Tropical Report

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Fri Sep 15 2017

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

The National Hurricane Center is issuing advisories on Tropical
Storm Jose, located over the southwestern Atlantic Ocean, and on
newly developed Tropical Depression Fourteen, located over the
eastern Atlantic Ocean.

1. A tropical wave located about 1200 miles east-southeast of the
Lesser Antilles continues to produce disorganized showers and
thunderstorms. Environmental conditions are expected to be
conducive for gradual development, and a tropical depression is
likely to form early next week. Interests in the Lesser Antilles
should closely monitor the progress of this system while it moves
westward to west-northwestward at about 15 mph.
* Formation chance through 48 hours…medium…40 percent.
* Formation chance through 5 days…high…80 percent.

Public Advisories on Tropical Depression Fourteen are issued under
WMO header WTNT34 KNHC and under AWIPS header MIATCPAT4.
Forecast/Advisories on Tropical Depression Fourteen are issued under
WMO header WTNT24 KNHC and under AWIPS header MIATCMAT4.

Forecaster Zelinsky

JOSE EXPECTED TO PRODUCE HIGH SURF AND LIFE-THREATENING RIP CURRENTS ALONG PORTIONS OF THE U.S. EAST COAST

Tropical Storm Jose Discussion Number 40
NWS National Hurricane Center Miami FL AL122017
500 AM AST Fri Sep 15 2017

Jose is showing signs of becoming better organized. The low-level
center is embedded well within a growing central dense overcast
(CDO). Despite the improved appearance of Jose, the Dvorak
classifications are largely unchanged since 6 hours ago, so the
intensity has been held at 60 kt. There has been no change in any
of the intensity guidance, so I see no reason to substantially
change the intensity forecast. The new NHC intensity forecast is
very close to the multi-model consensus, and continues to show Jose
regaining hurricane status later today. Beginning around 72 h, an
increase in shear should bring an end to intensification, and will
probably cause Jose to weaken. Once again, some of the global
models suggest that Jose will remain a tropical cyclone through day
5, but that extratropical transition could begin around that time.
If that happens, baroclinic forcing could help maintain the
intensity of Jose, even as the shear increases.

Because the low-level circulation center of Jose is hidden beneath
the CDO, the initial position and heading are fairly uncertain. My
best estimate of the current motion is 290/7 kt. Despite the
initial motion uncertainty, the global models are coming into better
agreement on the track of Jose. The UKMET is now more in line with
the other models in keeping the center of Jose offshore of the U.S.
That said, the most recent GFS and ECMWF runs show a farther west
track, so the official track forecast has been shifted about 30 n mi
in that direction. My new forecast is near the HFIP corrected
consensus, and now lies near the middle of the guidance envelope.

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 along the
mid-Atlantic coast of the U.S. during the next few days. These
swells are likely to cause dangerous surf and rip current
conditions.

2. Jose could produce other direct impacts next week along portions
of the east coast of the United States from North Carolina northward
to New England, but it is too soon to determine what those impacts
might be or where they could occur. Interests along U.S. east coast
from North Carolina northward to New England should monitor the
progress of Jose during the next several days.

FORECAST POSITIONS AND MAX WINDS

INIT 15/0900Z 25.9N 68.7W 60 KT 70 MPH
12H 15/1800Z 26.4N 70.0W 65 KT 75 MPH
24H 16/0600Z 27.4N 71.5W 70 KT 80 MPH
36H 16/1800Z 28.3N 72.4W 75 KT 85 MPH
48H 17/0600Z 29.4N 72.7W 80 KT 90 MPH
72H 18/0600Z 32.2N 72.4W 80 KT 90 MPH
96H 19/0600Z 35.0N 72.3W 75 KT 85 MPH
120H 20/0600Z 38.0N 71.0W 70 KT 80 MPH

$$
Forecaster Zelinsky

TROPICAL DEPRESSION MOVING WESTWARD OVER THE FAR EASTERN ATLANTIC… …FORECAST TO BECOME A TROPICAL STORM

Tropical Depression Fourteen Discussion Number 2
NWS National Hurricane Center Miami FL AL142017
500 AM AST Fri Sep 15 2017

The cloud pattern of the depression rapidly became better organized
several hours ago when advisories were initiated. Since that time,
the structure has changed little, and Dvorak T-numbers suggest that
the winds are still 30 kt. Currently, the cyclone is embedded
within a favorable environment of low shear, and the NHC forecast
calls for gradual intensification during the next 3 days. However,
the global models (primarily the GFS and the ECMWF) develop a large
upper-level trough over the central Atlantic which will bring high
shear over the cyclone by day 4. This should result in weakening as
indicated in the forecast.

Satellite fixes suggest that the depression has slowed down and is
moving toward the west or 270 degrees at 13 kt. The depression is
being steered by the subtropical ridge to the north. The same
trough that will cause an increase in the shear will also weaken the
subtropical ridge, causing the cyclone to turn more to the
west-northwest beyond 3 days. The NHC track is very close to HFIP
corrected consensus HCCA and the multi-model consensus TVCX. These
two models have been performing very well so far this season.

FORECAST POSITIONS AND MAX WINDS

INIT 15/0900Z 10.6N 27.3W 30 KT 35 MPH
12H 15/1800Z 11.0N 28.9W 35 KT 40 MPH
24H 16/0600Z 11.1N 30.4W 40 KT 45 MPH
36H 16/1800Z 11.2N 31.7W 45 KT 50 MPH
48H 17/0600Z 11.3N 32.6W 55 KT 65 MPH
72H 18/0600Z 12.2N 35.7W 60 KT 70 MPH
96H 19/0600Z 13.5N 40.0W 45 KT 50 MPH
120H 20/0600Z 15.0N 44.0W 40 KT 45 MPH

$$
Forecaster Avila