AREAS AFFECTED...NE IL...SRN LK MI...NRN IND...SWRN LWR MI
CONCERNING...SEVERE THUNDERSTORM WATCH 354...356...
VALID 242300Z - 250015Z
CORRECTED FOR INCORRECT GEOGRAPHICAL REFERENCE AND WATCH NUMBER.
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
354...356...CONTINUES.
SUMMARY...SVR MCS CONTINUES ACROSS NE IL WITH CONTINUED SVR
WINDS...SOME POSSIBLY SIGNIFICANT...EXPECTED. SVR THREAT WITHIN THE
LINE IS EXPECTED TO CONTINUE EWD ACROSS SRN LK MI AND INTO SWRN LWR
MI/NRN IND. AS A RESULT...A DOWNSTREAM WATCH WILL BE NEEDED SHORTLY.
DISCUSSION...SVR MCS CONTINUES EWD INTO NE IL /INCLUDING THE CHICAGO
METRO AREA/. ESTIMATED MOTION BASED ON RADAR IS 270/49 KT. STRONG TO
SVR WINDS HAVE BEEN MEASURED ALONG MUCH OF THE LINE DURING THE PAST
HOURS. BASED ON RADAR IMAGERY...THE NORTHERN PORTION OF THE LINE HAS
RECENTLY SURGED EWD...SUGGESTING THE SVR WINDS /SOME POSSIBLE
SIGNIFICANT/ SHOULD CONTINUE. THE REAR INFLOW JET WAS SAMPLED WELL
BY DVN VAD WITH A LARGE AREA OF FLOW GREATER THAN 50 KT BETWEEN 3
AND 6 KM. RADAR IMAGERY HAS ALSO SHOWN WEAKENING ECHOS IN THE WAKE
OF THE LINE...FURTHER CONFIRMING THE PRESENCE OF A WELL-DEVELOPED
REAR INFLOW JET.
AREA DOWNSTREAM OF THE CURRENT LINE ACROSS NRN IND/SRN LWR MI IS
CHARACTERIZED BY TEMPERATURES IN THE MID 80S AND DEWPOINTS IN THE
LOW TO MID 60S. CURRENT INDICATIONS FROM VISIBLE SATELLITE IMAGERY
AND MESOANALYSIS ARE THAT THE AREA IS WEAKLY CAPPED WITH ONLY MODEST
INSTABILITY /MLCAPE AROUND 1000 J PER KG/. HOWEVER...THE STRENGTH OF
THE MCS AND THE PRESENCE OF GOOD LOW-LEVEL MOISTURE SHOULD FAVOR
CONTINUED PROPAGATION INTO THIS AREA. AS SUCH...A DOWNSTREAM WATCH
WILL BE NEEDED SOON.
..MOSIER/CORFIDI.. 06/24/2013
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...IWX...GRR...LOT...ILX...MKX...DVN...
LAT...LON 42558893 42838709 42608501 40988514 40628763 40758962
42558893
