Slight Risk for Thursday.
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1252 AM CDT WED MAR 14 2012
VALID 151200Z - 161200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF LOWER MI
INTO NRN OH...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID MO VALLEY...
...SYNOPSIS...
VERY COMPLEX PATTERN WILL EVOLVE OVER THE NEXT FEW DAYS AS SEVERAL
WEAK IMPULSES/SHORT-WAVE TROUGHS WILL EJECT NEWD ACROSS THE MIDDLE
OF THE CONUS WITHIN A RELATIVELY WEAK FLOW REGIME FOR MARCH. THIS
FORECAST IS PREDICATED ON BOUNDARY LAYER MOISTURE RETURNING ACROSS
THE CNTRL PLAINS/MID MS VALLEY INTO THE OH VALLEY/LOWER MI.
...MI/OH...
TIMING OF INDIVIDUAL SHORT-WAVE TROUGHS WILL PROVE DIFFICULT THIS
PERIOD BUT LATEST NAM GUIDANCE SUGGESTS A WEAK FEATURE WILL APPROACH
MI/OH VALLEY BY 18Z THURSDAY. IF TIMING IS ACCURATE IT APPEARS
STRONG LOW LEVEL HEATING WILL CONTRIBUTE TO STEEP LAPSE RATES ALONG
A WEAK SFC BOUNDARY THAT WILL EXTEND ACROSS LOWER MI INTO NRN IND.
IF LOWER 60S DEW POINTS DO SURGE INTO THIS REGION BY PEAK HEATING
THEN SBCAPE VALUES COULD EASILY EXCEED 2000 J/KG WITHIN A MODESTLY
SHEARED ENVIRONMENT THAT WOULD SEEM TO FAVOR STRONG/SEVERE
MULTI-CELL UPDRAFTS. LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT
ALTHOUGH DAMAGING WINDS COULD ALSO BE A SECONDARY CONCERN AS TSTMS
PROPAGATE SLOWLY SEWD TOWARD NRN OH BY EARLY EVENING.
...MID MO VALLEY...
CONFIDENCE IS NOT REAL HIGH REGARDING THE TIMING OF THE SHORT-WAVE
FEATURE THAT IS EXPECTED TO APPROACH THE MID MO VALLEY BY EARLY
EVENING. THERE IS SOME MODEL DISCREPANCY REGARDING THIS SHORT-WAVE
BUT LATEST THINKING IS SUFFICIENT LOW LEVEL CONVERGENCE COMBINED
WITH STRONG HEATING WILL PROVE ADEQUATE IN GENERATING CONVECTION
ACROSS ERN NEB BY 21-23Z. LEE TROUGH/DRY LINE SHOULD SHARPEN SOME
DURING THE DAY WITH LOWER 60S SFC DEW POINTS EXPECTED TO SURGE INTO
SERN NEB PRIOR TO CONVECTIVE INITIATION. FORECAST SOUNDINGS SUGGEST
CONVECTIVE TEMPERATURES WILL BE BREACHED WHEN READINGS RISE INTO THE
UPPER 70S TO NEAR 80F. ONCE THIS OCCURS ISOLATED-SCT THUNDERSTORMS
ARE EXPECTED TO EVOLVE THEN PROPAGATE EWD INTO IA ALONG THE NOSE OF
A MODEST BUT VEERED LOW LEVEL JET. SWD EXTENT OF THIS ACTIVITY
COULD DEVELOP TOWARDS I-70 ACROSS NERN KS/NWRN MO. SHEAR PROFILES
FAVOR MULTI-CELL UPDRAFTS THAT COULD MERGE INTO A WEAK MCS IF LOW
LEVEL WARM ADVECTION IS MAINTAINED AS NAM SUGGESTS. HOWEVER...THIS
OVERNIGHT SCENARIO IS LIKELY TO REMAIN ONLY MARGINALLY SEVERE GIVEN
THE LLJ SHOULD REFOCUS FARTHER WEST BY MORNING.
...SRN HIGH PLAINS...
STRONG HEATING ALONG THE DRY LINE WILL REMOVE INHIBITION BY 21Z
ACROSS SWRN KS/INTO THE ERN TX PANHANDLE. IN THE ABSENCE OF
MEANINGFUL FORCING IT APPEARS ANY THUNDERSTORMS THAT DEVELOP ALONG
THE BOUNDARY WILL BE SHORT-LIVED WITHIN AN OTHERWISE MARGINALLY
SHEARED ENVIRONMENT.
..DARROW.. 03/14/2012
