Here comes Hurricane Arthur (Cat. 1) Update Six - Becoming Extratropical

000
WTNT41 KNHC 050237
TCDAT1

HURRICANE ARTHUR DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012014
1100 PM EDT FRI JUL 04 2014

Satellite and radar data indicates that Arthur has begun
extratropical transition.  The eye feature seen previously has
dissipated, and the remaining convection is now displaced somewhat
to the northeast of the low-level center.  In addition, microwave
total precipitable water data from a recent SSM/IS overpass shows
very dry air entraining into the west and south sides of the
cyclone.  SFMR data from the previous Air Force Reserve Hurricane
Hunter flight showed maximum winds of 60-65 kt, and based on this
the initial intensity is reduced to a possibly generous 65 kt.

The initial motion is now 045/27 kt.  Arthur should continue to move
northeastward during the next 24-36 hours in deep-layer
southwesterly flow ahead of a baroclinic trough over the
northeastern United States.  After that time, the post-tropical
cyclone is forecast to slow down and eventually turn
east-northeastward.  Based on the current motion and model trends,
this part of the forecast has been nudged a little to the east of
the previous track.  There remains a large amount of spread in the
track guidance after 48 hours on whether the former Arthur will turn
more northward or turn east-northeastward out into the Atlantic. The
new official forecast during that period has been revised based on
a blend of input from the Ocean Prediction Center along with the
GFS and ECMWF models.

Arthur is expected to complete extratropical transition in about 12
hours.  After transition, the former tropical cyclone should
steadily weaken, with winds dropping below gale force by 96 hours.
The intensity forecast has been revised downward based on input from
the OPC, as well as from the GFS and ECMWF models.

Winds in excess of gale/tropical storm force are expected over
portions of eastern Maine on Saturday.  Because Arthur is expected
to be extratropical by Saturday morning, and because the strong
winds in Maine will be post-frontal, this threat is being handled by
high wind warnings issued by local NWS offices.


FORECAST POSITIONS AND MAX WINDS

INIT  05/0300Z 41.2N  68.7W   65 KT  75 MPH
12H  05/1200Z 44.0N  66.0W   60 KT  70 MPH...POST-TROP/EXTRATROP
24H  06/0000Z 46.5N  63.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
36H  06/1200Z 48.5N  59.3W   40 KT  45 MPH...POST-TROP/EXTRATROP
48H  07/0000Z 51.5N  55.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
72H  08/0000Z 58.0N  51.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
96H  09/0000Z 60.0N  49.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
120H  10/0000Z 61.5N  44.5W   25 KT  30 MPH...POST-TROP/EXTRATROP

$$
Forecaster Beven

Here comes Hurricane Arthur (Cat. 1) Update Five

FXCN31 CWHX 050000
TROPICAL CYCLONE TECHNICAL INFORMATION STATEMENT ISSUED BY THE 
CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 8.34 PM ADT
FRIDAY 04 JULY 2014.

THE NEXT STATEMENT WILL BE ISSUED BY 3.00 AM ADT

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 9.00 PM ADT, HURRICANE ARTHUR WAS LOCATED NEAR LATITUDE 40.4 N AND 
LONGITUDE 69.2 W, ABOUT 64 NAUTICAL MILES OR 119 KM SOUTHEAST OF 
NANTUCKET. MAXIMUM SUSTAINED WINDS ARE ESTIMATED AT 70 KNOTS (130 
KM/H) AND CENTRAL PRESSURE AT 979 MB. ARTHUR IS MOVING NORTHEAST AT
30 KNOTS (56 KM/H).

