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< Day 3 Outlook    
Day 4-8 Severe Weather Outlook Issued on Oct 17, 2017
Updated: Tue Oct 17 06:57:02 UTC 2017
D4-8 D4 D5 D6 D7 D8
 Population  Cities  CWAs  Interstates  Counties  ARTCC  FEMA Regions

D4Fri, Oct 20, 2017 - Sat, Oct 21, 2017 D7Mon, Oct 23, 2017 - Tue, Oct 24, 2017
D5Sat, Oct 21, 2017 - Sun, Oct 22, 2017 D8Tue, Oct 24, 2017 - Wed, Oct 25, 2017
D6Sun, Oct 22, 2017 - Mon, Oct 23, 2017 (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 170655
   SPC AC 170655

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0155 AM CDT Tue Oct 17 2017

   Valid 201200Z - 251200Z

   ECMWF and GFS are in general agreement with large-scale pattern into
   the day5 period with a pronounced trough forecast to advance across
   the Rockies into the High Plains by 22/00z. In response to lowering
   heights across the western US, higher-PW plume should return inland
   across TX into portions of the southern/central Plains. Models are
   trending toward a more unified solution this weekend but the
   Canadian model differs considerably with intensity/latitude of the
   aforementioned trough. If ECMWF/GFS solutions are correct, it
   appears adequate instability will be present for organized
   thunderstorm development along a cold front as it surges across
   portions of KS/OK/north TX. Will not introduce severe probs at this
   time due to model uncertainty but the potential for robust
   convection appears to be increasing across this region by Saturday.

   ..Darrow.. 10/17/2017


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: October 17, 2017
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