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< Day 3 Outlook    
Day 4-8 Severe Weather Outlook Issued on Dec 16, 2018
Updated: Sun Dec 16 08:36:02 UTC 2018
D4-8 D4 D5 D6 D7 D8
 Population  Cities  CWAs  Interstates  Counties  ARTCC  FEMA Regions

D4Wed, Dec 19, 2018 - Thu, Dec 20, 2018 D7Sat, Dec 22, 2018 - Sun, Dec 23, 2018
D5Thu, Dec 20, 2018 - Fri, Dec 21, 2018 D8Sun, Dec 23, 2018 - Mon, Dec 24, 2018
D6Fri, Dec 21, 2018 - Sat, Dec 22, 2018 (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

   ACUS48 KWNS 160834
   SPC AC 160834

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0234 AM CST Sun Dec 16 2018

   Valid 191200Z - 241200Z

   Latest medium-range models continue to suggest a very active pattern
   will develop over the CONUS during the upcoming day4-8 time frame.
   One significant mid-level speed max/short-wave trough is forecast to
   eject across TX into the lower MS Valley region Wednesday. This
   feature may induce weak convection near the central Gulf coast day4.
   However, models are in general agreement that a much deeper upper
   trough is forecast to develop over the Gulf States by Thursday with
   substantial height falls expected to 25N latitude which may allow
   for air mass recovery downstream across portions of FL into coastal
   Carolinas by day6. While large-scale pattern is generally agreed
   upon, significant disruptive convection is likely to evolve over the
   central/eastern Gulf basin prior to the trough's influence over FL.
   Will not introduce 15% severe probs at this time over FL owing to
   some degree of uncertainty regarding buoyancy; although,
   strengthening shear profiles in advance of this strong trough do
   warrant some concern for potential organized severe.

   ..Darrow.. 12/16/2018


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 16, 2018
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