

622 

WWUS20 KWNS 301832

SEL0

SPC WW 301832

MIZ000-WIZ000-LMZ000-LSZ000-310100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 540

NWS STORM PREDICTION CENTER NORMAN OK

130 PM CDT MON JUL 30 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       UPPER PENINSULA OF MICHIGAN

       NORTHEAST WISCONSIN

       LAKE MICHIGAN

       LAKE SUPERIOR



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 800

PM CDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75

STATUTE MILES EAST AND WEST OF A LINE FROM 20 MILES NORTHEAST OF

MARQUETTE MICHIGAN TO 40 MILES SOUTHWEST OF GREEN BAY WISCONSIN.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU0).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



DISCUSSION...STORMS ARE EXPECTED TO INITIATE SHORTLY AHEAD OF A COLD

FRONT SPREADING EAST FROM NRN WI AND LAKE SUPERIOR. A CORRIDOR OF

UNSTABLE AIR HAS DEVELOPED FROM CNTRL WI NEWD ACROSS THE MIDDLE

PORTION OF THE LOWER PENINSULA OF MI. SBCAPE IN THIS CORRIDOR HAS

CLIMBED TO OVER 2000 J/KG WHERE SFC TEMPERATURES WERE IN THE LOWER

TO MIDDLE 80S F AND DEWPOINTS WERE HOLDING IN THE MID TO UPPER 60S

F. STORMS INITIATING ALONG OR JUST AHEAD OF THE FRONT SHOULD

INCREASE IN INTENSITY AS GREATER INSTABILITY IS REALIZED.

STRENGTHENING MID LEVEL FLOW OF AROUND 40KT WILL LEND SUFFICIENT

SHEAR FOR STORMS TO ORGANIZE INTO LONGER LIVED LINES/CLUSTERS AND

PERHAPS EVEN A SUPERCELL OR TWO. DAMAGING WINDS AND SOME HAIL WOULD

BE LIKELY WITH THIS ACTIVITY. EVENTUALLY...FOCUSED LINEAR ASCENT

ALONG THE ADVANCING FRONT MAY BE SUFFICIENT TO INDUCE A SQUALL LINE

LATER TODAY ACROSS ERN WI...THE MIDDLE PORTION OF THE U.P. OF

MI...AND PORTIONS OF NRN LAKE MICHIGAN.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 31025.





...CARBIN

