Day 4-8 Severe Weather Outlook Issued on Mar 24, 2021
Updated: Wed Mar 24 09:04:03 UTC 2021
Day 4 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 5 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 6 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 7 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 8 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4
Sat, Mar 27, 2021 - Sun, Mar 28, 2021
D7
Tue, Mar 30, 2021 - Wed, Mar 31, 2021
D5
Sun, Mar 28, 2021 - Mon, Mar 29, 2021
D8
Wed, Mar 31, 2021 - Thu, Apr 01, 2021
D6
Mon, Mar 29, 2021 - Tue, Mar 30, 2021
(All days are valid from 12 UTC - 12 UTC the following day)
Note: A severe weather area depicted in the Day 4-8 period indicates 15%, 30% or higher probability for severe thunderstorms within 25 miles of any point.
PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to: 1) large differences in the deterministic model solutions, 2) large spread in the ensemble guidance, and/or 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears unlikely (i.e., less than 15%) for the forecast day.
Forecast Discussion
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 240902
SPC AC 240902
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0402 AM CDT Wed Mar 24 2021
Valid 271200Z - 011200Z
...DISCUSSION...
Split-flow upper pattern is expected to evolve early in the day 4-8
period with a closed upper low likely to become situated over the
Southwest States day 4, while a more progressive northern-stream
trough moves through the northern Plains, upper MS Valley and Great
Lakes region. Considerable model differences arise with handling of
both the northern and southern streams, contributing to low
predictability with this update.
Day 4 (Saturday) - Thunderstorms will likely be ongoing north of a
warm front from the lower MS Valley into the TN Valley early in the
day and could pose some risk for hail. As a northern-stream trough
moves through the Great Lakes/Ohio Valley, a cold front will
accelerate southeast later Saturday night. While some risk for
severe storms will exist with activity developing along the cold
front from the lower MS Valley into the Southeast States Saturday
evening and overnight, confidence in a more robust threat is low at
this time.
Day 5 (Sunday) - Thunderstorms will likely continue developing along
the cold front through the Southeast States and the lower MS Valley
and may pose some severe threat. However, low-level winds will
probably remain weak, and activity will become increasingly removed
from the stronger winds aloft, lowering confidence in a more robust
threat. Some moisture may also be advected westward through
southwest TX as the trailing portion of the front stalls and begins
to lift north as a warm front. Severe threat in this region will be
dependent on when the closed upper low over the Southwest States
moves east into the Southern High Plains, but models currently
differ considerably regarding this feature.
Days 6 through 7 - A more substantial severe threat might evolve
from Texas (day 6) and farther east into the lower MS and TN Valley
regions (day 7). However, models differ considerably with regard to
the intensity and timing of when the Southwestern U.S.
southern-stream closed low finally begins to accelerate east.
..Dial.. 03/24/2021
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