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Day 4-8 Severe Weather Outlook Issued on Sep 4, 2017
Updated: Mon Sep 4 08:41:02 UTC 2017
Day 4-8 Severe Weather Outlook Graphics Issued on Sep 4, 2017
Day 4 Severe Weather Outlook Graphics Issued on Sep 4, 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 4, 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 4, 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 4, 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 4, 2017
Day 8 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4Thu, Sep 07, 2017 - Fri, Sep 08, 2017 D7Sun, Sep 10, 2017 - Mon, Sep 11, 2017
D5Fri, Sep 08, 2017 - Sat, Sep 09, 2017 D8Mon, Sep 11, 2017 - Tue, Sep 12, 2017
D6Sat, Sep 09, 2017 - Sun, Sep 10, 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 040839
   SPC AC 040839

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0339 AM CDT Mon Sep 04 2017

   Valid 071200Z - 121200Z

   ...DISCUSSION...
   Upper pattern will gradually transition away from the amplified
   western ridge/eastern trough configuration on D4/Thursday and
   D5/Friday. The eastern trough will drift northeastward as a series
   of shortwaves trough continue to rotate cyclonically through it. The
   western ridge will breakdown as a pair of shortwave troughs move
   through its northern periphery. 

   Modest surface lee troughing is likely on D4/Thursday with some
   strengthen/sharpening on D5/Friday. Upslope flow related to this lee
   troughing may contribute to thunderstorms but scant low-level
   moisture leads to uncertainty regarding convective initiation and
   coverage. Additionally, a strong dynamic low-level jet will lead to
   overnight thunderstorms on D5/Friday night across portions of the
   central Plains. Currently progged steep lapse rates and favorable
   directional shear are supportive of severe storms but run-to-run and
   model-to-model variability is currently too high for much forecast
   confidence.

   Primary feature of interest going into the weekend is Tropical
   Cyclone Irma. Irma may begin impacting portions FL as early as
   D6/Saturday. However, given typical predictability issues associated
   with tropical system, confidence in the forecast track remains
   limited.

   ..Mosier.. 09/04/2017

   CLICK TO GET WUUS48 PTSD48 PRODUCT
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Page last modified: September 04, 2017
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