873
AXNT20 KNHC 192331
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Thu Jun 20 2024

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...SPECIAL FEATURES...

Tropical Storm Alberto is centered near 21.9N 95.3W at 19/2100
UTC or about 150 nm east of Tampico, Mexico moving west-
southwest at 8 kt. The estimated minimum central pressure is 995
mb, and the maximum sustained wind speed is 35 kt with gusts to
45 kt. Peak seas are up to 19 ft, with the radii of seas 12 ft
or greater extending within 420 nm of the center in the NE
quadrant and within 390 nm of the center in the NW quadrant.
Satellite imagery shows numerous moderate to strong convection in
wide banding features that extend along and to well inland the
coast of Mexico from 18N to 22N between 92W and 98W and from 22N
to 26N between 95W and 100W. Numerous moderate to isolated strong
convection is the the north from 26N to 20N between 96W and
100W.

Alberto is forecast to resume a westward motion soon and
continue for the next day or so. On this track, the center of
Alberto is expected to reach the Gulf coast of Mexico early
Thu. Some slight strengthening is possible this evening or
tonight before the center of Alberto reaches land. Weakening is
expected once the center moves inland, and Alberto is likely to
dissipate over Mexico Thu or Thu night. Alberto is expected
to produce rainfall totals of 5 to 10 inches across northeast
Mexico into South Texas. Maximum totals around 20 inches are
possible across the higher terrain of the Mexican states of
Coahuila, Nuevo Leon, and Tamaulipas. This rainfall will likely
produce considerable flash and urban flooding along with new and
renewed river flooding. Mudslides are also possible in areas of
higher terrain across northeast Mexico. The combination of a
dangerous storm surge and the tide will cause normally dry areas
near the coast to be flooded by rising waters moving inland from
the shoreline. The deepest water will occur along the immediate
coast near and to the north of the landfall location, where the
surge will be accompanied by large and dangerous waves. Storm
surge will raise water levels by as much as 1 to 3 feet above
normal tide levels along the immediate coast of northeastern
Mexico in areas of onshore winds north of where the center makes
landfall. Near the coast, the surge will be accompanied by large
and destructive waves. Please consult products issued by your
local National Weather Service forecast office, and read the
latest HIGH SEAS FORECAST issued by the National Hurricane Center
at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the
latest Alberto NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

Gale Warning E of 35W: Strong high pressure that is currently
north of the Azores will shift southeastward through late Fri. A
tightening of the pressure gradient between the high pressure and
relatively lower pressures in West Africa will support gale-
force (Force 8 on the Beaufort Wind Scale) with severe gusts for
the marine zone of AGADIR beginning at 12Z on June 20 and
lasting to 00Z June 21th according to the METEO-FRANCE High Seas
warning issued at 1905Z today. Please read the latest High Seas
Forecast issued by Meteo-France for more details at website
https://wwmiws.wmo.int/index.php/metareas/display/2

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis along 24W from
05N to 18N. It is moving westward at 10 to 15 kt. Scattered
showers are within 180 nm east of the wave from 13N to 19N and
within 60 nm west of the wave from 06N to 12N.

An eastern Atlantic tropical wave has its axis along 40W from
04N to 17N, moving westward at around 15 kt. Scattered showers
and isolated thunderstorms are within 120 nm east of the wave
from 09N to 11N and within 60 nm west of the wave from 10N to
11N.

A central Atlantic tropical wave has its axis along 55W south of
16N, moving westward at 10 to 15 kt. This wave originated in the
mid-latitudes and moved southward to become embedded within the
tradewind easterlies. As typical for these types of tropical
waves that originate in the mid-latitude, it is embedded within
dry air so there is no significant convection noted at this time.
An ASCAT pass nicely depicted the shift from northeast to
southeast of moderate wind speeds across the wave axis.
Weakening scattered showers are within 60 nm either side of the
wave axis from 08N to 10N.

A central Caribbean tropical wave has its axis along 74W/75W
south of 19N to inland eastern Colombia, moving westward at 5 to
10 kt. Isolated showers and thunderstorms are within 60 nm
either side of the wave from 11N to 13N.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Africa across
northwest Guinea near 11N14W and continues to 10N24W. The ITCZ
extends from 10N24W to 09N40W to 07N45W to 08N53W and to the
coast of Guyana near 07N58W. Scattered moderate convection is
within 120 nm south of the ITCZ between 29W and 34W and within
60 nm north of the ITCZ between 34W and 39W.

...GULF OF MEXICO...

Please read the Special Features section for information on
Tropical Storm Alberto and its impacts. Alberto is the main
feature over the basin.

Aside from impacts discussed above, a tight gradient between
high pressure centered over the southeastern U.S. and Tropical
Storm Alberto is supporting strong to near-gale force easterly
winds over the Gulf waters west of 87W, with fresh to strong
winds east of 87W, including the Yucatan Channel. Latest buoy
observations show seas in the range of 9 to 14 ft north 24N and
west of 87W. Seas of 6 to 9 ft are south of 24N and west of 87W,
including the Bay of Campeche. Seas of 6 to 8 ft are east of 87W.