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE     TIME     LAT    LON   MSLP  MAX WIND
          ADT                    MB  KTS  KMH
JUL 04  9.00 PM  40.4N  69.2W   979   70  130
JUL 05  3.00 AM  42.0N  67.6W   980   65  120
JUL 05  9.00 AM  43.9N  66.2W   980   60  111 POST-TROPICAL
JUL 05  3.00 PM  45.3N  64.7W   977   55  102 POST-TROPICAL
JUL 05  9.00 PM  46.0N  63.1W   978   55  102 POST-TROPICAL
JUL 06  3.00 AM  47.1N  61.1W   981   50   93 POST-TROPICAL
JUL 06  9.00 AM  48.4N  59.0W   984   45   83 POST-TROPICAL
JUL 06  3.00 PM  50.4N  57.0W   984   45   83 POST-TROPICAL
JUL 06  9.00 PM  51.9N  55.0W   984   40   74 POST-TROPICAL
JUL 07  3.00 AM  53.4N  53.4W   984   40   74 POST-TROPICAL
JUL 07  9.00 AM  55.2N  51.7W   984   35   65 POST-TROPICAL
JUL 07  3.00 PM  59.3N  48.5W   984   35   65 POST-TROPICAL


3. TECHNICAL DISCUSSION

A. ANALYSIS

LATEST SATELLITE IMAGERY INDICATE THAT CLOUD TOPS HAVE WARMED AND 
CONVECTION HAS DIMINISHED ESPECIALLY IN THE EASTERN SEMI-CIRCLE. THE 
EYE IS BECOMING FILLED WITH CLOUDS BUT IT REMAINS EVIDENT ON BOTH 
VISUAL AND INFRA-RED IMAGES. RADAR DATA SUGGESTS THE DEVELOPMENT OF
AN AREA OF PRE-CURSOR HEAVY RAIN OVER SOUTHERN NEW ENGLAND AND
STARTING TO EXTEND INTO NEW BRUNSWICK. FLIGHTS INTO THE STORM THIS
AFTERNOON CONTINUE TO SHOW WINDS OF NEAR 100 KNOTS HOWEVER THESE
WINDS ARE NOT MIXING DOWN TO THE SURFACE. THE STORM IS STARTING TO
MOVE OVER MUCH COLDER WATERS TONIGHT AS IT PASSES EAST OF CAPE COD.
ARTHUR HAS MOVED INTO AN ENVIRONMENT WITH INCREASED DEEP LAYER SHEAR
AND A DRY INTRUSION STARTING TO WRAP AROUND THE SOUTH OF THE STORM
WHICH INDICATES EXTRATROPICAL TRANSITION OCCURRING.

B. PROGNOSTIC

ARTHUR IS ACCELERATING TOWARD THE NORTHEAST AHEAD OF A TROUGH JUST TO 
THE WEST, AND IS EXPECTED TO UNDERGO POST-TROPICAL TRANSITION BY THE 
TIME IT REACHES NOVA SCOTIA SATURDAY MORNING. THE STORM WILL BEGIN 
INTERACTING STRONGLY WITH THE TROUGH EARLY SATURDAY. AT THAT TIME THE 
SYSTEM WILL RECURVE TO THE NORTH-NORTHEAST AND SLOW DOWN AS IT PASSES 
ACROSS NORTHERN NOVA SCOTIA. THE SYSTEM WILL EVOLVE INTO A STRONG 
POST-TROPICAL STORM AS IT MOVES ACROSS THE MARITIMES SATURDAY AND
THEN ACROSS NEWFOUNDLAND SUNDAY BEFORE EXITING INTO THE NORTH
ATLANTIC AS A WEAKENING BAROCLINIC SYSTEM. THE FORECAST TRACK
CONTINUES TO BE FURTHER SOUTH THAN WHAT RDPS IS SUGGESTING DURING THE
NEXT 24 HOURS.


