(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 230936
SPC AC 230936
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0336 AM CST Thu Feb 23 2017
Valid 261200Z - 031200Z
Significant model variability is evident amongst medium-range
deterministic and ensemble data for the Sunday-Thursday (Day 4-8)
period. Both the GFS/ECMWF and MREF indicate the early stages of a
return-flow pattern from the Gulf of Mexico into the southern Great
Plains on Sunday (Day 4) and show a shortwave trough moving into the
southern High Plains late Sunday. The UKMET/CMC differ drastically
on the depiction of the mid-level impulse. On Monday (Day 5), the
recent GFS and MREF model solutions differ substantially from the
ECMWF in the placement of low-level boundaries across the
south-central states and MS Valley. The deterministic models and
their ensembles generally show the eastward progression of a
larger-scale mid-level trough from the western U.S. on Monday to the
central-southern Rockies on Tuesday. However, large differences are
noted in relevant low-level mass fields --effectively resulting in
large uncertainty and a predictability-too-low highlight for the
entire Day 4-8 period.
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