(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.
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 020853
SPC AC 020853
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0353 AM CDT WED SEP 02 2015
VALID 051200Z - 101200Z
PRIMARY INTEREST EARLY IN THE 4-8 PERIOD WILL BE THE POTENTIAL FOR
SEVERE STORMS AS PRIMARY UPPER TROUGH FINALLY EJECTS NEWD INTO THE
NRN PLAINS WHICH MODEL CONSENSUS INDICATE SHOULD BE AROUND THE DAY 5
/SUNDAY/ TIME FRAME. AN E-W ORIENTED COLD FRONT IS FORECAST TO STALL
OVER THE NRN PLAINS IN RESPONSE TO CYCLOGENESIS INDUCED BY THE
EJECTING SHORTWAVE TROUGH. A PACIFIC FRONT WILL ACCOMPANY THIS
IMPULSE AND ADVANCE THROUGH THE DAKOTAS AND EVENTUALLY THE UPPER MS
VALLEY. A MOIST WARM SECTOR WILL PRECEDE THE COLD FRONT. WHILE
STRONGER WINDS ALOFT ACCOMPANYING THE SHORTWAVE TROUGH MAY REMAIN IN
COOL SECTOR DEPENDING ON LOCATION OF STALLED FRONT...SUFFICIENT FLOW
MAY SPREAD ACROSS NRN PORTIONS OF WARM SECTOR FOR AN ORGANIZED
SEVERE THREAT AS STORMS REDEVELOP DURING THE AFTERNOON. PRIMARY
UNCERTAINTY AT THIS TIME REMAINS EVOLUTION OF EARLY STORMS. A
CATEGORICAL RISK AREA MAY NEED TO BE INTRODUCED FOR ERN PORTIONS OF
THE NRN PLAINS INTO THE UPPER MS VALLEY IN LATER OUTLOOKS.
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