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< Day 3 Outlook    
Day 4-8 Severe Weather Outlook Issued on Dec 4, 2021
Updated: Sat Dec 4 09:16:04 UTC 2021
D4-8 D4 D5 D6 D7 D8
 Pop.  Cities  CWAs  RFCs  Interstates  Counties  ARTCC  FEMA  Tribal

D4Tue, Dec 07, 2021 - Wed, Dec 08, 2021 D7Fri, Dec 10, 2021 - Sat, Dec 11, 2021
D5Wed, Dec 08, 2021 - Thu, Dec 09, 2021 D8Sat, Dec 11, 2021 - Sun, Dec 12, 2021
D6Thu, Dec 09, 2021 - Fri, Dec 10, 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 040914
   SPC AC 040914

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0314 AM CST Sat Dec 04 2021

   Valid 071200Z - 121200Z

   ...DISCUSSION...
   Modest amplification of the mid-level westerlies may occur over
   portions of the central/eastern CONUS on Day 4/Tuesday into Day
   5/Wednesday. Regardless, a prior frontal passage into the northern
   Gulf of Mexico should generally inhibit the inland advance of
   substantial low-level moisture along most of the Gulf Coast in this
   time frame. Parts of FL and southern GA may be an exception, but
   weak forecast instability should limit the threat for organized
   severe convection.

   Latest medium-range guidance is starting to come into better
   agreement with the prospect for another upper trough to amplify and
   move eastward across the western/central CONUS around Day 6/Thursday
   into Day 7/Friday. If this occurs, then the related low-level mass
   response would encourage the inland return of rich low-level
   moisture from the Gulf of Mexico into parts of the Southeast and
   perhaps even the OH Valley. Of course, there are differences in the
   placement and evolution of this upper trough and attendant surface
   features at this extended time frame. Still, an increase in severe
   potential is evident based on some of the latest models for parts of
   the lower MS Valley and Southeast on Day 8/Saturday. While it is too
   soon to include a 15% severe delineation due to model differences
   and inherent uncertainty, this scenario will be closely monitored.

   ..Gleason.. 12/04/2021

   CLICK TO GET WUUS48 PTSD48 PRODUCT


To retrieve previous Day 4-8 convective outlooks, enter the date YYYYMMDD (e.g., 20050310 for March 10, 2005.)
Data available since March 8, 2005.
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Page last modified: December 04, 2021
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