[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 241804
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

$$ Ramos
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