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NOAA Winter 2019-2020 Season Outlook – November 1, 2019
Tropical Weather Update – October 17, 2019
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Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Thu Oct 17 2019
For the North Atlantic…Caribbean Sea and the Gulf of Mexico:
1. Showers and thunderstorms associated with a broad area of low
pressure located over the southwestern Gulf of Mexico continue to
show signs of organization. Environmental conditions are expected
to be conducive for additional development, and a tropical or
subtropical storm is likely to form later today or tonight while the
system moves generally northeastward over the western Gulf of
Mexico. The low is forecast to approach the northern or
northeastern Gulf Coast on Friday or Saturday and regardless of
development, the system is likely to produce gusty winds and rough
surf over those areas. Locally heavy rainfall is also possible
across portions of the southeast U.S. late this week and this
weekend. Interests along the northern and northeastern Gulf coast
should monitor the progress of this system. For more information
about marine hazards while the low moves across the Gulf of Mexico,
see products issued by the Tropical Analysis and Forecast Branch of
the National Hurricane Center. An Air Force Reserve reconnaissance
aircraft is scheduled to investigate the system this afternoon, if
necessary.
* Formation chance through 48 hours…high…80 percent.
* Formation chance through 5 days…high…80 percent.
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFAT1, WMO header FZNT01
KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php
Offshore Waters Forecasts for the Gulf of Mexico issued by the
National Weather Service can be found under AWIPS header MIAOFFNT4,
WMO header FZNT24 KNHC, and online at
www.hurricanes.gov/text/MIAOFFNT4.shtml
Weather Outlook – Monday, October 7, 2019
Wind Fields Friday
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Oct 7 2019For the North Atlantic…Caribbean Sea and the Gulf of Mexico:
1. A non-tropical low pressure system located over the central Atlantic
Ocean between Bermuda and the Azores is producing gale-force winds
to the north of its center. Environmental conditions are forecast
to be generally conducive for the low to acquire some subtropical or
tropical characteristics during the next day or two, and this system
could become a tropical or subtropical storm on Tuesday or Wednesday
while it moves slowly westward. Upper-level winds are expected to
become unfavorable for further development by Wednesday night.
Additional information on this system can be found in High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours…medium…50 percent.
* Formation chance through 5 days…medium…50 percent.
2. Showers and thunderstorms located over the western Atlantic
between the southeastern coast of the United States and Bermuda
are associated with a trough of low pressure. This system is
forecast to move northwestward and a non-tropical low pressure area
is expected to form when the system interacts with a frontal
boundary in a couple of days. The low could acquire some
subtropical characteristics later in the week while it meanders
off the east coast of the United States. Additional information on
this system can also be found in High Seas Forecasts issued by the
National Weather Service.
* Formation chance through 48 hours…low…near 0 percent.
* Formation chance through 5 days…low…30 percent.
3. A trough of low pressure extending from the Straits of Florida
northeastward across the southern Florida peninsula is producing
disorganized showers and thunderstorms. Some slight development of
this system is possible on Tuesday when it moves over the far
western Atlantic. The disturbance is forecast to merge with a
frontal boundary and developing low off the east coast of the
United States by Wednesday, and no further development is
anticipated after that time. Regardless of development, this system
is expected to produce locally heavy rainfall over portions of the
the southern Florida peninsula during the next day or so.
* Formation chance through 48 hours…low…10 percent.
* Formation chance through 5 days…low…10 percent.
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFAT1, WMO header FZNT01
KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php
Tropical Depression #10 – September 17, 2019
Tropical Depression Ten Discussion Number 1
NWS National Hurricane Center Miami FL AL102019
1100 AM AST Tue Sep 17 2019
Deep convection associated with the area of low pressure over the
central Atlantic has become more persistent and better organized
this morning. Data T-numbers from both SAB and TAFB are 2.0 on the
Dvorak scale, therefore advisories are being initiated on a tropical
depression. The initial intensity is set at 30 kt, in line with the
satellite estimates. The depression is forecast to move over
gradually increasing sea surface temperatures within a favorable
upper-level environment. The only negative factor for
intensification appears to be some nearby dry air, but with low
shear conditions expected, so steady strengthening is forecast
during the next several days. The NHC forecast calls for the
depression to become a tropical storm later today, and attain
hurricane status within 72 hours. The NHC intensity forecast is in
good agreement with the SHIPS and LGEM statistical models.
