[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261129
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sun Feb 26 2023

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 0600 UTC surface analysis and satellite imagery through
1030 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: Tight pressure gradient will sustain
gale force winds north of Colombia through early this morning.
Seas will peak at 9 to 11 ft under the strongest winds.

Central Atlantic Gale Warning: A frontal low pressure off the
Carolina coast will deepen further as it moves toward Bermuda
through today, bringing fresh to strong westerly winds north of
28N between 56W and 70W. As this system moves farther east and
strengthens, winds will reach gale force north of 29N between 55W
and 60W by this evening. See paragraph below for a detailed
description of expected wave heights in this area.

Central Atlantic Significant Swell event: An earlier Altika
altimeter satellite pass indicated combined sea wave heights were
already reaching up to 20 ft near 30N between 45W and 55W. This
represents a new set of reinforcing northerly swell of 10 to 20
ft with 12 to 15 second periods moving into waters north of 20N
between 25W and 65W today. Looking ahead, another round of large
NW swell will impact the waters north of 28N between 35W and 55W
by mid week.

Please read the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and Offshore
Waters Forecast at www.nhc.noaa.gov/marine/offshores.php for
more details on these events.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic along the Sierra Leone coast near
Freetown and extends southwestward to 02N20W. Scattered moderate
convection is seen south of the trough from the Equator to the
Liberia coast between 10W and 13W. An ITCZ continues from 02N20W
across 00N28W to the Brazilian coast just east of Sao Luis.
Scattered showers are present near and north of the ITCZ from the
Equator to 04N between 26W and 41W.

...GULF OF MEXICO...

Dense fog are persisting up to 40 nm off the northern Gulf coast,
some coastal stations reported visibility down to 3/4 sm overnight.
Patchy fog is also evident farther out across the northern Gulf
waters with oil platforms indicated visibility down to 2 1/2 sm
earlier this morning. A surface trough with no significant weather
is over the central and southwestern Gulf. A 1024 mb high at the
east-central Gulf is dominating much of the region. Moderate to
locally fresh easterly winds and seas at 3 to 5 ft are present
north of the Yucatan and eastern Bay of Campeche. Light to gentle
winds with 1 to 3 ft seas are noted at the northeastern and east-
central Gulf. Gentle to moderate SE winds and seas of 4 to 5 ft
prevail for the rest of the Gulf.

For the forecast, the aforementioned high will dominate most of
the region through midweek next week. Expect gentle to moderate
southerly winds for the eastern Gulf, and moderate to occasional
fresh southerly winds at the western Gulf. This moist southerly
flow will continue to favor the development of marine fog across
the northern Gulf during night and early morning hours. Fresh to
locally strong winds will pulse each night into the early morning
hours near and northwest of the Yucatan Peninsula due to a diurnal
trough. Southerly flow will increase and reach fresh to strong by
Thu ahead of a cold front forecast to move eastward across the
Gulf on Fri. Gales could develop at the western Bay of Campeche.

...CARIBBEAN SEA...

Please read the Special Features section for information about
the ongoing gale warning.

A surface ridge extending east-northeastward from a 1023 mb high
over the northwest Bahamas is prolonging a trade-wind regime
across the entire basin. Patchy trade-wind showers are found at
the northeastern basin, including the Virgin Islands and Lesser
Antilles. Outside the Gale Warning area, fresh to strong ENE winds
and seas of 7 to 9 ft are present at the south-central basin.
Moderate to fresh ENE winds with 4 to 7 ft seas exist for the
north-central basin. Mainly moderate ENE to E winds and seas at 3
to 5 ft prevail for eastern and western basin.

For the forecast, tight gradient between a high over the
northwest Bahamas and Colombian low will sustain moderate to fresh
with locally strong easterly winds across the central Caribbean
through midweek next week. Winds off the coast of Colombia will
pulse to minimal gale-force through early this morning, and
possible Wed and Thu nights. Fresh to strong NE to E winds will
occur in the Windward Passage and lee of Cuba through this
morning, then become moderate by late this afternoon. Fresh to
occasional strong winds are expected in the Gulf of Honduras at
night through Wed. Moderate long-period N swell will impact the
northeastern Caribbean and passages through midweek next week.

...ATLANTIC OCEAN...

Please read the Special Features section for information about
the upcoming gale warning and significant swell.

A cold front curves southwestward from the western Azores across
31N36W and 25N45W to 25N56W, then continues westward as a
stationary front to 25N66W. Patchy rain are seen near and up to 80
nm northwest and north of this boundary. Convergent trade winds
are producing scattered showers and isolated thunderstorms from
the Equator to 07N between 45W and the Brazil/French Guiana
coast. Refer to the Monsoon Trough/ITCZ section for additional
weather in the Atlantic Basin.

Other than the winds and seas mentioned in the Special Features
section, moderate to fresh W to NW to N winds with 7 to 10 ft seas
are evident north of 25N between 36W and 60W. Farther west north
of 25N, gentle to moderate E to SE to S winds and seas at 4 to 7
ft exist between 60W and the Georgia/Florida coast. Near the
Canary Islands, gentle to moderate westerly winds with 4 to 7 ft
seas are noted north of 26N between the northwest African coast
and 36W. Across the Tropical Atlantic waters, gentle to occasional
ENE to NE trades and seas of 4 to 6 ft are seen from 04N to
25N/26N between the central African coast and Lesser Antilles.
Light to gentle winds and seas at 4 to 5 ft prevail elsewhere.

For the forecast west of 55W, a surface ridge along 27N will
maintain fresh to locally strong trades north of Hispaniola and
near Windward Passage until early this morning. A strong cold
front sinking southeastward from the Georgia/Carolinas coast will
reach from 31N63W to 29N74W by noon today. It should then push
eastward into the central Atlantic with its tail from 31N51W to
28N59W to 27N65W tonight. Fresh to strong NW to W winds and large
northerly swell behind this front will reach north of 28N east of
70W later this morning. By late this afternoon, these winds will
reach near-gale to gale force east of 65W with very large swell.
Looking ahead, another frontal boundary is going to move off the
Georgia/Carolinas coast on Mon, bringing fresh to strong westerly
winds and rising seas to the offshore waters of northeast Florida.

$$

Forecaster Chan
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