Extratropical Isaac Advisories

[CrazyC83]

At the rate it is going yes. However, I personally think the 60kt is a stretch - I would have held it at 50 or 55 personally.

[Evil Jeremy]

only 5 more MPH strengthening? i think that this could intensify well over 75 MPH!!!!!

I'd say around 85 to 100 mph.

my forecast calls for a 90 MPH max.

[P.K.]

TROPICAL STORM ISAAC ICAO ADVISORY NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
0900 UTC SAT SEP 30 2006

TC ADVISORY
DTG: 20060930/0900Z
TCAC: KNHC
TC: ISAAC
NR: 011
PSN: N3018 W05800
MOV: WNW 06KT
C: 0995HPA
MAX WIND: 060KT
FCST PSN + 12 HR: 301800 N3054 W05900
FCST MAX WIND + 12 HR: 065KT
FCST PSN + 18 HR: 010000 N3136 W05942
FCST MAX WIND + 18 HR: 070KT
FCST PSN + 24 HR: 010600 N3218 W06024
FCST MAX WIND + 24 HR: 070KT
NXT MSG: 20060930/1500Z

[P.K.]

TROPICAL STORM ISAAC DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
500 AM AST SAT SEP 30 2006

ISAAC LOOKS MUCH MORE TROPICAL THAN IT DID 24 HR AGO...WITH
CONVECTIVE TOPS COLDER THAN -60C NOT FAR NORTHWEST OF THE CENTER AND
THE FIRST SIGNS OF A 30-35 NM WIDE EYE. THE CONVECTION IS NOT YET
WRAPPED AROUND THE CENTER ENOUGH FOR THE DVORAK SATELLITE INTENSITY
ESTIMATES TO REACH HURRICANE STRENGTH...SO ISAAC REMAINS A 60 KT
TROPICAL STORM FOR THIS ADVISORY. THE STORM CURRENTLY HAS FAIR TO
GOOD CIRRUS OUTFLOW IN THE NORTHERN SEMICIRCLE.

THE INITIAL MOTION IS 300/6. WATER VAPOR IMAGERY SHOWS A LARGE
DEEP-LAYER TROUGH OVER THE EASTERN UNITED STATES AND THE ADJACENT
WESTERN ATLANTIC...WITH AN EMBEDDED SHORTWAVE TROUGH MOVING
SOUTHEASTWARD THROUGH THE OHIO VALLEY. A MID/UPPER-LEVEL
ANTICYCLONE IS CENTERED NEAR 36N56W WITH A SHORTWAVE RIDGE
EXTENDING NORTHWARD TO NEWFOUNDLAND. THE LARGE-SCALE MODELS
FORECAST THE U. S. TROUGH TO MOVE EASTWARD AND INTENSIFY OVER THE
WESTERN ATLANTIC DURING THE NEXT THREE DAYS AS AN ASSOCIATED
SURFACE LOW FORMS. THIS SHOULD TURN ISAAC NORTHWARD BY 36 HR AND
NORTH-NORTHEASTWARD BY 72 HR IN AGREEMENT WITH THE TRACK GUIDANCE.
THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK DURING THE
FIRST 36 HR...THEN SHIFTED A LITTLE WESTWARD THEREAFTER. IT IS IN
BEST AGREEMENT WITH THE CONSENSUS MODELS. DEPENDING ON HOW ISAAC
INTERACTS WITH THE LOW...THERE IS A CHANCE IT COULD MOVE MORE
NORTHWARD AFTER 48 HR THAN CURRENTLY FORECAST.

THE LARGE-SCALE MODELS FORECAST ISAAC TO REMAIN IN A LIGHT TO
MODERATE VERTICAL SHEAR ENVIRONMENT FOR ABOUT 36 HR. THE SHIPS
MODELS FORECAST A 65 KT INTENSITY IN 36 HR...THE FSU SUPERENSEMBLE
A 70 KT INTENSITY IN 48 HR...AND THE GFDL A 90 KT INTENSITY IN 48
HR. BASED ON THIS...THE INTENSITY FORECAST IS NUDGED UPWARD A
LITTLE FROM THE PREVIOUS ADVISORY. AFTER 36-48 HR...INCREASING
SHEAR AND INTERACTION WITH DEEP-LAYER TROUGH SHOULD LEAD TO
WEAKENING AND EXTRATROPICAL TRANSITION. ONE DISAGREEMENT IN THE
MODELS IS HOW LONG ISAAC WILL MAINTAIN ITS IDENTITY. THE GFS
ABSORBS THE STORM INTO THE BAROCLINIC LOW IN ABOUT 48 HR...WHILE
THE OTHER MODELS HOLD ON TO IT FOR ABOUT 72 HR. BASED ON THIS...
THE TIME OF BEING ABSORBED INTO THE LOW WILL BE MOVED UP A DAY FROM
THE PREVIOUS ADVISORY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 30/0900Z 30.3N 58.0W 60 KT
12HR VT 30/1800Z 30.9N 59.0W 65 KT
24HR VT 01/0600Z 32.3N 60.4W 70 KT
36HR VT 01/1800Z 34.7N 61.0W 70 KT
48HR VT 02/0600Z 39.0N 60.2W 60 KT
72HR VT 03/0600Z 47.5N 54.5W 50 KT...INLAND EXTRATROPICAL
96HR VT 04/0600Z...ABSORBED BY EXTRATROPICAL LOW

$$
FORECASTER BEVEN

[Derek Ortt]

CHC now at 60KT

WOCN31 CWHX 300600
TROPICAL STORM ISAAC INFORMATION STATEMENT ISSUED BY THE
CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 3.30 AM NDT
SATURDAY 30 SEPTEMBER 2006.

THE NEXT STATEMENT WILL BE ISSUED BY 9.30 AM NDT

...TROPICAL STORM ISAAC COULD HAVE IMPACT ON WEATHER OVER
PARTS OF ATLANTIC CANADA EARLY NEXT WEEK...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 3.30 AM NDT... TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE
30.2 N AND LONGITUDE 57.8 W... ABOUT 375 NAUTICAL MILES OR 695 KM
EAST SOUTHEAST OF BERMUDA. MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 60 KNOTS...111 KM/H...AND CENTRAL PRESSURE AT 994
MB. ISAAC IS MOVING WEST NORTHWEST AT 7 KNOTS... 13 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
NDT MB KTS KMH
SEP 30 3.30 AM 30.2N 57.8W 994 60 111
SEP 30 3.30 PM 31.1N 59.1W 988 65 120
OCT 01 3.30 AM 32.5N 60.3W 987 65 120
OCT 01 3.30 PM 34.7N 61.0W 990 60 111
OCT 02 3.30 AM 39.0N 60.2W 991 55 102 BEGINNING TRANSITION
OCT 02 3.30 PM 43.5N 57.0W 992 55 102 TRANSITIONING
OCT 03 3.30 AM 47.3N 51.8W 993 55 102 POST-TROPICAL
OCT 03 3.30 PM 50.7N 46.9W 993 50 93 POST-TROPICAL
OCT 04 3.30 AM 55.6N 44.6W 994 50 93 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
IT IS MUCH TOO EARLY TO PREDICT WHAT SORT OF IMPACTS WILL OCCUR.
PARTS OF NEWFOUNDLAND MAY SEE SOME WIND AND RAIN FROM ISAAC..OR ITS
REMNANTS..ON MONDAY AND/OR TUESDAY GIVEN OUR CURRENT FORECAST TRACK.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
GALE TO STORM FORCE WINDS ARE POSSIBLE OVER THE EASTERN MARITIMES
MARINE DISTRICT AS WELL AS EASTERN NEWFOUNDLAND WATERS ON MONDAY AND
TUESDAY.

5. TECHNICAL DISCUSSION

A. ANALYSIS
PRIOR TO GOES SATELLITE ECLIPSE ISAAC APPEARED TO BE INTENSIFYING
WITH AN EYE BECOMING APPARENT. ISAAC IS OVER 26- TO 27-DEGREE WATER.
DEEP TROPOSPHERIC WIND SHEAR IN THE VICINITY OF THE STORM REMAINS
UNDER 10 KTS AND IS DECREASING OVER THE PAST 24 HRS BASED ON CIMSS
IMAGERY.

B. PROGNOSTIC
THE AFOREMENTIONED WEAKENING OF VERTICAL WIND SHEAR IS HELPING ISAAC
TO INTENSIFY. CONTINUED INTENSIFICATION IS EXPECTED TODAY WITH A
GRADUAL NORTHWESTWARD TURN IN THE FORWARD MOTION. ON SUNDAY WE
FORECAST ISAAC TO BE MOVING IN A MORE NORTHWARD DIRECTION AND
STARTING TO WEAKEN OVER SLIGHTLY COOLER WATER.

