[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 092358
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
758 PM EDT Sat Sep 9 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2345 UTC.

...SPECIAL FEATURES...

At 10/0000 UTC, the center of Hurricane Irma is near 23.3N 80.8W
or about 95 NM SE of Key West, Florida, moving WNW, or 290
degrees, at 6 knots. The estimated minimum central pressure is
down to 932 mb. The maximum sustained wind speeds are 105 kt with
gusts to 120 kt. Numerous strong convection is noted within 120
nm in the E and 90 nm in the W semicircles of the center.
Scattered moderate isolated strong convection is elsewhere within
210 NM in the N semicircle and 150 NM in the S semicircle of the
center. WSR- 88D data from both Key West and Miami clearly show
the eye of hurricane Irma has begun to move away from the coast of
Cuba. Squalls have spread over the Florida Keys and south
Florida. Marathon, Florida reported a wind gust of 57 kt shortly
before 2100 UTC and Fort Lauderdale-Hollywood airport reported a
gust to 61 kt at 2025 UTC. Please read the latest NHC Intermediate
Public Advisory under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC
and, the Forecast/ Advisory under AWIPS/WMO headers
MIATCMAT1/WTNT21 KNHC for more details.

At 10/0000 UTC, the center of Hurricane Jose is near 19.4N 62.9W,
or about 70 NM N of the northern Leeward Islands, moving NW, or
305 degrees, at 12 knots. The estimated minimum central pressure
is 945 mb. The maximum sustained wind speeds are 125 kt with gusts
to 150 kt. Numerous strong convection is noted within 60 to 75 nm
of the center of Jose, and within 30-45 nm either side of a line
from 20N60W to 18N61W. Scattered moderate to strong convection is
elsewhere within 180 NM in the NE semicircle of the center. Please
read the latest NHC Intermediate Public Advisory under AWIPS/WMO
headers MIATCPAT2/WTNT32 KNHC and, the Forecast/Advisory under
AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details.

...TROPICAL WAVES...

A tropical wave has emerged off the west coast of Africa with
axis from 16N19W to 1010 mb low pressure near 10N20W to 04N20W
moving W at 10 to 15 kt. Scattered moderate to strong convection
as noted within 90 NM of the coast of Africa from 11N to 14N.
Scattered moderate isolated strong convection was noted within
180 NM W of the wave axis from 09N to 13N. Earlier Scatterometer
data indicated a closed low along the wave axis with convection
fairly well organized.

A tropical wave extends from 18N51W to 05N52W, moving west at 15
knots. This wave coincides with moderate troughing in 700 mb wind
fields. SSMI TPW satellite imagery indicates the wave is embedded
in an area of deep layer moisture. Scattered moderate to strong
convection is noted from 12N to 16N between 46W and 55W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the W coast of Africa near 14N17W
to 10N20W to 11N35W. The ITCZ continues from 11N35W to 11N45W to
10N55W to 12N60W. Scattered moderate convection was noted within
180 to 240 nm S of the monsoon trough/ITCZ between 25W and 40W.

...DISCUSSION...

...THE GULF OF MEXICO...

Multilayered cloudiness is increasing over the southeastern Gulf
of Mexico in advance of hurricane Irma. Surface observations
indicate NE winds are increasing over the Gulf E of 90W. Buoys
reports indicated seas are building to 7 to 9 ft over the region.
WSR-88D data from Key West shows bands of squalls extending from
the W coast of Florida S of Fort Myers to the N coast of Cuba
spreading NW. Patches of low clouds with pockets of shower
activity were noted elsewhere over the Gulf with the shower
activity focused along the coast of Mexico near Tampico. This
activity was near a surface trough which extended from 27N96W to
22N95W. Convection associated with the former T.D. Katia moved
inland over Mexico and is weakening. The potential for additional
locally heavy rainfall exists for portions of the Sierra Madre as
the remnants of Katia push further inland tonight and Sunday.

...THE CARIBBEAN SEA...

Hurricane Irma has emerged off the north coast of Cuba now moving
NW. Bands of strong convection are over sweeping over portions of
central Cuba producing very heavy rainfall and flash flooding.
Convective bands extend southward in the Caribbean to 19N. A large
area of scattered but weakening showers and thunderstorms were
noted over the central Caribbean Sea between 68W and 74W
streaming northward over portions of Haiti and the Dominican
Republic. Hurricane Jose is brushing by the northern Leeward
Islands with outer feeder bands sweeping over Antigua, Barbuda and
Anguilla. Outside of the influence of Irma, a light to moderate
sub-normal trade wind regime prevails over most of the Caribbean
as the pressure gradient to the south of Irma and Jose remains
weak. Seas outside the influence of Hurricanes Irma and Jose are
generally in the 3-5 ft range over the eastern Caribbean, and 2-4
ft over the western Caribbean.

...HISPANIOLA...

Scattered to numerous showers and thunderstorms are streaming
northward from the Caribbean across Haiti and the western
Dominican Republic. This low level moisture feed will gradually
move west of the island on Sunday as Hurricane Irma moves further
away from the area.

...THE ATLANTIC OCEAN...

Please see the special features section above for information
concerning Hurricanes Irma and Jose. Besides Hurricanes Irma and
T.S.Jose, gentle to moderate winds and seas in the 5-7 ft range
prevail. Seas over the extreme western north Atlantic waters are
in the 7-10 foot range as a result of swell generated by
Hurricane Irma. These seas will increase on Sunday as Hurricane
Irma is forecast to move northward along the Florida west coast
and the large wind field affects the western Atlantic. Otherwise,
a 1032 mb Azores high is centered near 42N33W with ridging
extending to the E Atlantic. A surface trough extended from
32N45W to 26N44W. Moderate to fresh trades are evident in
satellite derived wind data between the monsoon trough/ITCZ and
25N between 20W and 50W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Cobb
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