Tropical Report

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Mon Sep 18 2017

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

The National Hurricane Center is issuing advisories on Hurricane
Jose, located a few hundred miles southeast of Cape Hatteras, North
Carolina, on Tropical Depression Lee, located over the eastern
Atlantic Ocean, and on Hurricane Maria, located just east of the
Lesser Antilles.

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Cangialosi

 

NOAA AND AIR FORCE HURRICANE HUNTERS CURRENTLY INVESTIGATING JOSE… …DANGEROUS SURF AND RIP CURRENTS EXPECTED ALONG THE EAST COAST OF THE UNITED STATES

Hurricane Jose Discussion Number 52
NWS National Hurricane Center Miami FL AL122017
500 AM EDT Mon Sep 18 2017

Jose is certainly looking less tropical characteristically this
morning. The 25 to 30 kt of southwesterly shear indicated in the
CIMSS shear product and the SHIPS model has separated the fragmented
inner core of Jose farther to the northeast of the partially exposed
surface circulation center. What remains of the deep convective
banding features of the cyclone are confined to the north and east
portions. The initial intensity is lowered a bit to 75 kt based on
the deteriorating cloud pattern and a blend of the subjective
T-number Dvorak estimates from TAFB and SAB. The aforementioned
deep-layer shear and decreasing oceanic temperatures are forecast to
induce a slow weakening trend through day 5. Because of the
significantly cooler water north of the Gulf Stream and a
persistently harsh upper-level wind environment, Jose should lose
its tropical characteristics around day 4, if not sooner. The
official intensity forecast follows suit and is weighed heavily on
the global models solution and is close to, but a little above, the
SHIPS guidance.

The initial motion is a little uncertain because of the significant
cloud structure change during the past 6 hours. Shortwave and
enhanced BD-curve infrared imagery reveal a more
north-northeastward short term motion, with the center possibly as
far east as 71.1W. However, an earlier GPM microwave image
and the satellite classification fixes indicated a position bit
farther to the west near 71.2 to 71.5W. As a compromise, I elected
to split the initial position between the two solutions which
yields a northward motion, at about 360/8 kt. There are no
changes to the forecast track philosophy. Jose should continue
northward during the next day or so, then turn north-northeastward
Wednesday as a mid-tropospheric trough passes north of the
hurricane. After the shortwave trough moves northeastward in
3 days, Jose is forecast to drift eastward, then turn
gradually southeastward and southward around day 4 as high
pressure builds over the northeastern United States. The NHC
forecast track has been nudged slightly to the right of the
previous advisory, due primarily to the short term
north-northeastward motion, and is based on a blend of the HCCA and
GFEX (ECMWF/GFS) guidance.

KEY MESSAGES:

1. While the center of Jose is currently forecast to remain offshore
of the U.S. coast, the large cyclone could cause some direct impacts
from Delaware northward to New England, and any deviation to the
left of the NHC forecast track would increase the likelihood and
magnitude of those impacts. A Tropical Storm Watch is now in
effect from the Delaware coast to southeastern Massachusetts.
Interests elsewhere along the U.S. east coast from North
Carolina to New England should monitor the progress of Jose
through the next several days.

2. Minor to moderate coastal flooding is possible from Delaware
to southern New England during the next several days. Please see
products issued by local National Weather Service forecast offices.

3. Swells generated by Jose are affecting Bermuda, the Bahamas,
and much of the U.S. east coast. These swells are likely to cause
dangerous surf and rip current conditions for the next several days
in these areas.

4. Jose will produce heavy rain as it passes near southern New
England and the mid-Atlantic on Tuesday and Wednesday. Total
accumulations of 3 to 5 inches are expected over eastern Long
Island, southeast Connecticut, Rhode Island, and southeast
Massachusetts, including Martha’s Vineyard and Nantucket. Based on
the current forecast, the risk of flooding will be limited in scope.
Any deviation to the left of the forecast track, however, could
bring heavier and more widespread rainfall to southern New England,
Long Island, New York City, and New Jersey. If this deviation were
to occur, the risk of urban flash flooding and some river flooding
would increase.

