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 %
87,842
4,443,705
Shreveport, LA...Mesquite, TX...Tyler, TX...Longview, TX...Bossier City, LA...
15 %
121,386
21,145,430
Houston, TX...Dallas, TX...Austin, TX...Fort Worth, TX...Oklahoma City, OK...
5 %
132,351
10,834,506
Memphis, TN...New Orleans, LA...Birmingham, AL...Metairie, LA...Wichita Falls, TX...
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.
Houston, TX...Austin, TX...Oklahoma City, OK...Tulsa, OK...Baton Rouge, LA...
5 %
131,534
10,656,599
Memphis, TN...New Orleans, LA...Birmingham, AL...Metairie, LA...Wichita Falls, TX...
SPC AC 220545
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1245 AM CDT Wed Apr 22 2020
Valid 221200Z - 231200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY...
...SUMMARY...
Severe thunderstorms are expected to develop in the southern Plains
east of I-35 today, spreading eastward into the Arklatex and Lower
Mississippi Valley this evening into tonight. Very large hail will
be possible in the southern Plains with wind-damage and a tornado
threat likely from the southern Plains eastward into the Lower
Mississippi Valley.
...Southern Plains/Arklatex/Lower Mississippi Valley...
A positively tilted upper-level trough will move eastward across the
southern and central Plains today. Ahead of the trough, a corridor
of low-level moisture and instability will be in place at the start
of the period from the western Texas Hill Country northward into
western Oklahoma. At the start of the period, scattered
thunderstorms should be ongoing along the northern edge of moderate
instability in northwest Oklahoma extending eastward into the
stronger low-level flow over northeastern Oklahoma. The storms are
expected to move eastward this morning as the instability corridor
to the south becomes more unstable with time. At the surface, a low
will develop in central Oklahoma this morning. Further south along
and to the east of a surface trough and dryline, boundary-layer
heating will trigger cell initiation in an uncapped airmass. This
convection will increase in intensity just east of the I-35 corridor
late this morning. Forecast soundings across south-central Oklahoma
and east-central Texas by midday show moderate instability, strong
deep-layer shear and steep mid-level lapse rates. This will support
supercell development with large hail by late morning. Hailstones of
greater than 2 inches in diameter will be possible with the more
intense supercells along the most unstable portions of the surface
trough.
The tornado threat may begin in central Oklahoma near the surface
low and develop southward into east-central Texas with the
developing storms. The tornado threat is expected to become
maximized with an eastward-moving complex of storms into the
Arklatex during the afternoon. 0-3 km storm-relative helicities in
the 400 to 500 m2/s2 range could support a strong tornado with any
supercell that becomes dominant. This complex of storms should also
have a wind-damage threat. This threat should increase as the storms
move into the Arklatex this afternoon, coincident with downdraft
maturation. An enhanced-wind damage threat could extend as far east
as the Mississippi River this evening. Although the severe threat
should become more isolated during the overnight period, a
wind-damage and tornado threat could continue as far east as the
central Gulf Coast states.
..Broyles/Lyons.. 04/22/2020
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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