[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 011127
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed Mar 1 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...

Central Atlantic Gale Warning: A cold front east of Bermuda will
progress eastward across the central Atlantic through Thu. Strong
to near-gale force westerly winds will accompany the front north
of 28N. Some of these winds will reach minimal gale force north
of 30N between 40W and 53W late this afternoon through early Thu
morning. Please see the paragraph below for details on wave
heights. Please read the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

Central Atlantic Significant Swell Event: Recent altimeter
satellite data indicates wave heights in excess of 12 ft mainly
north of 26N and east of 55W, reaching as high as 20 ft near
31N45W. The large waves are related in part to successive groups
of long-period NW swell associated with deep low pressure system
well north of the area. Wave heights in excess of 8 ft are
reaching through the tropical Atlantic, east of 55W. Shorter-
period wind seas will mix with the NW swell north of 30N between
40W and 50W tonight, with combined seas reaching as high 20 ft in
that area. Expect seas in excess of 12 ft to persist north of 28N
east of 55W to the Canary Islands into Fri. Looking ahead, seas
will subside slight thereafter, but another round of NW swell can
be expect Sat and Sun north of 28N between 25W and 50W.

Caribbean Gale Warning: Tight gradient between a strengthening
high pressure near the Bahamas and lower pressure over
northwestern Colombia is prolonging strong to near-gale NE to ENE
winds at the south-central Caribbean. These winds are going to
peak at gale-force north of Colombia tonight and Thu night.

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

...MONSOON TROUGH/ITCZ...

A monsoon trough extends southwestward across the African coast
near the Guinea-Sierra Leone border to 01N20W. An ITCZ then
continues from 01N20W across 01S30W to the Brazilian coast just
east of Sao Luis. Scattered moderate convection is seen near both
features from the Equator to 12N between 10W and 43W.

...GULF OF MEXICO...

A modest surface ridge reaches west-northwestward from the Florida
Strait to just south of the Texas-Mexico border. Dense fog is
observed at the northwestern Gulf coastal waters near Galveston
with visibility down to 1 NM, while patchy fog farther out at the
offshore waters is reducing visibility to 3 NM this morning.
Gentle to moderate southerly winds and seas of 2 to 4 ft are
present across the northern Gulf. Moderate to fresh SE winds and 3
to 5 ft seas are noted north of the Yucatan Peninsula and at the
Bay of Campeche, due to a thermal surface trough in the vicinity.
Light to gentle winds and seas at 1 to 3 ft prevail for the rest
of the Gulf.

For the forecast, the ridge will continue to dominate the Gulf
waters through tonight. Expect southerly winds, gentle to moderate
for the eastern Gulf, and moderate to occasional fresh over the
western Gulf. This moist southerly flow will continue to favor the
development of marine fog across the northern Gulf early this
morning and tonight. Fresh to locally strong winds will pulse
until sunrise this morning and tonight near and northwest of the
Yucatan Peninsula due to a thermal trough. Southerly flow will
increase and reach fresh to strong by Thu, ahead of a cold front
forecast to move eastward across the Gulf late Thu night and Fri.
These winds will reach near-gale force across the Bay of Campeche
and central Gulf, and might peak at gale-force offshore from
Veracruz, Mexico. This front is anticipated to stall and weaken
across the east-central Gulf and eastern Bay of Campeche on Sat,
which should allow both winds and seas to gradually subside.

...CARIBBEAN SEA...

Please read the Special Features section for details on an
upcoming gale event.

A 1019 mb high near the southeast Bahamas is sustaining a fair
trade-wind regime across the entire basin. Fresh to strong ENE
winds and seas of 7 to 9 ft are evident at the south-central
basin and Gulf of Honduras. Moderate to fresh ENE winds with 4 to
7 ft seas are found at the north-central basin. Gentle to
moderate ENE to ESE winds and seas at 3 to 5 ft prevail for the
remainder of the basin.

For the forecast, the pressure gradient between high pressure
north of the area and the Colombian low will support fresh to
strong trade winds over the south-central Caribbean through Sat.
These winds will expand northward into the north-central basin on
Thu. Pulsing winds to minimal gale-force are expected tonight and
Thu night off the coast of Colombia. Fresh to strong winds will
persist in the Gulf of Honduras through tonight. By Thu, these
winds will become strong to near-gale force and spread over the
northwestern basin. Moderate long-period N swell will impact the
northeastern Caribbean and passages through this weekend.

...ATLANTIC OCEAN...

Please read the Special Features section for details about the
upcoming gales and ongoing significant swell.

A cold front curves southwestward from a deep low pressure
northeast of Bermuda across 31N52W to 28N65W, then turns west-
northwestward to beyond 31N at 75W. Scattered moderate convection
is flaring up near and up to 80 nm southeast of the front north of
28N. Scattered showers are seen near and up to 40 nm north of the
rest of the front. At the east-central Atlantic, another cold
front extends southwestward from the central Azores across 31N33W
to 24N46W. Scattered moderate convection is occurring near and up
to 100 nm northeast of this feature. Convergent trade winds are
causing scattered showers and isolated thunderstorms near the
coast of Suriname, French Guiana and northeastern Brazil, and
nearby Atlantic waters. Refer to the Monsoon Trough/ITCZ section
for additional convection in the basin.

Other than the winds and swell mentioned in the Special Features
section at the beginning, moderate to fresh westerly winds and
seas of 7 to 11 ft are noted north of 24N between 47W and 72W. To
the west, gentle to moderate westerly winds with 3 to 6 ft seas
are present from the Bahamas northward between 72W and the
Georgia-Florida coast. Near the Canary Islands, light to gentle
winds and seas at 4 to 7 ft exist north of 24N between the
northwest African coast and 30W. Near the Cabo Verde Islands,
moderate to fresh NNE to NE trades with 9 to 11 ft seas dominate
from 09N to 24N between the central African coast and 40W, and
also to the southwest, from 03N to 12N between 40W and the South
American coast. Further northwest, gentle to moderate ENE to E
trades and seas of 6 to 8 ft are found from 12N to 21N between 40W
and the Lesser Antilles. Light to gentle winds with 5 to 7 ft seas
in moderately N swell prevail elsewhere in the Atlantic Basin.

For the forecast west of 55W, rough seas generated by long-period
northerly swell will persist east of 63W through Thu. The cold
front will keep progressing eastward across the western Atlantic
waters through this afternoon, sustaining strong to near-gale
westerly winds north of 28N. Looking ahead, another cold front is
forecast to exit the U.S. southeast coast on Fri and track
eastward. It will bring southerly winds at strong to near-gale
force east of Florida, moderate to fresh across northwest Bahamas
along with moderate to rough seas Fri afternoon through Sat
morning. Afterward, fresh to strong SW winds and rough seas are
expected north of 29N this weekend.

$$

Forecaster Chan
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