Skip Navigation Links
NOAA NOAA United States Department of Commerce

Atlantic Tropical Weather Discussion



000
AXNT20 KNHC 220607
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Wed Sep 22 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 Depression Peter is centered near 20.8N 65.3W at 22/0300
UTC or 150 nm NNE of San Juan Puerto Rico, and moving NW at 6 kt.
Estimated minimum central pressure is 1009 mb. Maximum sustained 
winds are 30 kt with gusts to 40 kt. Seas are peaking at 11 to 12 
ft near and just NE of the center. An area of fresh to strong 
winds with seas at 7 to 10 ft are present up to 190 nm in a 
semicircle NE of the center. Numerous moderate convection is seen 
E and NE of the center from 19N to 23N between 60W and 65W. 
Scattered moderate convection is found S and SW of the center near
Puerto Rico from 18N to 19N between 65W and 67W. Peter will 
continue on a NW track, moving farther away from Puerto Rico and 
the Virgin Islands through Wed afternoon; then gradually turning N
away from the Bahamas with a decrease in speed Wed night and 
Thursday. A gradually weakening trend is expected and Peter might 
become a remnant low on Thu. The southern peripheral rainbands of 
Peter could produce additional heavy rainfall the Virgin Islands, 
Puerto Rico and the northern portions of Hispaniola through Thu 
morning. This rainfall may lead to areas of urban and small stream
flooding. In addition, swells generated by Peter will continue to
impact the above locations through Wednesday. Please 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 Peter NHC Forecast/Advisory and Public Advisory at 
www.hurricanes.gov for more details.

Rose has been downgraded to a tropical depression and is centered
near 22.9N 37.9W at 22/0300 UTC or 885 nm WNW of the Cabo Verde 
Islands, and moving NW at 9 kt. Estimated minimum central 
pressure is 1009 mb. Maximum sustained winds are 30 kt with gusts
to 40 kt. Seas are peaking at 12 to 13 ft near and just N of the 
center. An area of fresh to strong winds with seas at 8 to 11 ft 
are evident up to 210 nm in a semicircle E of the center. Due to a
combination of vertical wind shear and much drier air at the mid 
levels, scattered moderate convection is E of the center from 21N 
to 23N between 35W to 37W. Rose should gradually turn toward the 
north starting late Wed night or early Thu morning, then turning 
to the NE on Friday. Rose will remain a tropical depression 
through Thu and might weaken to a remnant low Friday. Please 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 Rose NHC Forecast/Advisory and Public Advisory at 
www.hurricanes.gov for more details.

Showers and thunderstorms associated with a tropical wave located 
several hundred miles southwest of the Cabo Verde Islands have 
increased since this morning and are beginning to show signs of 
organization. Recent satellite wind data also indicate that a broad 
area of low pressure has formed, but the system lacks a well-defined 
center. Environmental conditions are expected to remain conducive 
for additional development, and a tropical depression is likely to 
form within the next day or two while the system moves westward at 
10 to 15 mph across the eastern and central tropical Atlantic
Ocean. There is a high chance of tropical formation for this
system in the next 48 hours. Please refer to the Tropical Weather
Outlook at www.hurricanes.gov/gtwo.php?basin=atlc&fdays=2 for the
latest information.

...TROPICAL WAVES...

An Atlantic tropical wave is along 30W from 15N southward through
a broad 1010 mb low near 10N30W, and moving W near 10 kt.
Scattered moderate to isolated strong convection is flaring up
from 9N to 14N between 29W and 33W. Refer to the latest NHC
Tropical Weather Outlook at 
www.hurricanes.gov/gtwo.php?basin=atlc&fdays=2 for the latest
formation potential.

...MONSOON TROUGH/ITCZ...

A monsoon trough passes through the African coastal near the
Mauritania-Senegal border at 16N16W through the 1010 mb low
mentioned in the Tropical Waves section to 09N34W. The ITCZ 
continues from 05N33W to N of Suriname at 10N55W. Scattered
moderate convection is present S of the monsoon trough from 01N to
06N between 18W and 30W. No significant convection is noted near
the ITCZ.

The E end of E Pacific monsoon trough is producing scattered
showers and thunderstorms over E Panama and NW Colombia, and
adjacent waters.

...GULF OF MEXICO...

