000
FXUS61 KCAR 051509
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
1109 AM EDT Thu Sep 5 2019
.SYNOPSIS...
High pressure will build across the area into Friday. Tropical
Cyclone Dorian is expected to track south of the Gulf of Maine
Friday night into Saturday. High pressure will build toward the
region early next week.....
....SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
The remainder of the short term is focused on the potential
impacts of Hurricane Dorian as it approaches from the SW Friday
Night, then passes to the SE Saturday, then well into the
Canadian Maritimes Saturday night. The track of Dorian, the rate
of expansion of its wind field as it undergoes extratropical
transition and hence its ultimate impact on the CWA will be
determined by its interaction with a series of northern stream
shortwave troughs.
The first shortwave trough that is of interest crosses the Great
Lakes on Friday. The interaction of Dorian with this will
basically determine how far to the S/E of Cape Cod it will go.
The second shortwave trough core passes in between Hudson Bay
and the Great Lakes Saturday. The interaction between Dorian and
this shortwave will determine how far S/E Dorian will pass Nova
Scotia, or where it will make landfall in Nova Scotia. Both of
these shortwave troughs will help aid in the extratropical
transition of Dorian, with the degree helping to determine the
extent that its wind field expands. At this time it
confidence is increasing in the potential for low end tropical
storm force wind gusts over coastal portions of Washington
County Saturday afternoon, with the strongest winds likely
around Eastport. Elsewhere across Downeast Maine gusts of 25-35
mph are possible later Saturday, with lesser gusts possible
elsewhere over the CWA.
Confidence is also increasing in the potential for locally heavy
rainfall over Downeast Maine from late Friday night into
Saturday evening, with the potential for around 1 to 1.5 inches
of rainfall s/e of a Ellsworth to Grand Lake line, with locally
higher amounts possible. This could produce minor flooding of
known poor drainage areas and possibly isolated flash flooding.
At this time, only light, more spotty rain is expected over most
of the North from Late Friday night into Saturday evening. Rain
should taper off from SW to NE across the region Saturday night.
Refer to the latest products from the National Hurricane Center
for more information on Hurricane Dorian.....
000
WTNT45 KNHC 051455
TCDAT5
Hurricane Dorian Discussion Number 49
NWS National Hurricane Center Miami FL AL052019
1100 AM EDT Thu Sep 05 2019
The latest NOAA Doppler radar data, along with Air Force Reserve and
NOAA Hurricane Hunter reports, indicate that Dorian has an well-
defined eye with a diameter of about 40 n mi, with the northwestern
edge of the eyewall not far from the South Carolina coast. The
Hurricane Hunter data indicate that the flight-level and SFMR
surface winds have decreased some since 12 h ago, accompanied by a
rise in the central pressure. Based on this, the initial intensity
is decreased to a possibly generous 95 kt. The central pressure of
958 mb is based partly on data from NOAA buoy 41004, which is
currently inside the eye.
Dorian has nudged eastward during the past several hours and the
initial motion is now 020/7. The hurricane is now moving into the
mid-latitude westerlies, and during the next several hours it is
expected to turn northeastward with an increase in forward speed.
This should bring the eye near or over the coasts of eastern South
Carolina and southeastern North Carolina during the next 12-24 h.
After that, Dorian is forecast to move quickly across the northwest
Atlantic and be near or over the Canadian Maritimes/Atlantic
provinces by 72 h. The track guidance remains tightly clustered,
and the new forecast track is changed little from the previous
forecast.
Dorian is forecast to slowly weaken as it moves along the South and
North Carolina coasts. Extratropical transition should begin
around 48 h and be complete by 72 h, although Dorian is forecast
to maintain hurricane-force winds through the transition. After
72 h, the extratropical low should weaken over the far north
Atlantic.
The center of Dorian is expected to move very near or over the
coastline of the Carolinas and the southern Mid-Atlantic states.
Residents of these areas should already be prepared for damaging
winds, life-threatening storm surges, and flooding rains.
Key Messages:
1. Life-threatening storm surge and dangerous winds are expected
along portions the coasts of South Carolina and North Carolina, and
portions of southeast Virginia and the southern Chesapeake Bay,
regardless of the exact track of Dorian's center. Water levels
could rise well in advance of the arrival of strong winds. Residents
in these areas should follow advice given by local emergency
officials.
