[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171732
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sat Sep 17 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...SPECIAL FEATURES...

Tropical Storm Fiona is over the northeastern Caribbean Sea near
near 16.3N 63.5W at 17/1500 UTC or 110 nm W of Guadeloupe moving
W at 11 kt. Estimated minimum central pressure is 1004 mb.
Maximum sustained wind speed is 50 kt with gusts to 60 kt. Peak
wave heights are reaching 15 ft. Seas 12 ft or greater are
within 150 nm N semicircle 90 nm SE quadrant and 60 nm SW
quadrant.  Scattered to numerous moderate/strong convection
prevails from 12N-19N between 58W-67W. Data from Air Force
Reserve and NOAA Hurricane Hunter aircraft indicate that Fiona's
center has re-formed farther east. Hurricane conditions are
expected on Puerto Rico Sunday and Sunday night and are possible
in the U.S. Virgin Islands tonight. Hurricane conditions are
possible within the hurricane watch area in the Dominican
Republic Sunday night and Monday. Fiona is forecast to produce 2
to 4 inches of rain across the Leeward Islands and Northern
Windward Islands, 4 to 6 inches with local maximum of 10 inches
across the British and U.S. Virgin Islands, 12 to 16 inches with
local maximum (E and S of island) of 20 inches over Puerto Rico,
4 to 8 inches with local maximum (E coast) of 12 inches over
Dominican Republic, 1 to 3 inches with isolated maximum totals
of 4 inches for Haiti, and 4 to 6 inches over Turks and Caicos.
These rains are likely to produce flash and urban flooding,
along with mudslides in areas of higher terrain, particularly
southern and eastern Puerto Rico and the eastern Dominican
Republic.

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 NHC Public Advisory at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis extending along
33W from 04N-16N, moving westward at 10-15 kt. Scattered showers
are noted from 08N-12N between 33W-38W.

A central Atlantic tropical wave has its axis along 46W from 12N
to 25N, moving westward about 10-15 kt. Scattered moderate
convection prevails across the northern portion of the wave
mainly N of 19N between 39W-47W. Latest ASCAT data continues to
depict fresh to strong easterly winds from 18N to 25N between
41W-47W. Wave heights with these winds are in the 5-6 ft range.
Some slow development of this system is possible during the
early or middle part of next week while it moves slowly
northwestward. The latest Tropical Weather Outlook gives this
system a low chance of tropical cyclone formation through five
days.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the Atlantic through the coast of
Africa near 17N16W and continues to 12N26W. The ITCZ continues
from 12N26W to 12N32W. Aside from convection related to the
tropical waves described above, scattered moderate convection is
noted from 06N-12N between 19W-25W.

GULF OF MEXICO...

A surface trough extends from 30N88W to 26N91W. To the SW,
another trough extends across the Bay of Campeche from 22N96W to
18N94W. Scattered moderate convection is noted along this second
trough. A third trough extends across the Florida Peninsula
along 81W. This feature is supported at upper levels by a
shortwave trough which is enhancing convection mainly E of 84W.
Weak high pressure over the area supports gentle to moderate
easterly winds. Wave heights of 3-4 ft are over he northern
Gulf, especially N of 27N. Lower wave heights of 1-3 ft are
noted elsewhere in the basin.

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 for information on
Tropical Storm Fiona currently over the northeastern Caribbean.

Outside of Fiona, an area of low level convergence is enhancing
convection from 13N-17N between 70W-85W. Another area of
scattered moderate convection is noted N of the monsoon trough
from 09N-12N between 73W-83W. Moderate to fresh trade winds are
occurring in the north-central Caribbean, Windward Passage and
Gulf of Honduras per overnight ASCAT data passes. Wave heights
with these winds are in the 4-6 ft range. Gentle to moderate
trade winds along with lower wave heights of 2-4 ft are
elsewhere.

For the forecast, Tropical Storm Fiona will move to 16.6N 64.6W
this evening, 17.3N 66.0W Sun morning, strengthen to a hurricane
near 18.2N 67.3W Sun evening, 19.2N 68.3W Mon morning, 20.4N
69.2W Mon evening, and 21.6N 70.0W Tue morning. Fiona will
change little in intensity as it moves to 23.9N 70.6W early Wed.
Residual swell from Fiona will linger over the northeastern
Caribbean and northwestern part of the Tropical N Atlantic Tue
through Wed night.

ATLANTIC OCEAN...

Please see the sections above for information on Tropical Storm
Fiona and the tropical waves moving across the basin.

Abundant moisture prevails across the western Atlantic
supporting scattered moderate convection mainly W of 75W. To the
east, fresh to strong SW winds are noted ahead of a frontal
boundary north of 30N between 60W-66W. Wave heights are in the
range of 4-7 ft over the waters N of 29N between 60W-65W. To the
south, moderate to fresh trade winds are south of 21N and
between 71W-77W, with related wave heights of 4-7 ft. The
remainder of the basin is dominated by a large ridge over the
central Atlantic maintaining fairly tranquil weather conditions.

In the eastern Atlantic, latest ASCAT data depicts
fresh to strong north to northeast winds from 18N to 23N and
east of 20W. Wave heights are 6-9 ft north of 16N and east of
25W. Elsewhere, moderate or lighter winds winds are present
along with wave heights of 4-6 ft.

For the forecast west of 55W, Tropical Storm Fiona will move to
16.6N 64.6W this evening, 17.3N 66.0W Sun morning, strengthen to
a hurricane near 18.2N 67.3W Sun evening, 19.2N 68.3W Mon
morning, 20.4N 69.2W Mon evening, and 21.6N 70.0W Tue morning.
Fiona will change little in intensity as it moves to 23.9N 70.6W
early Wed. Scattered showers and thunderstorms are expected over
the far western part of the area through early next week as the
trough lingers offshore the Florida coast.

$$
ERA
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