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Day 4-8 Severe Weather Outlook Issued on Dec 31, 2017
Updated: Sun Dec 31 08:02:02 UTC 2017
Day 4-8 Severe Weather Outlook Graphics Issued on Dec 31, 2017
Day 4 Severe Weather Outlook Graphics Issued on Dec 31, 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 Dec 31, 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 Dec 31, 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 Dec 31, 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 Dec 31, 2017
Day 8 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4Wed, Jan 03, 2018 - Thu, Jan 04, 2018 D7Sat, Jan 06, 2018 - Sun, Jan 07, 2018
D5Thu, Jan 04, 2018 - Fri, Jan 05, 2018 D8Sun, Jan 07, 2018 - Mon, Jan 08, 2018
D6Fri, Jan 05, 2018 - Sat, Jan 06, 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

   ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 310800
   SPC AC 310800

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0200 AM CST Sun Dec 31 2017

   Valid 031200Z - 081200Z

   ...DISCUSSION...
   It appears that considerable upper trough amplification across the
   eastern U.S. into the Atlantic during the middle to latter portion
   of the coming week will be accompanied by strong cyclogenesis over
   the western Atlantic, from near/northeast of the Bahamas
   northeastward toward the Canadian Maritimes.  This likely will be
   accompanied by another intrusion of Arctic air to the east of the
   Mississippi Valley.  In its wake, models suggest that a more zonal
   mid/upper flow regime may develop off the Pacific through the U.S.
   late this week through next weekend.  This probably will be
   accompanied by a moderation of temperatures across the Plains,
   particularly to the lee of the central and southern Rockies. 
   However, sufficient boundary layer modification over the Gulf of
   Mexico to support a substantive inland return flow of moisture
   appears unlikely through at least this period, in the wake of recent
   cold intrusions.  This is expected to result in the maintenance of
   rather low convective potential.

   ..Kerr.. 12/31/2017

   CLICK TO GET WUUS48 PTSD48 PRODUCT
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Page last modified: December 31, 2017
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