

577 

WWUS20 KWNS 170915

SEL0

SPC WW 170915

ILZ000-INZ000-WIZ000-LMZ000-171400-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 310

NWS STORM PREDICTION CENTER NORMAN OK

410 AM CDT TUE JUN 17 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* TORNADO WATCH FOR PORTIONS OF

  NORTHERN ILLINOIS

  NORTHWEST INDIANA

  SOUTHERN WISCONSIN

  LAKE MICHIGAN



* EFFECTIVE THIS TUESDAY MORNING FROM 410 AM UNTIL 900 AM CDT.



* PRIMARY THREATS INCLUDE...

  A COUPLE TORNADOES POSSIBLE

  SCATTERED DAMAGING WINDS AND ISOLATED SIGNIFICANT GUSTS TO 75

    MPH POSSIBLE



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE

MILES EAST AND WEST OF A LINE FROM 15 MILES WEST NORTHWEST OF

MILWAUKEE WISCONSIN TO 20 MILES SOUTH SOUTHWEST OF MARSEILLES

ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS.



&&



DISCUSSION...LONG-LIVED ERN IA SQLN HAS TAKEN ON A NNE-SSW

ORIENTATION THAT NOW LIES AT A CONSIDERABLE ANGLE TO 60 KT DEEP

WSWLY FLOW ACROSS REGION PER AREA VWP DATA. GIVEN FACT THAT SQLN

WILL TRAVERSE A SWATH LARGELY UNTOUCHED BY EARLIER MCS NOW OVER LWR

MS...AND PERSISTENT LOW-LVL AIRMASS RECOVERY IN NRN IL/FAR SRN WI

ASSOCIATED WITH MOIST...50 KT SWLY LLJ...SETUP COULD SUPPORT

MAINTENANCE OF THE SQLN WITH AN ATTENDANT RISK FOR DMGG WIND. IN

ADDITION...GIVEN STRENGTH OF LOW-LVL SHEAR AND THE LIKELIHOOD FOR

AUGMENTATION OF SAME ALONG WSW-ENE ORIENTED OUTFLOW BOUNDARY NOW

OVER NRN IL LEFT BY EARLIER MCS...ENVIRONMENT ALSO COULD PROMOTE

DEVELOPMENT OF EMBEDDED LOW-LVL MESOCYCLONES/QLCS TORNADOES /REF MCD

1033/.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND

GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.

MEAN STORM MOTION VECTOR 26045.





...CORFIDI

