St. Louis, MO...Little Rock, AR...Fort Smith, AR...St. Charles, MO...North Little Rock, AR...
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
15 %
75,206
6,471,647
St. Louis, MO...Little Rock, AR...Springfield, MO...Columbia, MO...Fort Smith, AR...
SPC AC 141958
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0158 PM CST Sat Nov 14 2020
Valid 142000Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
MISSOURI AND ARKANSAS...
...SUMMARY...
Thunderstorms may produce damaging winds and the threat of a few
tornadoes this evening into tonight over parts of Missouri and
Arkansas.
...20Z Update...
The only appreciable change to the ongoing forecast has been to
expand the Marginal/Slight risk areas a little westward in
central/western MO based on latest observational and short-term
guidance trends. It still appears likely that surface-based
convective initiation along/ahead of a cold front across this area
will occur after 00Z this evening. Both damaging wind gusts and a
few tornadoes may occur with these initially semi-discrete storms,
before transitioning to more of an isolated strong/gusty wind threat
as storms congeal into one or more bowing line segments with
eastward extent later in the evening/overnight.
..Gleason.. 11/14/2020
.PREV DISCUSSION... /ISSUED 1017 AM CST Sat Nov 14 2020/
...MO/AR...
Latest water vapor loop shows an amplifying upper trough over the
central Rockies. This system will intensify and move into the
Plains this evening - and into the mid MS Valley overnight. At the
surface, a cold front will extend from central IA/MO into northeast
OK by evening. This boundary will provide the focus for
thunderstorm development.
Present indications are that thunderstorms will begin to form -
mainly after dark - from southeast IA into central MO and northwest
AR. Moisture/instability will be very limited in the northern parts
of the risk area, limiting a more robust severe event. However from
central MO southward into northwest AR, forecast soundings suggest
dewpoints approaching 60F and moderately steep mid-level lapse
rates. This should yield sufficient CAPE for a few vigorous
updrafts with supercells possible for a few hours. Very strong
vertical shear would suggest a risk of all hazards in these
fast-moving storms, including a few tornadoes. Storms will likely
organize into bowing segments tonight and move into a progressively
more stable air mass. Nevertheless, the potential for locally
damaging wind gusts could be maintained as far east as southern IL
and western KY/TN.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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