[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 241803
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
103 PM EST Sat Feb 24 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 1200 UTC surface analysis and satellite imagery through
1745 UTC.

...SPECIAL FEATURES...

A system of low pressure over the NE Atlc will support a cold
front forecast to extend from 31N35W to 28N48W by early Monday
morning. A strong pressure gradient between this area of low
pressure and surface ridging west of it will lead to the
development of gale-force winds east of 41W. Gale conditions are
forecast to prevail through Monday. For more details, refer to
the NHC High Seas Forecast under AWIPS/WMO Headers
MIAHSFAT2/FZNT02 KNHC.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends along 03N0W to 02N14W to 01N29W. The
ITCZ continues from that point to 02N40W to the coast of Brazil
near 01N50W. Numerous strong convection is N of the Equator
between 05E-12W. Scattered moderate convection is within 90 nm
either side of the monsoon trough between 12W-30W and within 120
nm N of the ITCZ W of 38W.

...DISCUSSION...

GULF OF MEXICO...

Fair weather prevails across the basin due to very dry conditions
at the lower and middle levels as indicated by GOES-16 water vapor
imagery. This is supporting mainly clear skies basin-wide. CIRA
microwave imagery at the lower levels show patches of shallow
moisture advecting to the NW Gulf, which is supporting dense fog N
of 26N W of 89W. A broad area of high pressure over the SW N Atlc
extending a ridge SW across Florida and the eastern Gulf continue
to support moderate to fresh SE flow across the basin, being the
strongest winds W of 90W. No significant changes are expected
through Sunday. On early Monday morning, a cold front is forecast to
move over the northwestern waters from Louisiana to Brownsville,
Texas to inland NE Mexico. By Monday afternoon, the front is
forecast to extend from the Florida Panhandle to 27N94W to inland
NE Mexico and then it will stall before it lifts northward along
the Gulf coast through Tue night. Scattered to isolated showers
will accompany this boundary.

CARIBBEAN SEA...

Water vapor imagery from GOES-16 show deep layer dry air across
the basin, which is supporting overall fair weather conditions.
However, isolated to scattered showers are possible during the
afternoon hours in the Greater Antilles as remnant shallow
moisture associated with a former front advects from the north or
SW N Atlc waters. An elongated upper level low centered NE of
Hispaniola will support this convection and currently supports
passing showers across Jamaica and southern adjacent waters. The
other area where scattered to isolated showers are being reported
is the SE Caribbean. Tropical Atlc moisture along with middle
level diffluence support the convection in this section. In terms
of winds, latest scatterometer data depict fresh trades across
the central and eastern basin, with locally strong winds within
90 nm of the coast of Colombia increasing to near gale-force at
night. Seas are highest near the coast of Colombia, up to 12 ft.
Moderate to fresh trades are in the NW Caribbean. Looking ahead,
winds and seas are expected to gradually lessen by Sunday morning
as the high pressure system north of the area weakens.

ATLANTIC OCEAN...

Gale-force winds are forecast to develop over NE Atlc waters by
early Monday morning. See the Special Features section above for
further details. In the SW N Atlc, a broad ridge anchored by a
1028 mb high near 31N69W continue to support fresh to locally
strong NE to E winds in the approaches of the Windward Passage and
the eastern Great Bahama Bank. A low pressure system over the NE
Atlantic continue to support a cold front that enters the area of
discussion from 30N27W SW to 25N40W where it starts to weaken.
Otherwise, a 1007 mb low and associated trough SW of the Canary
Islands continue to weaken. Little change is expected over the
remainder of the basin during the next day or two as the high
pressure system remains stationary and while it weakens.

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

$$
Formosa
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