CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 121603Z - 121700Z
DMGG WIND THREAT SHOULD SLOWLY INCREASE THROUGH EARLY AFTERNOON FROM
PORTIONS OF NRN IL/SERN WI EWD TOWARDS SWRN LWR MI. A WW DOES NOT
APPEAR IMMINENT PRIMARILY OWING TO MARGINAL INSTABILITY...BUT
CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW
THIS AFTERNOON.
A NARROW ZONE OF ASCENT FOCUSED ALONG THE SERN PERIPHERY OF A CLOSED
UPPER MIDWEST LOW HAS SUPPORTED A LINE OF TSTMS EXTENDING FROM 20 SE
MLI TO 30 E JVL. THIS ACTIVITY WAS LOCATED JUST W OF A LOW-LEVEL
MOISTURE AXIS...WITH MID-UPPER 50S DEW POINTS SLOWLY ADVECTING NWD
INTO SRN WI. PARTIAL CLEARING OVER NERN IL/SERN WI IS ALLOWING
TEMPERATURES TO REACH THE LOW 60S...YIELDING MLCAPE VALUES OF
200-500 J/KG. ADDITIONALLY...WEAK INHIBITION WAS NOTED IN 12Z
DVN/ILX SOUNDINGS...SUGGESTING CONVECTION IS LIKELY ROOTED NEAR THE
SFC ATTM. BACKGROUND FLOW FIELDS ARE QUITE STRONG /40-50 KTS 0.5-3
KM AGL LAYER MEAN FLOW AS SAMPLED BY LOT/ILX VWP/...AND WITH NEARLY
UNIDIRECTIONAL LOWER-TROPOSPHERIC WIND FIELDS...PRIMARY THREAT
THROUGH EARLY AFTERNOON APPEARS TO BE DMGG WINDS...BUT A BRIEF/WEAK
TOR THREAT MAY EXIST GIVEN MODERATELY STRONG 0-1 KM SHEAR AND A
MOIST BOUNDARY LAYER/LOW LCL/S. A WW IS NOT CURRENTLY
ANTICIPATED...WITH MARGINAL INSTABILITY BEING THE PRIMARY FACTOR
PRECLUDING A MORE SIGNIFICANT DMGG WIND THREAT ATTM...BUT CONVECTIVE
TRENDS WILL CONTINUE TO BE MONITORED.
..ROGERS.. 03/12/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...IWX...GRR...LOT...ILX...MKX...DVN...
LAT...LON 42728790 42658679 42378593 41968586 41508612 41398818
41288902 41148983 41149026 41469016 41978941 42388886
42628839 42748807 42728790
