Tropical Cyclone Information Statements

WOCN31 CWHX 071745
Tropical cyclone information statement updated by the Canadian
Hurricane Centre of Environment Canada at 1:48 PM ADT Friday
7 September 2012.
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Tropical cyclone information statement for:
      Labrador
      Newfoundland
      Nova Scotia
      Prince Edward Island.

      For tropical storm Leslie.


      The next statement will be issued by 9:00 AM ADT Saturday.

      Leslie weakening just below hurricane strength.  Still much
      Uncertainty if weather impacts will reach Canada.

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Tropical cyclone information statement ended for:
      New Brunswick.

      Probability of Leslie's influence in New Brunswick is very low
      At this point.  However general information statements will
      Continue to be issued at WWW.HURRICANES.CA.

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==discussion==
The Canadian Hurricane Centre continues to monitor the evolution of 
Leslie.  The storm remains parked over the cold water which it has 
stirred up.  This has resulted in winds dropping below hurricane 
force based on hurricane hunter aircraft data this morning.
Leslie should still regain hurricane strength when it eventually 
moves, unless it stirs up even cooler water for a longer period.
Most of the computer models still show a slow northward movement with 
acceleration early next week.  However - as mentioned and now 
observed - the computer models are known to have difficulty 
simulating these ocean feedback effects and situations where the 
atmospheric steering currents are very weak.  It is uncertain if 
Leslie will even strengthen to category 2 status given the latest 
developments - but the storm is quite large with an extensive area of 
rainfall, cloud cover and large waves.

In general, the threat of Leslie on Nova Scotia has been decreasing but still enough to bear watching.
The possibility of some impact in 
Newfoundland is greater, but still necessarily low (about 30%) for 
the Tuesday to Wednesday time-frame next week.  This may seem 
contradictory to the official track forecast which depicts the storm 
center just south of the Avalon Peninsula early Wednesday.
However the position only represents an average of an unusually broad 
range.  Stay tuned to our updates for the trend in the track and 
discussions.

One of The Key weather features that will tell the tale is the 
behaviour of a (easier-to-predict) trough of low pressure now 
approaching the Great Lakes.  This feature is forecast to slowly 
intensify and move southeastward over the weekend.  During the early 
part of next week the computer models are predicting that the trough 
will "pick up" the hurricane and drive it northward.  There could be 
a front merging with the storm and drawing moisture northward along 
it.  However, all this is contingent on the timing of the trough and 
position of the tropical storm/hurricane.

Much smaller but more intense hurricane Michael over 2000 kilometres 
east of Leslie now, will also move very slowly and is currently not 
expected to affect Eastern Canada.  Leslie and Michael will likely 
draw closer to each other over the next several days.  Since Leslie 
is much larger, its possible impact on Michael would likely be to 
shear-apart its upper clouds and acellerate it northward away from 
Leslie.  A true merging of the hurricanes is not expected based on 
their differing sizes.  But experience with this sort of situation is 
limited and we will certainly monitor it.

Moderate surf conditions related to Leslie will persist along 
south-facing coastlines of Nova Scotia and Newfoundland throughout 
the next several days.  If near the water, exercise caution knowing 
that wave heights can vary significantly over a span of several 
minutes and that rip currents can develop at local beaches.
Incident wave heights near 2 metres (7 feet) may break at the shore 
at heights near 3 metres (10 feet).

The Canadian Hurricane Centre will continue issuing these general 
information statements today and Saturday with more detailed track 
forecasts possibly beginning early Sunday.

Visit WWW.WEATHEROFFICE.GC.CA/HURRICANE/TRACK_E.HTML (all in lower 
case) for the latest hurricane track map.

Please also refer to the public and marine forecasts and warnings 
issued by Environment Canada for your area.

END/FOGARTY

Visit the Canadian Hurricane Centre to learn more about hurricanes.

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