[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 280005
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT Sun May 27 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 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...SPECIAL FEATURES...

The center of Subtropical Storm Alberto as of 27/2100 UTC, is
located near 28.0N 85.2W, or about 145 nautical miles W of Tampa,
FL, or about 105 nautical miles S of Apalachicola, FL. The
estimated minimum central pressure is 994 mb. The maximum
sustained wind speeds are 45 knots with gusts to 55 knots. Alberto
is moving NNW, or 345 degrees, 10 knots. Precipitation: isolated
to widely scattered moderate and isolated strong rainshowers cover
the area that extends from 20N northward between 70W in the
Atlantic Ocean and 90W in the Gulf of Mexico. This precipitation
covers parts of the NW Caribbean Sea, Cuba and the Bahamas,
Florida and the Gulf of Mexico and adjacent waters of the Atlantic
Ocean. Alberto is expected to become a tropical storm during the
early morning hours of Memorial Day Monday, and then move inland,
in the Florida Panhandle, by Monday afternoon. Alberto will
weaken after the landfall. Public Advisories about Subtropical
Storm Alberto are being listed under the WMO header WTNT31 KNHC,
and under the AWIPS header MIATCPAT1. The Forecast/Advisories
about Subtropical Storm Alberto are being listed under the WMO
header WTNT21 KNHC, and under the AWIPS header MIATCMAT1.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 27W/28W from 13N
southward, moving W 10 knots. The wave shows up well in lower
level precipitable water imagery. Precipitation: isolated moderate
rainshowers are from 06N southward between 25W and 30W.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of Guinea
near 10N14W, to 06N18W and 03N25W. The ITCZ continues from 02N31W,
to the Equator along 43W, to the coastal areas of Brazil near
01S49W. Precipitation: isolated moderate to locally strong
rainshowers are within 500 nm to the south of the line 09N13W
07N38W 04N51W.

...DISCUSSION...

GULF OF MEXICO...

Please read the Special Features section for information about
Subtropical Storm Alberto, currently in the eastern Gulf of Mexico.

A NW-to-SE oriented upper level trough passes through Louisiana,
beyond the Yucatan Channel, into the NW corner of the Caribbean
Sea.

Scatterometer data has been showing fresh to strong winds over
the east Gulf near Alberto, moderate to fresh winds over the
central Gulf, and gentle to moderate winds over the western Gulf
waters. Wave heights across the basin are ranging from 12-15 ft
near Alberto's center, 5-8 ft over the central Gulf and 2-3 ft for
the western Gulf waters. Expect for winds and seas to decrease
following landfall on Monday.

Subtropical Storm Alberto near 28.0N 85.2W 994 mb at
5 PM EDT moving NNW at 10 kt. Maximum sustained winds 45 kt gusts
55 kt. Alberto will move to 29.1N 85.7W Mon morning...inland to
30.4N 86.2W Mon afternoon...and inland to 32.2N 86.6W Tue
morning. Winds and seas will start to decrease after the storm
moves inland with ridging building in from the Atlantic. A strong
trough will impact the southern waters Wed and Thu.

CARIBBEAN SEA...

Please read the Special Features section for information about
Subtropical Storm Alberto, currently in the eastern Gulf of Mexico.

A NW-to-SE oriented upper level trough passes through Louisiana,
beyond the Yucatan Channel, into the NW corner of the Caribbean
Sea.

Scatterometer data has been showing moderate to fresh easterly
winds across most of the basin except west of 80W, where gentle to
moderate southerly winds prevail. Wave heights range between 4-6
ft across the far east and west Caribbean, while 5-7 ft seas will
continue between 69W- 74W.

Subtropical Storm Alberto in the eastern Gulf of
Mexico will continue to move N and away from the NW Caribbean.
High pressure in the central Atlantic will maintain fresh to
strong trade winds in the central Caribbean through the week.
The strongest winds are expected over the S central Caribbean. A
strong trough will move from the NW Caribbean to the Yucatan
Peninsula Wed through early Fri with associated increasing winds
and seas.

ATLANTIC OCEAN...

Please read the Special Features section for information about
Subtropical Storm Alberto, currently in the eastern Gulf of Mexico.

The surface pressure gradient between Subtropical Storm Alberto
and the Atlantic surface ridge may support increasing wind speeds
to near gale-force in the Florida coastal and offshore waters
through tonight.

A surface ridge extends across the basin, from a 1024 mb high
pressure center that is near 31N58W, to a 1029 mb high near
39N25W. Aside from the convection related to Alberto over the west
Atlantic west of 75W, the only area with shower activity at this
time is east of the Leeward Islands from 16N-19N between 54W-63W
due an upper-level trough.

A tight pres gradient will persist through Mon night
as Subtropical Storm Alberto moves through the eastern Gulf of
Mexico, while central Atlantic ridging lingers. Winds will be
near gale W of 79W and strong between 77W and 79W through tonight.
Conditions will improve Tue as the pres gradient slackens. A cold
front or frontal trough may drop into the NE waters Wed night
through Thu.

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

$$
MT
This weather bulletin was brought to you by:
www.nashvilleweather.net