[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271209
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
709 AM EST Tue Feb 27 2018

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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
1100 UTC.

...SPECIAL FEATURES...

A strong 968 mb low pressure system with storm force winds
centered over the north-central Atlantic near 38.5N32W supports
a cold front from 38N17W to 26N30W to 26N53W. A tight pressure
gradient associated with the deep low pressure and cold air
advection associated with cold front are supporting gale force
winds north of the front and east to 39W. Gale conditions are
forecast to prevail through tonight then will gradually diminish
as the low pressure moves farther away from the area and the
front dissipates. Gale force winds are also occurring ahead of
the front as noted in an earlier scatterometer pass, impacting
the area east of 30W to the Canary Islands. Altimeter satellite
passes are showing seas of 15 to 30 ft in northerly swell north
of 20N and east of 50W. For more details, refer to the NHC High
Seas Forecast under AWIPS/WMO Headers MIAHSFAT2/FZNT02 KNHC.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the eastern Atlantic through the coast
of Liberia near 06N11W to 02N17W, where it transitions to the
intertropical convergence zone which continues to 00N24W to 01N36W
to the coast of Brazil near 02S44W. Scattered moderate and
isolated strong convection is present from 06S to 02N between 02W
and 13W and from 05S to 04N between 24W and 29W.

...DISCUSSION...

GULF OF MEXICO...

A weakening stationary front reaches from near Panama City
Florida to Brownsville Texas. Radar from the across the northern
Gulf shows a few showers along and north of the frontal boundary,
mainly over the northeast Gulf, and what may be light rain or
drizzle in patches over the north central and northwest Gulf. A
weak surface trough is moving W from the Yucatan Peninsula into
the Bay of Campeche. No significant convection is associated with
this feature. Dew points are in the upper 60s to lower 70s over
the northwest Gulf, where platforms are showing areas of haze and
fog. Light southeast winds are noted south of the front with 2 to
4 ft seas.

For the forecast, the front will weaken through tonight. High
pressure is building across the region and will be suppressing
convection today through Wed night. Another, stronger cold front
will move into the NW Gulf Wed night. Gale conditions are possible
over the SW Gulf near Tampico Thu night and near Veracruz Fri
morning following the passage of this front.

CARIBBEAN SEA...

High pressure north of the area centered between Bermuda and the
northern Bahamas is supporting fresh to strong trade winds across
the south central Caribbean and to the lee of Cuba. Moderate to
fresh trade winds persist elsewhere. An upper-level low is
centered north of the Mona Passage near 23N65W. A sharp trough
extends SW from the low to Costa Rica. This trough is supporting
a few showers over Hispaniola and over portions of the northeast
Caribbean. Otherwise, convergent upper-level winds on the NW side
of the trough are suppressing convection over the western half of
the Caribbean.

Little change is expected over the next several days as moderate
to fresh winds generally prevail over the basin. Strong winds will
continue pulsing along the N coast of Colombia during the late
night and early morning hours. Strong winds will funnel through
the Windward Passage through Thu. Large long period swells will
reach the Atlantic passages in the Leeward and Windward Islands on
Thu.

ATLANTIC OCEAN...

A weak pressure gradient resides over the Atlantic waters west of
50W. Gentle to light winds north of 22N and moderate trade winds
south of 22N are generated by modest 1023 mb high pressure
centered near 26N71W. A weakening cold front crosses the waters NW
of the Bahamas from 32N73W to 30N81W. Cloudiness and isolated
showers are occurring along and up to 150 nm SE of this boundary.

Looking ahead, the cold front will weaken and continue heading SE
to reach the central Bahamas Wed evening, as high pressure builds
north of the front. Strong low pres passing north of the area
will drag another cold front into the NW waters Thu night, with
deteriorating conditions expected for the waters north of 27N and
W of 65W. The system will support gales Fri night through Sat
night over the waters N of 27N between 50W and 70W. A significant
swell event will accompany this system, affecting all waters east
of north Florida and Bahamas at the end of the week.

East of 50W, fresh to strong northwest winds are observed from 25N
to 30N E of 45W outside the areas of strong to gale force winds
noted in the Special Features sections. Because the subtropical
ridge is disrupted by the deep low pressure over the north central
Atlantic, only gentle to moderate trade winds deeper into the
tropics. Northerly swell of 8 to 12 ft is reaching as far south
as 15N. Looking ahead for the waters east of 50W, winds and seas
will gradually subside north of 25N through mid week, just ahead
of another powerful low pressure system approaching from the
western Atlantic, brining strong to near gale force winds and
large seas to the area north of 20N between 40W and 50W by late
week.

For additional information please visit
http://www.hurricanes.gov/marine

$$
McElroy
This weather bulletin was brought to you by:
www.nashvilleweather.net