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Day 4-8 Severe Weather Outlook Issued on Dec 17, 2017
Updated: Sun Dec 17 08:51:02 UTC 2017
Day 4-8 Severe Weather Outlook Graphics Issued on Dec 17, 2017
Day 4 Severe Weather Outlook Graphics Issued on Dec 17, 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 17, 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 17, 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 17, 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 17, 2017
Day 8 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4Wed, Dec 20, 2017 - Thu, Dec 21, 2017 D7Sat, Dec 23, 2017 - Sun, Dec 24, 2017
D5Thu, Dec 21, 2017 - Fri, Dec 22, 2017 D8Sun, Dec 24, 2017 - Mon, Dec 25, 2017
D6Fri, Dec 22, 2017 - Sat, Dec 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

   ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 170849
   SPC AC 170849

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0249 AM CST Sun Dec 17 2017

   Valid 201200Z - 251200Z

   ...DISCUSSION...
   ...Wednesday/Day 4 and Thursday/Day 5...
   The medium-range models including the ECMWF, GFS, UKMET and Canadian
   move an upper-level trough across the Southeast on Wednesday.
   Thunderstorms will be possible ahead of the system during the day
   across Alabama and Georgia. The upper-level trough is forecast to
   move eastward into the western Atlantic on Thursday. Further west,
   an upper-level trough is forecast to move into the Four Corners
   region as low-level moisture advection takes place in the southern
   Plains.

   ...Friday/Day 6 to Sunday/Day 8...
   The upper-level trough is forecast to move into the Great Plains on
   Friday as a moist airmass moves into the lower Mississippi Valley. A
   marginal severe threat will be possible along and ahead of a cold
   front moving into the lower Mississippi Valley. The ECMWF and GFS
   remain similar on Saturday with the cold front moving into the
   eastern U.S. and an upper-level trough moving into the central
   states. The upper-level trough is forecast to remain in place on
   Sunday as a cold and dry airmass settles over much of the CONUS. For
   this reason, thunderstorm activity should be limited on Saturday and
   Sunday.

   ..Broyles.. 12/17/2017

   CLICK TO GET WUUS48 PTSD48 PRODUCT
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Page last modified: December 17, 2017
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