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< Day 3 Outlook    
Day 4-8 Severe Weather Outlook Issued on Feb 20, 2018
Updated: Tue Feb 20 09:40:02 UTC 2018
D4-8 D4 D5 D6 D7 D8
 Population  Cities  CWAs  Interstates  Counties  ARTCC  FEMA Regions

D4Fri, Feb 23, 2018 - Sat, Feb 24, 2018 D7Mon, Feb 26, 2018 - Tue, Feb 27, 2018
D5Sat, Feb 24, 2018 - Sun, Feb 25, 2018 D8Tue, Feb 27, 2018 - Wed, Feb 28, 2018
D6Sun, Feb 25, 2018 - Mon, Feb 26, 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 200937
   SPC AC 200937

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0337 AM CST Tue Feb 20 2018

   Valid 231200Z - 281200Z

   Model consensus is that a significant shortwave trough will eject
   northeast through the central Plains and middle MS Valley region
   (Day 5) Saturday and Saturday night. Some deamplification of this
   feature is expected, but model differences persist. GFS maintains a
   more amplified trough with a deeper surface low suggesting the
   potential for a greater severe threat compared to ECMWF, UKMET and
   the Canadian. In either case a few severe storms might evolve in
   vicinity of frontal zone from east TX into the lower MS and TN
   Valley region as the low-level jet strengthens and shifts northeast
   in response to the approaching shortwave trough. Storms may be
   ongoing along baroclinic zone over a portion of this region, with
   potential to intensify within zone of modest destabilization and
   forcing associated with the migrating low-level jet. Limiting
   factors are likelihood of widespread clouds and tendency for the
   approaching shortwave trough to weaken with deeper forcing likely
   remaining northwest of warm sector.

   Some severe threat might linger into day 6, but overall potential
   should decrease later day 6 into day 7 as a cold front moves into
   the northern Gulf coast area.

   ..Dial.. 02/20/2018


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: February 20, 2018
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