Day 4-8 Severe Weather Outlook Issued on Jan 18, 2021
Updated: Mon Jan 18 09:52:03 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
Thu, Jan 21, 2021 - Fri, Jan 22, 2021
D7
Sun, Jan 24, 2021 - Mon, Jan 25, 2021
D5
Fri, Jan 22, 2021 - Sat, Jan 23, 2021
D8
Mon, Jan 25, 2021 - Tue, Jan 26, 2021
D6
Sat, Jan 23, 2021 - Sun, Jan 24, 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 180950
SPC AC 180950
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0350 AM CST Mon Jan 18 2021
Valid 211200Z - 261200Z
...DISCUSSION...
...Thursday/Day 4 and Friday/Day 5...
The medium-range models move a shortwave trough across the Desert
Southwest on Thursday as zonal mid-level flow remains from the
southern Plains to the Eastern Seaboard. Thunderstorm development
will be possible on Thursday across parts of the western and central
Gulf Coast region along the northern edge of a moist airmass.
Instability is expected to be too weak for severe thunderstorm
development. The shortwave trough is forecast to move into the Gulf
Coast States on Friday. Thunderstorms will again be possible in the
northern part of the moist airmass which should be located from the
Texas Coastal Plain eastward to the Florida Panhandle. Instability
is again forecast to be weak suggesting severe thunderstorm
potential will be minimal.
...Saturday/Day 6 to Monday/Day 8...
On Saturday, the medium-range models move an upper-level ridge
across the Mississippi Valley as southwest mid-level flow becomes
established from the Four Corners region eastward into the Great
Plains. The models are in reasonable agreement on Sunday moving an
upper-level trough across the Intermountain West. Moisture return is
forecast to take place ahead of this system in parts of the southern
Plains. Thunderstorm development will be possible during the day on
Sunday from Texas northward into Oklahoma along an axis of
instability. Although a severe threat can not be ruled out,
predictability remains low for Sunday. On Monday, the upper-level
trough is forecast to move into the Great Plains as a cold front
advances into the Arklatex. Thunderstorm development will be
possible along and ahead of the front across the lower to mid
Mississippi Valley during the day on Monday. If the forecasts
verify, a severe threat would be possible in areas that can heat up
sufficiently ahead of the front. However, predictability is low this
far out in the forecast period.
..Broyles.. 01/18/2021
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