2. Flash flooding will become more widespread across the eastern
Carolinas and far southeast Virginia today into tonight. There is a
high risk of flash flooding over these areas, where significant,
life-threatening, flash flooding is expected.
FORECAST POSITIONS AND MAX WINDS
INIT 05/1500Z 32.5N 79.1W 95 KT 110 MPH
12H 06/0000Z 33.5N 78.0W 90 KT 105 MPH
24H 06/1200Z 35.1N 75.8W 85 KT 100 MPH
36H 07/0000Z 37.2N 72.4W 80 KT 90 MPH
48H 07/1200Z 40.1N 68.0W 80 KT 90 MPH
72H 08/1200Z 48.0N 59.5W 65 KT 75 MPH...POST-TROP/EXTRATROP
96H 09/1200Z 54.5N 48.5W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 10/1200Z 59.5N 32.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
$$
Forecaster Beven
FXCN31 CWHX 051200
Tropical cyclone technical information statement issued by the
Canadian Hurricane Centre of Environment Canada at 8.42 AM ADT
Thursday 05 September 2019.
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 Dorian was located near latitude 32.2 N and
longitude 79.2 W, about 58 nautical miles or 108 km southeast of
Charleston. Maximum sustained winds are estimated at 100 knots (185
km/h) and central pressure at 957 MB. Dorian is moving
north-northeast at 6 knots (11 km/h).
2. Forecast position, central pressure and strength
Date time lat lon MSLP Max wind
ADT MB kts kmh
Sep 05 9.00 AM 32.2N 79.2W 957 100 185
Sep 05 9.00 PM 33.4N 78.1W 962 90 167
Sep 06 9.00 AM 35.2N 75.7W 967 85 157
Sep 06 9.00 PM 37.6N 72.3W 967 85 157
Sep 07 9.00 AM 40.5N 68.5W 970 80 148
Sep 07 9.00 PM 43.6N 63.8W 970 75 139
Sep 08 9.00 AM 48.1N 59.1W 963 70 130 post-tropical
Sep 08 9.00 PM 51.5N 54.6W 966 50 93 post-tropical
Sep 09 9.00 AM 54.1N 49.1W 968 45 83 post-tropical
Sep 09 9.00 PM 56.9N 40.5W 970 40 74 post-tropical
3. Technical discussion
A. Analysis
Satellite imagery is showing a large eye about 90 km in diametre with
the strongest convection currently rounding the southern half of the
storm. The centre over the last hour has also taken more of a
northeasterly direction as it approaches the South Carolina coast.
Heavy rain bands are now extend north well into North Carolina. The
initial intensity has been set at 100 knots with a north-northeast
motion of 6 knots.
B. Prognostic
The steering flow should become more southwesterly this morning with
little change in intensity expected. The forecast guidance is showing
some weakening as Dorian skirts the north carolinas coastline,
passing near Cape Hatteras on Friday. Further weakening is expected
as Dorian accelerates towards the Canadian offshore waters Friday
into Saturday. As is normally the case with a tropical cyclone about
to undergo transition, Dorian will remain a very potent storm as the
wind field expands significantly when it passes over the Atlantic
provinces. The main deterministic and ensemble models are very close
to the projected track, suggesting a high probability of landfall
over Eastern Nova Scotia late Saturday. The cyclone is expected to
become a very potent post-tropical system with hurricane or near
hurricane force winds as it crosses Newfoundland Sunday. Global
models are suggesting large amounts of rain north of the track with
the Canadian gdps giving the largest amounts showing a large area of
100 to 200 mm and a swath of more than 200 mm over Central Nova
Scotia. This is most likely due to the fact that the gdps is holding
on to the warm core and its associated convection longer than the
other models before transitioning to a post-tropical system.