For the forecast, Tropical Storm Alberto will move to near
22.0N 97.0W late tonight with maximum sustained wind speed
40 kt gusts 50 kt, then move inland and weaken to a tropical
depression near 22.1N 100.9W Thu afternoon and dissipate Fri
morning. Another broad area of low pressure is forecast to
develop over the southwestern Gulf of Mexico this weekend.
Environmental conditions are expected to be conducive for gradual
development of this system through early next week while it
moves slowly west-northwestward or northwestward.

...CARIBBEAN SEA...

A tight gradient between the broad cyclonic circulation
associated to Tropical Storm Alberto and high pressure ridging
that stretches southward from the southeastern U.S. to Florida
and western Cuba is supporting fresh to strong southeast winds
over the northwestern Caribbean west of about 83W. Seas over this
section of the sea are in the 7 to 10 ft range as indicated by
buoy 42056 located at 20N85W. Moderate to fresh southeast winds
are between 81W and 83W. Moderate to fresh trade winds are east
of 78W as seen partial ASCAT satellite data passes over that part
of the sea, and gentle to moderate trade winds are elsewhere.
Seas elsewhere across the basin are in the range 3 to 5 ft,
except for slighter lower seas of 2 to 4 ft are over the waters
from 15N to 18N between 72W and 80W and south of 11N west 80W.
Higher seas of 6 to 8 ft are from 15N to 20N between 80W and 85W
and 6 to 9 ft in the Gulf of Honduras. A very unstable
atmospheric environment in place, mainly a result of a broad
upper-level low that is north of the basin near the central
Bahamas has assisted in the development of numerous moderate to
isolated strong convection south of 15N and west of 74W to inland
some sections of Nicaragua, Costa Rica and Panama. Similar
convection is from just north of the Gulf of Honduras to 20N and
west of 86W to just inland the Yucatan Peninsula and Belize.
Other scattered moderate to isolated strong convection is
increasing over most of Cuba and Jamaica. Scattered clusters of
showers and thunderstorms are increasing over some areas of
Hispaniola and south of Puerto Rico to near 16N. Isolated showers
and thunderstorms are elsewhere east of 83W and north of 18N
west of 81W.

For the forecast, the fresh to strong southeast winds and rough
seas over the NW Caribbean will diminish to moderate to fresh
speeds and moderate seas from Sat afternoon through Sun night.
Moderate to fresh trade winds will continue across the eastern
and central Caribbean through Sat, pulsing to strong speeds over
the south-central basin tonight through Fri night. Winds across
these two regions will diminish to gentle to moderate speeds Sun.

...ATLANTIC OCEAN...

A surface trough extends from near 30N70W to low pressure of 1014
mb (Invest-AL92) near 26N71W and to near 22N71W. Scattered
moderate convection lifting northward is seen from 26N to 29N
between 69W and 71W. Similar convection also lifting northward
is from 19N to 25N between 63W and 68W, from along the coast of
Hispaniola north to 22N between 70W and 72W and west- southwest
of the Bahamas to along the central and western coasts of Cuba
and extending out over the Straits of Florida. Scattered moderate
convection moving quickly westward is noted from 26N to 29N west
of 78W, including the NW Bahamas and inland some areas of the
Florida peninsula. This activity is being further enhanced by an
upper- level low observed to be near 25N79W. A stationary front
enters the area through 31N52W and continues to 29N62W and to
28N69W. The pressure gradient between these features and high
pressure to the north is inducing fresh to strong northeast to
east winds north of a line from 30N60W to 29N70W to 26N74W and to
Palm Beach, Florida as depicted in ASCAT satellite data passes
over these waters and in buoy observations. These winds are
producing seas in the range of 8 to 12 ft, with buoy 41047
located at 27.5N 71.5W reporting combined seas of 12 ft.
Elsewhere north of 20N, winds are mainly gentle to moderate in
speeds with seas in the range of 4 to 6 ft. Moderate to locally
fresh winds are over the tropical Atlantic with seas of 4 to 6
ft. The main exception is in the vicinity of the tropical wave in
the eastern Atlantic, where fresh to locally strong winds, and
seas of 8 to 9 ft prevail.

For the forecast west of 55W, in reference to the aforementioned
surface trough that extends from near 30N70W to low pressure of 1014
mb (Invest-AL92) near 26N71W and to near 22N71W, environmental
conditions are marginally conducive for some gradual development
of this system during the next few days while it moves westward
or west-northwestward. The system is forecast to approach the
coast of the southeastern U.S. by Fri. Regardless of development,
fresh to strong northeast to east winds and rough seas to 12 ft
will continue over the waters north of 26N through Thu. High
pressure north of the area and associated ridging will dominate
the region afterwards, generally supporting gentle to moderate
east to southeast winds for the next few days.

$$
Aguirre