Falls, TX...Lawton, OK...Duncan, OK...Altus, OK...Chickasha, OK...
15 %
139,338
21,657,774
Houston, TX...Dallas, TX...Austin, TX...Fort Worth, TX...Oklahoma City, OK...
5 %
133,221
7,800,099
San Antonio, TX...Corpus Christi, TX...Shreveport, LA...Abilene, TX...Fort Smith, AR...
SPC AC 231613
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1113 AM CDT Fri Apr 23 2021
Valid 231630Z - 241200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
CENTRAL AND SOUTHERN OKLAHOMA...AS WELL AS PARTS OF EASTERN
TEXAS...CENTRAL LOUISIANA...AND SOUTHERN MISSISSIPPI...
...SUMMARY...
Severe wind, large to very large and destructive hail, and a few
tornadoes are possible today and tonight across parts of the
southern Plains to lower Mississippi Valley.
...TX early this afternoon...
Morning water vapor loop shows a trough progressing across AZ/NM and
northern Mexico into TX. Large-scale lift associated with this
trough will begin to overspread an increasingly moist/unstable air
mass over central TX by early afternoon - leading to scattered
thunderstorm development. Forecast soundings from north-central to
south-central TX show steep mid-level lapse rates and sufficient
CAPE to pose a risk of hail in the stronger cells. Low and mid
level winds are also sufficiently strong for a threat of
gusty/damaging winds.
...Southeast TX into LA/MS/AL this evening and tonight...
A strong southerly low-level jet is forecast to develop after dark
across far southeast TX and southern LA. This will help to focus
lift and shear along precipitation-reinforced boundary that will
extend across the region. Most CAM solutions show multiple
bow/supercell structures tracking along the boundary through the
evening and overnight into parts of southern MS/AL. Present
indications are that damaging winds will be the main threat with
these storms. However, there is increasing concern for a greater
tornado risk as well - both supercellular and QLCS. Will maintain
5% tornado probabilities at this time but may introduce higher
probabilities at 20z if confidence of the narrow corridor of threat
increases.
...Southeast TX Panhandle into Southern OK...
Southeasterly low-level winds continue to transport increasingly
moist/unstable air northward into the eastern TX panhandle and
southwest OK. This will lead to the development of scattered
intense thunderstorms this afternoon and evening. Forecast
soundings show very steep lapse rates and robust CAPE profiles,
along with strong deep-layer shear. This should promote supercells
capable of very large hail and a tornado or two. Activity is
expected to persist through the evening and spread eastward across
central/southern OK with an increasingly linear nature, along with
the potential of more widespread damaging wind risk.
..Hart/Smith.. 04/23/2021
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NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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