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< Day 3 Outlook    
Day 4-8 Severe Weather Outlook Issued on Aug 26, 2016
Updated: Fri Aug 26 08:51:02 UTC 2016
D4-8 D4 D5 D6 D7 D8
 Population  Cities  CWAs  Interstates  Counties  ARTCC  FEMA Regions

D4Mon, Aug 29, 2016 - Tue, Aug 30, 2016 D7Thu, Sep 01, 2016 - Fri, Sep 02, 2016
D5Tue, Aug 30, 2016 - Wed, Aug 31, 2016 D8Fri, Sep 02, 2016 - Sat, Sep 03, 2016
D6Wed, Aug 31, 2016 - Thu, Sep 01, 2016 (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 260849
   SPC AC 260849

   DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0349 AM CDT FRI AUG 26 2016

   VALID 291200Z - 031200Z

   ...DISCUSSION...
   THE MEDIUM RANGE MODELS INCLUDING THE ECMWF AND GFS BEGIN THE DAY 4
   TO 8 PERIOD WITH A ZONAL FLOW PATTERN OVER THE NRN UNITED STATES. ON
   MONDAY/DAY 4...THE MODELS DEVELOP AN UPPER-LEVEL RIDGE OVER THE NRN
   HIGH PLAINS MOVE THIS FEATURE SLOWLY EWD ACROSS THE NRN PLAINS ON
   TUESDAY/DAY 5. AT THE SFC...BOTH SOLUTIONS MOVE A COLD FRONT SEWD
   ACROSS THE NRN PLAINS ON MONDAY AND SHOW A POCKET OF INSTABILITY IN
   ERN PARTS OF THE NRN PLAINS EWD INTO THE UPPER MS VALLEY. AN AXIS OF
   INSTABILITY IS FORECAST TO DEVELOP IN THE NRN PLAINS TUESDAY.
   INFLUENCE FROM THE UPPER-LEVEL RIDGE SHOULD KEEP CONVECTION ISOLATED
   ACROSS THE REGION WITH A MARGINAL SEVERE THREAT POSSIBLE ALONG
   CORRIDORS OF THE INSTABILITY THAT DEVELOP.

   ON WEDNESDAY/DAY 6 AND THURSDAY/DAY 7...THE GFS AND ECMWF SOLUTIONS
   BEGIN TO DIVERGE BUT BOTH SOLUTIONS SUGGEST THAT THE UPPER-LEVEL
   RIDGE WILL REMAIN OVER THE NCNTRL STATES. THE ECMWF DEVELOPS AN AXIS
   OF INSTABILITY IN THE GREAT PLAINS WHILE THE GFS HAS THE SAME
   FEATURE EXCEPT A BIT FURTHER TO THE EAST. ISOLATED MARGINALLY SEVERE
   THUNDERSTORMS WILL AGAIN BE POSSIBLE WEDNESDAY AFTERNOON AND
   THURSDAY AFTERNOON ALONG THE CORRIDOR OF STRONGEST INSTABILITY. ON
   FRIDAY/DAY 8...BOTH SOLUTIONS MAINTAIN A SIMILAR UPPER-LEVEL PATTERN
   BUT DIVERGE EVEN MORE ON THE DETAILS. THIS WOULD AGAIN MAKE A
   MARGINAL SEVERE THREAT POSSIBLE IN THE NCNTRL STATES ON FRIDAY
   AFTERNOON BUT UNCERTAINTY REMAINS SUBSTANTIAL LATE IN THE PERIOD.

   ..BROYLES.. 08/26/2016

   CLICK TO GET WUUS48 PTSD48 PRODUCT


To retrieve previous Day 4-8 convective outlooks, enter the date YYYYMMDD (e.g., 20050310 for March 10, 2005.)
Data available since March 8, 2005.
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Page last modified: August 26, 2016
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