FORECAST POSITIONS AND MAX WINDS

INIT 18/0900Z 33.0N 71.4W 75 KT 85 MPH
12H 18/1800Z 34.2N 71.4W 75 KT 85 MPH
24H 19/0600Z 35.8N 71.5W 70 KT 80 MPH
36H 19/1800Z 37.4N 71.2W 65 KT 75 MPH
48H 20/0600Z 38.8N 70.5W 60 KT 70 MPH
72H 21/0600Z 39.9N 68.5W 50 KT 60 MPH
96H 22/0600Z 39.2N 68.1W 50 KT 60 MPH…POST-TROPICAL
120H 23/0600Z 38.3N 68.2W 45 KT 50 MPH…POST-TROPICAL

$$
Forecaster Roberts

 

POORLY ORGANIZED LEE EXPECTED TO BECOME A REMNANT LOW BY TONIGHT

Tropical Depression Lee Discussion Number 14
NWS National Hurricane Center Miami FL AL142017
500 AM AST Mon Sep 18 2017

Lee’s cloud pattern has deteriorated considerably this morning.
All that remains of the deep convection are a few fragmented bands
in the northeast quadrant. The initial intensity is generously
held at 30 kt for this advisory. Deep-layer shear is expected to
increase during the next 12 to 24 hours, and this inhibiting
factor should prevent the cyclone from maintaining what is left
of the deep convection. Consequently, Lee should degenerate into a
remnant low by tonight.

The initial motion is estimated to be west-northwestward or 290/11
kt. A west-northwestward to northwestward motion is expected
through the entire forecast period, or until the cyclone dissipates
in 3 days or earlier. No significant changes were made to the NHC
track from previous advisory and the official forecast is based
mainly on the HFIP Corrected Consensus technique.

FORECAST POSITIONS AND MAX WINDS

INIT 18/0900Z 14.1N 39.8W 30 KT 35 MPH
12H 18/1800Z 14.9N 41.2W 25 KT 30 MPH
24H 19/0600Z 16.0N 42.7W 25 KT 30 MPH…POST-TROP/REMNT LOW
36H 19/1800Z 17.1N 44.0W 25 KT 30 MPH…POST-TROP/REMNT LOW
48H 20/0600Z 18.5N 45.1W 20 KT 25 MPH…POST-TROP/REMNT LOW
72H 21/0600Z…DISSIPATED

$$
Forecaster Roberts

 

MARIA HEADED FOR THE LEEWARD ISLANDS… …EXPECTED TO BECOME A MAJOR HURRICANE BY TONIGHT OR EARLY TUESDAY

Hurricane Maria Discussion Number 8
NWS National Hurricane Center Miami FL AL152017
500 AM AST Mon Sep 18 2017

Maria is maintaining a fairly circular area of intense convection
with some accompanying banding features. There has also been
considerable lightning occurring near the center over the past
several hours, confirming the vigor of the core convection. The
current intensity is set at 80 kt which is a blend of Dvorak
estimates from TAFB and SAB. An Air Force Reserve Unit Hurricane
Hunter aircraft is scheduled to investigate Maria in a couple of
hours and will give another estimate of the strength of the
hurricane. With warm waters and weak shear anticipated along the
projected track of Maria, additional strengthening is forecast.
According to the SHIPS-RI guidance, there is a significant
probability of rapid intensification over the next day or two. The
official intensity forecast is similar to the model consensus and
the latest HWRF simulation. Maria is likely to be at category 3 or
4 intensity by the time it moves into the extreme northeastern
Caribbean Sea.

Geostationary satellite fixes and the position estimates from the
Martinique radar give a motion of about 290/11 kt. A high pressure
area to the north of Maria should maintain the west-northwestward
motion for the next several days. Late in the forecast period, the
high weakens and this should cause a turn toward the
north-northwest. The official track forecast is similar to the
HFIP Corrected Consensus model as well as the ECMWF and lies on the
left side of the guidance suite.

KEY MESSAGES:

1. Maria is likely to strengthen significantly, and is expected to
be at major hurricane intensity when it affects portions of the
Leeward Islands over the next few days, bringing dangerous wind,
storm surge and rainfall hazards.

2. Maria is likely to affect the British and U.S. Virgin Islands and
Puerto Rico by mid week as a dangerous major hurricane. Hurricane
watches have been issued for the U.S. and British Virgin Islands
as well as for Puerto Rico. Interests in these areas should monitor
the progress of Maria and follow any advice given by local
officials.

FORECAST POSITIONS AND MAX WINDS

INIT 18/0900Z 14.6N 59.5W 80 KT 90 MPH
12H 18/1800Z 15.1N 60.6W 90 KT 105 MPH
24H 19/0600Z 15.8N 62.0W 105 KT 120 MPH
36H 19/1800Z 16.6N 63.4W 115 KT 130 MPH
48H 20/0600Z 17.4N 64.8W 120 KT 140 MPH
72H 21/0600Z 19.0N 67.7W 115 KT 130 MPH
96H 22/0600Z 21.0N 70.4W 110 KT 125 MPH
120H 23/0600Z 23.5N 72.0W 105 KT 120 MPH

$$
Forecaster Pasch