A stationary front across the S Texas and Louisiana coast is
producing scattered showers and thunderstorms along the NW edge of
the Gulf. A surface trough near the W coast of the Yucatan 
Peninsula is coupling with divergent winds aloft to trigger 
numerous heavy showers and scattered thunderstorms over the E Bay 
of Campeche. Locally moderate to fresh winds and seas up to 4 ft 
are possible near these showers and thunderstorms. A mid-level 
trough near 28N82W is inducing scattered showers and isolated 
thunderstorms over central Florida. Otherwise, a 1017 mb high over
the central Gulf dominates the region with light to gentle winds 
and seas of 1 to 3 ft.

For the forecast, weak high pressure will persist across the 
E and central Gulf through tonight, then dissipate ahead of an 
early season cold front expected to enter the NW Gulf early Wed. 
The front will reach from the NE Gulf to central Bay of Campeche 
by late Thu before stalling, supporting increased winds and seas 
over the NW and N central Gulf Tue night through Thu. Winds and 
seas will diminish through late Sun as high pressure builds across
the N Gulf in the wake of the dissipating front.

...CARIBBEAN SEA...

Please read the Special Features section above for details on 
Tropical Depression Peter. Its S peripheral rainbands can still 
bring heavy rain to parts of the Greater Antilles through Thu.

Convergent trades are causing scattered showers and isolated
thunderstorms over the NW and N central basin, including S Cuba
and Hispaniola. Refer to the Monsoon Trough/ITCZ section for 
additional convection across the basin. Light to gentle trades and
seas of 2 to 4 ft prevail across much of the basin. Seas at the 
Mona Passage will be higher at 4 to 6 ft due to swell produced by 
Tropical Depression Peter.

For the forecast, Tropical Depression Peter is near 20.8N 65.3W 
1009 mb at 22/0300 UTC, and moving NW at 6 kt. Maximum sustained 
winds 30 kt gusts 40 kt. Peter will continue north of the area 
while weakening to a remnant low by late Wed night and continuing 
to south of Bermuda from Fri through late Sat. As this occurs, 
trade winds over the S central Caribbean will diminish through 
Thu night. Fresh trade winds will return to the S central 
Caribbean by late Sun as high pressure builds N of the area. 

...ATLANTIC OCEAN...

Please read the Special Features section above for details on 
Tropical Depressions Peter NNE of San Juan, Puerto Rico, and
Rose WNW of the Cabo Verde Islands; and the tropical formation
potential of a low pressure/tropical wave SW 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. Satellite imagery
shows volcanic ash approximately 30 nm W of the volcano as well
as the hot spot related to the eruption. 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/.

A frontal boundary curves southwestward from the NE Atlantic
across 30N47W to near 27N58W, then continues northwestward to 
near Georgia/South Carolina border. Scattered showers and isolated
thunderstorms are see N of 26N between 52W and 77W. A robust
upper-level low and its related trough near 30N26W are producing
scattered moderate convection SW and W of the Canary Islands N of
23N between 19W and 30W. Refer to the Tropical Waves and Monsoon
Trough/ITCZ sections for additional convection across the Atlantic
Basin. Moderate to fresh winds and seas of 5 to 8 ft associated
with the aforementioned frontal boundary are evident N of 27N
between 47W and 74W. Gentle to moderate with locally fresh trades
and seas at 4 to 6 ft are present N of 13N between the African
coast and 47W. Outside the influence of Peter and Rose, light to
gentle winds and seas of 4 to 5 ft prevail for the remainder of
the basin.

For the forecast west of 65W, Tropical Depression Peter is near 
20.8N 65.3W with 1009 mb at 22/0300 UTC, and moving NW at 6 kt. 
Maximum sustained winds are 30 kt with gusts 40 kt. Peter will 
move to 21.6N 66.2W Wed morning, 22.6N 66.8W Wed evening as it 
weakens further. The remnant low of Peter will continue to move 
farther N, reaching 26N 65W Fri morning before dissipating by Fri 
evening. Elsewhere gentle to moderate winds and slight to moderate
seas will continue through late Wed night, except for moderate to
fresh winds between the Bahamas and Cuba and elsewhere betwen 65W
and 70W. Winds will then become light and variable W of 70W 
through the weekend. A weak cold front will move across the waters
east of NE Florida Thu and stall through Sun.

$$

Chan