[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 252356
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
656 PM EST Wed Dec 25 2019

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 1800 UTC surface analysis and satellite imagery through
2345 UTC.

...SPECIAL FEATURES...

...CENTRAL ATLANTIC GALE WARNING...

A 1005 mb low is near 30N52W, with a cold front extending SW from
the low to a second low near 25N63W. Gale force winds are occurring
in the eastern semicircle of the first low, north of 29N. Gales
will continue in the eastern and southern quadrants of the low,
and east of the cold front, north of 28N, as the system moves
eastward and then east-northeastward during the next 24 hours.
Gales are forecast for the area north of 28N between 40W-53W this
afternoon and evening. Thursday morning, gales are expected north
of 29N between 35W-43W. Winds will decrease to below gale force,
south of 32N, by late Thursday afternoon. Seas of 10-14 ft will
develop this afternoon, with 12-16 ft expected by this evening.
Please refer to the latest NWS High Seas Forecast issued by the
National Hurricane Center under AWIPS/WMO headers MIAHSFAT2/FZNT02
KNHC for further details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the west coast of Africa near the
Sierra Leone/Liberia border near 06N11W to 05N15W. The ITCZ
extends from 05N15W to 03N35W to the coast of NE Brazil near
00N49W. Scattered moderate convection is seen within 100 nm
either side of the ITCZ between 25W-32W. Isolated moderate
convection is within 180 nm of the ITCZ between 40W-46W.

GULF OF MEXICO...

A 1022 mb surface high is over the Carolinas extending south
west across the Gulf of Mexico. Mid-upper level ridging covers
the eastern and central Gulf of Mexico. A surface trough is
analyzed from 28N89W to 19N84W, with little to no precipitation
noted. The latest ASCAT pass shows moderate E winds east of the
surface trough. Gentle anticyclonic winds prevail west of the
surface trough.

A ridge will reside N of the Gulf through Fri night. A weak
surface trough will drift W across the central and western Gulf
tonight through Fri. Fresh to locally strong E to SE winds are
expected on the E side of the trough. A cold front entering the
NW Gulf Sat night and Sun will usher in moderate fresh to strong
N to NE winds and building seas. A developing surface trough will
generate strong winds over the NW Gulf Mon and MOn night.

CARIBBEAN SEA...

A cold front extends from Haiti near 18N73W to 15N75W. Isolated
showers are along the front. In the far SW Caribbean, the east
Pacific monsoon trough is inducing scattered moderate convection
from 12N south between 75W-82W, including over western Panama and
far SE Costa Rica. The latest ASCAT pass shows moderate to fresh
south winds in the SW Caribbean from 15N south between 77W-83W,
but these winds should decrease to fresh this evening. Gentle
winds currently prevail across the central Caribbean between 70W
and the front. Fresh to strong N winds are seen between the front
and the coasts of Nicaragua and Costa Rica.

A nearly stationary front extending from Haiti to SE of Jamaica
near 16N76W will dissipate tonight. Fresh N winds are expected
along the coast of Nicaragua tonight. Winds and seas will diminish
across the central Caribbean Thu, then increase again on Fri as
high pressure builds N of area.

ATLANTIC OCEAN...

Refer to the section above for details on the Gale Warning
currently in effect for the central Atlantic.

A 1004 mb surface low is centered near 28N66W. A surface trough
extends westward from the low to Northern Bahamas, with little to
no shower activity noted along the trough. An occluded front
extends from the low to a triple point near 25N63W. A cold front
extends from 25N63W to 19N70W. The surface low and front are
being supported by a strong mid-upper level low. Ahead of the cold
front, numerous moderate with embedded scattered strong convection
is seen 180 nm southeast of a line from 19N66W to 25N59W. These
strong thunderstorms are likely producing wind gusts to gale
force. Scattered moderate convection is elsewhere within the area
north of 24N between 54W-63W.

Farther E, a 1025 mb surface high is near 36N18W, with a surface
ridge axis extending west-southwestward from the high to the
Lesser Antilles. An weakening Atlantic cold front extends from
30N15W to 25N20W. Scattered showers are seen over water from 25N-
32N between 11W-17W.

A low pressure system well N of Puerto Rico near 28N66W will move
to the E of the forecast waters Thu. The pressure gradient between
the low and high pres building over the western Atlc will support
fresh to strong NE to E winds mainly S of 28N through Sat.

$$
MMTorres
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