[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 091815 CCA
TWDAT

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
215 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...SPECIAL FEATURES...Corrected for Irma position

At 09/1800 UTC, the center of Hurricane Irma is near 23.1N 80.2W
or about 125 NM SE of Key West, Florida, moving W, or 280
degrees, at 8 knots. The estimated minimum central pressure is
up to 941 mb. The maximum sustained wind speeds are 110 kt with
gusts to 135 kt. Numerous strong convection is noted within 60
nm in the NW and 90 nm in the SE semicircles of the center.
Scattered moderate isolated strong convection is elsewhere
within 240 NM in the NE quadrant, 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 moving along the N coast of Cuba.
Squalls have spread over the Florida Keys and south Florida.
Homestead, Florida reported a wind gust of 54 kt shortly before
1500 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 09/1500 UTC, the center of Hurricane Jose is near 18.8N
61.9W, or about 85 NM E 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 nm of the center of Jose. Scattered moderate to strong
convection is elsewhere within 150 NM in the NE and 90 NM in the
SE semicircles 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.

At 09/1200 UTC, the center of the remnant low of Katia is near
20.0N 97.9W, moving WSW, or 240 degrees, at 2 knots. The
estimated minimum central pressure is 1004 mb. The maximum
sustained wind speeds are 25 kt with gusts to 30 kt. Clusters of
moderate to strong convection is within 90-120 NM of the center
over the high terrain of SE Mexico. The last advisory has been
issued on T.D. Katia.

...TROPICAL WAVES...

A tropical wave has emerged off the west coast of Africa with
axis from 17N17W to 1012 mb low pressure near 10N19W to 04N19W
moving W at 10 to 15 kt. Scattered moderate to strong convection
as noted within 240 NM W of the wave axis and low pressure near
10N19W. Scatterometer data indicated a closed low along the wave
axis with convection fairly well organized.

A tropical wave extends from 15N49W to 05N51W, moving west at 15
to 20 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 15N between 47W and 54W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the W coast of Africa near 12N17W
to 09N20W to 11N27W. The ITCZ continues from 11N27W to 11N40W to
09N55W to 12N59W. ASide from convection associated with the two
tropical waves, there is no significant convection associated
with the monsoon trough/ITCZ.

...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 much of the Gulf E of 90W.
WSR-88D data from Key West shows a band of squalls extending from
near Marco Island Florida to near the N coast of Cuba spreading
NW. Patches of low clouds with pockets of shower activity were
noted elsewhere over the Gulf. Most of the convection associated
with former T.D. Katia moved inland over Mexico as the system has
dissipated along the Sierra Madre Mountains. The potential for
additional 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 is along the north coast of Cuba moving W. 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 to numerous showers and thunderstorms
were noted over the central Caribbean Sea between 68W and 75W
streaming northward over portions of Haiti and the Dominican
Republic. Hurricane Jose is approaching 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 4-6 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 mosture 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 9-13 foot range as a result of swell generated by
Hurricane Irma. These seas will increase on Sunday as Hurricane
Irma moves along the Florida west coast and the large wind field
affects the western Atlantic. Otherwise, a 1031 mb Azores high
is centered near 43N32W with ridging extending to the W
Atlantic. 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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