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Old 09-02-2010, 01:28 PM
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Default Re: Hurricane Earl - Atlantic Canada Threat

The CHC expects to issue further watches later today.

Code:
SEVERE WEATHER BULLETIN
ISSUED BY THE CANADIAN HURRICANE CENTRE
OF ENVIRONMENT CANADA
AT 10:40 AM ADT THURSDAY 2 SEPTEMBER 2010.
---------------------------------------------------------------------
TROPICAL STORM WATCH FOR:
     QUEENS COUNTY
     SHELBURNE COUNTY
     YARMOUTH COUNTY.

     IN COORDINATION WITH THE NATIONAL HURRICANE CENTER IN MIAMI THE
     CANADIAN HURRICANE CENTRE HAS POSTED A TROPICAL STORM WATCH.

     A TROPICAL STORM WATCH MEANS THAT A TROPICAL STORM OR AN
     INCIPIENT TROPICAL STORM CONDITION POSES A POSSIBLE THREAT TO
     THE SPECIFIED AREAS LISTED ABOVE.

---------------------------------------------------------------------
==DISCUSSION==
A TROPICAL STORM WATCH IS IN EFFECT FOR THE ABOVE REGIONS DUE TO THE
POSSIBILITY THAT TROPICAL STORM FORCE WINDS AHEAD OF HURRICANE EARL
COULD REACH EXTREME SOUTHWESTERN NOVA SCOTIA LATE FRIDAY EVENING.
FURTHER DETAILS WILL BE PROVIDED IN THE 4.00 PM PUBLIC FORECAST WHICH
WILL COVER THE FRIDAY NIGHT FORECAST PERIOD IN GREATER DETAIL.

PLEASE REFER TO THE LATEST FORECASTS FOR FURTHER DETAILS.

END/..

Code:
HURRICANE EARL INFORMATION STATEMENT ISSUED BY THE CANADIAN
HURRICANE CENTRE OF ENVIRONMENT CANADA AT 9.04 AM ADT THURSDAY
02 SEPTEMBER 2010.

..MAJOR HURRICANE EARL MOVING TOWARDS CAPE HATTERAS..WILL AFFECT
THE MARITIMES ON SATURDAY..

THE NEXT STATEMENT WILL BE ISSUED BY 3.00 PM ADT
1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 9.00 AM ADT... HURRICANE EARL WAS LOCATED NEAR LATITUDE 30.1 N
AND LONGITUDE 74.8 W... ABOUT 310 NAUTICAL MILES OR 575 KM
SOUTH SOUTHEAST OF CAPE HATTERAS. MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 125 KNOTS... 230 KM/H... AND CENTRAL PRESSURE
AT 938 MB. EARL IS MOVING NORTH NORTHWEST AT 16 KNOTS... 30 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE     TIME     LAT    LON   MSLP  MAX WIND
         ADT                    MB  KTS  KMH
SEP 02  9.00 AM  30.1N  74.8W   928  125  230
SEP 02  9.00 PM  33.2N  74.9W   935  120  222
SEP 03  9.00 AM  36.6N  73.3W   950  110  204
SEP 03  9.00 PM  40.5N  69.8W   964   90  167
SEP 04  9.00 AM  44.9N  65.5W   974   75  139 TRANSITIONING
SEP 04  9.00 PM  49.4N  62.0W   980   65  120 TRANSITIONING
SEP 05  9.00 AM  54.2N  58.8W   981   55  102 POST-TROPICAL
SEP 05  9.00 PM  58.5N  55.5W   980   50   93 POST-TROPICAL
SEP 06  9.00 AM  62.5N  51.8W   980   40   74 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
IN COORDINATION WITH THE NHC IN MIAMI TROPICAL STORM WATCHES WERE
POSTED FOR YARMOUTH.. SHELBURNE.. AND QUEENS COUNTIES OF NOVA SCOTIA
EARLIER THIS MORNING.  IT IS LIKELY THESE WATCHES.. INCLUDING
HURRICANE WATCHES.. WILL BE EXTENDED TO OTHER REGIONS OF NOVA
SCOTIA..NEW BRUNSWICK.. AND PRINCE EDWARD ISLAND LATER TODAY.

