NHC Atlantic Tropical Weather Discussion

By | September 23, 2022

000
AXNT20 KNHC 231734
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Fri Sep 23 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 
1730 UTC.

...SPECIAL FEATURES...

Major Hurricane Hurricane Fiona is centered near 35.9N 64.2W at 
23/1500 UTC or about 220 nm N of Bermuda moving NNE at 22 kt. 
Estimated minimum central pressure is 936 mb. Maximum sustained 
wind speed is 110 kt with gusts to 135 kt. Satellite imagery shows 
that Fiona remains very powerful land large hurricane, with a
well-defined eye. Numerous moderate to isolated strong convection
is noted within 120 nm NE, 120 nm SE and 60 nm NW quadrants of the 
eye. The SW quadrant is being hampered by dry air as numerous 
moderate convection only extends 30 nm from the eye there. 
Numerous moderate convection is from 30N to 34N between 60W-65W, 
and elsewhere from 34N to 39N between 56W-64W. Seas of 12 ft or 
higher are occurring within 300 nm in the NE quadrant, 390 nm in
the S semicircle and 480 nm in the NW quadrant, with peak seas 
near 60 ft. Fiona is forecast to obtain a slower motion north- 
northeast or north motion is expected later today through Sun. On 
the forecast track, the center of Fiona will approach Nova Scotia 
later today, move across Nova Scotia and into the Gulf of St. 
Lawrence on Sat, and then across Labrador and over the Labrador 
Sea on Sun. Fiona is a category 4 hurricane on the Saffir-Simpson 
Hurricane Wind Scale. Although gradual weakening is forecast, 
Fiona is expected to be a powerful hurricane-force cyclone when it
moves across Atlantic Canada. A hurricane warning is in effect 
for Nova Scotia from Hubbards to Brule, Prince Edwards Island, 
Newfoundland and from Parson's Pond to Francois. Hurricane 
conditions are expected in portions of the hurricane warning area 
in Canada late tonight or early Sat. Tropical storm conditions are
expected in portions of the tropical storm warning area in Canada
later today. Tropical storm conditions are possible in the watch 
area in Labrador on Sun. Swells generated by Fiona are affecting 
the Turks and Caicos Islands, the Bahamas, the southeastern United
States coast, and Bermuda. These swells will continue to spread 
northwestward across the western Atlantic toward the mid-Atlantic 
and northeast coasts of the United States and Atlantic Canada 
today. These swells are likely to 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 Ocean Prediction Center at website 
https://ocean.weather.gov/shtml/NFDHSFAT1.php and the latest NHC 
Forecast/Advisory and Public Advisory at www.hurricanes.gov for 
more details.

Tropical Storm Gaston is centered near 40.2N 29.1W at at 23/1500 
UTC or about 100 N of Faial Island in the Central Azores moving 
ESE at 6 kt. Estimated minimum central pressure is 995 mb. Maximum
sustained wind speed is 50 kt with gusts to 60 kt. Satellite
imagery shows that improving in satellite presentation as
scattered to numerous moderate convection is developing and  
wrapping around the northern and western sides of its circulation.
This convection extends within 120 nm of the center in the NE
quadrant, within 120 nm of the center in the southern semicircle
and within 60 nm of the center in the NW quadrant. Isolated
showers and thunderstorms are seen from 37N to 40N between
24W-30W. A slower south-southeastward and then southward motion 
is forecast today, followed by a southwestward motion tonight and 
early Sat, and a westward motion on Sun. Gradual weakening is 
expected over the next few days. A Tropical Storm Warning is in 
effect for the Azores, where the forecast track will move the 
cyclone near or over portions of the Azores today through early 
In addition to gusty winds, heavy rain and swells will impact 
portions of the Azores into the weekend. The swells are likely to 
cause life-threatening surf and rip current conditions. Please 
read the latest High Seas Forecast issued by the Ocean Prediction 
Center at website https://ocean.weather.gov/shtml/NFDHSFAT1.php 
and the latest NHC Forecast/Advisory and Public Advisory at 
www.hurricanes.gov for more details.