THE FORECAST THEREAFTER BECOMES VERY UNCERTAIN AS ISAAC MAY BE
INTERACTING WITH A SHORTWAVE TROUGH APPROACHING FROM THE EASTERN
UNITED STATES. MOST NUMERICAL MODELS INDICATE EXTRATROPICAL
CYCLOGENESIS EAST OF CAPE COD AND SOUTH OF NOVA SCOTIA BY THE END OF
THE WEEKEND. WE EXPECT ISAAC TO BE ON THE SOUTHEASTERN PERIPHERY OF
THAT AREA OF LOW PRESSURE BY THAT TIME. ON MONDAY IT IS EXPECTED THAT
ISAAC WILL REMAIN SEPARATE FROM THE EXTRATROPICAL LOW AND BE
ACCELERATING SWIFTLY TO THE NORTH-NORTHEAST TOWARD SOUTHEASTERN
NEWFOUNDLAND..AS INDICATED BY OUR OFFICIAL FORECAST TRACK. HOWEVER..
IT IS POSSIBLE THAT ISAAC COULD MERGE WITH THE EXTRATROPICAL LOW..SO
THERE IS A HIGH DEGREE OF UNCERTAINTY WITH THE TRACK FORECAST ON
MONDAY AND TUESDAY (2/3 OCT.)

C. PUBLIC WEATHER
SEE ABOVE.

D. MARINE WEATHER

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
30/06Z 100 110 90 90 45 50 50 45 0 0 0 0
30/18Z 100 110 90 90 45 50 50 45 30 30 0 0
01/06Z 120 120 90 90 45 50 50 45 30 30 0 0
01/18Z 120 120 60 90 40 55 50 45 0 0 0 0
02/06Z 120 120 110 90 50 40 50 50 0 0 0 0
02/18Z 150 150 140 90 90 90 60 60 0 0 0 0
03/06Z 210 240 150 100 90 90 60 60 0 0 0 0
03/18Z 240 360 150 120 90 90 60 60 0 0 0 0
04/06Z 240 400 150 120 90 90 60 60 0 0 0 0

THESE RADII REFLECT THE TRANSITION OF ISAAC IN THE LONG TERM AND
ARE ONLY INTENDED TO SHOW A CONCEPTUAL..RATHER THAN DETERMINISTIC
TREND FOR THE OVERALL WIND PATTERN.

END FOGARTY

[cycloneye]

WOCN31 CWHX 301200
TROPICAL STORM ISAAC INFORMATION STATEMENT ISSUED BY THE
CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 9.30 AM NDT
SATURDAY 30 SEPTEMBER 2006.

THE NEXT STATEMENT WILL BE ISSUED BY 3.30 PM NDT

...TROPICAL STORM ISAAC COULD HAVE IMPACT ON WEATHER OVER
PARTS OF ATLANTIC CANADA EARLY NEXT WEEK...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 9.30 AM NDT... TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE
30.6 N AND LONGITUDE 58.5 W...ABOUT 330 NAUTICAL MILES OR 615 KM
EAST SOUTHEAST OF BERMUDA. MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 60 KNOTS...111 KM/H...AND CENTRAL PRESSURE AT 993
MB. ISAAC IS MOVING WEST-NORTHWEST AT 7 KNOTS...13 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
NDT MB KTS KMH
SEP 30 9.30 AM 30.6N 58.5W 993 60 111
SEP 30 9.30 PM 31.7N 59.7W 983 70 130
OCT 01 9.30 AM 33.5N 60.8W 983 70 130
OCT 01 9.30 PM 36.6N 61.0W 987 65 120
OCT 02 9.30 AM 41.5N 58.8W 991 55 102 TRANSITIONING
OCT 02 9.30 PM 45.7N 54.8W 992 55 102 POST-TROPICAL
OCT 03 9.30 AM 48.8N 49.4W 993 55 102 POST-TROPICAL
OCT 03 9.30 PM 51.4N 43.7W 994 50 93 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
IT IS TOO EARLY TO PREDICT WHAT SORT OF IMPACTS WILL OCCUR. PARTS OF
NEWFOUNDLAND MAY SEE SOME WIND AND RAIN FROM ISAAC..OR ITS
REMNANTS..ON MONDAY AND/OR TUESDAY GIVEN OUR CURRENT FORECAST TRACK.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
GALE TO STORM FORCE WINDS ARE POSSIBLE OVER THE EASTERN MARITIMES
MARINE DISTRICT AS WELL AS EASTERN NEWFOUNDLAND WATERS ON MONDAY AND
TUESDAY.

5. TECHNICAL DISCUSSION

A. ANALYSIS
ISAAC IS LOOKING QUITE HEALTHY IN SATELLITE IMAGERY AND IS LIKELY
VERY CLOSE TO HURRICANE INTENSITY. ISAAC IS OVER 26- TO 27-DEGREE
WATER. DEEP TROPOSPHERIC WIND SHEAR IN THE VICINITY OF THE STORM
REMAINS UNDER 10 KTS AND IS DECREASING OVER THE PAST 24 HRS BASED
ON CIMSS IMAGERY.

B. PROGNOSTIC
THE AFOREMENTIONED WEAKENING OF VERTICAL WIND SHEAR IS HELPING ISAAC
TO INTENSIFY. CONTINUED INTENSIFICATION IS EXPECTED TODAY WITH A
GRADUAL NORTHWESTWARD TURN IN THE FORWARD MOTION. ON SUNDAY WE
FORECAST ISAAC TO BE MOVING IN A MORE NORTHWARD DIRECTION AND
STARTING TO WEAKEN OVER SLIGHTLY COOLER WATER.

THE FORECAST THEREAFTER BECOMES VERY UNCERTAIN AS ISAAC MAY BE
INTERACTING WITH A SHORTWAVE TROUGH APPROACHING FROM THE EASTERN
UNITED STATES. MOST NUMERICAL MODELS INDICATE EXTRATROPICAL
CYCLOGENESIS EAST OF CAPE COD AND SOUTH OF NOVA SCOTIA BY THE END OF
THE WEEKEND. WE EXPECT ISAAC TO BE ON THE SOUTHEASTERN PERIPHERY OF
THAT AREA OF LOW PRESSURE BY THAT TIME. ON MONDAY IT IS EXPECTED THAT
ISAAC WILL REMAIN SEPARATE FROM THE EXTRATROPICAL LOW AND BE
ACCELERATING SWIFTLY TO THE NORTH-NORTHEAST TOWARD SOUTHEASTERN
NEWFOUNDLAND..AS INDICATED BY OUR OFFICIAL FORECAST TRACK. HOWEVER..
THERE IS A SMALL POSSIBILITY THAT ISAAC COULD MERGE WITH THE
EXTRATROPICAL LOW..SO THERE IS SOME UNCERTAINTY WITH THE TRACK
FORECAST ON MONDAY AND TUESDAY (2/3 OCT.)

C. PUBLIC WEATHER
SEE ABOVE.

D. MARINE WEATHER

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
30/12Z 100 110 90 90 45 50 50 45 0 0 0 0
01/00Z 100 110 90 90 45 50 50 45 30 30 0 0
01/12Z 100 110 90 90 45 50 50 45 30 30 0 0
02/00Z 120 120 90 90 50 60 50 50 30 30 0 0
02/12Z 120 150 130 90 60 40 50 50 0 0 0 0
03/00Z 180 190 150 90 90 90 60 60 0 0 0 0
03/12Z 240 330 150 120 90 90 60 60 0 0 0 0
04/00Z 240 400 150 120 90 90 60 60 0 0 0 0

THESE RADII REFLECT THE TRANSITION OF ISAAC IN THE LONG TERM AND
ARE ONLY INTENDED TO SHOW A CONCEPTUAL..RATHER THAN DETERMINISTIC
TREND FOR THE OVERALL WIND PATTERN LATER IN THE FORECAST PERIOD.

END FOGARTY/CAMPBELL

[cycloneye]

BULLETIN
HURRICANE ISAAC ADVISORY NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
1100 AM AST SAT SEP 30 2006

...ISAAC BECOMES THE FIFTH HURRICANE OF THE 2006 SEASON...

INTERESTS IN NOVA SCOTIA AND NEWFOUNDLAND CANADA SHOULD MONITOR THE
PROGRESS OF ISAAC.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 1100 AM AST...1500Z...THE EYE OF HURRICANE ISAAC WAS LOCATED
BY SATELLITE IMAGERY NEAR LATITUDE 30.9 NORTH...LONGITUDE 58.7 WEST
OR ABOUT 370 MILES... 600 KM...EAST-SOUTHEAST OF BERMUDA.

ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 7 MPH...11 KM/HR...AND
THIS GENERAL MOTION IS FORECAST TO CONTINUE WITH A GRADUAL TURN
TOWARD THE NORTH-NORTHWEST EXPECTED BY SUNDAY. ON THE FORECAST
TRACK... ISAAC SHOULD PASS WELL TO THE EAST OF BERMUDA.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 75 MPH...120
KM/HR...WITH HIGHER GUSTS. ISAAC IS A CATEGORY ONE HURRICANE ON
THE SAFFIR-SIMPSON SCALE. SOME FURTHER STRENGTHENING IS FORECAST
DURING THE NEXT 24 HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 40 MILES...65 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 125
MILES...205 KM.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB...29.29 INCHES.