LANDFALL OF EARL MAY OCCUR IN VICINITY OF WESTERN NOVA SCOTIA
TO THE FUNDY COAST OF NEW BRUNSWICK EARLY SATURDAY MORNING. THE
DETAILS OF THE PUBLIC IMPACTS WILL BE ASSESSED FURTHER LATER TODAY
AND TONIGHT. IT IS VERY LIKELY THAT HIGH WIND AND HEAVY RAIN WILL
AFFECT THE MARITIMES ON SATURDAY. RAINFALL AMOUNTS AND WIND SPEED
INFORMATION WILL APPEAR IN OUR NEXT BULLETIN AT 3.00 PM.

THE PUBLIC SHOULD CERTAINLY PAY CLOSE ATTENTION REGARDING WEEKEND
PLANS THAT MAY BE SENSITIVE TO HIGH WIND AND HEAVY RAIN CONDITIONS.
IT IS EMPHASIZED THAT UPDATED FORECASTS SHOULD BE CONSULTED FOR THE
LATEST FORECAST DECISIONS AND RATIONALE. THESE ARE ISSUED FOUR
TIMES DAILY.


4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY

GALE WARNINGS ARE IN EFFECT FOR BROWNS BANK AND GEORGES BANK
WITH THE APPROACH OF EARL FRIDAY EVENING. IT IS VERY LIKELY
THAT THESE GALES WILL BE EXPANDED TO OTHER MARINE AREAS
AND THAT STORM WARNINGS AND HURRICANE FORCE WIND WARNINGS WILL
BE REQUIRED FOR PORTIONS OF THE ATLANTIC CANADIAN MARINE DISTRICT.
THESE WARNINGS WOULD BE ISSUED WITH 3.00 AM FRIDAY MORNING MARINE
FORECAST.

OCEAN SWELL WILL BEGIN TO REACH THE NOVA SCOTIA COAST TODAY WELL
AHEAD OF EARL.

WITH THE ARRIVAL OF EARL HIGH WAVES AND POUNDING SURF CAN
EXPECTED ALONG THE COAST OF THE SOUTHERN MARITIMES FRIDAY NIGHT AND
SATURDAY MORNING AND ALONG THE GULF OF ST. LAWRENCE COASTLINES
SATURDAY AFTERNOON AND EVENING.

HIGH WATER LEVELS AT THE COAST COULD BE AN ISSUE IF THE ARRIVAL
OF EARL IS TIMED WITH HIGH TIDE SATURDAY MORNING. THIS TIMING
WILL BE ASSESSED FURTHER AS WE GET CLOSER TO EARL'S ARRIVAL.


5. TECHNICAL DISCUSSION FOR METEORLOGISTS

A. ANALYSIS

SATELLITE IMAGERY SHOWS EARL WITH DISTINCT EYE AND CLASSIC OUTFLOW
PATTERN.  THE MOTION CONTINUES WITH ITS NORTHWESTWARD TRACK.  IT WAS
NOTED THAT BOUY 41047 REPORTED 9.6 METRE SEAS 100 NAUTICAL MILES
DUE EAST OF EARL.

B. PROGNOSTIC

EARL IS ROUNDING THE WESTERNMOST FLANK OF THE SUBTROPICAL RIDGE
HENCE WILL GRADUALLY TAKE ON A MORE NORTHWARD MOTION THROUGH THE
DAY.  THEREAFTER IT WILL BE INCREASINGLY GUIDED BY AN UPPER TROUGH
MOVING THROUGH THE GREAT LAKES.  THIS WILL CAUSE IT TO ACCELERATE
THROUGH ATLANTIC CANADA AS IT WEAKENS.  GIVEN THE HIGH POTENTIAL
TEMPERATURES OF THE AIRMASS OVER THE MARITIMES EARL MAY CONTINUE TO
HOLD ONTO ITS TROPICAL CHARACTERISTICS WELL INTO OUR REGION.  AS
POINTED OUT IN PREVIOUS MESSAGES.. WATER TEMPERATURES SOUTH OF NOVA
SCOTIA ARE ABOVE NORMAL BY 2 TO 4 DEGREES AND HAVE BEEN PERSISTENTLY
WARM DURING THE LATTER PART OF AUGUST.  THIS FACTOR WILL PLAY INTO
OUR FORECAST OF INTENSITY AS THE STORM MOVES OVER THOSE WATERS.
ALSO EARL WILL BE MOVING INTO A PRE-EXISTING TROPICAL AIRMASS AS IS
BEING EXPERIENCED OVER EASTERN CANADA RECENTLY. THAT COULD PERMIT
EARL TO RETAIN MORE TROPICAL CHARACTERISTICS AS IT ENTERS OUR REGION.

