Tuesday, September 10, 2013

Tropical Storm Gabrielle a potential long range threat to the region

















WOCN31 CWHX 101145
TROPICAL CYCLONE INFORMATION STATEMENT ISSUED BY THE CANADIAN
HURRICANE CENTRE OF ENVIRONMENT CANADA AT 9:17 AM ADT TUESDAY
10 SEPTEMBER 2013.
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TROPICAL CYCLONE INFORMATION STATEMENT FOR:
=NEW= NEWFOUNDLAND
=NEW= NOVA SCOTIA.

      FOR TROPICAL STORM GABRIELLE.

      THE NEXT STATEMENT WILL BE ISSUED BY 3:00 PM ADT.

      TROPICAL STORM GABRIELLE REFORMS SOUTH OF BERMUDA.
      POSSIBLE IMPACTS NOVA SCOTIA AND OR NEWFOUNDLAND LATE WEEK OR
      WEEKEND.

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==DISCUSSION==
1. SUMMARY OF BASIC INFORMATION AT 9.00 AM ADT.

LOCATION: 29.9NORTH 64.9WEST ABOUT 260 KILOMETRES SOUTH OF BERMUDA.

MAXIMUM SUSTAINED WINDS: 65 KM/H.

PRESENT MOVEMENT: NORTH AT 22 KM/H.

MINIMUM CENTRAL PRESSURE: 1008 MB.

2. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY.

TROPICAL STORM GABRIELLE REFORMED SOUTH OF BERMUDA LAST NIGHT AND 
WILL MOVE TOWARD BERMUDA OVER THE NEXT 24 HOURS.  A SLOWER MOTION IS 
EXPECTED THEREAFTER WITH GRADUAL INTENSIFICATION.  THE STORM SHOULD 
THEN ACCELERATE NORTH-NORTHEASTWARD TOWARD NOVA SCOTIA OR 
NEWFOUNDLAND ON FRIDAY.  MORE INFORMATION WILL BECOME AVAILABLE IN 
OUR AFTERNOON UPDATE AFTER WE ANALYSE THE WEATHER CHARTS AND
COMPUTER MODELS.

3. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY.

MOST COMPUTER MODELS BRING GABRIELLE OR THE REMNANTS INTO CANADIAN 
WATERS FRIDAY AND SATURDAY.  WE WILL PROVIDE AN ANALYSIS OF POSSIBLE 
SCENARIOS IN OUR AFTERNOON UPDATE.

VISIT WEATHER.GC.CA/HURRICANE (ALL IN LOWER CASE) FOR THE
LATEST HURRICANE TRACK INFORMATION MAP.

PLEASE ALSO REFER TO THE PUBLIC AND MARINE FORECASTS AND WARNINGS 
ISSUED BY ENVIRONMENT CANADA FOR YOUR AREA.

END/FOGARTY

000
WTNT42 KNHC 101439
TCDAT2

TROPICAL STORM GABRIELLE DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072013
1100 AM AST TUE SEP 10 2013

THE CONVECTIVE PATTERN OF GABRIELLE CONTINUES TO FEATURE VERY COLD
CLOUD TOPS IN A CDO TYPE FEATURE. MICROWAVE AND GEOSTATIONARY
SATELLITE IMAGERY CONTINUE TO SUGGEST THAT THE LOW-LEVEL CENTER IS
LOCATED ON THE SOUTHWESTERN SIDE OF THE DEEP CONVECTION...AND THIS
STRUCTURE IS CONSISTENT WITH THE 25 KT OR SO OF SOUTHWESTERLY SHEAR
ANALYZED OVER THE SYSTEM BY UW-CIMSS. THE INITIAL INTENSITY REMAINS
35 KT IN AGREEMENT WITH THE LATEST DVORAK CLASSIFICATIONS FROM TAFB
AND SAB. AN AIR FORCE RESERVE AIRCRAFT WILL INVESTIGATE GABRIELLE
THIS AFTERNOON TO PROVIDE MORE DETAILED INFORMATION ON THE EXACT
LOCATION AND STRENGTH OF THE CYCLONE.

THE ENVIRONMENT WILL REMAIN MARGINAL FOR STRENGTHENING DURING THE
NEXT COUPLE OF DAYS...AS GABRIELLE REMAINS OVER SSTS ABOVE 27C WITH
MODERATE SOUTHWESTERLY TO WESTERLY VERTICAL SHEAR. THE NHC
INTENSITY FORECAST IS UNCHANGED FROM THE PREVIOUS ADVISORY AND IS
CLOSE TO THE CONSENSUS AIDS FOR THE FIRST 48 HOURS. LATE IN THE
PERIOD...THE GLOBAL MODELS SHOW LITTLE CHANGE IN INTENSITY DURING
AND AFTER EXTRATROPICAL TRANSITION...WHICH SHOULD BE COMPLETE BY 96
HOURS. GABRIELLE SHOULD DISSIPATE OR BE ABSORBED BY DAY 5.

THE INITIAL MOTION ESTIMATE IS 360/10...AS THE CYCLONE IS CURRENTLY
SITUATED BETWEEN A MID-LEVEL RIDGE TO THE EAST AND A MID/UPPER-
LEVEL LOW TO THE WEST. THE FORWARD MOTION OF GABRIELLE WILL SLOW AS
THE STEERING FLOW WEAKENS...AND THE CYCLONE SHOULD TURN GRADUALLY
TOWARD THE NORTHWEST BY 48 HOURS. LATER IN THE PERIOD...GABRIELLE
WILL ACCELERATE NORTHEASTWARD AHEAD OF A DEEP-LAYER TROUGH MOVING
INTO EASTERN NORTH AMERICA IN 3-4 DAYS. THE NHC FORECAST IS LARGELY
AN UPDATE OF THE PREVIOUS ONE THROUGH 48 HOURS AND THEN TRENDS A
LITTLE SLOWER AT DAYS 3 AND 4...LYING BETWEEN THE FASTER ECMWF AND
THE SLOWER TVCA MULTI-MODEL CONSENSUS.


FORECAST POSITIONS AND MAX WINDS

INIT  10/1500Z 30.6N  65.0W   35 KT  40 MPH
12H  11/0000Z 31.9N  64.9W   40 KT  45 MPH
24H  11/1200Z 33.1N  65.2W   45 KT  50 MPH
36H  12/0000Z 34.0N  65.8W   45 KT  50 MPH
48H  12/1200Z 35.2N  66.2W   45 KT  50 MPH
72H  13/1200Z 39.5N  65.0W   45 KT  50 MPH
96H  14/1200Z 49.0N  56.5W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  15/1200Z...DISSIPATED

$$
FORECASTER BRENNAN