AREAS AFFECTED...PORTIONS OF EXTREME ERN IA...SRN WI...NRN
IL...LM...SRN LOWER MI AND ADJACENT LH
CONCERNING...SEVERE THUNDERSTORM WATCH 504...
VALID 302214Z - 302315Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 504
CONTINUES.
SUMMARY...THE SVR THREAT CONTINUES ACROSS THE WW AREA...WITH THE
GREATEST POTENTIAL ACROSS WRN PORTIONS THRU 02Z.
DISCUSSION...SVR TSTMS ACROSS EXTREME SERN WI CONTINUE TO MOVE S AT
30 KTS INTO NRN IL...WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS.
STRENGTHENING COLD POOL/MERGING OUTFLOWS SUGGEST THAT A SWD-MOVING
CLUSTER OF SVR TSTMS WILL LIKELY CONTINUE FOR A FEW MORE HOURS. THE
ENVIRONMENT IMMEDIATELY DOWNSTREAM REMAINS SUPPORTIVE OF SVR WX WITH
MLCAPE OF 2500 J/KG...AND RELATIVELY STEEP LOW/MID-LEVEL LAPSE
RATES. DAMAGING WINDS WILL REMAIN THE PRIMARY THREAT...WITH LARGE
HAIL AND A BRIEF TORNADO ALSO POSSIBLE.
ACROSS ERN PORTIONS OF THE WW...TSTMS HAVE BEEN SLOWER TO
STRENGTHEN...HOWEVER A CELL OVER BAY CO MI HAS SHOWN SOME
INTENSIFICATION SINCE 21Z. OVERALL ENVIRONMENT OVER LOWER MI PORTION
OF THE WW IS CHARACTERIZED BY MODERATE INSTABILITY /MLCAPES
1500-2000 J/KG/ AND 35-40 KTS OF DEEP SHEAR. STRONGER STORMS OVER
ERN PORTIONS OF THE WW WILL HAVE THE POTENTIAL TO EXHIBIT SUPERCELL
STRUCTURES WITH AN ASSOCIATED THREAT OF LARGE HAIL AND DAMAGING
GUSTS.
ELSEWHERE..AN ISOLATED INTENSE TSTM OVER DUBUQUE CO IA IS LOCATED
WITHIN AN INSTABILITY AXIS WHERE MLCAPE APPROACHES 3000 J/KG.
DEEP-LAYER SHEAR IS SLIGHTLY LOWER IN THIS AREA...BUT STILL
SUFFICIENT FOR ORGANIZED TSTMS WITH A LOCALIZED SVR WIND/HAIL
THREAT.
..BUNTING/CORFIDI.. 08/30/2013
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DTX...APX...IWX...GRR...LOT...ILX...MKX...DVN...
ARX...
LAT...LON 42809135 43138964 43088805 43538684 43818607 44008343
44128288 43918246 43408237 43108294 42748390 41998463
41278747 41088903 41318994 42149094 42809135
