Day 4-8 Severe Weather Outlook Issued on Dec 15, 2020
Updated: Tue Dec 15 08:34:02 UTC 2020
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
Fri, Dec 18, 2020 - Sat, Dec 19, 2020
D7
Mon, Dec 21, 2020 - Tue, Dec 22, 2020
D5
Sat, Dec 19, 2020 - Sun, Dec 20, 2020
D8
Tue, Dec 22, 2020 - Wed, Dec 23, 2020
D6
Sun, Dec 20, 2020 - Mon, Dec 21, 2020
(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 150832
SPC AC 150832
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0232 AM CST Tue Dec 15 2020
Valid 181200Z - 231200Z
...DISCUSSION...
Medium-range models continue to indicate increasing amplification
within branching flow, downstream of a persistent strong and zonal
mid/upper jet across the western and central, southern mid-latitude
Pacific. It appears that this will include building mid-level
ridging to the west of the U.S./Canadian Pacific coast by early next
week, though downstream short wave developments are more uncertain.
Regardless, there currently appears little opportunity for
substantive, deep Gulf of Mexico boundary-layer moistening and
inland return flow, which is expected to contribute to the
maintenance of generally low convective potential through the
period.
..Kerr.. 12/15/2020
CLICK TO GET WUUS48 PTSD48 PRODUCT
weather.gov 
@NWSSPC
