Tropical Weather Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
734
AXNT20 KNHC 152344 CCA
TWDAT

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
0005 UTC Wed Jun 16 2021

Corrected Special Features Section

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 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...SPECIAL FEATURES...

Tropical Storm Bill is centered near 41.6N 59.6W at 15/2100 UTC
or 250 nm SE of Halifax Nova Scotia moving NE at 31 kt. Estimated
minimum central pressure is 998 mb. Maximum sustained wind speed
is 50 kt with gusts to 60 kt. Bill is well on its way to becoming
an extratropical cyclone. It is forecast to become a post-tropical
low by this evening, and dissipate on Wed.
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.

...TROPICAL WAVES...

A tropical wave is analyzed near 27W from 18N southward just
west of the Cabo Verde Islands, moving W at 15 to 20 kt. Shower
activity is limited in association with this wave. Only a few
showers are noted where the wave meets the ITCZ. Development, if
any, should be slow to occur during the next couple of days while
the wave moves westward. Thereafter, a combination of dry air
aloft and strong upper-level winds should end the chances of
formation when the wave reaches the central tropical Atlantic.

A second tropical wave is along 48W from 03N to 19N, moving W at
15 to 20 kt. Scattered showers are near the wave axis.

A tropical wave is moving across the central Caribbean with axis
along 72W from 17N southward to across western Venezuela and
eastern Colombia, moving W at 10 to 15 kt. The wave is likely
enhancing some convective activity over western Venezuela and
eastern Colombia.

A tropical wave crosses Guatemala and combined with the broad
area of low pressure over the Bay of Campeche will continue to
support showers and thunderstorms across northern central
America. Please, see the Special Features section for more
details.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Africa near Guinea-
Bissau to 11N20W. The ITCZ continues from 11N20W to 07N30W to
05N40W. Scattered moderate convection is from 02N to 10N E of 16W
to the coast of Africa.

GULF OF MEXICO...

Disorganized showers and thunderstorms continue over the Bay of
Campeche and southern Mexico in association with a broad low
pressure area. This system is expected to move little during the
next day or so, and any development should be slow to occur
during that time period.  However, the disturbance should begin
to move northward by Thursday, and a tropical depression is
likely to form late in the week when the low moves across the
central or northwestern Gulf of Mexico. Regardless of
development, heavy rainfall will continue over portions of
Central America and southern Mexico during the next several
days. Heavy rains could also begin to impact portions of the
northern Gulf Coast on Friday. Please consult products from your
local meteorological service for more information. The latest
Tropical Weather Outlook gives this system a low chance of
tropical cyclone formation trough 48 hours, and a high chance
through 5 days. Please see the latest Tropical Weather Outlook
at hurricane.gov

Otherwise, a weak ridge dominates the remainder of the Gulf
waters. Mainly light to gentle winds and seas of 1-3 ft prevail
across the northern half of the Gulf, with gentle to moderate
winds in the Bay of Campeche and NW of the Yucatan Peninsula
where some convective activity is noted. An area of fresh to
strong NW winds are observed on the west side of the low
pressure and near the Veracruz region. Seas over the southern
half of the Gulf are in the 2-3 ft range with the exception of 4-
6 ft in the Bay of Campeche. A band of scattered to numerous
showers and thunderstorms are along the northern Gulf coast from
northern Florida to the upper Texas coast. Convective activity
is also noted over parts of the Yucatan peninsula, SE Mexico and
the Bay of Campeche.

For the forecast, gradual development of a broad area of low
pressure in the Bay of Campeche is possible while it meanders
near the coast of Mexico. This system may bring an increase in
winds and seas across the Gulf waters toward the end of the
work-week as it is forecast to become a tropical depression.

CARIBBEAN SEA...

A tropical wave is moving across the central Caribbean. Refer to
the tropical waves section above for details.

The most recent scatterometer data provide observations of fresh
to locally strong trades over the south-central Caribbean and
mainly moderate winds elsewhere, except S of 11N where light and
variable winds area noted. Seas are generally in the 4 to 6 ft
range, except in the lee of Cuba, Windward Passage and near the
coast of Honduras and Nicaragua.

Showers and thunderstorms have developed over most of Cuba and
northern Central America under a diffluent pattern aloft.

For the forecast, a ridge north of the basin combined with lower
pressure over Central America and Colombia will support pulsing
fresh to strong trades over the S central Caribbean and Gulf of
Honduras through the upcoming weekend. Moderate to fresh trades
will prevail elsewhere, except light to gentle south of 11N.

ATLANTIC OCEAN...

Refer to the Special Features section above for details on
Tropical Storm Bill located well north of the discussion area.
A pair of tropical waves are moving westward between the west
coast of Africa and the Lesser Antilles. Refer to the tropical
waves section above for details.

A ridge dominate the entire Atlantic forecast area anchored by
the Bermuda-Azores High located north of the area near 35N35W.
The ridge extends across the Bahama, Cuba and southern Florida
into the Gulf of Mexico. Moderate to fresh southerly flow is
noted on the western periphery of the ridge and mainly N of 27N
between 70W-80W. Scattered showers and thunderstorms are over
much of Florida and also N of 27N between 70W-77W. Strong SW flow
ahead of an upper-level trough over the eastern CONUS is helping
to induce this convective activity. An upper-level low is also
producing some shower activity over the central Atlantic from
20N-26N between 40W-47W. Moderate to fresh trades are seen E of
the Lesser Antilles with seas of 6-7 ft.

For the forecast west of 65W, For the forecast west of 65W, a ridge
of high pressure across the area will continue to weaken today.
Winds will be fresh to strong north of 28N through mid-week as a
pair of cold fronts move by north of the area.

Farther E, tightening pressure gradient between the Bermuda-
Azores high and lower pressure over Africa is causing fresh N-NE
winds from 15N-25N E of 30W to the coast of W Africa. seas of 7-8
ft are within these winds.

$$
GR/jl



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.