926
AXNT20 KNHC 200506
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 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 0000 UTC surface analysis and satellite imagery through
0506 UTC.

...SPECIAL FEATURES...

Tropical Storm Alberto is centered near 21.5N 95.9W at 20/0300
UTC moving west at 8 kt. The estimated minimum central pressure
is 993 mb, and the maximum sustained wind speed is 45 kt with
gusts to 55 kt. Peak seas are up to 16 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 19N to 22N between 94W and
98W and from 22N to 27N between 96W and 100W.

Alberto westward motion is expected to continue for the next day
or so. On this track, the center of Alberto is expected to reach
the Gulf coast of Mexico early Thursday.  Some slight
strengthening is possible tonight before the center of Alberto
reaches land. Weakening is expected once the center moves
inland, and Alberto is likely to dissipate over Mexico on
Thursday or Thursday night. Alberto is a large tropical storm,
with tropical-storm-force winds extending outward up to 400 nm
from the center.

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...

An eastern Atlantic tropical wave have been relocated and is
axis is analyzed along 28W from 04N to 17N. No significant
convection is depicted at this time in association with this
wave.

A central Atlantic tropical wave has its axis along 44W from
04N to 16N, moving westward at around 15 kt. Scattered showers
and isolated thunderstorms are found from 08N to 10N between the
wave axis and 48W.

A central Atlantic tropical wave has its axis along 58W 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.
Scattered moderate convection is depicted from 08.5N to 10N
between 53W and the wave axis.

The central Caribbean tropical wave has been absorbed by the
large monsoon circulation that remains around Tropical Storm
Alberto.

A cluster of moderate to strong convection is depicted south of
11N moving off the coast of west Africa. This activity is likely
related to the next tropical wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Africa near
14N17W and continues southwestward to 10N22W. The ITCZ extends
from 10N22W to 10N27W to 10N30W to 08N42W to 08N45W and to
06N53W. Scattered moderate convection is found from 05N to 10N
between 30W and 40W.

...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 88W, with fresh to strong
winds east of 88W, including the Yucatan Channel. Seas of 12 to
to 18 ft are found west of 90W. Seas are 8 to 12 ft between 85W
and 90W. Elsewhere seas are 5 to 8 ft.

For the forecast, Tropical Storm Alberto is near 21.5N 95.9W at
11 PM EDT, and is moving west at 8 kt. Maximum sustained winds
are 45 kt with gusts to 55 kt, and the minimum central pressure
is 993 mb. Alberto will move inland to 21.7N 98.6W Thu morning,
and dissipate Thu evening. Another broad area of low pressure is
forecast to form near the Yucatan Peninsula of Mexico on Friday.
Environmental conditions appear to be conducive for gradual
development thereafter, and this system could become a tropical
depression over the southwestern Gulf of Mexico this weekend
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, including the
Gulf of Honduras. Seas over this sections of the sea are in the
7 to 10 ft range. Moderate to fresh southeast winds are between
81W and 83W. Moderate to fresh trade winds are east of 76W and
gentle to moderate trade winds are elsewhere. Seas elsewhere
across the basin are in the range 3 to 5 ft. 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 west of 69W.

For the forecast, fresh to near gale-force SE winds and rough
seas over the NW Caribbean will diminish to moderate to fresh
speeds and moderate seas Sat afternoon through early next week.
Moderate to fresh trade winds will continue across the eastern
and central Caribbean through Sat before diminishing to moderate
speeds. Winds will pulse to strong speeds over the south-
central Caribbean through Fri night.

...ATLANTIC OCEAN...

A 1013 mb low pressure near 26.4N72.3W (Invest-AL92) has formed
about 300 miles east of the northwestern Bahamas this evening
with disorganized shower and thunderstorm activity from 25N to
29N between 70W and 75W.

Scattered moderate convection is depicted from 20N to 23N
between 65W and 75W and between 78W and the Straits of Florida.
A stationary front enters the area through 31N51W and continues
to 29N59W and to 30N67W. Isolated showers and thunderstorms are
depicted ahead of the stationary front north of 28N between 40W
and 51W. 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 29N69W, and to 26N75W.
These winds are producing seas in the range of 8 to 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 fresh
winds are over the tropical Atlantic with seas of 6 to 10 ft.


For the forecast west of 55W, a small area of low pressure has
formed about 300 miles east of the northwestern Bahamas this
evening with disorganized shower and thunderstorm activity.
While environmental conditions are only marginally conducive due
to nearby dry air, further development of this system is
possible while the low moves west-northwestward and approaches
the northeastern coast of Florida or Georgia early on Friday.
Regardless of development, fresh to strong NE to E winds and
rough seas will prevail across the waters N of 26N through Thu
night. High pres will build in the wake of the area of low
pressure supporting gentle to moderate winds through early next
week.

$$
KRV