C. PREDICTED WIND RADII (NM)

TIME          GALES           STORMS            HURRICANE
         NE  SE  SW  NW    NE  SE  SW  NW    NE  SE  SW  NW
05/00Z  120 140 105  75    65  85  55  40    35  50  30  20
05/06Z  130 170 120  80    70  90  65  50    40  40  30  30
05/12Z  140 240 135  85    70  95  75  55     0   0   0   0
05/18Z  150 255 165 100    70  80  70  50     0   0   0   0
06/00Z  120 265 195 120    50  65  60  40     0   0   0   0
06/06Z  105 255 205 120    40  65  60  35     0   0   0   0
06/12Z   90 240 210 115     0   0   0   0     0   0   0   0
06/18Z   90 210 180  90     0   0   0   0     0   0   0   0
07/00Z   90 175 150  65     0   0   0   0     0   0   0   0
07/06Z   90 165 135  35     0   0   0   0     0   0   0   0
07/12Z   90 150 120   0     0   0   0   0     0   0   0   0
07/18Z   90 150 120   0     0   0   0   0     0   0   0   0


END/HATT/COUTURIER/MERCER

000
WTNT31 KNHC 042336
TCPAT1

BULLETIN
HURRICANE ARTHUR INTERMEDIATE ADVISORY NUMBER  16A
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012014
800 PM EDT FRI JUL 04 2014

...ARTHUR MOVING QUICKLY NORTHEASTWARD...
...TROPICAL-STORM-FORCE WINDS EXPECTED OVER CAPE COD AND
NANTUCKET DURING THE NEXT SEVERAL HOURS...


SUMMARY OF 800 PM EDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...40.3N 69.6W
ABOUT 95 MI...150 KM SSE OF CHATHAM MASSACHUSETTS
ABOUT 300 MI...480 KM SW OF YARMOUTH NOVA SCOTIA
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...NE OR 45 DEGREES AT 28 MPH...45 KM/H
MINIMUM CENTRAL PRESSURE...976 MB...28.82 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* NANTUCKET
* CAPE COD FROM PROVINCETOWN TO WOODS HOLE
* NOVA SCOTIA INCLUDING CAPE BRETON ISLAND
* PRINCE EDWARD ISLAND
* NEW BRUNSWICK FROM THE U.S./CANADA BORDER TO GRAND-ANSE

IN ADDITION...HIGH WIND WARNINGS...FOR WINDS IN EXCESS OF 40 MPH...
ARE IN EFFECT FOR PORTIONS OF EASTERN MAINE.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 PM EDT...0000 UTC...THE CENTER OF HURRICANE ARTHUR WAS
LOCATED NEAR LATITUDE 40.3 NORTH...LONGITUDE 69.6 WEST. ARTHUR IS
MOVING TOWARD THE NORTHEAST NEAR 28 MPH...45 KM/H...AND THIS
MOTION IS EXPECTED TO CONTINUE DURING THE NEXT DAY OR SO. ON THE
FORECAST TRACK...THE CENTER OF ARTHUR WILL PASS SOUTHEAST OF NEW
ENGLAND TONIGHT...AND BE NEAR OR OVER WESTERN NOVA SCOTIA EARLY ON
SATURDAY...AND OVER THE GULF OF ST. LAWRENCE SATURDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH...130 KM/H...WITH HIGHER
GUSTS.  WEAKENING IS FORECAST DURING THE NEXT 48 HOURS...AND ARTHUR
IS EXPECTED TO BECOME A POST-TROPICAL CYCLONE SATURDAY MORNING.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 160
MILES...260 KM.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE
RESERVE HURRICANE HUNTER AIRCRAFT IS 976 MB...28.82 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH THE WARNING
AREA IN NEW ENGLAND THIS EVENING.  TROPICAL STORM CONDITIONS ARE
EXPECTED TO REACH THE WARNING AREA IN CANADA TONIGHT AND SPREAD
NORTHWARD ON SATURDAY.  IN ADDITION...WINDS IN EXCESS OF 40 MPH ARE
EXPECTED OVER PORTIONS OF EASTERN MAINE ON SATURDAY...BEHIND A COLD
FRONT OVERTAKING THE CIRCULATION OF ARTHUR.

STORM SURGE...COASTAL FLOODING IS POSSIBLE ALONG CAPE COD TONIGHT.
FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE SEE PRODUCTS ISSUED
BY YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE.

