[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 092344
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat Sep 10 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
2315 UTC.

...SPECIAL FEATURES...

Hurricane Earl is centered well north of the area near 35.9N
58.7W at 09/2100 UTC or 370 nm NE of Bermuda moving NE at 23 kt.
Estimated minimum central pressure is 954 mb. Maximum sustained
wind speed is 90 kt with gusts to 110 kt. Peak seas have build
significantly to 53 ft, and they extend as far as 330 nm from the
center of Earl in the SE quadrant. Satellite imagery shows that
eye has become partially obscured by clouds again. Numerous
moderate to isolated strong convection, in tight banding
features, is noted within 90 nm of the center in the SE
semicircle, and within 60 nm of the center in the NW semicircle.
Numerous moderate convection is in the outer periphery of the NW
semicircle from 37N to 40N between 53W-60W. Earl is accelerating
toward the northeast. A faster northeastward motion is
anticipated tonight. Earl is then forecast to slow down
considerably Sat night through Mon. Slight fluctuations in
intensity are possible this evening. Earl is expected to complete
its transition to a powerful hurricane-force extratropical low
on Saturday and then steadily weaken through early Mon. Swells
generated by Earl are affecting Bermuda and portions of the U.S.
East Coast and are expected to reach Nova Scotia and Newfoundland
tonight and on Sat. These swells are likely to cause life-
threatening surf and rip current conditions through the weekend.
Please consult products from your local weather office

Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml for
more details.

...TROPICAL WAVES...

A far eastern tropical wave has its axis along 29W from 01N to
16N, with low pressure of 1007 mb along its axis near 08N. It is
moving westward around 10-15 kt. Scattered moderate convection
is from 05N-09N between 30W-34W. Isolated showers and thunderstorms
are to its northeast within 30 nm of a line from 17N21W to the
Cabo Verde Islands to 13N26W and to 12N29W. No significant
development is expected of this system through the middle of
next week while it moves westward or west-northwestward.

A central Atlantic tropical wave has its axis extending from near
27N47W to low pressure near 21N46W 1010 mb and to 11N46W. It is
moving westward near 10 kt. An area of scattered showers and
thunderstorms is displaced well to the northeast of the low from
22N to 28N between 38W-49W. Isolated showers and thunderstorms
are within 60 nm NW of the low. The earlier gale winds associated
with this system have diminished to strong to near gale-force
speeds. These winds are east to southeast in direction from 20N
to 26N between 42W-46W as inferred from the most recent ASCAT
data pass over this system. Seas with these winds are 10-14 ft.
Strong upper-level winds are expected to prevent significant
development of this system while it moves generally west-
northwestward or northwestward for the next day or so. The
disturbance is then forecast to merge with a non-tropical system
over the weekend.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis passes through the coast of Senegal near
15N17W to 11N23W through low pressure of 1007 mb that is near
08N29W and to 09N40W. Other than the convection associated with
the tropical wave above, scattered moderate is well to the south
of the trough within 60 nm of 09N19W.

...GULF OF MEXICO...

A weak 1006 mb low is analyzed near 27N90W, with a surface
trough extending south-southwestward to 23N92W and to 19N93W and
northeast to near 27N89W. Another trough extends from the Big
Bend area of Florida southwestward to 29N86W. Both of these
features are supported by a vigorous deep-layer trough over the
north-central Gulf. Mid to upper-level diffluent flow east of the
upper trough is supporting scattered moderate to isolated strong
convection east of a line from near Pensacola to 24N90W and to
22N88W. Winds over the southeastern Gulf are moderate to fresh
with seas 2-4 ft. Elsewhere winds and seas are quiet outside of
localized thunderstorms as a weak pressure pattern remains in
place.

For the forecast, the aforementioned surface trough extending
from the NE Gulf to the SW Gulf will drift northwestward through
the weekend and meander along the N Gulf coasts. The deep-layer
upper trough across the central Gulf will support very active
weather along and east of the surface trough through Sun. Fresh
southerly return flow will develop across the eastern half of the
basin tonight into Sat night. Winds and seas will diminish
through early next week as a trough lingers across the SW Gulf
and weak high pressure develops over the eastern Gulf.

...CARIBBEAN SEA...

A weak pressure gradient across the Caribbean is allowing for
moderate or lighter trade winds across the basin. Seas are
relatively low, in the 2-4 ft range. Scattered moderate is
occurring over the northwestern Caribbean west of 81W. This
activity is being sustained by the deep layer trough over the
central Gulf of Mexico. Isolated showers and thunderstorms moving
westward are over most of the basin. Scattered showers and
thunderstorms are over the interior sections of the Greater
Antilles.

For the forecast, moderate southeast trade winds and slight seas
will continue across most of the Caribbean tonight, and locally
fresh in the NW Caribbean. Very active weather will continue
across the far NW Caribbean and Yucatan Channel through Sat.
Moderate to fresh trade winds will return to the southeast
Caribbean and off Honduras tonight through Tue, becoming locally
strong in the south-central Caribbean Sat night and again Sun
night.

...ATLANTIC OCEAN...

Please read the Special Features section for details on Hurricane
Earl.

A 1022 mb high pressure center is near 30N31W, with ridging
extending westward to near 48W and southwestward to 24N58W and to
the central Bahamas. Another ridge extends from this high east-
northeastward to near 32N16W. The tail-end of a cold front
reaches to near 32N27W. Scattered moderate convection moving
east-southeastward is from 32N to 35N between 25W-31W.
 South of the ridge and north of the ITCZ/monsoon trough, the
trades are moderate to fresh with seas 8-10 ft. South of the
ITCZ/monsoon trough, winds are light with seas 4-7 ft. Aside from
the convection associated with the tropical wave that is along
46W/47W along with its attendant low pressure of 1010 mb near
21N46W, scattered moderate convection is seen north of 27N west
of 75W. This activity is being focused along and near a
stationary front that is along 31N and west of 73W.

For the forecast west of 55W, other than the effects of
departing Earl, weak high pressure will remain to the south and
southwest of Earl through Sun. A cold front will move south of
31N late Sat and extend from near 31N55W to 28N65W to 30N72W
Sun morning then reach along 26N and dissipate by late Mon.
Northeasterly swell will follow the front, and spread across the
area waters Sun through Tue.

$$
Aguirre
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