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< Day 3 Outlook    
Day 4-8 Severe Weather Outlook Issued on Sep 16, 2014
Updated: Tue Sep 16 08:54:02 UTC 2014
D4-8 D4 D5 D6 D7 D8
 Population  Cities/Towns  CWAs  Interstates  Counties  FEMA Regions

Severe Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4Fri, Sep 19, 2014 - Sat, Sep 20, 2014 D7Mon, Sep 22, 2014 - Tue, Sep 23, 2014
D5Sat, Sep 20, 2014 - Sun, Sep 21, 2014 D8Tue, Sep 23, 2014 - Wed, Sep 24, 2014
D6Sun, Sep 21, 2014 - Mon, Sep 22, 2014 (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 a 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 highly unlikely during the entire period (e.g. less than a 30% probability for a regional severe storm area across the CONUS through the entire Day 4-8 period).
 Forecast Discussion

   ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 160852
   SPC AC 160852

   DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0352 AM CDT TUE SEP 16 2014

   VALID 191200Z - 241200Z

   ...DISCUSSION...
   THE ECMWF AND GFS MODELS BEGIN THE DAY 4 TO 8 PERIOD WITH AN
   UPPER-LEVEL RIDGE OVER ERN PARTS OF THE GREAT PLAINS AND MOVE THIS
   FEATURE EWD INTO THE MID TO UPPER MS VALLEY ON FRIDAY/DAY 4. AT THE
   SAME TIME...AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE INTO THE HIGH
   PLAINS FRIDAY AFTERNOON OVER A MOIST AIRMASS. THIS WOULD SUGGEST
   THUNDERSTORM DEVELOPMENT WITH SOME POSSIBLY SEVERE...MAY OCCUR IN
   THE LATE AFTERNOON AND EARLY EVENING ON FRIDAY IN THE SRN AND CNTRL
   PLAINS. THE UPPER-LEVEL TROUGH IS FORECAST TO MOVE ACROSS THE CNTRL
   PLAINS AND UPPER MIDWEST ON SATURDAY/DAY 5. THUNDERSTORM DEVELOPMENT
   WILL AGAIN BE POSSIBLE SATURDAY AFTERNOON ALONG THE TROUGH DURING
   THE LATE AFTERNOON AND EARLY EVENING. ALTHOUGH THE ECMWF AND GFS
   SOLUTIONS DIVERGE ON SUNDAY/DAY 6...BOTH SOLUTIONS MOVE THE
   UPPER-LEVEL TROUGH EWD ACROSS THE MID MS AND LOWER OH VALLEYS.
   THUNDERSTORM DEVELOPMENT WOULD BE POSSIBLE FROM THE OH VALLEY SWWD
   INTO THE MID MS VALLEY AND SRN PLAINS SUNDAY AFTERNOON. ON
   MONDAY/DAY 7...BOTH SOLUTIONS DRIVE A COLD FRONT SEWD INTO THE GULF
   COAST STATES SUGGESTING THAT THUNDERSTORM ACTIVITY WILL BE POSSIBLE
   THERE MONDAY AFTERNOON. ALTHOUGH THERE APPEARS TO BE A REASONABLE
   CHANCE FOR SEVERE THUNDERSTORM DEVELOPMENT IN PARTS OF THE GREAT
   PLAINS AND UPPER MIDWEST ON FRIDAY AND SATURDAY...UNCERTAINTY STILL
   REMAINS CONCERNING THE AMOUNT INSTABILITY THAT WILL BE IN PLACE
   REGARDING THE SEVERE THREAT.

   ..BROYLES.. 09/16/2014

   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: September 16, 2014
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