AREAS AFFECTED...SERN MN...NERN IA...SWRN WI...NRN IL
CONCERNING...SEVERE THUNDERSTORM WATCH 493...
VALID 182007Z - 182100Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 493
CONTINUES.
SUMMARY...CONVECTIVE COVERAGE IS INCREASING ACROSS SERN MN AND NERN
IA...AND MAY EVOLVE INTO AN ESEWD PROGRESSING MCS CAPABLE OF DMGG
WINDS OVER THE NEXT FEW HOURS.
DISCUSSION...20Z WV IMAGERY INDICATES A SUBTLE UPPER TROUGH...WITH
IMPLIED FORCING FOR ASCENT AND MODEST WLY FLOW ALOFT PROGRESSING
INTO MN/IA ATTM. IN COMBINATION WITH A WEAK MCV AND REMNANT OUTFLOW
BOUNDARY NOTED NEAR THE N CNTRL IA/S CNTRL MN BORDER...CONVECTION IS
BEGINNING TO INCREASE IN COVERAGE AND INTENSITY OVER SERN MN/NERN
IA. AMBIENT MOISTURE AND DIURNAL HEATING HAVE SUPPORTED TEMPERATURES
IN THE UPPER 90S TO NEAR 100 F S OF THE STATIONARY FRONT IN ADVANCE
OF THE ONGOING COMPLEX. WITH THE ASSOCIATED STEEP LOW-LEVEL LAPSE
RATES...THERE IS SOME POTENTIAL THAT AN ORGANIZED COLD POOL COULD
DEVELOP...WITH AN ATTENDANT THREAT OF DMGG WINDS ACROSS THE WW AREA.
ADDITIONAL DEVELOPMENT IS POSSIBLE ALONG THE COLD FRONT ACROSS SRN
WI...WHERE CU FIELDS HAVE BECOME INCREASINGLY AGITATED.
..HURLBUT.. 07/18/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...MKX...DVN...ARX...MPX...DMX...
LAT...LON 41289142 42399306 43229381 43829350 43909225 43669044
43028951 42048812 41318771 40638781 40738932 41289142
