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 160842
SPC AC 160842
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0342 AM CDT WED MAY 16 2012
VALID 191200Z - 241200Z
...DISCUSSION...
ISOLATED SEVERE POTENTIAL SHOULD EXIST ON SAT/D4 FROM THE UPPER MS
VALLEY TO THE CNTRL PLAINS...WITH INCREASINGLY LIMITED PROSPECTS
THEREAFTER. ABOVE-AVERAGE CONFIDENCE PERSISTS WITH HIGH CONTINUITY
AMONG THE 00Z ECMWF/GFS AND GEFS MEAN WITH THE DEPICTION OF A
DAMPENING SHORT WAVE TROUGH EJECTING FROM THE SRN ROCKIES INTO THE
CNTRL PLAINS ON D4. AT THE SURFACE...A COLD FRONT WILL ADVANCE
E/SEWD...LIKELY REACHING THE UPPER MS VALLEY TO CNTRL PLAINS BY SAT
AFTERNOON. CONCERNS OVER WARM SECTOR MOISTURE RETURN DESCRIBED IN
THE D2/3 OUTLOOKS SUGGEST GFS/GEFS MEAN SURFACE DEW POINTS CONTINUE
TO DISPLAY A HIGH BIAS. GFSX MOS AND THE ECMWF APPEAR MORE
REASONABLE WITH GENERALLY 50S SURFACE DEW POINTS. GIVEN THE
DAMPENING NATURE OF THE SHORT WAVE TROUGH...MID-LEVEL FLOW NEARLY
PARALLELING THE SURFACE FRONT AND LIKELY ONLY MODERATE
BUOYANCY...SETUP DOES NOT RENDER SEVERE PROBABILITIES AOA 30 PERCENT
ATTM.
..GRAMS.. 05/16/2012
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