TORNADO WATCH NUMBER 74

URGENT - IMMEDIATE BROADCAST REQUESTED
   TORNADO WATCH NUMBER 74
   NWS STORM PREDICTION CENTER NORMAN OK
   735 PM EDT MON MAR 12 2012
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   TORNADO WATCH FOR PORTIONS OF 
   
          EASTERN LOWER MICHIGAN
          NORTHWEST OHIO
          LAKE ERIE
          LAKE HURON
EFFECTIVE THIS MONDAY NIGHT ANDTUESDAY MORNING FROM 735 PM UNTIL
   300 AM EDT.
   
   TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
   GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
   AREAS.
   
   THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 45 STATUTE
   MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH NORTHEAST OF
   BAD AXE MICHIGAN TO 25 MILES SOUTH SOUTHWEST OF TOLEDO OHIO.  FOR
   A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
   OUTLINE UPDATE (WOUS64 KWNS WOU4).
   
   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.
   
   OTHER WATCH INFORMATION...CONTINUE...WW 73...
   
   DISCUSSION...MIGRATORY SHORT-WAVE TROUGH WILL PROGRESS ACROSS THE
   WATCH AREA TONIGHT...FOCUSING A BAND OF TSTMS ALONG AND AHEAD OF
   ATTENDANT SURFACE COLD FRONT.  THOUGH INSTABILITY WILL REMAIN QUITE
   MARGINAL...THE DEGREE OF FORCING FOR ASCENT AND RATHER STRONG LOW-
   AND DEEP-LAYER SHEAR WILL MAINTAIN A RISK FOR EMBEDDED SUPERCELL
   AND/OR BOWING STRUCTURES CAPABLE OF DAMAGING WINDS AND PERHAPS A
   COUPLE OF TORNADOES.
   
   AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
   SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
   WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
   350. MEAN STORM MOTION VECTOR 23040.

Tornadoes Probability of 2 or more tornadoes  Mod (40%) Probability of 1 or more strong (F2-F5) tornadoes Low (20%)

Wind Probability of 10 or more severe wind events Mod (30%) Probability of 1 or more wind events > 65 knots Mod (30%)

Hail Probability of 10 or more severe hail events Mod (40%) Probability of 1 or more hailstones > 2 inches Low (<5%) Combined Severe Hail/Wind Probability of 6 or more combined severe hail/wind events High (70%)