WWCN11 CWTO 191650
SEVERE WEATHER BULLETIN
ISSUED BY ENVIRONMENT CANADA
AT 12:50 PM EDT FRIDAY 19 AUGUST 2005.
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WATCHES/WARNINGS IN EFFECT FOR SOUTHERN ONTARIO...

TORNADO WATCH FOR:
=NEW= GODERICH - BLUEWATER - SOUTHERN HURON COUNTY 
=NEW= WINGHAM - BLYTH - NORTHERN HURON COUNTY 
=NEW= KITCHENER - CAMBRIDGE - REGION OF WATERLOO 
=NEW= GUELPH - ERIN - SOUTHERN WELLINGTON COUNTY 
=NEW= DUFFERIN - INNISFIL =NEW= GREY - BRUCE 
=NEW= BARRIE - COLLINGWOOD - HILLSDALE 
=NEW= MIDLAND - COLDWATER - ORR LAKE.

      ..RISK OF A TORNADO AHEAD OF A COLD FRONT THIS AFTERNOON..

      THIS IS AN ALERT TO THE POTENTIAL DEVELOPMENT OF TORNADOES AND
      SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS.

      MONITOR WEATHER CONDITIONS..LISTEN FOR UPDATED STATEMENTS.
      IF THREATENING WEATHER APPROACHES..TAKE IMMEDIATE SAFETY
      PRECAUTIONS.

SEVERE THUNDERSTORM WATCH FOR:
      ELGIN
      LONDON - MIDDLESEX
      SIMCOE - DELHI - NORFOLK
      DUNNVILLE - CALEDONIA - HALDIMAND
      OXFORD - BRANT
      NIAGARA
      CITY OF HAMILTON
      STRATFORD - MITCHELL - SOUTHERN PERTH COUNTY
      LISTOWEL - MILVERTON - NORTHERN PERTH COUNTY
      MOUNT FOREST - ARTHUR - NORTHERN WELLINGTON COUNTY.

      ..POTENTIAL FOR SEVERE THUNDERSTORMS TO DEVELOP THIS
      AFTERNOON..

      THIS IS AN ALERT TO THE POTENTIAL DEVELOPMENT OF SEVERE
      THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS.

      MONITOR WEATHER CONDITIONS..LISTEN FOR UPDATED STATEMENTS.
      IF THREATENING WEATHER APPROACHES TAKE IMMEDIATE SAFETY
      PRECAUTIONS.

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WATCHES/WARNINGS ENDED FOR SOUTHERN ONTARIO...

SEVERE THUNDERSTORM WATCH UPGRADED TO TORNADO WATCH FOR:
      GODERICH - BLUEWATER - SOUTHERN HURON COUNTY
      WINGHAM - BLYTH - NORTHERN HURON COUNTY
      KITCHENER - CAMBRIDGE - REGION OF WATERLOO
      GUELPH - ERIN - SOUTHERN WELLINGTON COUNTY
      SAUGEEN SHORES - KINCARDINE - SOUTHERN BRUCE COUNTY
      HANOVER - DUNDALK - SOUTHERN GREY COUNTY.

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==DISCUSSION==
A FRONTAL SYSTEM CROSSING THE ABOVE REGIONS WILL COLLIDE WITH AN INCREASINGLY 
MOIST AND UNSTABLE AIRMASS TO PRODUCE FAVOURABLE CONDITIONS FOR SEVERE THUNDERSTORMS 
AND POSSIBLY TORNADOES THIS AFTERNOON INTO EARLY THIS EVENING.  RADAR IS CURRENTLY 
SHOWING TWO LINES OF STRONG THUNDERSTORMS..THE FIRST FROM SOUTH OF OWEN SOUND TO 
EXETER AND A SECOND LINE APPROACHING THE EAST SHORE OF LAKE HURON.
SOME OF THESE STORMS HAVE BEEN EXHIBITING SIGNS OF ROTATION ON DOPPLER RADAR AND 
THERE IS POTENTIAL FOR THESE STORMS TO PRODUCE A TORNADO.  AS OF THIS MOMENT THERE 
HAVE BEEN NO REPORTS OF ACTUAL TORNADOES.  THESE STORMS WILL ALSO BE CAPABLE OF 
PRODUCING DAMAGING WIND GUSTS IN EXCESS OF 90 KM/H..LARGE HAIL IN EXCESS OF 2 
CENTIMETRES AND LOCALLY HEAVY RAINFALL IN EXCESS OF 50 MILLIMETRES IN ONE HOUR.

PLEASE REFER TO THE LATEST PUBLIC FORECASTS FOR FURTHER DETAILS.

END/TUGWOOD