REPEATING THE 1100 AM AST POSITION...30.9 N...58.7 W. MOVEMENT
TOWARD...NORTHWEST NEAR 7 MPH. MAXIMUM SUSTAINED WINDS...75 MPH.
MINIMUM CENTRAL PRESSURE...992 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 PM AST.

$$
FORECASTER BLAKE/STEWART

646
WTNT44 KNHC 301457
TCDAT4
HURRICANE ISAAC DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
1100 AM EDT SAT SEP 30 2006

SATELLITE IMAGES INDICATE THAT ISAAC FORMED A RAGGED EYE SHORTLY
AFTER THE PREVIOUS ADVISORY. A HIGH RESOLUTION QUIKSCAT PASS NEAR
1000 UTC SHOWED ONE BELIEVABLE WIND SPEED OF 63 KT. HOWEVER THE
SATELLITE PRESENTATION HAS IMPROVED SOMEWHAT IN ORGANIZATION SINCE
THAT TIME. AFTER BECOMING OBSCURED A FEW HOURS AGO... THE EYE HAS
BECOME A LITTLE BETTER-DEFINED IN VISIBLE IMAGERY. IN ADDITION...
A SATELLITE ESTIMATE FROM TAFB IS AT T4.0... 65 KT... WHILE
CIMSS/CIRA AMSU ESTIMATES ARE BOTH ANALYZING ISAAC WITH 64 KT
WINDS. THEREFORE ISAAC IS UPGRADED TO A HURRICANE WITH 65 KT
WINDS... THE FIFTH HURRICANE OF THE SEASON. THE ENVIRONMENT LOOKS
CONDUCIVE FOR A LITTLE STRENGTHENING AS ISAAC REMAINS IN A
RELATIVELY LIGHT SHEAR AREA AND OVER SUFFICIENTLY WARM WATER
TEMPERATURES. HOWEVER... SOUTHWESTERLY SHEAR SHOULD BEGIN TOMORROW
DUE TO AN APPROACHING UPPER TROUGH AND LIMIT ANY FURTHER
INTENSIFICATION. THE INTENSITY FORECAST IS A BLEND OF THE FSU
SUPERENSEMBLE... GFDL AND THE PREVIOUS FORECAST. ISAAC IS EXPECTED
TO REMAIN A STRONG EXTRATROPICAL LOW BEFORE ITS EVENTUAL ABSORPTION
BY A LARGER LOW.

THE INITIAL MOTION ESTIMATE IS 300/6. A GRADUAL RIGHTWARD TURN
SHOULD OCCUR DURING THE NEXT 24 HOURS AS ISAAC ROUNDS THE WESTERN
PORTION OF THE SUBTROPICAL RIDGE. THEREAFTER THE CYCLONE SHOULD BE
ACCELERATING NORTHWARD AHEAD OF A DEEP MIDDLE-LATITUDE TROUGH OVER
THE WESTERN ATLANTIC OCEAN. MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT AND THE OFFICIAL FORECAST IS BASICALLY AN UPDATE OF THE
PREVIOUS ONE. ISAAC SHOULD ENCOUNTER A MORE BAROCLINIC ENVIRONMENT
IN 36-48 HOURS... WHICH IS EXPECTED TO CAUSE IT TO TRANSITION INTO
AN EXTRATROPICAL CYCLONE BY 3 DAYS. GLOBAL MODELS ARE FORECASTING
THE REMNANTS OF ISAAC TO BE ABSORBED BY A LARGER EXTRATROPICAL LOW
NEAR THE 96 HOUR TIME FRAME.

FORECAST POSITIONS AND MAX WINDS

INITIAL 30/1500Z 30.9N 58.7W 65 KT
12HR VT 01/0000Z 31.6N 59.6W 70 KT
24HR VT 01/1200Z 33.4N 60.5W 75 KT
36HR VT 02/0000Z 36.8N 60.5W 70 KT
48HR VT 02/1200Z 41.5N 59.0W 60 KT...EXTRATROPICAL
72HR VT 03/1200Z 50.0N 50.0W 50 KT...EXTRATROPICAL
96HR VT 04/1200Z...ABSORBED

$$
FORECASTER BLAKE/STEWART

[Derek Ortt]

Now a cane per CHC


WOCN31 CWHX 301800
HURRICANE ISAAC INFORMATION STATEMENT ISSUED BY THE CANADIAN
HURRICANE CENTRE OF ENVIRONMENT CANADA AT 3.30 PM NDT SATURDAY
30 SEPTEMBER 2006.

THE NEXT STATEMENT WILL BE ISSUED BY 9.30 PM NDT

...ISSAC IS NOW THE FIFTH HURRICANE OF THE SEASON...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 3.30 PM NDT... HURRICANE ISAAC WAS LOCATED NEAR LATITUDE
31.2 N AND LONGITUDE 59.1 W... ABOUT 290 NAUTICAL MILES OR 540 KM
EAST SOUTHEAST OF BERMUDA. MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 65 KNOTS... 120 KM/H... AND CENTRAL PRESSURE AT 988
MB. ISAAC IS MOVING NORTHWEST AT 6 KNOTS... 11 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
NDT MB KTS KMH
SEP 30 3.30 PM 31.2N 59.1W 988 65 120
OCT 01 3.30 AM 32.5N 60.2W 983 70 130
OCT 01 3.30 PM 34.6N 61.0W 983 70 130
OCT 02 3.30 AM 39.0N 59.6W 989 65 120
OCT 02 3.30 PM 43.5N 57.0W 992 55 102 TRANSITIONING
OCT 03 3.30 AM 47.4N 52.2W 993 55 102 POST-TROPICAL
OCT 03 3.30 PM 50.2N 46.7W 993 50 93 POST-TROPICAL
OCT 04 3.30 AM 52.4N 40.4W 994 50 93 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
IT IS STILL TOO EARLY TO PREDICT WHAT SORT OF WEATHER IMPACTS
WILL OCCUR. PARTS OF NEWFOUNDLAND WILL LIKELY SEE SOME WIND AND RAIN
FROM ISAAC..OR ITS REMNANTS..ON MONDAY AND/OR TUESDAY GIVEN
OUR CURRENT FORECAST TRACK.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
GALE TO STORM FORCE WINDS ARE LIKELY OVER THE EASTERN MARITIMES
MARINE DISTRICT AS WELL AS EASTERN NEWFOUNDLAND WATERS ON MONDAY AND
TUESDAY.

5. TECHNICAL DISCUSSION

A. ANALYSIS
ISSAC IS NOW A HURRICANE AS INFERRED FROM SATELLITE DATA AT THE
NHC IN MIAMI. ISSAC IS OVER SST OF 26 OR 27 C. AS WELL..
ISSAC IS IN A ENVIRONMENT OF MINIMAL WIND SHEAR SO IT WILL MAINTAIN
ITS HURRICANE STATUS IN THE NEAR TERM.

B. PROGNOSTIC
THERE IS LITTLE CHANGE FROM PREVIOUS TRACK. ISSAC IS MOVING IN A
NORTHERLY DIRECTION AROUND THE FLANK OF AN UPPER RIDGE. WITH APPROACH
OF UPPER TROUGH FROM THE WEST..ISSAC WILL BEGIN A TURN TOWARD
THE NORTHEAST SUNDAY EVENING AS IT ENCOUNTERS INCREASING
SOUTHWESTERLY SHEAR. AFTER 02/06Z ISSAC WILL ENTER
COLDER WATER AND IT WILL MARKEDLY WEAKEN. THE MAIN FORECAST PROBLEM
WILL BE THE AMOUNT OF INTERACTION ISSAC WILL HAVE WITH AN
EXTRATROPICAL SYSTEM FORECAST TO MOVE INTO THE MARITIMES ON MONDAY.
SO FAR..DYNAMIC MODELS ARE EITHER KEEPING ISSAC A SEPERATE ENTITY
AS IT MOVES OVER NEWFOUNDLAND OR MERGING THE TWO. I HAVE THE FEELING
THAT ISSAC WILL REMAIN A DISTINCT ENTITY AS INDICATED BY OUR
FORECAST TRACK.

C. PUBLIC WEATHER
AMOUNT OF WIND AND RAIN FOR NEWFOUNLAND WILL DEPEND ON THE
INTERACTION BETWEEN ISSAC AND THE EXTRATROPICAL LOW.

D. MARINE WEATHER

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
30/18Z 110 100 45 90 60 45 30 50 35 30 0 30
01/06Z 120 100 60 90 60 45 40 50 45 40 30 40
01/18Z 120 120 60 90 60 45 40 50 45 40 30 40
02/06Z 120 120 75 90 70 60 50 50 0 0 0 0
02/18Z 150 150 100 90 90 90 60 60 0 0 0 0
03/06Z 210 240 150 100 90 90 60 60 0 0 0 0
03/18Z 240 360 150 120 90 90 60 60 0 0 0 0
04/06Z 240 440 150 120 90 90 90 60 0 0 0 0

END CAMPBELL

[dwsqos2]

000
WTNT34 KNHC 302032
TCPAT4
BULLETIN
HURRICANE ISAAC ADVISORY NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
500 PM AST SAT SEP 30 2006

...ISAAC STRENGTHENS BUT IS NO IMMEDIATE THREAT TO LAND...

INTERESTS IN NOVA SCOTIA AND NEWFOUNDLAND CANADA SHOULD MONITOR THE
PROGRESS OF ISAAC.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 500 PM AST...2100Z...THE CENTER OF HURRICANE ISAAC WAS LOCATED
NEAR LATITUDE 31.6 NORTH...LONGITUDE 59.5 WEST OR ABOUT 315 MILES...
505 KM...EAST OF BERMUDA.

ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 10 MPH...17 KM/HR...AND
A TURN TOWARD THE NORTH-NORTHWEST IS EXPECTED LATER TONIGHT OR EARLY
SUNDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH...130 KM/HR...WITH HIGHER
GUSTS. ISAAC IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. SOME INCREASE IN STRENGTH IS FORECAST DURING THE NEXT 24
HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 40 MILES...65 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 125
MILES...205 KM.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB...29.21 INCHES.

REPEATING THE 500 PM AST POSITION...31.6 N...59.5 W. MOVEMENT
TOWARD...NORTHWEST NEAR 10 MPH. MAXIMUM SUSTAINED WINDS...80 MPH.
MINIMUM CENTRAL PRESSURE...989 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.

$$
FORECASTER BLAKE/STEWART







WTNT44 KNHC 302032
TCDAT4
HURRICANE ISAAC DISCUSSION NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
500 PM EDT SAT SEP 30 2006

CONVECTION HAS CONTINUED TO INCREASE IN THE EYEWALL OF ISSAC THIS
AFTERNOON. IN ADDITION THE EYE HAS BECOME A LITTLE BETTER-DEFINED
WITH AN EXPANDING OUTFLOW PATTERN IN ALL QUADRANTS EXCEPT TO THE
SOUTHWEST. DVORAK T-NUMBERS FROM SAB/AFWA ARE INCREASING...
AND THE LOCAL 3 HOUR OBJECTIVE T-NUMBERS ARE NEAR T4.2... EQUATING
TO 70 KT. THE INITIAL INTENSITY WILL BE SET AT 70 KT FOR THIS
ADVISORY IN AGREEMENT WITH THE ABOVE ESTIMATES. ISAAC STILL HAS A
LITTLE MORE TIME TO INTENSIFY BEFORE SOUTHWESTERLY SHEAR ASSOCIATED
WITH AN UPPER TROUGH IMPACTS THE HURRICANE. STEADY WEAKENING
SHOULD BEGIN BY LATE TOMORROW AS THE SHEAR BECOMES STRONG AND
WATERS COOL BELOW 26C. THE OFFICIAL FORECAST IS SIMILAR TO THE
PREVIOUS ONE AND IS CLOSE TO ICON... THE INTENSITY CONSENSUS OF
GFDL AND SHIPS. GFDL CONTINUES TO INSIST ON STRENGTHENING AFTER
RECURVATURE BUT THIS MAY BE OVERDONE DUE TO VERY STRONG SHEAR
FORECAST TO OCCUR BY ALL GLOBAL MODELS. THESE GLOBAL MODELS ALSO
EXPECT ISAAC TO BE A POWERFUL EXTRATROPICAL LOW UNTIL IT IS
EVENTUALLY ABSORBED BY A LARGER MIDDLE-LATITUDE CYCLONE.

THE CYCLONE HAS SPED UP AND IS NOW MOVING ABOUT 310/9... THOUGH A
SHORTER-TERM MOTION IS FASTER. THE FORECAST PHILOSOPHY IS THE SAME
AS BEFORE. ISAAC IS EXPECTED TO MOVE IN BETWEEN A RIDGE TO THE EAST
OVER THE CENTRAL ATLANTIC AND A LARGE TROUGH OVER THE WESTERN
ATLANTIC. AT THIS POINT THE BIGGEST QUESTION IS HOW CLOSE WILL
EXTRATROPICAL ISAAC GET TO NEWFOUNDLAND. THE ECMWF...GFS AND GFS
ENSEMBLE MEAN MODELS WHIP EXTRATROPICAL ISAAC AROUND A LARGER
EXTRATROPICAL LOW AND ARE... CONSEQUENTLY... FARTHER TO THE LEFT
THAN THE OTHER MODELS... WHICH KEEP ISAAC MORE SEPARATE FROM THE
LOW. GLOBAL MODELS DO AGREE THAT ITS REMNANTS WILL FORM A POWERFUL
STORM OVER THE NORTH ATLANTIC AND MIGHT BE SIMILAR TO THE STRENGTH
OF EXTRATROPICAL FLORENCE A FEW WEEKS AGO. THE OFFICIAL FORECAST IS
CLOSE TO THE PREVIOUS FORECAST TRACK WITH THE MODELS NOW HONED IN ON
RECURVATURE ALONG ABOUT 61W... AND SHOWS SOME THREAT TO
NEWFOUNDLAND IN ABOUT 2-3 DAYS AS A STRONG EXTRATROPICAL SYSTEM.

FORECAST POSITIONS AND MAX WINDS

INITIAL 30/2100Z 31.6N 59.5W 70 KT
12HR VT 01/0600Z 32.6N 60.3W 75 KT
24HR VT 01/1800Z 35.0N 60.8W 75 KT
36HR VT 02/0600Z 39.0N 60.0W 70 KT...BECOMING EXTRATROPICAL
48HR VT 02/1800Z 44.0N 56.8W 60 KT...EXTRATROPICAL
72HR VT 03/1800Z 52.0N 46.0W 45 KT...EXTRATROPICAL
96HR VT 04/1800Z...ABSORBED

$$
FORECASTER BLAKE/STEWART

[Thunder44]

000
WTNT34 KNHC 010254
TCPAT4
BULLETIN
HURRICANE ISAAC ADVISORY NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
1100 PM AST SAT SEP 30 2006

...ISAAC TURNING A LITTLE MORE TOWARD THE NORTH...

INTERESTS IN NOVA SCOTIA AND NEWFOUNDLAND CANADA SHOULD CLOSELY
MONITOR THE PROGRESS OF ISAAC.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 1100 PM AST...0300Z...THE CENTER OF HURRICANE ISAAC WAS LOCATED
NEAR LATITUDE 32.5 NORTH...LONGITUDE 59.9 WEST OR ABOUT 285 MILES...
460 KM...EAST OF BERMUDA.

ISAAC IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 10 MPH...17 KM/HR...
AND A GRADUAL TURN TOWARD THE NORTH IS EXPECTED DURING THE NEXT 24
HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH...130 KM/HR...WITH HIGHER
GUSTS. ISAAC IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 24
HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 15 MILES...30 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 105
MILES...165 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB...29.21 INCHES.

REPEATING THE 1100 PM AST POSITION...32.5 N...59.9 W. MOVEMENT
TOWARD...NORTH-NORTHWEST NEAR 10 MPH. MAXIMUM SUSTAINED WINDS...80
MPH. MINIMUM CENTRAL PRESSURE...989 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 AM AST.

$$
FORECASTER RHOME/KNABB


000
WTNT44 KNHC 010257
TCDAT4
HURRICANE ISAAC DISCUSSION NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
1100 PM EDT SAT SEP 30 2006

LATEST GOES IMAGERY SHOWS THAT THE EYE OF ISAAC HAS INTERMITTENTLY
APPEARING AND DISAPPEARING THROUGHOUT THE EVENING. GIVEN A LACK OF
SIGNIFICANT CHANGE IN THE SATELLITE PRESENTATION...THE INITIAL
INTENSITY IS HELD AT 70 KT FOR THIS ADVISORY...BASED ON A BLEND OF
DVORAK INTENSITY ESTIMATES BETWEEN 65 AND 77 KT. THE INTENSITY
FORECAST CONTINUES TO BE PROBLEMATIC GIVEN OFFSETTING FACTORS IN
THE SHORT-TERM...AND A COMPLEX INTERACTION WITH A MID-LATITUDE
TROUGH THEREAFTER. ISAAC HAS ABOUT 12-24 HOURS OVER WATERS OF AT
LEAST 26C. HOWEVER...WATER VAPOR IMAGERY SHOWS THAT ISAAC IS
EXPERIENCING INCREASING SOUTHERLY SHEAR. BEYOND 24 HOURS...THE
HURRICANE WILL BEGIN TO INTERACT WITH A LARGE MID-LATITUDE TROUGH
MOVING OFF THE EAST COAST OF THE UNITED STATES. THE GLOBAL MODELS
DISAGREE ON WHETHER ISAAC WILL BE ABLE TO UTILIZE THE AVAILABLE
BAROCLINIC ENERGY TO STRENGTHEN DURING EXTRATROPICAL TRANSITION...
OR INSTEAD BE ABSORBED BY A MORE DOMINANT EXTRATROPICAL LOW WHICH
COULD FORM TO ITS WEST. SHOULD ISAAC MERGE WITH A SECOND LOW...IT
WOULD PROBABLY PRODUCE A BROADER AND WEAKER PRESSURE GRADIENT.
CONVERSELY...IF ISAAC REMAINS THE DOMINANT SYSTEM...IT COULD
RE-INTENSIFY AS AN EXTRATROPICAL CYCLONE...IN A SIMILAR MANNER TO
HELENE. THE OFFICIAL FORECAST ESSENTIALLY SPLITS THE DIFFERENCE
BETWEEN THESE TWO SCENARIOS BY SHOWING SLOW WEAKENING THROUGH THE
FIRST 48 HOURS. THE NEW OFFICIAL FORECAST NOW SHOWS SLIGHT
WEAKENING IN THE SHORT-TERM AND LITTLE CHANGE DURING EXTRATROPICAL
TRANSITION.