Tropical Depression Nine is centered near 14.2N 70.1W at 23/1500 
UTC or about 450 nm ESE of Kingston Jamaica moving WNW at 11 kt. 
Estimated minimum central pressure is 1006 mb. Maximum sustained 
wind speed is 30 kt with gusts to 40 kt. Visible satellite 
imagery shows that the depression is mainly a sheared system, 
with the exposed and elongated center located roughly about 70 nm 
to the northeast of its deep convection. The convection consists 
of the numerous moderate to strong intensity from 11N to 16N 
between 71W-76W. Scattered moderate convection is within 30 nm of 
a line from 16N73W to 17N72W. Tropical Depression Nine is expected
to produce heavy rainfall and flash flooding along with possible 
mudslides of higher terrain in Jamaica and Cuba into tonight. 
Heavy rain will likely spread into Jamaica and the Cayman Islands 
into the weekend. A westward motion is expected to begin later 
today and continue through Sat, followed by a turn toward the 
west-northwest and northwest on Sun and Mon. On the forecast 
track, the center of the cyclone is forecast to move across the 
central Caribbean Sea through Sat, pass south of Jamaica on 
Sat night and Sun, and approach the Cayman Islands on Sun night 
and early on Mon. Some slow strengthening is forecast during the 
next day or so, and the depression is expected to become a 
tropical storm by tonight. More significant intensification is 
forecast on Sun and Mon. 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.

Newly formed Tropical Depression Ten is over the far eastern
Atlantic near 17.9N 19.8W at 23/1500 UTC, or about 265 nm east- 
northeast of the Cabo Verde Islands moving NNW at 10 kt. Estimated
minimum central pressure is 1003 mb. Maximum sustained wind speed
is 30 kt with gusts to 40 kt. Satellite imagery shows bursts of 
numerous moderate to strong convection within 120 nm of the center
in the NE quadrant. Numerous moderate to isolated strong 
convection is within 60 nm of the center in the NW quadrant, and 
also in trailing convergence band that is within 30 nm either 
side of a line from 11N22N to 14N19W and to 17N18W. Seas are in 
the 8-11 ft range with the depression. The depression is forecast 
to decrease its current motion this weekend. The depression could 
become a tropical storm during the next day or so before weakening
later this weekend. It is expected to produce 2 to 4 inches of 
rain across the Canary Islands through this weekend. Please read 
the latest High Seas Forecast issued by Meteo-France at website 
http://weather/gmdss.org/ll.html and the latest NHC 
Forecast/Advisory and Public Advisory at www.hurricanes.gov for 
more details.

...TROPICAL WAVES...

Please read the Special Features section above for information 
about the newly formed Tropical Depression Ten located over the 
far eastern Atlantic.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis passes off the west coast of southern 
Mauritania near 18N16W to just east of newly formed Tropical 
Depression Ten that previously was a 1003 mb low near 18N20W. It 
resumes to its southwest near 16N21W and continues to 12N28W and 
to low pressure of 1009 mb near 11N35W and to 09N42W, where it 
transitions to the ITCZ to 08N50W and to 08N59W. Aside from 
convection associated with Tropical Depression Ten, numerous 
moderate to isolated strong convection is within 270 nm south of 
the trough and the 1009 mb between 32W-35W and within 180 nm north
of the trough between 15W-18W. Scattered moderate convection is 
north of the ITCZ from 09N to 15N between 43W-59W.

GULF OF MEXICO...

A 1015 mb surface high pressure is analyzed over the far NW 
Gulf near 29N93W. A weak surface trough extends from near 30N93W 
to 29N96W. Another surface trough extends from near 24N95W to the
central Bay of Campeche. The nocturnal trough moved off the 
Yucatan Peninsula, and extends from 21N91W to inland Mexico at 
19N92W. The first autumn cold front has pushed into the far NE 
Gulf. Latest ASCAT data depicts moderate northeast winds north of 
the front. Seas with these winds are 2-4 ft. No convection is 
along or near this front as the air mass over the northern Gulf is
pretty dry. The gradient across the area supports gentle to 
moderate winds throughout the basin, with low seas of 1-3 ft. 
Isolated showers and thunderstorms are over the far western Gulf 
south of 26N and west of 95W. 

