[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 061058
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
558 AM EST Fri Mar 6 2020

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
1000 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: Strong winds will continue across the
south central Caribbean through Sun night, pulsing to minimal
gale force near the coast of Colombia this morning. These winds
are occurring due to a locally tight pressure gradient with high
pressure ridging NE of the area, and low pressure over northern
Colombia. Seas will build to 8-11 ft with these winds. Please
refer to the Atlantic High Seas Forecast under the AWIPS header
MIAHSFAT2 and under the WMO header FZNT02 KNHC or at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of northern Senegal
near 11N15W to 03N20W to 00N29W. The intertropical convergence
zone continues from 00N29W to 04S37W. Scattered moderate
convection is observed from 02N to 04N between 22N and 25N.

GULF OF MEXICO...

A cold front was analyzed at 06 UTC from near Sarasota Florida to
the northeast portion of Yucatan. A few showers and thunderstorms
are active over the far southeast Gulf of Mexico ahead of the
front. No other significant shower or thunderstorm activity is
observed across the Gulf. A reinforcing cold front over Texas is
approaching the northwest Gulf this morning. The second front is
noted over eastern Texas and central Louisiana, approaching the
northwest Gulf. Seas are building behind the first front, with
buoy data showing generally 5 to 7 ft. Buoy and scatterometer
satellite data indicate moderate to fresh northerly flow behind
the first front.

The first front will continue southeast then exit the basin later
today. Fresh to strong winds and building seas are expected
through early Sat in association with the front, and the
reinforcing front moving through the northern part of the basin.
Strong NE to E winds will prevail through the Straits of Florida
and SE Gulf through Mon night before conditions gradually improve
basin wide.

CARIBBEAN SEA...

Please read the Special Features section for more details about
the Gale Warning in effect in the S-central Caribbean Sea.

Earlier scatterometer satellite passes indicated a large area of
strong trade winds between these pressure fields over the south
central Caribbean, reaching near gale force off the higher terrain
along the coast of northeast Colombia. Seas are generally 8 to 9
ft in the area of strong trade winds over the south central
Caribbean, reaching as high as 11 ft off Colombia in the area of
near gale force winds. Elsewhere moderate to fresh trade winds
prevail with 3 to 5 ft seas. No significant showers or
thunderstorms are evident on satellite imagery or regional radar,
other than a few passing trade wind showers in the eastern
Caribbean.

The strong winds will continue across the south-central Caribbean
through Tue night, pulsing to minimal gale force near the coast
of Colombia at night Sun through Tue. A cold front will enter the
NW Caribbean this afternoon. The front will reach from eastern
Cuba to the central Gulf of Honduras Sat afternoon, from central
Hispaniola to near the Honduras- Nicaragua border Sun morning,
then stall from the Virgin Islands into central Caribbean Mon.
Strong to near gale force NE winds and large seas will develop
behind the front across the Caribbean and Atlc Passages through
late Mon. Gale conditions are possible off the coast of Hispaniola
Sun night.

ATLANTIC OCEAN...

A cold front is moving off the northeast coast of Florida
currently, with a line of thunderstorms active north of 30N about
180 nm east of the front. Recent scatterometer satellite data
shows fresh to strong SW winds ahead of the front. The axis of the
subtropical ridge has shifted slightly southward to roughly 25N,
through the central Bahamas, ahead of the advancing frontal
boundary.

The front will reach from 31N69W to western Cuba this evening,
from 25N65W to the Windward Passage Sat evening, then stall and
weaken over the SE waters Sun night through Mon. Strong to near
gale force winds are expected across the waters N of 29N ahead of
the front today and tonight. Strong winds and large seas
developing behind the front will prevail through Tue.

Farther east, a mid to upper low is centered near 28N38W. This is
supporting a nearly stationary surface low near 25N45W. A few
showers and thunderstorms remain active within 90 nm of the
surface low, supported by the cold-core low aloft. The presence
of the surface low has disrupted the subtropical ridge over the
area, and is maintaining only moderate trade wind flow farther
south in the deep tropical Atlantic west of the Cabo Verde
Islands. The divergence aloft on the southeast side of the upper
trough along with the trade wind convergence in the lower levels
of the atmosphere is supporting a couple of clusters of showers
and thunderstorms near the ITCZ. Even though trade winds are
suppressed, recent altimeter satellite data shows 8 to 11 ft seas,
mainly north of 15N and east of 50W, likely due to northerly
swell.

The surface low is forecast to weaken through today as the upper
support diminishes and lifts to the northeast. This will allow
trade wind flow to increase slightly by Sat over the tropical
Atlantic waters as the ridge builds to the north.

$$
Christensen
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