ISAAC IS MOVING JUST A LITTLE TO THE RIGHT...OR EAST...OF THE
PREVIOUS ADVISORY WITH AN INITIAL MOTION ESTIMATE OF 330/09.
GLOBAL MODELS REMAIN IN GENERAL AGREEMENT ON A GRADUAL NORTHWARD
TURN THROUGH 24 HOURS...FOLLOWED BY ACCELERATION TO THE NORTHEAST
AS THE CYCLONE GETS CAUGHT UP IN SOUTHWESTERLY FLOW AHEAD OF THE
MID-LATITUDE TROUGH. THE ECMWF...GFS...AND GFS ENSEMBLE MEAN
ARE ALONG THE LEFT SIDE OF THE MODEL SUITE AND SHOW THE CYCLONE
MOVING OVER OR NEAR NEWFOUNDLAND. CONVERSELY...THE GFDL AND GFDN ARE
MUCH FARTHER EAST. REMAINING IN BETWEEN THOSE EXTREMES AND CLOSE TO
THE MODEL CONSENSUS...THE OFFICIAL FORECAST IS NUDGED A LITTLE TO
THE RIGHT DURING THE FIRST 36 HOURS...AND IS ESSENTIALLY AN UPDATE
OF THE PREVIOUS FORECAST THEREAFTER.

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/0300Z 32.5N 59.9W 70 KT
12HR VT 01/1200Z 34.0N 60.5W 70 KT
24HR VT 02/0000Z 37.2N 60.2W 65 KT
36HR VT 02/1200Z 42.0N 57.9W 60 KT...BECOMING EXTRATROPICAL
48HR VT 03/0000Z 46.8N 53.5W 60 KT...EXTRATROPICAL
72HR VT 04/0000Z 53.0N 43.0W 50 KT...EXTRATROPICAL
96HR VT 05/0000Z 56.0N 30.0W 45 KT...EXTRATROPICAL
120HR VT 06/0000Z...ABSORBED

$$
FORECASTER RHOME/KNABB

[Derek Ortt]

WWCN31 CWHX 010740
SEVERE WEATHER BULLETIN
ISSUED BY THE CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA
AT 4:40 AM ADT SUNDAY 1 OCTOBER 2006.
---------------------------------------------------------------------
TROPICAL STORM WATCH FOR:
=NEW= ST. JOHN'S AND VICINITY
=NEW= AVALON PENINSULA NORTH
=NEW= AVALON PENINSULA SOUTH.

TROPICAL STORM-FORCE WINDS NEAR 65 KM/H ARE POSSIBLE OVER THE
ABOVE REGIONS MONDAY AS THE REMNANTS OF HURRICANE ISAAC
APPROACH NEWFOUNDLAND.

---------------------------------------------------------------------
==DISCUSSION==
HURRICANE ISAAC IS FORECAST TO APPROACH SOUTHEASTERN NEWFOUNDLAND ON
MONDAY POTENTIALLY BRINGING HIGH WINDS AND HEAVY RAINFALL.
THERE REMAINS SOME UNCERTAINTY WHETHER THE CENTRE OF THE STORM WILL
TRACK OVER THE AVALON PENINSULA OR SOUTH OF IT. IF IT APPEARS THAT
THE STORM WILL TRACK OVER OR VERY CLOSE TO THE AVALON..THIS WATCH MAY
BE UPGRADED TO A WARNING.

A TROPICAL STORM WATCH MEANS THAT SUSTAINED TROPICAL STORM-FORCE
WINDS OF 65 KM/H ARE POSSIBLE WITHIN APPROXIMATELY 36 HOURS.

PLEASE REFER TO THE LATEST FORECASTS FOR FURTHER DETAILS.

END/FOGARTY


TS watch for Newfoundland

[Thunder44]

000
WTNT34 KNHC 010857
TCPAT4
BULLETIN
HURRICANE ISAAC ADVISORY NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
500 AM AST SUN OCT 01 2006

...ISAAC STRENGTHENS SLIGHTLY WELL EAST OF BERMUDA...
...TROPICAL STORM WATCH ISSUED FOR SOUTHEASTERN NEWFOUNDLAND...

AT 340 AM AST...0740 UTC...THE CANADIAN METEOROLOGICAL SERVICE
ISSUED A TROPICAL STORM WATCH FOR THE ENTIRE AVALON PENINSULA OF
NEWFOUNDLAND...WHICH INCLUDES THE CITIES OF CAPE RACE AND ST.
JOHNS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 500 AM AST...0900Z...THE CENTER OF HURRICANE ISAAC WAS LOCATED
NEAR LATITUDE 33.1 NORTH...LONGITUDE 60.1 WEST OR ABOUT 280 MILES...
450 KM...EAST-NORTHEAST OF BERMUDA.

ISAAC IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 9 MPH...15 KM/HR.
A TURN TO THE NORTH WITH A GRADUAL INCREASE IN FORWARD SPEED IS
EXPECTED DURING THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 85 MPH...140 KM/HR...WITH HIGHER
GUSTS. ISAAC IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. LITTLE CHANGE IN STRENGTH IS EXPECTED DURING THE NEXT 24
HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 25 MILES...35 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115
MILES...185 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 985 MB...29.09 INCHES.

REPEATING THE 500 AM AST POSITION...33.1 N...60.1 W. MOVEMENT
TOWARD...NORTH-NORTHWEST NEAR 9 MPH. MAXIMUM SUSTAINED WINDS...85
MPH. MINIMUM CENTRAL PRESSURE...985 MB.

AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE
CENTER AT 800 AM AST FOLLOWED BY THE NEXT COMPLETE ADVISORY AT 1100
AM AST.

$$
FORECASTER LANDSEA/STEWART


000
WTNT44 KNHC 010851
TCDAT4
HURRICANE ISAAC DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
500 AM EDT SUN OCT 01 2006

METEOSAT IMAGERY DURING THE GOES ECLIPSE SHOWED THAT THE RAGGED EYE
OF ISAAC CONTINUED TO BE PRESENT OVERNIGHT. DVORAK INTENSITY
ESTIMATES ARE BOTH T4.5...77 KT...FROM TAFB AND SAB...WHICH IS
CONSISTENT WITH EARLIER AMSU INTENSITY VALUES AS WELL. A
WELL-DEFINED EYE WAS ALSO OBSERVED AT 0013 UTC IN SSMIS MICROWAVE
IMAGERY. THEREFORE...THE INTENSITY IS ANALYZED TO BE 75 KT.

CURRENT MOTION OF ISAAC IS 335/8...A BIT TO THE RIGHT OF SIX HOURS
EARLIER. THE HURRICANE IS SITUATED BETWEEN THE SOUTHWESTERN FLANK
OF A RATHER SMALL DEEP LAYERED SUBTROPICAL RIDGE AND A VERY LARGE
TROUGH ALONG THE UNITED STATES ATLANTIC SEABOARD. ISAAC IS LIKELY
TO MAKE THE TURN TO THE NORTH IN THE NEXT 12 HOURS AND WILL BE
ACCELERATING UNDER THE INFLUENCE OF STRONG SOUTWESTERLIES. ALL
RELIABLE GUIDANCE ARE TIGHTLY CLUSTERED THROUGH 72 HOURS WITH THIS
RECURVING SCENARIO. THE FORECAST TRACK IS CLOSE TO THE MODEL
CONSENSUS AND THE PREVIOUS ADVISORY THROUGH 48 HOURS. AT 72 HOURS
THE TRACK IS SOMEWHAT SLOWER THE THE LAST FORECAST.

ISAAC LIKELY IS NEAR PEAK INTENSITY...AS INCREASING VERTICAL SHEAR
SHOULD SOON BE IMPINGING ON THE CYCLONE. ADDITIONALLY...IT SHOULD
ENCOUNTER VERY COLD SSTS BEGINNING IN 24-36 HOURS AS IT MOVES NORTH
OF THE GULF STREAM. ALL GLOBAL MODELS SUGGEST A QUICK
TRANSFORMATION TO AN EXTRATROPICAL CYCLONE MAY OCCUR IN ABOUT 24-36
HOURS AS ISAAC INTERACTS WITH A STRONG BAROCLINIC ZONE. ONLY THE
GFDL HURRICANE MODEL RETAINS ISAAC AS A TROPICAL CYCLONE FOR MORE
THAN 36 HOURS. ALSO THE GLOBAL MODELS HAVE BACKED OFF SOMEWHAT AS
TO THE INTENSITY OF THE EXTRATROPICALLY-TRANSITIONED ISAAC AT DAYS
4 AND 5. AFTER ABOUT THREE DAYS...HOWEVER...IT IS DIFFICULT TO
DISTINGUISH ISAAC'S VORTEX FROM A LARGER EXTRATROPICAL STORM. THE
INTENSITY FORECAST IS FOR GRADUAL WEAKENING DURING THE NEXT 24
HOURS...THEN SOMEWHAT QUICKER WEAKENING AFTERWARD AS AN
EXTRATROPICAL CYCLONE. THIS PREDICTION IS SIMILAR TO THE PREVIOUS
ADVISORY AND IS A BLEND OF THE SHIPS...GFDL...AND GLOBAL MODELS.

DUE TO THE UNCERTAINTY IN THE EXTRATROPICAL TRANSITION TIMING...THE
CANADIAN WEATHER SERVICE HAS ISSUED A TROPICAL STORM WATCH FOR THE
AVALON PENINSULA.