ULTIMATELY.. THE GREAT LAKES TROUGH WILL ADVANCE THROUGH EASTERN
CANADA AND STEADILY DRAIN EARL OF ITS ENERGY AS EARL BECOMES
GRADUALLY INCORPORATED INTO THIS FEATURE.  FRICTIONAL DEGRADATION IS
ANOTHER FACTOR WHICH WILL WEAKEN EARL.

A MULTITUDE OF NUMERICAL MODELS CONTINUE TO SHOW LITTLE SIGNIFICANT
CHANGE ON EARL'S FORECAST TRACK TOWARD ATLANTIC CANADA.  AS A
RESULT.. OUR CONFIDENCE IS INCREASING THAT EARL WILL MOVE INTO
SOUTHERN NOVA SCOTIA SATURDAY MORNING.  HOWEVER.. OUR EXPERIENCE
SHOWS THAT WE MUST CAUTIOUS AT THE SAME TIME.  THOUGH OUR ENVELOPE
OF POSSIBILIIES ON EARL'S TRACK IS NARROWING.. EARL COULD END
UP AS FAR WEST AS WESTERN NEW BRUNSWICK OR AS FAR EAST AS EASTERN
MAINLAND NOVA SCOTIA.

THE OFFICIAL TRACK MAP POSTED ON OUR WEBSITES.. ALTHOUGH SPECIFIC IN
TERMS OF A LINE MARKED WITH STORM POSITIONS AT SPECIFIC TIMES AND
SHOWING EARL AS A LANDFALLING CATEGORY-ONE HURRICANE..SIMPLY
REPRESENTS THE AVERAGE OF MANY FACTORS.

PROBABILISTIC COMPUTER MODELS GENERALLY SHOW ABOUT A 90 PERCENT
CHANCE OF AT LEAST GALE-FORCE WINDS (60 TO 70 KM/H) OVER LAND IN
NOVA SCOTIA. OUR STATISTICAL GUIDANCE INDICATES ABOUT AN 90 PERCENT
CHANCE OF EARL ENTERING CANADIAN FORECAST WATERS AS A HURRICANE..AND
50 TO 60 PERCENT CHANCE OF A LAND FALLING HURRICANE IN NOVA SCOTIA
OR NEW BRUNSWICK. THERE IS ABOUT A 20 PERCENT CHANCE OF EARL BEING
AT HURRICANE STATUS AFTER CROSSING NOVA SCOTIA INTO PRINCE EDWARD
ISLAND LANDFALL TIME COULD BE AS EARLY AS OVERNIGHT FRIDAY INTO
SATURDAY MORNING..TO SOMETIME SATURDAY AFTERNOON.


C. PUBLIC WEATHER

ASYMMETRIES IN THE WIND AND RAIN FIELDS WILL DEVELOP AS THE STORM
MOVES TOWARD THE MARITIMES. HEAVIEST RAIN WILL LIKELY MOVE TOWARD
THE FRONT AND LEFT SIDE OF THE STORM AND HIGHEST WINDS CONCENTRATED
TO THE RIGHT OF THE STORM TRACK.  THIS IS IMPORTANT TO KEEP IN MIND
WHEN CONSIDERING THE TRACK FORECAST RELATIVE TO YOUR LOCATION.
HIGHEST RAINFALLS WITH STORMS LIKE THIS WILL LIKELY BE TO THE LEFT
(WEST) OF THE STORM TRACK. LATER TODAY WE WILL INTRODUCE ESTIMATES OF
WIND SPEEDS AND RAINFALL IN A TRACK-RELATIVE SENSE..THEN ESTABLISH
GEOGRAPHICALLY-SPECIFIC DETAILS GOING INTO FRIDAY. REGARDING
RAINFALL POTENTIAL..FOR A STORM OF THIS NATURE..2500 DIVIDED BY
TWICE THE STORM SPEED IN KNOTS IS A RULE OF THUMB FOR RAINFALLS
ASSOCIATED WITH THE STORM CORE.  THAT ROUGHLY EQUATES TO 40 TO 70 MM
POTENTIAL.

END FOGARTY/BORGEL/CAMPBELL
__________________
Regional Municipality of Waterloo, Ontario
All Ontario tornadoes:
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Last edited by Derecho; 09-02-2010 at 01:30 PM.
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