[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 302332
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT Tue Apr 30 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
2310 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of
Guinea near 10N14W to 05N20W. The ITCZ continues from 05N20W,
crossing the Equator along 26W, to 04S36W, across inland coastal
sections of Brazil to 02S50W. Isolated moderate to locally
strong rainshowers are to the south of the line that extends
from the coast of Guinea-Bissau near 12N16W to 06N30W, to the
coast of Brazil near 04N51W, and from 10W westward.

GULF OF MEXICO...

The GFS model for 250 mb shows an upper level ridge along 90W in
the center of the Gulf of Mexico. The GFS model for 500 mb and
for 700 mb shows anticyclonic wind flow with a ridge from 90W
eastward, a trough from the Texas coast southeastward, cyclonic
wind flow from 25N southward between the Yucatan Peninsula and
93W, and anticyclonic wind flow elsewhere to the east of Mexico
from 20N to 25N.

Upper level moisture covers the area from 93W westward, moving
northeastward across parts of Mexico and Texas.

A surface ridge extends from the Florida Panhandle into the SW
corner of the Gulf of Mexico.

A surface trough, that currently is to the E of the Florida
Peninsula in the Atlantic Ocean, will drift westward, reaching
the eastern Gulf of Mexico on Thursday. The trough will weaken
gradually, as it continues NW through the end of the week. High
pressure, that is to the NE of the area, will support mainly
moderate to fresh return flow. Fresh to strong wind speeds will
pulse NW of the Yucatan Peninsula at night with the daily
development of a surface trough across the peninsula. The
surface pressure gradient will weaken this weekend, allowing for
return flow to diminish slightly.

FOR PARTS OF THE CARIBBEAN SEA AND THE ATLANTIC OCEAN...

An upper level cyclonic circulation center is on top of the
central Bahamas. Upper level cyclonic wind flow covers the
Atlantic Ocean, parts of the Caribbean Sea, and Florida, from
15N northward between 64W and 87W in the Yucatan Channel. A
surface trough is along 27N72W 23N75W 19N76W, from the Atlantic
Ocean, across the central Bahamas, to SE Cuba. Widely scattered
moderate to isolated strong rainshowers cover the areas that are
from Jamaica to Hispaniola and SE Cuba, to the southern Bahamas
and in the Atlantic Ocean from 17N to 29N between 66W and 79W.
24-hour rainfall totals that are listed for the period that
ended at 30/1200 UTC...according to the PAN AMERICAN TEMPERATURE
AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.03 in
Nassau in the Bahamas and in St. Thomas in the Virgin Islands,
and 0.02 in Freeport in the Bahamas. The surface trough will
linger in the area of the Bahamas during the next couple of
days, while high pressure builds NE of the area. This pattern
will support moderate to fresh E to SE winds, except fresh to
strong S of 27N through Wednesday night. The wind speeds also
will pulse to strong offshore of Hispaniola, mainly at night
through Friday night. The upper level cyclonic circulation
center and the surface trough will weaken and shift W toward the
end of this week, allowing the wind speeds to diminish and the
sea heights to subside in this region. An upper level ridge and
subsident middle level air are inhibiting extensive amounts of
precipitation in the Caribbean Sea on the S side of this trough.
Areas of smoke may reduce the visibility in the Gulf of
Honduras. The upper level cyclonic circulation center will
remain close enough to Cuba and Hispaniola during the next
couple of days in order to trigger rainshowers, primarily in
the higher terrain during the hours of daytime heating.

FOR THE REST OF THE CARIBBEAN SEA...

Isolated moderate to locally strong rainshowers are in the SW
corner of the area, from 10N southward. A surface trough extends
from the coastal areas of the northern part of Colombia, across
parts of Panama, and southernmost Costa Rica, into the eastern
Pacific Ocean.

Surface high pressure N of the area, and low pressure in
Colombia, will support fresh to strong trade winds in the
central Caribbean Sea and in the Gulf of Honduras through the
week. The wind speeds will pulse to near gale off the coast of
Colombia during the late night and early morning hours. The wind
speeds will diminish slightly by this weekend, as high pressure
weakens and the pressure gradient slackens. Mainly moderate to
fresh trade winds will prevail elsewhere. N to NE swell will
move into the waters E of the Windward Islands by Wednesday.

FOR THE REST OF THE ATLANTIC OCEAN...

A surface trough is along 37W/38W from 25N to 31N. Rainshowers
are possible within 60 nm to 90 nm on either side of the trough.

A surface trough, that is currently across the southern Bahamas,
will drift W and weaken gradually through Thursday, while high
pressure builds NE of the area. This pattern generally will
support moderate to fresh E to SE winds, except fresh to strong
winds S of 27N through tonight, shifting NW through Wednesday
night. High pressure will weaken and drift eastward from Friday
through Sunday, allowing for the wind speeds to diminish and the
sea heights to subside. Fresh to strong winds will pulse
offshore of Hispaniola through late week, mainly at night.

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

$$
mt
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