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/0900Z 33.1N 60.1W 75 KT
12HR VT 01/1800Z 35.5N 60.4W 75 KT
24HR VT 02/0600Z 39.8N 58.9W 65 KT
36HR VT 02/1800Z 44.6N 55.4W 55 KT...EXTRATROPICAL
48HR VT 03/0600Z 48.5N 50.9W 50 KT...EXTRATROPICAL
72HR VT 04/0600Z 52.5N 42.0W 45 KT...EXTRATROPICAL

$$
FORECASTER LANDSEA/STEWART

[cycloneye]

235
WTNT34 KNHC 011151
TCPAT4
BULLETIN
HURRICANE ISAAC INTERMEDIATE ADVISORY NUMBER 15A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
800 AM AST SUN OCT 01 2006

...ISAAC CONTINUES NORTH-NORTHWESTWARD...

A TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE AVALON PENINSULA
OF NEWFOUNDLAND...WHICH INCLUDES THE CITIES OF CAPE RACE AND ST.
JOHNS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 800 AM AST...1200Z...THE CENTER OF HURRICANE ISAAC WAS LOCATED
NEAR LATITUDE 33.6 NORTH...LONGITUDE 60.2 WEST OR ABOUT 275 MILES...
440 KM...EAST-NORTHEAST OF BERMUDA.

ISAAC IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 9 MPH...15 KM/HR.
A TURN TO THE NORTH WITH A GRADUAL INCREASE IN FORWARD SPEED IS
EXPECTED DURING THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH...140 KM/HR...WITH HIGHER
GUSTS. ISAAC IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. SOME WEAKENING IS EXPECTED DURING THE NEXT 24 HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 25 MILES...35 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115
MILES...185 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 985 MB...29.09 INCHES.

REPEATING THE 800 AM AST POSITION...33.6 N...60.2 W. MOVEMENT
TOWARD...NORTH-NORTHWEST NEAR 9 MPH. MAXIMUM SUSTAINED WINDS...80
MPH. MINIMUM CENTRAL PRESSURE...985 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 AM AST.

$$
FORECASTER BROWN/FRANKLIN

[cycloneye]

238
WTNT34 KNHC 012358
TCPAT4
BULLETIN
HURRICANE ISAAC INTERMEDIATE ADVISORY NUMBER 17A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
800 PM AST SUN OCT 01 2006

...ISAAC ACCELERATING TOWARD THE NORTH-NORTHEAST...

A TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE AVALON PENINSULA
OF NEWFOUNDLAND...WHICH INCLUDES THE CITIES OF CAPE RACE AND ST.
JOHNS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 800 PM AST...0000Z...THE CENTER OF HURRICANE ISAAC WAS LOCATED
NEAR LATITUDE 37.3 NORTH...LONGITUDE 59.6 WEST OR ABOUT 715 MILES...
1150 KM...SOUTH-SOUTHWEST OF CAPE RACE NEWFOUNDLAND.

ISAAC IS MOVING TOWARD THE NORTH-NORTHEAST NEAR 23 MPH...37 KM/HR.
AN INCREASE IN FORWARD SPEED IS EXPECTED DURING THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH...130 KM/HR...WITH HIGHER
GUSTS. ISAAC IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. ONLY SLIGHT WEAKENING IS FORECAST DURING THE NEXT 24 HOURS.
ISAAC IS EXPECTED TO BECOME EXTRATROPICAL AS IT NEARS NEWFOUNDLAND.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 25 MILES...35 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 145
MILES...230 KM...MAINLY TO THE EAST OF THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 985 MB...29.09 INCHES.

REPEATING THE 800 PM AST POSITION...37.3 N...59.6 W. MOVEMENT
TOWARD...NORTH-NORTHEAST NEAR 23 MPH. MAXIMUM SUSTAINED WINDS...80
MPH. MINIMUM CENTRAL PRESSURE...985 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.

$$
FORECASTER RHOME/KNABB

[P.K.]

WOCN31 CWHX 020600
HURRICANE ISAAC INFORMATION STATEMENT ISSUED BY THE CANADIAN
HURRICANE CENTRE OF ENVIRONMENT CANADA AT 3.30 AM NDT MONDAY
02 OCTOBER 2006.

THE NEXT STATEMENT WILL BE ISSUED BY 9.30 AM NDT

...HURRICANE ISAAC ACCELERATING TOWARD THE NORTHEAST..RAIN AND
WIND TODAY OVER NEWFOUNDLAND...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 3.30 AM NDT...HURRICANE ISAAC WAS LOCATED NEAR LATITUDE
39.8 N AND LONGITUDE 58.8 W... ABOUT 250 NAUTICAL MILES OR 470 KM
SOUTH SOUTHEAST OF SABLE ISLAND. MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 65 KNOTS...120 KM/H...AND CENTRAL PRESSURE AT 988
MB. ISAAC IS MOVING NORTH NORTHEAST AT 25 KNOTS...46 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
NDT MB KTS KMH
OCT 02 3.30 AM 39.8N 58.8W 988 65 120
OCT 02 9.30 AM 42.5N 57.4W 988 65 120 TRANSITIONING
OCT 02 3.30 PM 44.8N 55.4W 990 60 111 TRANSITIONING
OCT 02 9.30 PM 46.8N 53.0W 990 60 111 POST-TROPICAL
OCT 03 3.30 AM 48.8N 50.0W 993 55 102 POST-TROPICAL
OCT 03 9.30 AM 50.5N 46.9W 993 55 102 POST-TROPICAL
OCT 03 3.30 PM 51.8N 43.3W 993 50 93 POST-TROPICAL
OCT 03 9.30 PM 52.6N 39.4W 993 50 93 POST-TROPICAL
OCT 04 3.30 AM 53.5N 35.0W 993 50 93 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
PERIODS OF HEAVY RAIN AND GUSTY NORTHEAST WINDS ASSOCIATED
WITH THE REMNANTS OF ISAAC AND A FRONTAL ZONE WILL CONTINUE TODAY
OVER SOUTHEASTERN NEWFOUNDLAND. RAINFALL AMOUNTS OF 40 TO 60 MM MAY
FALL BEFORE THE END OF THE DAY TODAY. THE ATLANTIC STORM PREDICTION
CENTRE IS MAINTAINING RAINFALL WARNINGS FOR SOUTHEASTERN
NEWFOUNDLAND.

A TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE AVALON PENINSULA
FOR NORTHEAST WINDS OF 60 GUSTING TO 90 KM/H LATER THIS AFTERNOON
AND EVENING. THERE IS A POSSIBILITY THAT THE STORM CENTRE COULD
TRACK SLIGHTLY FARTHER TO THE WEST CROSSING THE AVALON PENINSULA..
THEN A TROPICAL STORM WARNING MAY BE REQUIRED FOR THAT AREA. AT THIS
TIME WE STILL BELIEVE THAT THE CENTRE WILL NOT CROSS OVER LAND.

RAINFALL AND WIND FORECAST OVER THE MARITIME PROVINCES TODAY IS NOT
RELATED TO HURRICANE ISAAC..RATHER..A SEPARATE AREA OF LOW PRESSURE
SOUTH OF NOVA SCOTIA.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
A HURRICANE FORCE WIND WARNING IS IN EFFECT FOR THE SOUTHEASTERN
HALF OF LAURENTIAN FAN. GALE AND STORM FORCE WIND WARNINGS
ASSOCIATED WITH ISAAC ARE IN EFFECT FOR THE EASTERN PORTION OF
THE MARITIMES MARINE DISTRICT AND THE SOUTHERN AND EASTERN PORTIONS
OF THE NEWFOUNDLAND MARINE DISTRICT.

A STORM WARNING FOR THE SOUTH COAST MARINE DISTRICT OF NEWFOUNDLAND
REMAINS IN EFFECT..BUT WILL BE ENDED TODAY IF IT APPEARS THAT ISAAC
WILL TRACK TO THE EAST OF THAT AREA. THE SAME HOLDS TRUE FOR THE
SOUTHEASTERN HALF OF THE BANQUEREAU DISTRICT.

SIGNIFICANT WAVE HEIGHTS ARE EXPECTED TO BE 7 TO 9 METRES TO THE
RIGHT (EAST) OF THE STORM TRACK OVER THE SOUTHERN GRAND BANKS.

IF ISAAC TRACKS SLIGHTLY FARTHER TO THE WEST..THEN PARTS OF THE
AVALON PENINSULA COULD EXPERIENCE HIGH WAVES..ROUGH SURF AND STORM
SURGE.

5. TECHNICAL DISCUSSION

A. ANALYSIS
SATELLITE IMAGERY PRIOR TO THE ECLIPSE SHOWED THAT ISAAC WAS MOVING
TO THE EAST OF THE PREVIOUS FORECAST TRACK. WATER VAPOUR IMAGERY ALSO
CONFIRMS THAT THE MIGRATING SHORTWAVE TROUGH MOVING OFF THE U.S. EAST
COAST IS EXPENDING ENERGY INTO THE BAROCLINIC LOW SOUTH OF NOVA
SCOTIA AND NOT ISAAC.

B. PROGNOSTIC
IN LIGHT OF SATELLITE OBSERVATIONS..ISAAC SHOULD REMAIN SEPARATE
FROM THE LOW TO THE WEST. THIS SUPPORTS KEEPING THE SAME TRACK WE
HAVE BEEN ISSUING FOR THE LAST SEVERAL FORECASTS. THAT WOULD KEEP
THE HIGHEST WINDS OFFSHORE OF THE AVALON PENINSULA..BUT THERE STILL
REMAINS A POSSIBILITY FOR THE STORM CENTRE TO CROSS THE AVALON
PENINSULA..AND THAT IS WHY WE MAINTAIN A TROPICAL STORM WATCH FOR
THAT AREA.

