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Day 4-8 Severe Weather Outlook Issued on Sep 26, 2017
Updated: Tue Sep 26 08:54:03 UTC 2017
Day 4-8 Severe Weather Outlook Graphics Issued on Sep 26, 2017
Day 4 Severe Weather Outlook Graphics Issued on Sep 26, 2017
Day 4 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 5 Severe Weather Outlook Graphics Issued on Sep 26, 2017
Day 5 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 6 Severe Weather Outlook Graphics Issued on Sep 26, 2017
Day 6 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 7 Severe Weather Outlook Graphics Issued on Sep 26, 2017
Day 7 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 8 Severe Weather Outlook Graphics Issued on Sep 26, 2017
Day 8 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4Fri, Sep 29, 2017 - Sat, Sep 30, 2017 D7Mon, Oct 02, 2017 - Tue, Oct 03, 2017
D5Sat, Sep 30, 2017 - Sun, Oct 01, 2017 D8Tue, Oct 03, 2017 - Wed, Oct 04, 2017
D6Sun, Oct 01, 2017 - Mon, Oct 02, 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

   ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 260852
   SPC AC 260852

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0352 AM CDT Tue Sep 26 2017

   Valid 291200Z - 041200Z

   ...DISCUSSION...
   Latest medium-range model runs appear to be in fair agreement with
   respect to the large-scale pattern through roughly Day 5 (Saturday
   9-30), as an upper trough moves onshore over the Pacific Northwest
   and then shifts inland -- reinforcing longer-wavelength western U.S.
   troughing.  Beyond Day 5 however, model agreement deteriorates, with
   differences in both orientation of the trough, and timing of the
   eastward advance of the feature.  With these differences also
   reflected at the surface, with respect to eventual eastward advance
   of a High Plains lee trough into the Plains in response to the
   progression of the upper system, confidence in assessing
   thunderstorm potential ahead of this system remains low.

   ..Goss.. 09/26/2017

   CLICK TO GET WUUS48 PTSD48 PRODUCT
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Page last modified: September 26, 2017
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