AXNT20 KNHC 181733

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
133 PM EDT Mon Mar 18 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 1200 UTC surface analysis and satellite imagery through 
1715 UTC.


...Caribbean Sea Gale Warning...

NE gale-force winds are expected again tonight near the coast of 
Colombia from 19/0000 UTC to 19/1500 UTC. Thereafter, a low 
developing near the Bahamas will weaken the ridge over the western
Atlantic and allow the nocturnal gale winds to diminish. Please 
read the latest High Seas Forecast issued by the National 
Hurricane Center under the AWIPS/WMO header MIAHSFAT2/FZNT02 KNHC 
or the website, for 
more details.


The monsoon trough extends SW from the coast of Sierra Leone 
near 07N12W to 02N17W. The ITCZ continues from 02N17W to 03S30W 
to the coast of Brazil near 03S43W. Scattered moderate with
embedded isolated strong convection is seen within 150 nm of the
monsoon trough and ITCZ between the coast of Africa and 22W.
Scattered moderate convection is noted from 04S-00N between 17W-
30W, from 05S-03N between 33W-39W, and from 02S-02N between 44W- 
51W. Isolated showers and thunderstorms are possible in between
those clusters of convection.


A stationary front extends from the Straits of Florida near 
24N80W to 23N90W to a 1014 mb low over the SW Gulf of Mexico near
21N94W. A stationary front extends SE from the low to the Bay of 
Campeche near 19N91W. Scattered showers and isolated thunderstorms
are within 60 nm of the front. Elsewhere scattered to numerous
moderate rainshowers are from 24N-28N between 90W-98W. Isolated
showers are elsewhere south of 29N and west of 85W. Higher
pressure is over the southern United States, NW Gulf of Mexico and
northeast Mexico. A recent ASCAT pass shows strong to near gale- 
force winds on the west side of the surface low in the SW Gulf of
Mexico, south of 24N and W of 93W. These winds are occurring due
to the tight pressure gradient between the areas of low and high 
pressure. Fresh to strong NE winds are over the central Gulf N of
the frontal system. The remainder of the Gulf has fresh NE-E 
winds. An upper-level trough is west of the Gulf over Texas and 
Mexico. The CIMSS upper-level wind analysis indicates a 
considerable amount of upper-level divergence in the northwest 
Gulf, helping to enhance convection. Total precipitable water 
products indicate increasing water vapor content in the southwest 
Gulf of Mexico associated with the low and front.

The strong to near gale force winds in the SW Gulf will diminish 
to strong winds on Tuesday, and to moderate winds on Wednesday. 
Strong northeast to east winds will cover almost the entire Gulf 
of Mexico on Tuesday and Tuesday night, and the far eastern Gulf 
of Mexico on Wednesday as the front begins to move SE as a cold 
front, exiting the area to NW Cuba early on Wednesday. It is 
possible that the wind speeds may approach near gale-force in 
parts of the SE Gulf of Mexico, as the weak low pressure center 
moves along the front through Tuesday. A new surface ridge will 
build S across the area from Thursday through Friday night. 


Fresh trades cover most of the eastern and central Caribbean Sea,
with strong to locally near-gale winds near the coast of Colombia.
Gentle E winds cover the NW Caribbean north of 15N and W of 79W.
No significant convection is over the Caribbean, other than
typical isolated showers moving westward with the trade winds over
portions of the Greater Antilles as well as the west-central
Caribbean towards eastern Honduras.

High pressure that is centered over the Atlantic to the NE of the
Caribbean, will support fresh to strong trade winds across much 
of the central Caribbean Sea through early Wednesday, before the 
high pressure center moves E, and the wind speeds diminish for the
remainder of the week. The trade winds will be pulsing to minimal
gale-force along the coast of Colombia, from tonight until the 
middle of Tuesday morning. Moderate to fresh trade winds will 
continue across the remainder of the area through Friday.


A cold front enters the western Atlantic near 32N63W and extends
WSW to a 1015 mb low near 29N73W. The cold front continues SW
through the NW Bahamas to 24N80W, where it becomes a stationary
front, which continues W through the southern Gulf of Mexico.
Scattered showers are located over the Florida Straits, offshore 
the E coast of Florida and over the NW Bahamas. Scattered showers
are elsewhere within 120 nm of the front and near the low. Two 
weak surface troughs - one near the Turks and Caicos Islands, and 
the other from 21N67W to 24N65W - are producing isolated showers.
A 1022 mb high is over the central Atlantic near 28N54W. A 1016 
mb low is centered over the E Atlantic near 28N38W. A surface 
trough extends S from this low to 23N39W to 20N44W. This is a 
deep-layered low pressure system with an upper level low nearly 
vertically stacked over the surface low, enhancing showers and 
thunderstorms. Scattered moderate convection is from 25N-30N 
between 33W-40W. Scattered showers are near the remainder of the 
trough axis.

The cold front in the W Atlantic will move slowly SE, reaching 
from near 31N65W to the Straits of Florida on Tuesday morning, 
from near 27N65W to northwest Cuba by early on Tuesday night, then
from near 26N65W to central Cuba on Wednesday, and begin to 
weaken as it reaches from near 25N65W to east central Cuba on 
Thursday, and become stationary through Friday night.

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