MOST OF THE FORECASTING FOR TODAY WILL HINGE ON RAW WEATHER
OBSERVATIONS..SATELLITE..AND RADAR IMAGERY. GLOBAL MODELS IN GENERAL
HAVE NOT INITIALIZED ISAAC VERY WELL AT 02/00Z. THE GFS AND GEM RGNL
FAIL TO KEEP ISAAC SEPARATE FROM THE LOW SOUTH OF NOVA SCOTIA..WHILE
THE NAM MODEL HAS A SOLUTION IN CLOSER AGREEMENT WITH OUR OFFICIAL
FORECAST WHICH BRINGS THE CENTRE NEAR CAPE RACE AT 03/00Z.

ISAAC WILL UNDERGO EXTRATROPICAL TRANSITION (ET) TODAY AS IT MOVES
INTO THE OLD FRONTAL ZONE. THE NAM MODEL INDICATES THAT ISAAC WILL
BE ENCLOSED BY THE 570 DAM THICKNESS CONTOUR AT 03/00Z..SUGGESTING
THAT ISAAC WILL RETAIN SOME OF ITS TROPICAL CHARACTER FOR A BIT
LONGER THAN INDICATED. THE RAINFALL DIRECTLY ASSOCIATED WITH ISAAC
WILL LIKELY MIGRATE AHEAD AND TO THE LEFT OF THE TRACK TODAY.

C. PUBLIC WEATHER
MOST OF THE RAINFALL OVER SOUTHEAST NEWFOUNDLAND TODAY WILL BE
ASSOCIATED WITH AN OLD FRONTAL ZONE NORTH OF ISAAC. RAINFALL
ASSOCIATED WITH ISAAC ITSELF WILL NOT LIKELY ARRIVE UNTIL LATER THIS
AFTERNOON AND EVENING.

D. MARINE WEATHER

OUR TRAPPED FETCH WAVE MODEL INDICATES SIG WAVES NEAR 7 METRES AS
THE STORM PASSES NORTH OF THE SOUTHERN GRAND BANKS.

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
02/06Z 150 120 75 75 70 60 50 50 45 40 30 20
02/12Z 180 150 90 100 70 90 50 50 30 25 20 0
02/18Z 180 180 120 120 90 140 60 0 0 0 0 0
03/00Z 180 230 150 120 90 150 60 0 0 0 0 0
03/06Z 210 250 150 130 90 140 60 0 0 0 0 0
03/12Z 240 300 150 140 90 130 60 0 0 0 0 0
03/18Z 240 310 150 140 70 90 45 0 0 0 0 0
04/00Z 240 310 150 140 70 90 45 0 0 0 0 0
04/06Z 240 310 150 140 70 90 45 0 0 0 0 0

THESE RADII ARE PRIMARILY ASSOCIATED WITH ISAAC'S CIRCULATION AND
THE COMPRESSED PRESSURE GRADIENT OUT AHEAD OF IT.

END SZETO/FOGARTY

[cycloneye]

BULLETIN
TROPICAL STORM ISAAC INTERMEDIATE ADVISORY NUMBER 20A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
200 PM AST MON OCT 02 2006

...ISAAC APPROACHING SOUTHEASTERN NEWFOUNDLAND...

A TROPICAL STORM WARNING REMAINS IN EFFECT FOR THE AVALON PENINSULA
IN SOUTHEASTERN NEWFOUNDLAND.

ENVIRONMENT CANADA HAS DISCONTINUED THE TROPICAL STORM WATCH FOR THE
BURIN PENINSULA AND THE BONAVISTA PENINSULA.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 200 PM AST...1800Z...THE CENTER OF TROPICAL STORM ISAAC WAS
LOCATED NEAR LATITUDE 45.0 NORTH...LONGITUDE 53.5 WEST OR ABOUT 120
MILES...190 KM...SOUTH OF CAPE RACE NEWFOUNDLAND.

ISAAC IS MOVING TOWARD THE NORTH-NORTHEAST NEAR 40 MPH...65 KM/HR...
AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE DURING THE NEXT 24
HOURS. ON THIS TRACK THE CENTER WILL PASS NEAR SOUTHEASTERN
NEWFOUNDLAND LATER THIS AFTERNOON.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/HR...WITH HIGHER
GUSTS. SOME WEAKENING IS FORECAST DURING THE NEXT 24 HOURS. A
CANADIAN BUOY REPORTED SUSTAINED WINDS OF 51 MPH...83 KM/HR WITH A
PEAK WIND GUST TO 65 MPH...104 KM/HR...AS THE CENTER PASSED NEARBY.
ISAAC IS LOSING TROPICAL CHARACTERISTICS AND IS EXPECTED TO BECOME
AN EXTRATROPICAL CYCLONE LATER TODAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 290 MILES...465 KM
MAINLY TO THE EAST OF THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB...29.29 INCHES.

COASTAL STORM SURGE FLOODING OF 2 TO 3 FEET ABOVE NORMAL TIDE
LEVELS...ALONG WITH LARGE AND DANGEROUS BATTERING WAVES...CAN BE
EXPECTED NEAR AND TO THE EAST OF WHERE THE CENTER MAKES LANDFALL.

RAINFALL TOTALS OF 2 TO 3 INCHES WILL BE POSSIBLE OVER SOUTHEASTERN
NEWFOUNDLAND TODAY.

REPEATING THE 200 PM AST POSITION...45.0 N...53.5 W. MOVEMENT
TOWARD...NORTH-NORTHEAST NEAR 40 MPH. MAXIMUM SUSTAINED WINDS...60
MPH. MINIMUM CENTRAL PRESSURE...992 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 PM AST.

$$
FORECASTER BROWN/PASCH

[cycloneye]

WOCN31 CWHX 021800 CCB
CORRECTED TROPICAL STORM ISAAC INFORMATION STATEMENT ISSUED BY THE
CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 3.30 PM NDT
MONDAY 02 OCTOBER 2006.

THE NEXT STATEMENT WILL BE ISSUED BY 6.30 PM NDT

... ISAAC TO REMAIN JUST EAST OF THE AVALON PENINSULA...

CORRECTIONS TO LATITUDE POSITION IN TABLE... AND TO ADD GUSTS IN
SECTION 4.

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 3.30 PM NDT... TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE
46.1 N AND LONGITUDE 52.6 W... ABOUT 31 NAUTICAL MILES OR 58 KM
SOUTHEAST OF CAPE RACE . MAXIMUM SUSTAINED WINDS ARE ESTIMATED AT 50
KNOTS... 93 KM/H... AND CENTRAL PRESSURE AT 995 MB. ISAAC IS MOVING
NORTHEAST AT 35 KNOTS... 65 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
NDT MB KTS KMH
OCT 02 3.30 PM 46.1N 52.6W 995 50 93 BECOMING POST-TROPICAL
OCT 02 9.30 PM 48.9N 49.0W 995 50 93 POST-TROPICAL
OCT 03 3.30 AM 50.4N 44.9W 995 50 93 POST-TROPICAL
OCT 03 9.30 AM 51.1N 41.1W 995 50 93 POST-TROPICAL
OCT 03 3.30 PM 51.1N 37.6W 995 50 93 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY

TROPICAL STORM WARNINGS FOR THE AVALON PENINSULA WILL END SHORTLY.
ALL OTHER TROPICAL STORM WATCHES HAVE ENDED.

ISAAC IS A SMALL TROPICAL STORM AND SLIGHT CHANGES IN TRACK DIRECTION
HAVE LARGE IMPLICATIONS IN THE FORECAST. THIS IS THE CASE FOR THE
AVALON PENINSULA NOW THAT IT APPEARS THAT ISAAC WILL REMAIN JUST
OFFSHORE. HIGH WINDS OVER THE AVALON ARE NOT LIKELY NOW...
ESPECIALLY IN NORTHWESTERN PORTIONS OF THE AVALON. AS WELL THE AREA
OF RAIN HAS NOT EXPANDED WESTWARD VERY FAR. THIS COUPLED WITH THE
QUICK FORWARD MOTION OF THE STORM MEANS THAT RAINFALL AMOUNTS WILL
BE MUCH LESS THAN EARLIER EXPECTED.

THE ATLANTIC STORM PREDICTION CENTRE MAY BE ENDING RAINFALL AND
WIND WARNINGS IN THEIR AFTERNOON UPDATES AND THE PUBLIC ARE ADVISED
TO MONITOR THEIR BULLETINS.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
THERE ARE NO REMAINING WARNINGS IN MARITIME WATERS. GALE TO STORM
FORCE WINDS REMAIN FOR SOME SOUTHEASTERN NEWFOUNDLAND WATERS WITH
THE PASSAGE OF ISAAC. ISAAC IS A SMALL STORM WITH VIRTUALLY ALL OF
ITS STRONG WINDS TO THE RIGHT SIDE OF THE STORMS TRACK.

