(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 170655
SPC AC 170655
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0155 AM CDT Tue Oct 17 2017
Valid 201200Z - 251200Z
ECMWF and GFS are in general agreement with large-scale pattern into
the day5 period with a pronounced trough forecast to advance across
the Rockies into the High Plains by 22/00z. In response to lowering
heights across the western US, higher-PW plume should return inland
across TX into portions of the southern/central Plains. Models are
trending toward a more unified solution this weekend but the
Canadian model differs considerably with intensity/latitude of the
aforementioned trough. If ECMWF/GFS solutions are correct, it
appears adequate instability will be present for organized
thunderstorm development along a cold front as it surges across
portions of KS/OK/north TX. Will not introduce severe probs at this
time due to model uncertainty but the potential for robust
convection appears to be increasing across this region by Saturday.
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