AREAS AFFECTED...ERN AND NERN IL AND NWRN IND
CONCERNING...SEVERE THUNDERSTORM WATCH 255...257...
VALID 310303Z - 310430Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
255...257...CONTINUES.
SUMMARY...A THREAT FOR DAMAGING WINDS CONTINUES ACROSS ERN-NERN IL
INTO NWRN IND LATE THIS EVENING AS A LINE OF TSTMS TRACKS NNEWD
THROUGH THE COUNTIES IN THE ERN HALF OF WW 255 AND WW 257. THE
THREAT FOR DAMAGING WINDS COULD REACH NWRN IND BETWEEN
04-05Z...WHILE THE NEED FOR A DOWNSTREAM WATCH APPEARS LOW GIVEN
FURTHER STRENGTHENING OF SURFACE BASED INHIBITION INTO NRN IND AND
SWRN LOWER MI.
DISCUSSION...AT 0235Z...REGIONAL RADAR IMAGERY SHOWED A LINE OF
TSTMS ARCING SWD FROM LIVINGSTON COUNTY IL TO CUMBERLAND COUNTY
IL...WITH THIS LINE MOVING NNEWD AT 35-45 KT. ADDITIONAL STORMS
WERE CURRENTLY MOVING INTO THE SRN EXTENT OF WW 257. VWP DATA PER
ILX WSR-88D INDICATED 40-50 KT SSWLY WINDS AT 1-2 KM AGL AND
ORIENTED ACROSS THE AFOREMENTIONED NNEWD MOVING LINE OF STORMS.
ALTHOUGH SURFACE BASED INHIBITION IS GRADUALLY STRENGTHENING...SOME
HIGHER MOMENTUM AIR COULD STILL REACH THE SURFACE PRODUCING DAMAGING
WINDS.
MEANWHILE...AN OUTFLOW BOUNDARY...ATTENDANT TO AN MCS THAT MOVED
ACROSS PARTS OF CENTRAL/NRN IL EARLIER...EXTENDED FROM SWRN LAKE
MICHIGAN SSWWD AND INTERSECTED THE LINE OF STORMS IN FAR SERN
LIVINGSTON COUNTY. THE PORTION OF THE STORMS MOVING NNEWD ATOP A
MORE STABLE AIR MASS W OF THE OUTFLOW BOUNDARY SHOULD TEND TO REMAIN
SUB-SVR...WITH THE GREATEST SVR THREAT THROUGH 05-06Z REMAINING E OF
THE OUTFLOW.
..PETERS.. 05/31/2013
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...IWX...IND...LOT...ILX...LSX...
LAT...LON 38618867 39238876 40068826 40598844 41238798 42448750
42428688 42428688 41318685 40518709 40488745 39378754
38618766 38618867