BUOY 44138 IN THE SOUTHWESTERN GRAND BANKS REPORTED PEAK WINDS IN
EXCESS OF 50 KNOTS FOR TWO CONSECUTIVE HOURS AS ISAAC PASSED JUST TO
THE WEST OF THE BUOY LOCATION. SIGNIFICANT WAVE HEIGHTS AT THE BUOY
REACHED 5 METRES. IT IS EXPECTED THAT WAVE HEIGHTS OF 6-7 METRES
ARE LIKELY RUNNING FARTHER EAST THROUGH THE GRAND BANKS.

WIND GUSTS TO 60 KNOTS SHOULD STILL BE EXPECTED TO THE EAST OF THE
TRACK OF ISAAC.

5. TECHNICAL DISCUSSION

A. ANALYSIS
SATELLITE IMAGERY HAS BEEN MARGINALLY USEFUL TODAY EXCEPT OVER THE
LAST HOUR OR SO WHEN LOW LEVEL CIRCULATION HAS BECOME MORE APPARENT
UNDER THE SOUTHWEST PERIPHERY OF THE STORM. THE FORWARD MOTION IS
BETWEEN 35-40 KNOTS AND PRESSURE IS LIKELY IN THE MID 990S AS THE
BUOY REPORTED 1000 MB FOR 2 CONSECUTIVE HOURS.

PERHAPS THE MOST SURPRISING ASPECT OF THE STORM HAS BEEN ITS
DETERMINATION TO REMAIN AS A COHERENT TROPICAL-LOOKING CIRCULATION
IN SPITE OF THE DEVELOPING BAROCLINIC SYSTEM TO ITS WEST.

THE HEAVIEST CLOUD SHIELD HAS ALREADY PASED NEWFOUNDLAND.

B. PROGNOSTIC
OUR FORECAST TRACK IS BASED EXCLUSIVELY ON KINEMATIC TECHNIQUES
AND FOLLOWING THE DEEP LAYER FLOW AROUND THE RIDGE AS IT MOVES
EAST OF NEWFOUNDLAND. ITS PERSISTENCE TO MAINTAIN STORM FORCE WINDS
EVEN TO THIS POINT CONVINCES US TO KEEP THIS AS A 50-KNOT SYSTEM
THROUGH OUR WATERS.

WINDS ARE BEGINNING TO BACK AT CAPE RACE AT 17Z SO THIS ADDS MORE
WEIGHT TO THE STORM PASSING SOUTHEAST OF THE AVALON.

C. PUBLIC WEATHER
NEWFOUNDLAND WILL DODGE THE WORST IMPACTS OF ISAAC AS IT SLIPS BY
JUST TO THE SOUTH.

D. MARINE WEATHER

NONE.

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
02/18Z 100 180 90 60 60 60 0 0 0 0 0 0
03/00Z 120 200 100 60 60 90 0 0 0 0 0 0
03/06Z 140 210 120 60 60 90 0 0 0 0 0 0
03/12Z 160 240 120 60 60 90 0 0 0 0 0 0
03/18Z 180 240 120 60 60 90 0 0 0 0 0 0

END BOWYER

[cycloneye]

261
WTNT34 KNHC 022033
TCPAT4
BULLETIN
TROPICAL STORM ISAAC ADVISORY NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
500 PM AST MON OCT 02 2006

...ISAAC BECOMING EXTRATROPICAL AFTER PASSING NEAR SOUTHEASTERN
NEWFOUNDLAND...

ENVIRONMENT CANADA IS DISCONTINUING THE TROPICAL STORM WARNING FOR
THE AVALON PENINSULA OF SOUTHEASTERN NEWFOUNDLAND.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE THAT ISAAC IS
LOSING TROPICAL CHARACTERISTICS AS IT HEADS FOR THE FAR NORTH
ATLANTIC.

AT 500 PM AST...2100Z...THE CENTER OF ISAAC WAS LOCATED NEAR
LATITUDE 47.1 NORTH...LONGITUDE 52.2 WEST OR ABOUT 50 MILES...
80 KM...EAST-NORTHEAST OF CAPE RACE NEWFOUNDLAND.

ISAAC IS MOVING TOWARD THE NORTHEAST NEAR 40 MPH...65 KM/HR...
A TURN TO THE EAST-NORTHEAST IS FORECAST DURING THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/HR...WITH HIGHER
GUSTS. SOME WEAKENING IS FORECAST DURING THE NEXT 24 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 260 MILES...415 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB...29.29 INCHES.

REPEATING THE 500 PM AST POSITION...47.1 N...52.2 W. MOVEMENT
TOWARD...NORTHEAST NEAR 40 MPH. MAXIMUM SUSTAINED WINDS...60 MPH.
MINIMUM CENTRAL PRESSURE...992 MB.

THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON ISAAC. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE
FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER
SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

$$
FORECASTER BROWN/PASCH

804
WTNT44 KNHC 022034
TCDAT4
TROPICAL STORM ISAAC DISCUSSION NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092006
500 PM EDT MON OCT 02 2006

THE SATELLITE APPEARANCE OF ISSAC HAS CONTINUED TO DETERIORATE TODAY
AS THE CENTER HAS BECOME EXPOSED SOUTHWEST OF THE AREA OF COLD
CLOUD TOPS SEEN IN INFRARED IMAGERY. AROUND 1600 UTC... THE CENTER
MOVED BY CANADIAN BUOY 44138...WHICH REPORTED SUSTAINED WINDS OF 45
KT WITH A PEAK GUST TO 56 KT. ISAAC'S CENTER RECENTLY PASSED JUST
OFFSHORE CAPE RACE NEWFOUNDLAND WHERE WIND GUSTS TO 52 KT WERE
REPORTED.

THE ESTIMATED INITIAL MOTION IS 035/35. ISAAC IS BECOMING
EXTRATROPICAL AND IS FORECAST TO SOON MERGE WITH THE LARGER
BAROCLINIC SYSTEM TO ITS WEST. THE UKMET...GFS...AND ECMWF
INDICATE THAT THE SMALL ISAAC WILL LIKELY MERGE WITH THE
SYSTEM ALONG AN EAST TO WEST FRONTAL BOUNDARY IN 12-24 HOURS.
IN DEFERENCE TO THE INITIAL MOTION...THE OFFICIAL FORECAST IS
FASTER THAN THE AVAILABLE GUIDANCE DURING THE NEXT 12 HOURS.

SINCE IT IS QUICKLY LOSING TROPICAL CHARACTERISTICS...THIS WILL BE
THE LAST ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON ISAAC.
ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

FORECAST POSITIONS AND MAX WINDS

INITIAL 02/2100Z 47.1N 52.2W 50 KT...BECOMING EXTRATROPICAL
12HR VT 03/0600Z 51.5N 48.0W 50 KT...EXTRATROPICAL
24HR VT 03/1800Z 53.5N 41.0W 45 KT...EXTRATROPICAL
36HR VT 04/0600Z...DISSIPATED

$$
FORECASTER BROWN/PASCH

[AnnularCane]

I'm a bit confused... Is the NHC only writing some of the advisories?

[cycloneye]

WOCN31 CWHX 022100
POST-TROPICAL STORM ISAAC INTERMEDIATE INFORMATION STATEMENT ISSUED
BY THE CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT
6.30 PM NDT MONDAY 02 OCTOBER 2006.

THE NEXT STATEMENT WILL BE ISSUED BY 9.30 PM NDT

... ISAAC NOW A POST-TROPICAL STORM EAST OF NEWFOUNDLAND...

AT 6.30 PM NDT... POST-TROPICAL STORM ISAAC WAS LOCATED NEAR
LATITUDE 47.0 N AND LONGITUDE 51.5 W... ABOUT 66 NAUTICAL MILES OR
122 KM EAST SOUTHEAST OF ST. JOHNS NEWFOUNDLAND.

ISAAC HAS NOW MOVED EAST OF NEWFOUNDLAND AS IT HEADS TO THE OPEN
SEA. ISAAC... WHICH WAS A HURRICANE THIS MORNING... HAS CONTINUED TO
TRANSFORM AND WEAKEN THROUGHOUT THE DAY AND IS NOW A POST-TROPICAL
STORM OF 50 KNOTS OR 93 KM/H WITH HIGHER GUSTS.

ALL INLAND WATCHES AND WARNINGS HAVE ENDED. SOME LINGERING COASTAL
GALES ALONG THE EAST COAST OF NEWFOUNDLAND ARE THE RESULT OF A
TIGHTENING PRESSURE PATTERN AHEAD OF ISAAC BUT NOT DIRECTLY
ASSOCAITED WITH THE POST-TROPICAL STORM.

MAXIMUM CONDITIONS OBSERVED MONDAY AFTERNOON WITH THE PASSAGE OF
ISAAC...
PEAK WINDS OBSERVED AT SEA WERE 56 KNOTS... OR 104 KM/H AT BUOY
44138. MAXIMUM OBSERVED SIGNIFICANT WAVE HEIGHTS WERE 6.1 METRES A
THE SAME BUOY. MAXIMUM REPORTED WIND IN COASTAL AREAS WAS 40 GUSTING
52 KNOTS... OR 74 GUSTING 96 KM/H AT CAPE RACE. RAINFALL AMOUNTS
ASSOCIATED WITH ISAAC DID NOT AMOUNT TO MUCH AS MOST OF IT REMAINED
OFFSHORE.

END BOWYER