[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200612
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Mon Sep 20 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 0000 UTC surface analysis and satellite imagery through
0530 UTC.

...SPECIAL FEATURES...

Tropical Storm Peter is centered near 18.6N 58.5W at 20/0300 UTC
or 265 nm E of the Northern Leeward Islands, and moving WNW at 12
kt. Estimated minimum central pressure is 1004 mb. Maximum
sustained wind speed is 45 kt with gusts to 55 kt. Seas are
peaking near 15 ft near and just NE of the center. Fresh to strong
winds and seas at 8 to 11 ft are found farther E to NE to N of the
center from 17N to 21N between 54W and 59W. Due to strong upper-
level wind shear, numerous moderate to isolated strong convection
is noted up to 200 nm in a NE semicircle from the center. An
outer band of scattered moderate convection is seen farther N of
the center from 20N to 22N between 55W and 59W. Peter is expected
to continue on a WNW track with little change in speed through
Tue morning, then gradually turn toward the NW Tue night. On the
forecast track, Peter is anticipated to pass north of the Leeward
Islands Mon and Mon night, then well N of Puerto Rico on Tue.
Strong wind shear should cause Peter to gradually weaken over the
next few days. Peripheral rainbands S of Peter have been producing
heavy showers across the Northern Leeward and Virgin Islands,
Guadeloupe has received 1.79 inches of rain in the past 24 hours.
This trend will continue and spread to Puerto Rico later today.
As a result, the chance for urban and small stream flooding will
greatly increase through Tue. Please read the latest NHC Public
Advisory at https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and
Forecast Advisory at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml
for more details. Marine interests in the area can read the
latest NHC Offshore Waters Forecasts at
https://www.nhc.noaa.gov/marine/offshores.php

Tropical Storm Rose is centered near 15.3N 31.1W at 20/0300 UTC
or 390 nm W of the Southernmost Cabo Verde Islands, and moving
NW at 14 kt. Estimated minimum central pressure is 1005 mb.
Maximum sustained wind speed is 35 kt with gusts to 45 kt. Seas
are peaking at 8 to 10 ft near the center. Numerous moderate to
isolated strong convection is noted up to 200 nm in a semicircle
NW of the center. Rose is anticipated to move NW with little
change in speed over the next few days. Slight strengthening is
forecast through tonight before gradual weakening by Tue. Please
read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and Forecast
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for more
details. For sea conditions near this system, please read the
Meteo-France High Seas Forecast at http://weather.gmdss.org/II.html

...TROPICAL WAVES...

An Atlantic tropical wave is along 19W from 19N southward and
moving W near 15 kt. Scattered moderate to isolated strong
convection is seen from 04N to 13N between the African coast and
26W. Scattered moderate convection is noted from 12N to 19N
between 21W and 24W.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends across the Senegal coast near 14N17W
to near the Cabo Verde Islands at 15N24W. The ITCZ is found
farther SW from 10N26W to 06N42W. Scattered moderate convection is
present near the ITCZ from 03N to 09N between 32W and 44W. No
significant convection is found near the monsoon trough.

The eastern end of the Pacific monsoon trough is triggering
scattered showers and isolated thunderstorms across Panama and N
Colombia, and adjacent waters.

...GULF OF MEXICO...

A persistent surface trough stretches east-northeastward from near
the Texas-Mexico border across the N Gulf to N Florida. Scattered
showers and thunderstorms are present from the N central Gulf
eastward to N Florida. Another surface trough locating near the W
coast of the Yucatan Peninsula is triggering similar conditions
over the E Bay of Campeche. Locally moderate winds and seas up to
4 ft are possible near these showers and thunderstorms. Otherwise,
a modest 1015 mb high over the E central Gulf is providing light
to gentle winds and seas of 1 to 3 ft across much of the Gulf.

For the forecast, weak high pressure will persist across the
eastern and central Gulf of Mexico through Tue. This pattern will
support continued gentle to moderate winds and mostly slight seas
across the Gulf. An early season cold front is expected to enter
the NW Gulf early Wed and reach from the NE Gulf to central Bay of
Campeche by late Thu.

