[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131803
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Mon Sep 13 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 Nicholas is centered near 26.4N 96.8W at 13/1500
UTC or 40 nm NE of mouth of The Rio Grande and moving N at 10 kt.
Estimated minimum central pressure is 1002 mb. Maximum sustained
winds are 50 kt with gusts to 60 kt. Numerous moderate to strong
convection is noted within a 160 nm semicircle E of the center.
Scattered moderate to isolated convection is seen up to 50 nm SW
of the center. Similar conditions are also found farther N of the
center, along the Texas coast and adjacent waters. Seas are
peaking at 16 to 17 ft near and just NE of the center. Dangerous
storm surge is expected from the Mouth of the Rio Grande
northeastward to Intracoastal City. On the forecast track, the
center of Nicholas will pass near or just offshore of the coast of
south Texas this morning and move onshore along the coast of
south or central Texas late this afternoon or this evening.
Strengthening is forecast today, and Nicholas could reach the
northwest Gulf coast as a hurricane. Weakening is anticipated on
Tuesday and Wednesday while Nicholas moves over land. Nicholas is
expected to produce 6 to 10 inches of rain with locally higher
amounts from just NE of Corpus Christi northeastward across
Houston to E of Lake Charles. Flooding at urban and low-lying
areas, as well as near rivers and streams is likely. The potential
for flash flooding will also increase.

Please read the latest High Sea Forecast issued by the National
Hurricane Center at website -
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest
Nicholas NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

A tropical wave is along the African coast near Senegal, Gambia
and Guinea. Scattered moderate convection is seen from 06N to 13N
between the coast and 23W. The National Hurricane Center is
monitoring this feature and there is a low chance of tropical
cyclone formation through the next 48 hours, and a high chance
through the next 5 days. Please read the latest Tropical Weather
Outlook at www.hurricanes.gov for more information.

An Atlantic tropical wave is along 33W from 19N southward and
moving W at 10 to 15 kt. Scattered moderate convection is noted
from 02N to 9N between 27W to 35W.

Another Atlantic tropical wave is near 55W from 20N southward and
moving W near 15 kt. Drier air at mid levels is hindering any
significant convection near this wave.

A Caribbean tropical wave is along 74W from W Hispaniola to
N Colombia, and moving W at 10 to 15 kt. No significant convection
is seen near this wave.

Another Caribbean tropical wave is near 88W from the coast of
Belize southward across Honduras and El Salvador to the E Pacific
Ocean, and moving W near 10 kt. No significant convection is
found.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic ocean near Guinea-Sierra
Leone border at 09N13W to 08N34W. Numerous moderate to isolated
strong convection is occurring over Guinea and SW Senegal. The
ITCZ continues from 08N34W to 06N45W. Scattered moderate
convection is present up to 70 nm on either side of the ITCZ
between 35W and 41W.

The eastern end of the E Pacific monsoon trough is triggering
scattered showers and isolated thunderstorms over the SW Caribbean
Basin, including the coast of Panama, Costa Rica and S Nicaragua.

...GULF OF MEXICO...

Refer to the Special Features section above for details on
Tropical Storm Nicholas moving northward across the NW Gulf.

Convergent fresh to strong SE winds feeding toward Nicholas are
triggering scattered showers and thunderstorms over the Bay of
Campeche. Convergent trade winds are producing scattered showers
and isolated thunderstorms across the SE Gulf, including the
Florida Strait and Keys.

Outside of Nicholas, the latest scatterometer pass provides
observations of fresh to strong SE to S winds with seas at 6 to 9
ft across the central and W central Gulf. Elsewhere, mainly
gentle to moderate E to ESE winds and seas of 2 to 5 ft are
found.

For the forecast, Tropical Storm Nicholas is near 26.4N 96.8W
with a central pressure at 1002 mb at 1500 UTC. It is moving N at
10 kt with maximum sustained winds at 50 kt with gusts to 60 kt.
Nicholas will move to 27.5N 96.7W this evening, inland to 29.1N
96.3W Tue morning, move inland and weaken to a tropical depression
near 30.2N 95.4W Tue evening, inland to 31.0N 94.0W Wed morning,
inland to 31.5N 92.5W Wed evening, and become a remnant low and
move to 32.0N 91.1W Thu morning. Nicholas will dissipate by early
Fri.

...CARIBBEAN SEA...

Convergent trades are coupling with divergent winds aloft to
produce scattered showers and thunderstorms over the NE corner of
the basin, including the Leeward Islands. Refer to the Tropical
Waves and Monsoon Trough/ITCZ sections for additional convection
in the Caribbean Basin.

Satellite derived wind data show mainly gentle with locally
moderate trades across the basin. Seas at 3 to 5 ft across the
majority of the waters, except 2 to 3 ft N of Venezuela.

For the forecast, moderate to fresh trades will prevail across
the basin through Wednesday. By the end of the week, fresh SE
winds return in the Gulf of Honduras.

...ATLANTIC OCEAN...

A stationary front reaches west-southwestward from E of Bermuda
to N Florida. Scattered showers and isolated thunderstorms are
evident near this feature N of 28N between 45W and 71W. An upper-
level low near the N coast of Hispaniola at 20N71W is generating
scattered showers and thunderstorms from 19N to 22N between 61W
and 71W, and farther N from 24N to 26N between 62W and 67W.
Moderate to fresh winds and seas at 5 to 7 ft are noted near these
showers and thunderstorms. Convergent trades are causing scattered
showers and isolated thunderstorms from SE Florida, northeastward
across the NW Bahamas to near 28N71W. Another upper-level low near
28N50W is producing isolated thunderstorms over the central
Atlantic. A weakening cold front is generating scattered showers
near the Canary Islands. Refer to the Tropical Waves and Monsoon
Trough/ITCZ sections for additional convection. Light to gentle E
to ESE trades and seas of 2 to 4 ft prevail off the Florida-
Georgia coast. Otherwise, gentle to moderate trades and seas at 4
to 6 ft dominate the rest of the Atlantic Basin.

For the forecast west of 65W, a frontal boundary will linger
across the area through today which will bring showers and
thunderstorms across the area. Otherwise, quiescent conditions
will prevail through Wednesday. Meanwhile, an area of low pressure
is forecast to form by midweek a couple of hundred miles north of
the southeastern or central Bahamas as a tropical wave interacts
with an upper-level trough. Some gradual development of this
system is possible thereafter, and a tropical depression could
form later this week while the system moves north-northwestward or
northward across the western Atlantic. This system has a low
chance of formation in the next 48 hours and a medium chance
through the next 5 days.

$$

Chan
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