C. Predicted wind radii (NM)
Time gales storms hurricane
NE SE SW NW NE SE SW NW NE SE SW NW
05/12Z 195 185 110 130 90 85 65 80 60 50 45 50
06/00Z 220 220 130 125 85 85 65 70 60 50 40 50
06/12Z 245 245 165 130 90 90 70 75 55 50 40 50
07/00Z 235 260 190 145 95 95 75 80 55 50 45 50
07/12Z 250 270 200 155 115 145 80 80 55 55 55 55
08/00Z 280 290 210 180 105 185 100 80 70 85 60 45
08/12Z 255 270 215 195 105 170 80 95 45 40 25 35
09/00Z 225 265 220 190 60 75 50 80 0 0 0 0
09/12Z 210 250 225 190 0 0 0 0 0 0 0 0
10/00Z 180 250 225 190 0 0 0 0 0 0 0 0
END/MCARTHUR/MERCER/COUTURIER
8:35 AM ADT Thursday 05 September 2019
Tropical cyclone information statement for:
New Brunswick:
Acadian Peninsula
Fredericton and Southern York County
Fundy National Park
Grand Lake and Queens County
Grand Manan and Coastal Charlotte County
Kent County
Kouchibouguac National Park
Miramichi and area
Moncton and Southeast New Brunswick
Oromocto and Sunbury County
Saint John and County
St. Stephen and Northern Charlotte County
Stanley - Doaktown - Blackville Area
Sussex - Kennebecasis Valley and Kings County
Newfoundland and Labrador:
Cartwright to Black Tickle
Eagle River
Newfoundland
Norman Bay to Lodge Bay
Red Bay to L'Anse-au-Clair
Nova Scotia
Prince Edward Island
Québec - south:
Anticosti
Blanc-Sablon
Chevery
Îles-de-la-Madeleine
For Hurricane Dorian.
The next information statement will be issued by 03:00 p.m. ADT.
Hurricane Dorian is expected to severely impact parts of the Atlantic provinces this weekend.
1. Summary of basic information at 09:00 a.m. ADT.
Location: 32.2 North 79.4 West.
About 95 kilometres southeast of Charleston.
Maximum sustained winds: 185 kilometres per hour.
Present movement: northerly at 11 kilometres per hour.
Minimum central pressure: 957 millibars.
2. Public weather impacts and warnings summary.
Based on the latest forecast guidance, the most likely track projection brings Hurricane Dorian south of the Maritimes on Saturday, pushing through eastern Nova Scotia late in the day, and then over western Newfoundland by Sunday morning. Severe winds and rainfall will have major impacts for southeastern New Brunswick, Prince Edward Island, Nova Scotia, Western Newfoundland, and the Quebec Lower North Shore. There will also be large waves, especially for the Atlantic coasts of Nova Scotia and Newfoundland and eastern portions of the Gulf of St. Lawrence. Finally, there is a chance that storm surge may affect parts of Nova Scotia and Newfoundland.
a. Wind.
Most regions will experience some tropical storm force winds. Near and to the south of the forecast track, winds should reach hurricane force. As the storm moves across Nova Scotia, there is a possibility of hurricane force northwesterlies behind it. Wind impacts will likely be enhanced by foliage on the trees, enhancing
tree damage and tree falls, and potentially causing power outages.
b. Rainfall.
Rainfall will be significant, especially north and west of Dorian's track, where heavy rainfall could lead to flooding. The highest rainfall amounts are likely for Nova Scotia and the Gulf of St. Lawrence region. Forecast guidance is suggesting widespread amounts in excess of 50 mm, but north and west of Dorian, a swath of more than 100 mm is likely. Some districts have received large quantities of rain from Post-tropical Storm Erin last week, and with the soil moisture still very high from Erin, excessive runoff may exacerbate the flooding potential.
c. Surge/Waves.
There will also be some rough and pounding surf, especially for parts of Nova Scotia and Newfoundland. Large waves will reach the Southwestern Shore of Nova Scotia on Saturday and build to near 10 metres over the Eastern Shore Saturday night. These waves will likely reach southern Newfoundland by Sunday morning. Waves near or higher than 5 metres will impact north facing coasts of the Gulf of St. Lawrence. Note that waves will break higher along some of the coastlines, and dangerous rip currents are likely. Please exercise extreme caution. Storm surge is possible, mainly for parts of Nova Scotia, Prince Edward Island, and Newfoundland, but it is too early to be specific about significant impacts, if any.
3. Marine weather impacts and warnings summary.
As Hurricane Dorian moves into our waters, there is a good chance of hurricane force southeasterlies near and south of the track, mainly over southern Atlantic forecast waters. As the storm moves into the Maritimes, storm to hurricane force northwesterlies will likely develop behind it. Waves in excess of 12 metres are likely south of the storm track, beginning late Saturday over southwestern waters and approaching southern Newfoundland Sunday morning.
Forecasters: McArthur, Mercer, Couturier
