

351 

WWUS20 KWNS 251354

SEL2

SPC WW 251354

MIZ000-LSZ000-251900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 672

NWS STORM PREDICTION CENTER NORMAN OK

855 AM CDT THU OCT 25 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       UPPER PENINSULA OF MICHIGAN

       LAKE SUPERIOR



EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 855 AM UNTIL

200 PM CDT.



HAIL TO 1 INCH 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 45

STATUTE MILES EITHER SIDE OF A LINE FROM 25 MILES NORTH NORTHEAST

OF MARQUETTE MICHIGAN TO 10 MILES WEST SOUTHWEST OF IRON MOUNTAIN

MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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...BOWING SEGMENT OF CONVECTION RACING NORTHEAST AT

50-60KT HAS ALREADY PRODUCED OBSERVED GUSTS AT RHI AROUND 50KT IN

WEAK CAPE BUT INTENSE SHEAR ENVIRONMENT. EXPECT THE STORMS TO

CONTINUE NEWD TOWARD LAKE SUPERIOR OVER THE NEXT 2 HOURS WITH A

CONTINUING POTENTIAL FOR SEVERE WINDS ALONG THE PATH OF THE BOW.

GREATEST POTENTIAL WILL BE NEAR THE APEX OF THE BOWING SEGMENT WHICH

APPEARS TO BE CO-LOCATED WITH A FRONTAL WAVE RIPPLING NEWD ALONG THE

STRONG BAROCLINIC ZONE. GIVEN STEEP MID LEVEL LAPSE RATES AND ASCENT

ACROSS THE REGION...ISOLATED SEVERE HAIL AROUND 1 INCH WILL ALSO BE

POSSIBLE.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION

VECTOR 23050.





...CARBIN



407 

WWUS20 KWNS 251354

SEL2

SPC WW 251354

MIZ000-LSZ000-251900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 672

NWS STORM PREDICTION CENTER NORMAN OK

855 AM CDT THU OCT 25 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       UPPER PENINSULA OF MICHIGAN

       LAKE SUPERIOR



EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 855 AM UNTIL

200 PM CDT.



HAIL TO 1 INCH 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 45

STATUTE MILES EITHER SIDE OF A LINE FROM 25 MILES NORTH NORTHEAST

OF MARQUETTE MICHIGAN TO 10 MILES WEST SOUTHWEST OF IRON MOUNTAIN

MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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...BOWING SEGMENT OF CONVECTION RACING NORTHEAST AT

50-60KT HAS ALREADY PRODUCED OBSERVED GUSTS AT RHI AROUND 50KT IN

WEAK CAPE BUT INTENSE SHEAR ENVIRONMENT. EXPECT THE STORMS TO

CONTINUE NEWD TOWARD LAKE SUPERIOR OVER THE NEXT 2 HOURS WITH A

CONTINUING POTENTIAL FOR SEVERE WINDS ALONG THE PATH OF THE BOW.

GREATEST POTENTIAL WILL BE NEAR THE APEX OF THE BOWING SEGMENT WHICH

APPEARS TO BE CO-LOCATED WITH A FRONTAL WAVE RIPPLING NEWD ALONG THE

STRONG BAROCLINIC ZONE. GIVEN STEEP MID LEVEL LAPSE RATES AND ASCENT

ACROSS THE REGION...ISOLATED SEVERE HAIL AROUND 1 INCH WILL ALSO BE

POSSIBLE.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION

VECTOR 23050.





...CARBIN