...CARIBBEAN SEA...

Outer rainbands associated with Tropical Storm Peter to the E
over the Atlantic are producing scattered heavy showers and
thunderstorms across NE Puerto Rico, the Virgin and Northern
Leeward Islands. Please read the Special Features section above
for details on Tropical Storm Peter which is forecast to track
well N of these locations.

Convergent trade winds are triggering scattered showers and
isolated thunderstorms over the NW and N central basin, including
De Pinos Island and W Hispaniola. Refer to the Monsoon
Trough/ITCZ section above for additional convection in the basin.
Moderate trades and seas near 4 ft are evident over the S central
basin. Light to gentle trades and seas at 2 to 3 ft prevail for
the rest of the basin.

For the forecast, Tropical Storm Peter is near 18.6N 58.5W 1004
mb at 0300 UTC, and moving WNW at 12 kt. Maximum sustained winds
are 45 kt with gusts to 55 kt. Peter will move to 19.3N 60.6W Mon
morning, 20.1N 62.9W Mon evening, 21.0N 65.0W Tue morning, and
22.0N 66.7W Tue evening. Peter will weaken to a tropical depression
as it continues to move northward toward Bermuda through the rest
of the week. As this occurs, trade winds over the S central
Caribbean will diminish through Thu night. Look for associated
squalls and thunderstorms to affect the Leeward Islands and
adjacent waters through Tue.

...ATLANTIC OCEAN...

Please read the Special Features section above for details on
Tropical Storm Peter east of the Leeward Islands and Tropical
Storm Rose WSW of the Cabo Verde Islands.

The Cumbre Vieja volcano on the island of La Palma in the Canary
Islands has been erupting since 19/1410 UTC. The ash plume is
expected to remain below 1000 ft in the vicinity of the volcano
while drifting SE, causing a reduction in visibility. Marine and
aviation interests should monitor this on-going situation by
reading Volcanic Ash Advisory issued by Meteo-France at
http://vaac.meteo.fr/volcanoes/la-palma/

The southwestern end of a cold front is causing scattered moderate
convection S of Bermuda from 27N to 31N between 60W and 66W. A
surface trough near 22N29W is creating similar conditions NW of
the Cabo Verde Islands from 19N to 22N between 26W and 29W.
Convergent ESE to SE winds near a surface trough over N Florida is
triggering scattered showers and thunderstorms off the Georgia-Florida
coast N of 27N and W of 77W. Refer to the Monsoon Trough/ITCZ
section for additional convection in the basin.

The Atlantic ridge stretching west-southwestward from a 1033 mb
Azores high to Florida continues to provide light to gentle winds
and seas of 3 to 4 ft N of 23N between 37W and the Georgia-Florida
coast. Outside the influence of Tropical Storm Peter and Rose,
gentle to moderate trades and seas at 4 to 7 ft are found N of 17N
between the African coast and 37W, and from 10N to 23N between the
central African coast and the Lesser Antilles. Light to gentle S
to SW winds and seas of 4 to 6 ft prevail for the remainder of the
basin.

For the forecast west of 55W, Tropical Storm Peter near 18.6N
58.5W 1004 mb at 0300 UTC moving WNW at 12 kt. Maximum sustained
winds 45 kt gusts 55 kt. Peter will move to 19.3N 60.6W Mon
morning, 20.1N 62.9W Mon evening, 21.0N 65.0W Tue morning, 22.0N
66.7W Tue evening, weaken to a tropical depression near 23.0N
67.9W Wed morning, and 23.9N 68.6W Wed evening. Peter will change
little in intensity as it moves northward toward Bermuda
throughout the rest of the week. Elsewhere west of 70W, gentle to
moderate winds and slight to moderate seas will persist over open
waters through the early part of the week, with swell to 8 ft
associated with the tropical storm reaching the waters east of 72W
by Wed.

$$

Chan
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