[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 081805
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Jul 8 2021

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 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...SPECIAL FEATURES...

Tropical Storm Elsa is centered near 35.0N 79.7W at 08/1500 UTC
or 70 nm SW of Raleigh North Carolina moving NE at 17 kt.
Estimated minimum central pressure is 1006 mb. Maximum sustained
wind speed is 40 kt with gusts to 50 kt. On the forecast track,
Elsa will move over South Carolina and North Carolina today, pass
near the eastern mid-Atlantic states by tonight, and move near or
over the northeastern United States on Friday and Friday night.
The system should move over Atlantic Canada by Friday night and
Saturday. Elsa is forecast to become a post-tropical cyclone by
Friday night.

As Elsa moves across North Carolina and Virginia today, heavy
rainfall may result in limited flash and urban flooding.  Heavy
rainfall from the Mid-Atlantic into New England through Friday
could lead to considerable flash and urban flooding.

Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT5.shtml, Forecast/Advisory
at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml, and the High
Seas Forecast issued by the NWS Ocean Prediction Center at
https://ocean.weather.gov/shtml/NFDHSFAT1.php for more details.
For marine information within 60 nm of the coast, please see
products from your local NWS Weather Forecast Office at
www.weather.gov.

Caribbean Sea Gale Warning: An ASCAT pass from this morning
revealed gale force winds over the south- central Caribbean near
the coast of Colombia due to the combination of high pressure
north of the area and lower pressures over northern Colombia.
Gales will pulse tonight through tomorrow with seas building to
12 to 14 ft. Please read the latest NWS High Seas Forecast issued
by the National Hurricane Center at the website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml.

Gale warning E of 35W: The pressure gradient between high
pressure of 1029 mb located about 400 nm east-northeast of the
Azores and lower pressures over Africa is resulting in strong
to gale-force north to northeast winds north of 20N and east of
25W, including the Canary Islands. Meteo-France has issued a Gale
Warning for Agadir from 08/12 UTC to 09/00 UTC. The forecast calls
for north winds Force 8 in the Beaufort Wind scale with gusts.
For more details, refer to the Meteo-France High Seas Forecast
listed in their website:
www.meteofrance.com /previsions- meteo- marine/
bulletin/grandlarge/metarea2.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis along 24W south
of 10N southward, moving westward at 10-15 kt. This wave is
surrounded by a moist atmospheric environment. Scattered moderate
convection is within 340 nm W of the wave axis from 03N-08N.

A central Atlantic tropical wave, with a larger amplitude, has
its axis extending from 23N35W to 14N36W and to 04N36W. It is
moving westward 10-15 kt. A small area of scattered moderate
convective is within 200 nm of the wave south of 07N.

A tropical wave has its axis along 58W extending south of 12N to
inland over South America, moving westward at 10-15 kt. Scattered
moderate convection is within 300 nm of the wave from 07N-10N.

A tropical wave over the south-central Caribbean has its axis
along 76W south of 14N. It is quickly moving westward due to the
strong trade winds near 20 kt. Isolated showers are possible near
this wave over the extreme southwestern Caribbean.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the coast of Guinea near
11N15W to 07N21W to 08N34W. A segment of the ITCZ is analyzed from
07N38W to 07N48W. Scattered moderate convection is well south of
the monsoon trough from 02N to 07N between 10W to 18W.

GULF OF MEXICO...

A middle to upper-level low is over southern Texas. A trough
extends from the low to over northern Mexico. At the surface, a
1007 mb low is analyzed over southern Texas. A trough is just
inland over the Texas coast extending south along the northeastern
coast of Mexico. The combination of divergence east of the upper-
level trough along with the aforementioned surface features is
leading to large clusters of scattered moderate to strong convection
over the NW Gulf from 21N to 30N and W of 91W. A recent ASCAT pass
revealed gusty winds associated with this convection. This
activity will continue into the evening.

Elsewhere in the Gulf, moderate to fresh SE winds continue
except in the northeast section of the basin where gentle
southwest to west winds remain in the wake of Tropical Storm Elsa.
Seas are generally 3-6 ft throughout the Gulf.

For the forecast: High pressure from the Atlantic will build
westward across the area through the next few days, with
relatively quiet conditions expected. A trough over the Yucatan
Peninsula will shift westward to the SW Gulf during the mornings
through the weekend followed by fresh to strong southeast winds.
Scattered to numerous showers and thunderstorms over the NW Gulf
are expected to continue through this evening.

CARIBBEAN SEA...

Please see Special Features above for details on the Gale Warning
in effect for the south-central Caribbean near the coast of
Colombia.

Strong trades continue in the central Caribbean, with resulting
wave heights of 8-12 ft. Fresh strong trades are also occurring
in the Gulf of Honduras with wave heights of 4-6 ft. Moderate to
fresh trades prevail over the remainder of the Caribbean. Wave
heights range from 5-8 ft in the eastern Caribbean, 6-9 ft in the
north central Caribbean, and 4-6 ft in the NW Caribbean and
Windward Passage.

For the forecast: A ridge of high pressure north of the area
combined with the Colombian low will continue to enhance near gale
force winds pulsing to gale force in the south-central Caribbean
and strong winds in the central Gulf. Widespread fresh to strong
trades will continue in the south- central Caribbean and the Gulf
of Honduras through Fri night. Fresh to strong winds will pulse at
night in the Gulf of Honduras through early next week.

ATLANTIC OCEAN...

As of 1700 UTC, scattered moderate convection is over waters north
of the Bahamas, west of 76W. A cluster of showers and thunderstorms
is moving northeastward off the coast of Florida, north of 27.5
north. Seas in this region are 3 to 5 ft.

The Bermuda-Azores high dominates the Atlantic forecast waters.
The 1030 mb high is centered near 37N37W. Circulation around the
high results in gentle to moderate easterly winds and seas of 5 to
7 ft across the basin north of 23N and mainly west of 25W. Fresh
to strong NE are located east of 25W from the Canary Islands to
20N due to the pressure gradient caused by the Azores high and
lower pressures over Africa. Seas in this region are 6 to 9 ft.

For the forecast W of 65W: Fresh to strong south to southwest winds
over the far northwest part of the area will lift north of the
area this morning as Tropical Storm Elsa, currently over South
Carolina, continues to pull away from the region. High pressure
will then build westward across the area through Sun night. East
winds will pulse to fresh to strong speeds at night between the
southeastern Bahamas and Hispaniola through the period.

$$
Mora
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