[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 280053
TWDAT

Tropical Weather Discussion...Update
NWS National Hurricane Center Miami FL
0005 UTC Sat Aug 28 2021

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
0000 UTC.

Updated Special Features section below

...SPECIAL FEATURES...

Hurricane Ida is centered near 22.4N 83.5W at 27/0000 UTC or 80
nm SW of Havana, Cuba and moving NW at 13 kt. Estimated minimum
central pressure is 985 mb. Maximum sustained wind speed is 70 kt
with gusts to 85 kt. The maximum sea heights are 23 ft. Numerous
moderate to strong convection extends 70 nm in a semi circle W of
the center, with scattered moderate to strong convection 40 nm in
a semi circle E of the center, including W Cuba and the NW corner
of the Island of Youth. Ida will move across W Cuba overnight,
then exit into the Gulf of Mexico on Saturday. Afterward, Ida is
expected to continue a NW track with a slight increase in forward
speed across the central Gulf Saturday evening and Sunday morning.
On Sunday night, Isa will turn toward the N and slow down while
approach the US Louisiana and Mississippi coastline.
Strengthening, possibly rapid, is expected, and Ida is forecast to
become a major hurricane by Sat evening as it moves into the
central Gulf. Ida is forecast to be a major Category 4 hurricane
at landfall along the northern Gulf coast Sun. A dangerous storm
surge is forecast for portions of the Louisiana, Mississippi and
Alabama coasts. Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT4.shtml and
Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml
for more details. Refer to the NHC High Seas Forecasts at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for marine impacts.

Showers and thunderstorms associated with a 1008 mb low pressure
midway between the Cabo Verde Islands and the Lesser Antilles have
continue to flare up this evening. Scattered moderate isolated
strong convection is from 13N to 17N between 44W and 49W.
Additional development of this system is expected, and a tropical
depression is likely to form Saturday or Saturday night before it
moves into a less favorable environment. The disturbance is
forecast to move west-northwestward tonight, then turn northward
Saturday. This system has a high chance of tropical cyclone
formation during the next 48 hours. Please refer to the NHC
Tropical Weather Outlook at www.hurricanes.gov for more details.

An elongated 1014 mb low pressure centered east of Bermuda near
33N53W has a surface trough that extends SW from it to 29N59W.
Disorganized scattered moderate convection is noted from 30N to
34N between 50W and 54W. Environmental conditions are expected to
be marginally conducive for development. However, a tropical
depression could still form by early next week The system is
expected to drift eastward through Saturday, then accelerate
northeastward Sunday toward the central north Atlantic. This
system has a medium chance of tropical cyclone formation during
the next 48 hours. Please refer to the NHC Tropical Weather
Outlook at www.hurricanes.gov for more details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 29W from 18N southward,
moving W at 10 to 15 kt. Scattered moderate isolated strong
convection is seen from 03N-11N between 24W-36W.

A Caribbean Sea tropical wave is along 67W from Venezuela to
Puerto Rico, moving W at 10 to 15 kt. No significant convection
is related to the wave at this time.


...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Mauritania near
18N16W to 13N31W to 13N48W. The ITCZ continues from 10N51W to
09N60W. Aside from the convection discussed in the sections above,
isolated moderate convection is noted from 08N-15N between 36W-
40W.

...GULF OF MEXICO...

See Special Features Section above for information on recently
upgraded Hurricane Ida, which is forecast to become a major
hurricane over the central and northern Gulf of Mexico this
weekend.

A surface trough extends from Louisiana to the northern Yucatan
Peninsula. Scattered moderate to isolated strong convection is
noted N of 27N between 87W and 92W. Fresh E to SE winds are
located E of this trough over much of the eastern Gulf of Mexico.
Seas are 4 to 6 ft in this area. Another surface trough that had
been along the Texas coast has dissipated, along with associated
convection. Gentle wind and slight seas dominate the western Gulf.

A band of showers and thunderstorms has moved W of the FL
peninsula this afternoon. This activity should diurnally diminish.

Hurricane Ida near 22.1N 83.2W 985 mb at 5 PM EDT moving NW at 13
kt. Maximum sustained winds 70 kt gusts 85 kt. Ida will move to
23.5N 84.8W Sat morning, 25.3N 86.9W Sat afternoon, 27.1N 89.0W
Sun morning, 28.6N 90.6W Sun afternoon, inland to 30.0N 91.3W Mon
morning, and move inland and weaken to a tropical storm near 31.5N
91.1W Mon afternoon. Ida will weaken to a tropical depression
while moving inland near 34.4N 89.3W Tue afternoon. Light to
gentle variable winds are expected in the SW gulf and far western
basin through Mon. Otherwise, moderate to locally fresh return
flow will establish across the basin Tue and Wed.

...CARIBBEAN SEA...

Hurricane Ida is currently affecting portions of the NW
Caribbean Sea. Please see the Special Features section above for
details.

Outside of the influence of Ida, dry conditions prevail with fresh
trades over the eastern and central basin and gentle winds over
the western basin.

Hurricane Ida near 22.1N 83.2W 985 mb at 5 PM EDT
moving NW at 13 kt. Maximum sustained winds 70 kt gusts 85 kt.
Ida will move to 23.5N 84.8W Sat morning, 25.3N 86.9W Sat
afternoon, 27.1N 89.0W Sun morning, 28.6N 90.6W Sun afternoon,
inland to 30.0N 91.3W Mon morning, and move inland and weaken to
a tropical storm near 31.5N 91.1W Mon afternoon. Weather
conditions in the NW Caribbean associated with Ida will be N of
the area by Sat. Moderate to fresh winds are expected elsewhere
through the forecast period, except for locally strong winds in
the south-central Caribbean through the weekend. Otherwise, fresh
to strong winds will pulse at night in the Gulf of Honduras Sun
to Tue.

...ATLANTIC OCEAN...

Please see Special Features sections above for information on two
low pressures that have the potential for tropical development,
east of the Lesser Antilles and east of Bermuda, respectively.

Thunderstorms previously over Florida and adjacent Atlantic waters
have diminished or moved W into the Gulf of Mexico. Portions of
the Florida Straits is experiencing strong wind as well as the
outermost rainbands of Hurricane Ida. See Special Features section
above for information on Hurricane Ida, which will not have
significant impacts on Atlantic waters.

A surface trough extends from 28N67W to 23N72W. Convection
previously associated with this trough has diminished this
afternoon. Moderate to fresh E to SE winds and seas of 4 to 6 ft
prevail across much of the western Atlantic, west of 65W. A 1019
mb high pressure is near 26N61W. A ridge axis with gentle winds
extends from this high to another 1021 mb high near 34N36W.
Farther east, a surface trough extends from 31N27W to 24N33W, with
only moderate NE winds observed west of the trough. A 1019 mb
high is near 33N20W. Moderate to fresh trade are occurring S of
25N and E of 45W, along with seas of 7 to 9 ft.

For the forecast west of 65W, surface ridging will extend
southward into the SW N Atlantic through Sun night supporting
gentle to moderate E to SE winds. A weaker pressure gradient is
expected the remainder forecast period, which will result in light
to gentle variable winds. Otherwise, fresh to locally strong
winds are expected to pulse N of Hispaniola during the evening
hours through Sat night.

$$

Chan
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