[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200434
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Sep 20 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 0000 UTC surface analysis and satellite imagery through
0420 UTC.

...SPECIAL FEATURES...

Hurricane Fiona is centered near 20.6N 70.3W at 20/0300 UTC or 70
nm SE of Grand Turk Island moving NNW at 9 kt. Estimated minimum
central pressure is 971 mb. Maximum sustained wind speed is 95 kt
with gusts to 115 kt. Maximum seas with this system can reach 26
ft at this time, but are forecast to build to 46 ft over the next
48 hours as Fiona moves to a position near 26N71W by 22/0000 UTC.
Scattered to numerous moderate to strong convection is noted
within 210 nm of the center in the E semicircle, 180 nm SW
quadrant and 75 nm NW quadrant. Scattered moderate convection is
elsewhere within 300 nm NE quadrant, 360 nm SE quadrant and 150 nm
NW quadrant, including over Puerto Rico, the Virgin Islands, the
Dominican Republic and the Turks and Caicos Islands. Satellite
imagery shows a small eye of about 10 nm in diameter.
Strengthening is expected during the next couple of days, and
Fiona is forecast to become a major hurricane later today. On the
forecast track, the center of Fiona will pass near easternmost
Turks and Caicos early today. Swells generated by Fiona are
affecting the Virgin Islands, Puerto Rico, the northern coast of
Hispaniola, the Turks and Caicos Islands, and the southeastern
Bahamas. These swells will spread W across the SW Atlantic toward
the central and northwestern Bahamas and the east coast of the
United States through midweek. The swells could cause life-
threatening surf and rip current conditions. 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 NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

Shower and thunderstorm activity has increased in association
with a 1014 mb low pressure located over the central subtropical
Atlantic near 30N46W. Scattered moderate convection is noted north
of 29N between 46W-47W. Recent ASCAT satellite wind data show
fresh winds associated with this low pressure. Some slow
development is possible during the next couple of days, and a
tropical depression could form during that time before
environmental conditions become less conducive later this week.
The system should generally move toward the N or NE. The system
has a medium chance of tropical cyclone development within the
next 48 hours.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave extends its axis along 49/50W from
15N southward, moving W at 15 kt. Scattered moderate and isolated
strong convection is seen within 120 nm either side of the wave
axis from 07N to 13N.

An Atlantic Ocean tropical wave extends its axis along 59W from
20N southward to Guyana, moving W at 10-15 kt. A surface trough
extends N of the wave from 20N58W to 26N55W. Scattered moderate
convection is noted within 90 nm east and within 60 nm west of the
wave axis from 11N to 14.5N. These showers and thunderstorms will
affect the Windward Islands this morning during the next several
hours. Isolated showers and tstorms are along and E of the
surface trough, from 22N-28N between 50W-58W.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through coastal Senegal near 14N17W to
10N24W to 08N36W. The ITCZ continues from 08N36W to 11N48W, then
resumes W of a tropical wave from 10N51W to 11N57W. Scattered
moderate convection is noted from 06N to 12N between 28W and 38W,
and from 07N-13N between 52W-57.5W.

GULF OF MEXICO...

High pressure over the southeastern United States extends weak
surface ridging southwestward into the north-central and NW Gulf
of Mexico, supporting moderate NE to E winds across the eastern
and central Gulf. A surface trough is over the far eastern Gulf,
off southwest Florida. Recent buoy observations indicate seas are
2-4 ft across the Gulf, highest in the central Gulf. Seas could be
as high as 5 ft there. For the forecast, high pressure over the
southeastern U.S. will maintain gentle to moderate easterly
breezes and slight seas the next few days.

CARIBBEAN SEA...

Please see the Special Features section above for information on
Hurricane Fiona.

Outside of convection associated with Fiona, scattered showers
and thunderstorms are within 60 nm of the coast of Honduras.
Scattered showers and tstorms are noted within 120 nm off the
coast of Venezuela.

Fresh N to NE winds are occurring in the Windward Passage, and in
between Jamaica and Haiti currently, where seas are 4-5 ft.
Moderate SE winds are occurring east of 70W, while moderate W
winds are noted on the latest scatterometer data between 70W-78W.
Seas are still 5-7 ft over the east Caribbean in large swell
coming through the Mona Passage. Seas are still 8 ft or higher in
the Mona passage, but will be subsiding later today. In the NW
Caribbean, gentle to moderate NE to E winds prevail, where seas
are 1-2 ft.

Hurricane Fiona is north of the basin, located about 70 nm SE of
Grand Turk Island, and will continue to move farther away from the
Caribbean through Wed while strengthening. Residual swell over
the eastern Caribbean from Fiona will subside through today. A
tropical wave, currently east of the area near 50W, is expected to
move across the Tropical N Atlantic tonight through Wed, across
the eastern Caribbean Wed night through Fri night and across the
central Caribbean Sat and Sat night.

ATLANTIC OCEAN...

Refer to the Special Features section above for details on
Hurricane Fiona and the 1014 mb low near 30N46W. Refer to the
Tropical Waves section for details on the tropical waves moving
across the basin.

A surface trough extends from 31N79W southwestward across the
Florida Peninsula. Scattered showers and tstorms prevail across
the western Atlantic waters mainly north of 28N and west of 76W.
Fresh trade winds are noted in the tropical Atlantic from 11N-18N
between 40W-56W. Seas are 5-6 ft in this area. Elsewhere outside
of the circulation of Fiona, winds are moderate or weaker with
seas 3-6 ft.

The area of 20 kt or greater winds associated with the circulation
of Fiona currently extend from the Greater Antilles to 25N
between 65W-73W. Seas of 8 ft or greater extend from 18N-26N
between 65W-73W

For the forecast west of 55W, Hurricane Fiona will strengthen to
a major hurricane later this morning near 22N71W, move to near
25N71W Wed morning, to near 28.5N70W Thu morning, and to near
31N68W Thu evening. Fiona will move well north of the forecast
waters through Sat, transitioning to a post-tropical cyclone Sat
night. Swells generated by Fiona will spread westward across the
southwestern Atlantic toward the central and northwestern Bahamas
through Wed night. A cold front will drop south over the northern
and central waters Fri through Sat night followed by fresh
northeast winds and building seas. High pressure will build in
behind the cold front.

$$
Hagen
This weather bulletin was brought to you by:
www.nashvilleweather.net