RAINFALL...RAINFALL ACCUMULATIONS OF 2 TO 4 INCHES ARE EXPECTED
OVER EXTREME EASTERN RHODE ISLAND...EASTERN MASSACHUSETTS...COASTAL
MAINE...NOVA SCOTIA...NEWFOUNDLAND...AND NEW BRUNSWICK...WITH
ISOLATED MAXIMUM AMOUNTS OF 6 INCHES POSSIBLE OVER DOWNEAST MAINE
AND CANADA.

SURF...SWELLS GENERATED BY ARTHUR ARE AFFECTING PORTIONS OF THE
COAST OF NORTH CAROLINA...THE MID-ATLANTIC...AND NORTHEAST UNITED
STATES. SWELLS WILL BEGIN AFFECTING PORTIONS OF SOUTHEASTERN CANADA
TONIGHT. THESE SWELLS ARE EXPECTED TO CAUSE LIFE-THREATENING SURF
AND RIP CURRENTS. FOR MORE INFORMATION...PLEASE MONITOR PRODUCTS
ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 PM EDT.

$$
FORECASTER BEVEN

Here comes Hurricane Arthur (Cat. 1) Update Four

000
WTNT41 KNHC 042056
TCDAT1

HURRICANE ARTHUR DISCUSSION NUMBER  16
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012014
500 PM EDT FRI JUL 04 2014

The cloud pattern of Arthur remains very symmetric with a hint of an
eye remaining in visibile and infrared satellite imagery, although
the cloud tops have continued to gradually warm during the day.
Recent reconnaissance data show that the radius of maximum winds has
increased, which is likely the first sign that the hurricane is
beginning the transition to a post-tropical cyclone. The aircraft
data also indicate that the winds aloft are not mixing down as
efficiently as they were overnight and this morning. In fact, during
the latest pass through the southeastern quadrant the aircraft
measured a peak 700-mb flight level wind of 103 kt, but the surface
winds underneath were only 63 kt. Based on these data, the initial
intensity is lowered to 70 kt.  Arthur is now located over sea
surface temperatures of around 24C. The hurricane will be moving
over progressively colder waters and into an area of increasing
southwesterly shear, which should result in continued weakening.
Global model guidance indicates that Arthur should become
post-tropical tomorrow morning.  After the extratropical transition,
the cyclone is forecast to continue weakening as it moves over the
North Atlantic.

The initial motion estimate is 040/23 kt. The hurricane should
continue to move northeastward during the next 24 to 36 hours in
deep-layer southwesterly flow ahead of the approaching deep-layer
trough. After that time, the post-tropical cyclone is forecast to
slow down and eventually turn east-northeastward.  There is still
a large amount of spread in the track guidance after 48 hours. The
updated NHC forecast is between the ECWMF and GFS models, and leans
toward guidance provided by the NOAA Ocean Prediction Center.

Winds in excess of gale/tropical storm force are expected
over portions of eastern Maine on Saturday.  Because Arthur is
expected to be extratropical by Saturday morning, and because the
strong winds in Maine will be post-frontal, this threat is being
handled by high wind warnings issued by local NWS offices.

FORECAST POSITIONS AND MAX WINDS

INIT  04/2100Z 39.4N  71.1W   70 KT  80 MPH
12H  05/0600Z 42.2N  68.2W   60 KT  70 MPH
24H  05/1800Z 45.3N  65.3W   55 KT  65 MPH...POST-TROP/EXTRATROP
36H  06/0600Z 47.0N  61.9W   50 KT  60 MPH...POST-TROP/EXTRATROP
48H  06/1800Z 49.4N  57.2W   40 KT  45 MPH...POST-TROP/EXTRATROP
72H  07/1800Z 56.0N  51.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
96H  08/1800Z 60.0N  49.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
120H  09/1800Z 61.0N  42.5W   25 KT  30 MPH...POST-TROP/EXTRATROP

$$
Forecaster Brown