Day 1 Outlook Day 2 Outlook Day 3 Outlook Days 4-8 Outlook

Day 4-8 Outlook
Day 4 - 8 Outlook
Day 4-8 Severe Weather Outlook. A depicted severe weather area indicates a 30% or higher probability for severe thunderstorms within 25 miles of a point.
D4Mon, Nov 20, 2017 - Tue, Nov 21, 2017 D7Thu, Nov 23, 2017 - Fri, Nov 24, 2017
D5Tue, Nov 21, 2017 - Wed, Nov 22, 2017 D8Fri, Nov 24, 2017 - Sat, Nov 25, 2017
D6Wed, Nov 22, 2017 - Thu, Nov 23, 2017 (All days are valid from 12 UTC - 12 UTC)
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. 1) large differences in the deterministic model solutions,
  2. 2) large spread in the ensemble guidance, and/or
  3. 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears highly unlikely during the entire period (e.g. less than a 30% probability for a regional severe storm area across the CONUS through the entire Day 4-8 period).

Images courtesy of the NWS Storm Prediction Center
 Forecast Discussion

ACUS48 KWNS 170930
SPC AC 170929

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0329 AM CST Fri Nov 17 2017

Valid 201200Z - 251200Z

Ensembles indicate that in the mean, the large-scale pattern will
remain dominated by a trough over the eastern states through most of
the day 4-8 period, limiting potential for significant low-level
moisture return and severe storms. However, around day 5 (Tuesday)
models continue to depict a shortwave trough becoming detached from
the northern stream and moving southeast through TX with a modest
surface response. Partially modified gulf air will precede this
feature into coastal TX as mid-level lapse rates steepen. Storms may
develop in vicinity of a lee trough across south TX where vertical
shear and destabilization might support at least a marginal severe

..Dial.. 11/17/2017