(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 080748
SPC AC 080748
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0248 AM CDT THU OCT 08 2015
VALID 111200Z - 161200Z
THE MEDIUM RANGE MODELS BEGIN THE DAY 4 TO 8 PERIOD WITH AN
UPPER-LEVEL TROUGH ALONG THE ERN SEABOARD AND AN UPPER-LEVEL RIDGE
FROM THE CNTRL U.S. NEWD INTO THE GREAT LAKES REGION. THE MODELS
MOVE THE RIDGE EWD AS AN UPPER-LEVEL TROUGH MOVES INTO THE NRN HIGH
PLAINS ON SUNDAY/DAY 4. THIS SYSTEM MOVES QUICKLY EWD INTO THE GREAT
LAKES REGION ON MONDAY/DAY 5 AS A COLD FRONT ADVANCES SEWD INTO THE
MS VALLEY. ON TUESDAY/DAY 6...NORTHWEST FLOW IS FORECAST TO BECOME
ESTABLISHED ACROSS MUCH OF THE CONUS AS SFC HIGH PRESSURE SETTLES
INTO THE ERN THIRD OF THE NATION. ON WEDNESDAY/DAY 7 AND
THURSDAY/DAY 8...THE ECMWF AND GFS REMAIN IN REASONABLE AGREEMENT
DEVELOPING AN UPPER-LEVEL TROUGH OVER THE NCNTRL STATES. DUE TO DRY
AIR IN PLACE ACROSS MOST OF THE CONUS...THE POTENTIAL FOR
THUNDERSTORM ACTIVITY APPEARS LOW THROUGH THE DAY 4 TO 8 PERIOD.
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