[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 152336
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Fri Sep 16 2022

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...SPECIAL FEATURES...

Tropical Storm Fiona is centered near 16.1N 56.1W at 15/0000 UTC
or 330 nm E of the Leeward Islands moving W at 12 kt. Estimated
minimum central pressure is 1005 mb. Maximum sustained wind
speed is 50 kt with gusts to 60 kt. Seas are currently peaking at
20 to 22 ft near and northeast of the center. Deep convection
has been sheared to the east of the center that is partially
exposed. Satellite imagery show numerous moderate to scattered
strong convection just east and southeast of the center from 14N
to 17N between 51W and 55W. On the forecast track, the center of
Fiona is expected to move across the Leeward Islands Friday night
and early Saturday, and move near the Virgin Islands and Puerto
Rico late Saturday into Sunday. Data from an Air Force Reserve
Hurricane Hunter aircraft indicate that maximum sustained winds
are near 52 kt (95 km/h) with higher gusts. Little change in
strength is forecast during the next few days. Fiona is expected
to produce heavy rainfall that could lead to flash and urban
flooding, along with isolated mudslides in higher terrains across
the aforementioned locations. Considerable flood impacts are
possible across eastern portions of Puerto Rico. Swells generated
by Fiona are beginning to affect the Leeward Islands and will
spread westward to the Virgin Islands and Puerto Rico on Friday
and Saturday. These swells could cause life- threatening surf and
rip current conditions. Please consult products from your local
weather office.

Please read the latest HIGH SEAS FORECAST issued by the National
Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest
T.S. Fiona NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is along 20W and S of 14N
moving W around 15 kt. Scattered moderate convection is ahead of
the wave axis from 06N to 12N between 20W and 27W.

A central Atlantic tropical wave is near 36W from 20N southward,
moving W at 10 to 15 kt. A few showers are near the northern end
of the wave axis.

A western Caribbean tropical wave is along 82W from western Cuba
southward to near western Panama, moving W around 10 kt. The wave
is helping to induce scattered showers and thunderstorms over
central Cuba and the Cayman Islands as well as over most of
Nicaragua and NE Honduras. A diffluent pattern aloft also support
this convective activity.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic Ocean through Guinea
Bissau near 12N16W, passing south of the Cabo Verde Islands at
11N24W to 15N40W. Aside for the convection associated with the
tropical wave along 20W, no significant convection is noted.

The eastern end of the East Pacific monsoon trough is triggering
scattered showers and thunderstorms over the southwestern
Caribbean Sea.

...GULF OF MEXICO...

A weak stationary front extends across northern Florida and the
northern Gulf of Mexico. Numerous showers and thunderstorms are
noted over Florida south of the front. Scattered showers and
thunderstorms are along the frontal boundary over the Gulf
waters. The most recent scatterometer data indicate moderate to
locally fresh NE winds in the wake of the front while mainly
gentle to moderate winds prevail ahead of the front. Seas are
generally 1-3 ft. Winds and seas could be higher near thunderstorms.

For the forecast, the stationary front will stick around for
another couple of days before dissipating late in the weekend.
High pressure will build over the southeast U.S. following the
front, maintaining gentle to moderate easterly breezes and slight
seas through early next week.

...CARIBBEAN SEA...

Tropical Storm Fiona is forecast to impact the northeast Caribbean.
Please refer to the Special Features Section for more details.

The pressure gradient between high pressure to the N near 29N57W
and Tropical Storm Fiona is creating a trade-wind surge over the
NE Caribbean. Recent scatterometer data show and area of fresh to
locally strong NE winds extending from the northern Leeward
Islands to S of Puerto Rico near 16N68W. Scattered showers and
isolated thunderstorms are within this area of winds. Similar
convective activity is also noted over the central Caribbean
behind the wave axis.

Satellite derived wind data also show gentle to moderate trades
across the remainder of the basin, with the exception of an area
of fresh to locally strong winds along the wave axis over the SW
Caribbean, just E of Providence and San Andres Islands. Seas are
generally 3-5 ft, except 5-6 ft over the central Caribbean.

For the forecast, T.S. Fiona will move to near 16.5N60W Fri afternoon,
17N64W Sat afternoon, 18N67W Sun afternoon, and 19N69W Mon afternoon.
Expect increasing winds and squalls over the NE Caribbean by Fri
and into the weekend. Otherwise, moderate to fresh trades will
prevail over the central Caribbean through Fri.

...ATLANTIC OCEAN...

Tropical Storm Fiona is forecast to impact portions of the
Atlantic and northeast Caribbean. Please refer to the Special
Features Section for more details.

A stationary front enters the forecast area near 31N77W, and
continues SW to across northern Florida. Numerous showers and
thunderstorms are over Florida and the NW Bahamas south of the
front. A surface trough is analyzed ahead of this front and runs
from 31N75W to south-central Florida. Moderate to fresh winds and
seas of 4-6 ft are in the wake of the front while mainly
moderate southerly winds and seas of 3-5 ft are ahead of the
front.

The remainder of the Atlantic forecast waters is under the
influence of a couple of high pressure systems. A surface trough
is between these features extending from 31N40W to 25N53W.
Convection is limited near the trough axis. Outside of Fiona,
mainly gentle to moderate winds dominate the Atlantic waters with
seas of 6-9 ft in northerly swell N of 20N and E of 50W. Moderate
to locally fresh NE winds are N of of the Leeward Islands and
Puerto Rico with seas of 5-7 ft.

For the forecast west of 55W, Tropical Storm Fiona will move to
near 16.5N60W Fri afternoon, 17N64W Sat afternoon, 18N67W Sun
afternoon, and 19N69W Mon afternoon. Expect increasing winds,
seas and squalls near the path of Fiona. A stationary front is
draped off the northeast Florida coast. Expect this front to
linger near this area through most of the weekend, bringing
moderate NE winds north of it along with showers and
thunderstorms.

$$
GR
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