For the forecast, Tropical Depression Nine, located about 450 nm 
easts-southeast of Kingston, Jamaica is forecast to intensify 
into a hurricane as it moves NW toward the NW Caribbean into the 
weekend. Conditions will likely begin to deteriorate across the 
eastern Gulf of Mexico by early next week. Expect gentle to 
moderate winds across the Gulf through the weekend as the weak 
cold front currently over the far NE Gulf slowly drifts southward 
over the next few days and dissipates by the end of the weekend. 

CARIBBEAN SEA...

Please read the Special Features section above for details about
Tropical Depression Nine. 

The eastern section of the east Pacific monsoon trough is 
inducing scattered moderate convection south of  17N, mainly 
within about 90 nm of the Central American coast. Light to gentle 
winds prevail across the western and central Caribbean, west of 
72W. Seas in this area are 1-2 ft. Fresh to near-gale force winds 
and seas of 5-10 ft prevail over the eastern Caribbean in 
association with the tropical depression.

For the forecast, Tropical Depression Nine near 14.2N 70.1W 1006 
mb at 11 AM EDT is moving WNW at 12 kt, with maximum sustained 
winds 30 kt gusts 40 kt. The tropical will strengthen to a 
tropical storm near 14.5N 71.7W this evening, move to 14.7N 74.1W 
Sat morning, 15.1N 76.3W Sat evening, 16.1N 78.3W Sun morning, 
17.8N 79.9W Sun evening, and strengthen to a hurricane near 19.8N 
81.4W Mon morning. Nine will change little in intensity as it 
moves near 23.5N 82.8W early Tue. Deteriorating marine conditions 
can be expected near the track of Nine, including the central 
Caribbean today through early Sunday, and portions of the 
northwest Caribbean later on Sunday and Monday. Locally heavy 
rainfall and gusty winds will impact Curacao and Aruba today, then
Jamaica and the Cayman Islands this weekend. 

ATLANTIC OCEAN...

See Special Features section above for information on Hurricane
Fiona, Tropical Storm Gaston, and on the newly formed Tropical 
Depression Ten over the far eastern Atlantic.

Outside the special features, the first autumn cold front has
entered the area from near 30N77W to inland northern Florida, and 
westward to the NE Gulf of Mexico. Fresh to strong northeast winds
and seas of 8-11 ft are behind the front. Isolated showers are
near the front north of 28N. Otherwise, surface high pressure 
ridging remains cross most of the basin, north of 20N and east of
60W, anchored by a 1025 mb high pressure centered just north of 
the area near 32N39W. Mostly moderate winds and 4-6 ft seas 
prevail across the central Atlantic between 40W-60W. Over the 
eastern Atlantic, winds are mostly fresh elsewhere within 240 nm 
in the NW semicircle of Tropical Depression Ten.

For the forecast west of 55W, Major Hurricane Fiona is N of the 
area and is near 35.9N 64.2W 936 mb at 11 AM EDT moving NE at 30 
kt. Maximum sustained winds 115 kt gusts 140 kt. Fiona will move 
to 40.8N 61.4W this evening, become extratropical and move to 
45.5N 60.6W by Sat morning. Swells generated by Fiona is currently
reaching as far south as 21N and as far east as 56W. As Fiona 
continues to move farther away from the forecast waters, swell 
from this system will gradually move eastward and subside. By Mon 
morning, conditions should improve. Impacts from Tropical 
Depression Nine, currently over the southeastern Caribbean Sea, 
may affect areas offshore Florida early next week. Swells 
generated by Fiona are affecting the Turks and Caicos Islands, the
Bahamas, the southeastern United States coast, and Bermuda. These
swells will continue to spread northwestward across the western 
Atlantic toward the mid-Atlantic and northeast coasts of the 
United States and Atlantic Canada today. These swells are likely 
to cause life-threatening surf and rip current conditions. 
Impacts from newly formed Tropical Depression Nine, currently in 
the southeastern Caribbean Sea may affect areas offshore Florida 
early next week.

$$
Aguirre

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