[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211744
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Fri Jul 21 2023

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 Don is centered near 35.8N 46.5W at 21/1500 UTC
or 940 nm W of the Azores moving WNW at 9 kt. Estimated minimum
central pressure is 1002 mb. Maximum sustained wind speed is 45
kt with gusts to 55 kt. Scattered moderate convection is noted
up to 60 nm in a southern semicircle from the center. Since the
time, the convection has become somewhat more fragmented, but
there is still a well-defined curved band that wraps about three-
quarters of the way around Don's center. Seas are peaking to 20 ft
near the center. A turn toward the northwest with a slightly
faster forward speed is expected later today. A north-
northwestward to northward motion is forecast on Saturday,
followed by a north-northeastward turn by late Sunday. Little
overall change in strength is forecast during the next day or so.
Weakening is forecast to begin by Sunday morning.

Please read the latest HIGH SEAS
FORECAST issued by National Hurricane Center at web-site
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest T.S.
Don Forecast/Advisory and Public Advisory at www.hurricanes.gov
for more details.

Central Tropical Atlantic (AL95):
A small area of low pressure, located several hundred miles west-
southwest of the Cabo Verde Islands, is producing an area of
disorganized showers and thunderstorms over the central tropical
Atlantic. Although there is dry air located to the north of the
system, favorable upper-level winds are expected to allow for
gradual development during the next several days. This system
could become a tropical depression early next week, as it moves
westward across the tropical Atlantic. Refer to the latest
Tropical Weather Outlook at www.hurricanes.gov
for more details.

Gale Warning E of 35W: Meteo-France is forecasting frequent gusts
to gale force and rough to very rough seas mainly in the east part
of the Agadir Marine Zone. Please read the High Sea Forecast and
Warning at https://wwmiws.wmo.int for more information.

...TROPICAL WAVES...

An eastern Atlantic tropical wave was relocated based on wave
diagnostics and its axis is now along 30W from 11N southward. Isolated
scattered convection is seen east of the wave axis from 06N to
11N between 26W and 30W.

A central Caribbean tropical wave has its axis along 78W south of
eastern Jamaica to inland eastern Panama. It is moving westward
around 15 kt. No significant convection is seen in association to
this wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic along the Mauritania coast
just near Nouakchott and continues southwestward to 15N22W to
14N27W to low pressure near 11.7N39.2W 1014 mb and to 09N46W.
Aside from convection noted in the SPECIAL FEATURES and the TROPICAL
WAVES sections above, scattered moderate to isolated strong
convection is seen from 07N to 10N between the Guinea- Sierra
Leone coast and 22W.

...GULF OF MEXICO...

No significant convection is seen in the basin, however, a
surface trough is located over the central Gulf from 27N86W to
24N88W. Otherwise, broad and weak high pressure is present over
the region. The associated gradient is allowing for generally
light to gentle winds and seas of 1-2 ft over the eastern and
north- central Gulf. Gentle to moderate east- southeast winds and
seas of 2-4 ft are seen in the southwest Gulf.

For the forecast, the aforementioned weak high pressure will
remain over the area into early next week. This will support
mainly gentle to moderate winds, except over the eastern Bay of
Campeche where winds will be enhanced by a thermal trough coming
off the Yucatan Peninsula during the night hours.

...CARIBBEAN SEA...

Convergent easterly trade winds are coupling with mid-level
troughing leading to scattered to numerous showers and
thunderstorms over the northwest section of the basin north of
16N and west of 82W. Elsewhere, GOES-16 Saharan Air Layer
Tracking product is showing an area of Saharan dust moving west
across the Atlantic Ocean and into the central Carribbean reaching
central Cuba. Therefore, expect above normal temperatures with
dry conditions, hazy skies, and patches of lower visibility. A
tight pressure gradient between the Bermuda High and Colombian Low
is maintaining strong to near- gale easterly winds along with
seas of 8-11 ft over the south- central part of the basin north of
Colombia. Fresh to strong east winds and seas of 6-9 ft are over
the north- central part of the basin. Gentle to moderate northeast
to east winds with seas of 6-8 ft due to an easterly swell.
Moderate to fresh easterly trades and seas of 3-6 ft seas are
elsewhere in the basin.

For the forecast, the aforementioned pressure gradient between
the Bermuda High and lower pressure over Central America and
northern South America will maintain strong trades across the
central Caribbean into Sat night. Winds should diminish to fresh
to strong Sun into Tue night. Fresh to locally strong trades will
develop over the Gulf of Honduras Sat night through Mon.

...ATLANTIC OCEAN...

Scattered to isolated strong convection is seen north of 21N
between 60W and 67W in association with an upper level
disturbance. Another area of similar convection is seen north of
29N between 66W and 77W in association to a frontal boundary.
Please see the SPECIAL FEATURES, TROPICAL WAVES, and the MONSOON
TROUGH/ITCZ sections for more information on Tropical Storm Don in
the north- central Atlantic, gale winds in the eastern Atlantic,
and convection in the tropical Atlantic. Elsewhere, GOES-16
Saharan Air Layer Tracking product is showing an area of Saharan
dust moving west across the Atlantic Ocean. Therefore, expect
above normal temperatures with dry conditions, hazy skies, and
patches of lower visibility.

Weak gradient is supporting light to gentle winds and seas of 3
to 5 ft north of 24N between 43W and the Georgia- Florida coast,
outside of convection. To the south, moderate with locally fresh
northeast to east to east- southeast winds and seas at 4-6 ft are
noted from 20N to 23N and between 43W and the Bahamas. Farther
east, the Azores High is channeling gentle to moderate northeast
winds with 5-7 ft seas north of 20N between 25W-20W. Near the
Canary Islands, moderate to fresh with locally strong north to
northeast trade winds and seas of 7-9 ft are present. North of 16N
between the Africa coast and 35W moderate northeasterly winds and
seas 4-6 ft are seen. For the tropical Atlantic, gentle to
moderate northeast to east trades and seas of 4-6 ft are present.
Gentle to moderate southerly and monsoonal westerly winds along
with seas of 4-6 ft prevail for the remainder of the Atlantic
Basin.

For the forecast west of 55W, the Bermuda High centered near
26N68W will weaken and shift east-southeastward through the
weekend. Fresh trades just north of Hispaniola and over the
Windward Passage will diminish tonight. Elsewhere across forecast
waters, winds will be moderate or weaker into Tue night.

$$
KRV
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