Tropical Report

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sat Sep 16 2017

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Hurricane
Jose, located several hundred miles south-southeast of Cape
Hatteras, North Carolina, and on Tropical Depression Fourteen,
located over the eastern Atlantic Ocean.

1. Showers and thunderstorms associated with a tropical wave located
about 700 miles east of the Windward Islands continue to show signs
of organization, but it is unclear if the system has a well-defined
center of circulation. Environmental conditions are conducive for
additional development, and a tropical depression or tropical storm
could form at any time today or on Sunday while the system moves
west-northwestward at about 15 mph. Hurricane or tropical storm
watches could be issued for portions of the Lesser Antilles later
today, and interests on those islands should closely monitor the
progress of this system.
* Formation chance through 48 hours…high…90 percent.
* Formation chance through 5 days…high…90 percent.

Forecaster Berg

 

JOSE MOVING STEADILY NORTHWESTWARD… …TROPICAL STORM WATCHES POSSIBLE IN THE UNITED STATES LATER TODAY

Hurricane Jose Discussion Number 44
NWS National Hurricane Center Miami FL AL122017
500 AM EDT Sat Sep 16 2017

NOAA buoy 41047 has been very helpful in determining the position
and central pressure of Jose this morning. The center of Jose
passed just north of the buoy around 0500 UTC, and a surface
pressure of 986 mb with 20-30 kt of winds was measured. Since the
buoy did not sample the stronger northeast quadrant of the storm,
the initial intensity has been held at 70 kt. Another
reconnaissance flight later today will provide a better estimate of
the max winds.

There is some indication of northeasterly shear inhibiting the
outflow of Jose, which is restricted in the northwest quadrant.
Since it appears to be negatively affecting the cyclone, the shear
may inhibit any more substantial intensification. The intensity
guidance is a little lower than before, so the new NHC forecast has
been lowered slightly, and is now close to the intensity consensus
throughout the forecast.

Jose has moved just a little to the southwest of the expected track,
and the initial motion remains 305/8 kt. However, Jose is still
expected to begin turning toward the north later today, so no
significant changes were needed for the early part of the forecast.
More importantly, the GFS and ECMWF have met in the middle of their
previous solutions, and have come into much better agreement on the
forward speed of the hurricane beyond day 2. The new track forecast
is very close to a 50/50 blend of the GFS and ECMWF. Although
confidence in the track forecast is a little higher due to the model
agreement, it is still important to note that the average NHC track
errors at days 4 and 5 are about 175 and 225 miles, respectively.

While the official track forecast keeps the center of Jose offshore
for the next few days, all of the global models show the hurricane
becoming rather large by late this weekend as it moves to the east
of North Carolina. For that reason, a tropical storm watch may be
needed for a portion of the North Carolina coast later today.

KEY MESSAGES:

1. Swells generated by Jose are affecting Bermuda, the Bahamas, the
northern coasts of Hispaniola and Puerto Rico, and the southeast
coast of the United States, and will spread northward, reaching the
mid-Atlantic coast and the coast of southern New England during the
next few days. These swells are likely to cause dangerous surf and
rip current conditions.

2. Although the center of Jose is forecast to pass well east of the
North Carolina coast early next week, tropical-storm-force winds are
expected to extend well west of the center and could approach the
North Carolina Outer Banks on Monday. Farther north along the U.S.
east coast, the chance of some direct impacts from Jose is
increasing, but it is too soon to determine their exact magnitude
and location. Interests along the U.S. east coast from North
Carolina to New England should monitor the progress of Jose through
the weekend.

FORECAST POSITIONS AND MAX WINDS

INIT 16/0900Z 27.9N 71.8W 70 KT 80 MPH
12H 16/1800Z 28.6N 72.5W 75 KT 85 MPH
24H 17/0600Z 29.7N 72.5W 75 KT 85 MPH
36H 17/1800Z 31.2N 72.2W 75 KT 85 MPH
48H 18/0600Z 32.9N 72.1W 75 KT 85 MPH
72H 19/0600Z 35.8N 71.8W 65 KT 75 MPH
96H 20/0600Z 39.5N 70.5W 60 KT 70 MPH
120H 21/0600Z 41.0N 66.5W 50 KT 60 MPH

$$
Forecaster Zelinsky

 

DEPRESSION MOVING WESTWARD OVER OPEN WATERS

Tropical Depression Fourteen Discussion Number 6
NWS National Hurricane Center Miami FL AL142017
500 AM AST Sat Sep 16 2017

The center of the depression continues to be located on the north
side of a curved band of deep convection, and the outflow is only
expanding to the south and west. Dvorak T-numbers have not changed
and support an initial intensity of 30 kt. The depression has the
opportunity to become a tropical storm during the next 24 to 36
hours before a pronounced upper-level trough digs southward over the
eastern Atlantic and brings strong northerly shear over the cyclone.
The NHC forecast shows some strengthening through Sunday, but
weakening should begin thereafter. The system should degenerate
into a remnant low in about 4 days.

The depression is moving westward at 6 kt, steered by a narrow
mid-level ridge to the north. The same trough that is bringing the
shear will likely further weaken the ridge to the north, and this
should result in a turn of the cyclone toward the west-northwest.
The NHC track is in the middle of the guidance envelope through 48
hours, but after that time the forecast is uncertain since the
guidance spreads out considerably. During that last period, the NHC
forecast follows the HFIP corrected consensus HCCA and the trend of
the ECMWF.

FORECAST POSITIONS AND MAX WINDS

INIT 16/0900Z 12.6N 32.1W 30 KT 35 MPH
12H 16/1800Z 12.6N 33.2W 30 KT 35 MPH
24H 17/0600Z 12.6N 34.5W 35 KT 40 MPH
36H 17/1800Z 12.7N 35.7W 40 KT 45 MPH
48H 18/0600Z 13.3N 37.3W 30 KT 35 MPH
72H 19/0600Z 15.2N 41.0W 30 KT 35 MPH
96H 20/0600Z 17.0N 44.3W 25 KT 30 MPH…POST-TROP/REMNT LOW
120H 21/0600Z 18.0N 48.0W 25 KT 30 MPH…POST-TROP/REMNT LOW

$$
Forecaster Avila