Tuesday, June 11, 2013

Mesoscale Discussion 13:42:28.4885452

AREAS AFFECTED...E-CNTRL IL...SWRN/S-CNTRL IND

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 111841Z - 111945Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A CONDITIONAL SVR RISK WILL EXIST THIS AFTERNOON ACROSS
E-CNTRL IL INTO PARTS OF WRN IND. A DISORGANIZED CLUSTER OF ELEVATED
TSTMS HAS TRACKED ACROSS THE MID-MS VALLEY INTO CNTRL IL...BUT MAY
POSE A DOWNSTREAM THREAT FOR DMGG WINDS AND LARGE HAIL IF CONVECTIVE
TRENDS INCREASE AND TSTMS CAN BECOME SFC-BASED. GIVEN THE HIGH
DEGREE OF UNCERTAINTY...A WW IS NOT CURRENTLY ANTICIPATED...BUT
TRENDS WILL BE MONITORED.

DISCUSSION...ELEVATED CONVECTION ASSOCIATED WITH A DECAYING TSTM
CLUSTER HAS PERSISTED INTO CNTRL IL EARLY THIS AFTERNOON. WHILE THIS
ACTIVITY HAS LARGELY REMAINED WEAK AND DISORGANIZED...RECENT RADAR
TRENDS SUGGEST NEW DEVELOPMENT HAS OCCURRED ALONG OUTFLOW
IMMEDIATELY AHEAD OF THIS CLUSTER...WITH A N-S LINE OF TSTMS
POSITIONED FROM JUST W OF DEC TO 15 N BMI AS OF 1830Z. PRIMARY
UNCERTAINTY ATTM REVOLVES AROUND THE POSSIBILITY FOR TSTMS TO BECOME
SFC-BASED...AS 12Z REGIONAL RAOBS INDICATE A STRONGLY CAPPED
ENVIRONMENT MAY STILL BE LIMITING THE POTENTIAL FOR SFC-BASED
PARCELS...DESPITE TEMPERATURES REACHING THE MID-80S F.
HOWEVER...SHOULD A STRONG ENOUGH COLD POOL DEVELOP AND ALLOW
ORGANIZATION INTO A FORWARD PROPAGATING LINE...A DMGG WIND AND HAIL
THREAT COULD DEVELOP AND EXTEND INTO E-CNTRL IL INTO SWRN
IND...GIVEN MODERATELY STRONG MIDLEVEL FLOW AND STEEP MIDLEVEL LAPSE
RATES.

..ROGERS/CORFIDI.. 06/11/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LMK...IND...PAH...LOT...ILX...LSX...

LAT...LON 39758605 38828591 38108677 38058756 38238804 38628886
39108908 39648914 40128911 40608890 40498794 40298720
39758605