Since the depression is still in the development phase, the initial
motion is a somewhat uncertain 295/10 kt. A strong deep-layer
ridge to the north of the cyclone should steer the depression
generally west-northwestward at a faster forward speed during the
next few days. The track guidance is in relatively good agreement
through 72 hours, and brings the cyclone near the northern Leeward
Islands in about 3 days. By late in the period, the cyclone is
expected to reach the western periphery of the ridge, and there is
increasing spread among the guidance. The global model ensemble
means are along the right side of the envelope while the HWRF and
UKMET are along the left side. The NHC track lies close the
consensus aids, which is also in good agreement with the latest
ECMWF.
Interests in the northern Leeward Islands should monitor the
progress of this system.
FORECAST POSITIONS AND MAX WINDS
INIT 17/1500Z 12.9N 44.9W 30 KT 35 MPH
12H 18/0000Z 13.8N 46.1W 35 KT 40 MPH
24H 18/1200Z 14.7N 47.9W 40 KT 45 MPH
36H 19/0000Z 15.5N 50.2W 45 KT 50 MPH
48H 19/1200Z 16.3N 52.9W 55 KT 65 MPH
72H 20/1200Z 18.2N 59.2W 65 KT 75 MPH
96H 21/1200Z 20.2N 64.7W 75 KT 85 MPH
120H 22/1200Z 22.5N 69.0W 80 KT 90 MPH
Update Hurricane Dorian – September 6, 2019
Hurricane Dorian Discussion Number 52
NWS National Hurricane Center Miami FL AL052019
500 AM EDT Fri Sep 06 2019
The center of the eye of Hurricane Dorian is located just off the
coast of North Carolina not far from Cape Lookout. Based on data
from the Air Force Hurricane Hunters and Doppler radar velocities,
the initial intensity is set at 80 kt. This estimate is a
compromise between the flight-level winds and SFMR values. The
minimum pressure remains quite low, 956 mb, based on surface
observations and aircraft fixes. There have been several reports in
eastern North Carolina of sustained tropical-storm-force winds and
hurricane-force gusts, with the strongest winds being reported in
the northern eyewall.
Dorian is moving northeastward at 12 kt. A faster northeastward
motion is expected during the next few days as a mid- to upper-level
trough, currently over the U.S. Great Lakes, approaches the system
and accelerates the steering flow. This track forecast takes the
hurricane along the coast of North Carolina during the next several
hours and near or over Atlantic Canada this weekend. The models
are tightly clustered, and the NHC track forecast lies near the
middle of the guidance envelope.Hu
The hurricane is expected to gradually weaken during the next couple
of days due to an increase in wind shear and drier air. Dorian is
expected to cross the north wall of the Gulf Stream current in about
36 hours, and head over much colder waters after that. These
atmospheric and oceanic conditions should cause the cyclone to
become a powerful hurricane-force extratropical in about 2 days. As
the system gains latitude, the tropical-storm-force winds are
expected to expand significantly. The NHC intensity forecast is
largely an update of the previous one and in line with the various
consensus aids.
Key Messages:
- Life-threatening storm surge and dangerous winds are expected
to continue along portions of the North Carolina coast, portions of
southeast Virginia and the southern Chesapeake Bay. 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.
- Flash flooding is occurring, and will continue to become more
widespread across the eastern Carolinas and far southeast Virginia
this morning. 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 06/0900Z 34.6N 76.2W 80 KT 90 MPH
12H 06/1800Z 36.0N 74.1W 75 KT 85 MPH
24H 07/0600Z 38.8N 69.9W 75 KT 85 MPH
36H 07/1800Z 42.5N 65.4W 70 KT 80 MPH
48H 08/0600Z 46.7N 61.6W 60 KT 70 MPH…POST-TROP/EXTRATROP
72H 09/0600Z 53.0N 52.0W 45 KT 50 MPH…POST-TROP/EXTRATROP
96H 10/0600Z 58.0N 36.0W 40 KT 45 MPH…POST-TROP/EXTRATROP
120H 11/0600Z 0.0S 0.0W 0 KT 0 MPH…DISSIPATED