[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202249
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat May 21 2022

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
2140 UTC.

...SPECIAL FEATURES...

A broad area of low pressure, known as the Central American Gyre
(CAG), is developing across Central America and the adjacent
southwest Caribbean today. The monsoon trough has begun to shift
northward across the tropical northeast Pacific, increasing SW
winds and advecting tropical moisture over Central America. Heavy
to extreme rainfall is possible over portions of Guatemala, El
Salvador, Nicaragua, Honduras, Costa Rica, and Panama. There is
potential for flash flooding and mudslides, especially across
mountainous terrain. This event is expected to last through early
next week. Please refer to products issued by your local weather
service for more information.

...TROPICAL WAVES...

A tropical wave is in the Atlantic with axis along 51W, from 01N
to 14N moving west around 20-25 kt. Scattered moderate isolated
strong convection is noted from 00N-07N between 44W-54W.

A tropical wave is exiting the far western Caribbean with axis
south of 19N along 89W and across Central America, moving west
around 10 kt. Associated convection is occurring over land near
the wave at this time, and extends across the adjacent Pacific
waters. Scattered moderate isolated strong convection is noted
behind the wave from 14N-16.5N between 80W-84W.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the African coast near 14N16W to
07N21W. The ITCZ continues from 07N21W to 02N45W. Scattered to
numerous moderate to strong convection is noted from 04N-09W east
of 25W. Scattered moderate isolated strong convection is noted
south of 07N between 44W-54W. The eastern North Pacific's monsoon
trough extends across Central America, along the border of Costa
Rica and Nicaragua, and extends to 11N75W along the coast of Colombia.
Widely scattered moderate convection is noted south of 14N west
of 76W.

...GULF OF MEXICO...

The gradient between the Bermuda High and lower pressure over NE
Mexico is supporting moderate to fresh S to SE flow across the
majority of the basin, with strong winds occurring along the SE
Texas coast. Seas are 2-4 ft in the eastern Gulf and 4-7 ft in
the western Gulf. Low level moisture has moved from the southeast
Gulf this morning to offshore of central Florida, where divergent
upper-level flow is supporting scattered moderate convection
from 26.5N-28N and east of 85W. Otherwise, clear to mostly fair
skies prevail across the basin. Smoke from seasonal agricultural
fires over Mexico continues to spread northward and is producing
hazy skies across the western two-thirds of the basin.

For the forecast, high pressure will build over the western
Atlantic through Sun as low pressure develops over Central America
and the Bay of Campeche. This will allow for mostly fresh
southeast winds over the western Gulf to expand eastward tonight
into Sat. Fresh to strong southeast winds from the northwestern
Caribbean Sea will surge into the central Gulf waters and Yucatan
Channel from from Sat through Sun, diminishing to fresh speeds Sun
night. Elsewhere, winds and seas will then diminish slightly
across most of the basin Sun into Mon as the pressure gradient
relaxes, leaving only pulses of fresh to occasionally strong winds
at night off the northern and western Yucatan Peninsula. Fresh
return flow is expected over the western Gulf Mon night through
Tue night.

...CARIBBEAN SEA...

Please see the Special Features section for information on a
potential heavy rainfall event associated with a Central American
Gyre (CAG).

The Bermuda High is interacting with lower pressure over Central
America, associated with the developing Central American Gyre, and
is forcing fresh to strong E to SE trades over the central and W
Caribbean with moderate to fresh trades over the E Caribbean. Seas
are 7-10 ft over the central Caribbean, 5-7 ft over the W
Caribbean, and 4-6 ft over the E Caribbean. Scattered moderate
and isolated strong convection is noted from 26.5N-28N and east of
85W in association with a tropical wave and the developing
Central American Gyre. Mostly fair and hazy skies prevail
elsewhere east of 75W as Saharan Air and areas of suspended dust
have moved into the basin behind the tropical wave.

For the forecast, winds and seas across the basin will increase
tonight into the weekend as the western Atlantic ridge
strengthens and broad low pressure over Central America
gradually shifts west to northwestward. The strongest winds and
highest seas are expected to be over parts of the northwestern
and south-central Caribbean during this period. Looking ahead,
winds and seas will start to diminish across the basin early
next week as the pressure gradient relaxes.

...ATLANTIC OCEAN...

Ridging associated with the Bermuda and Azores Highs stretches
across the basin along 29N-32N. Winds north of a line from 26N30W
to 21N57W to 28N80W are gentle or weaker with seas 3-5 ft.
South of the line and east of 60W, the NE to E trades are
moderate to fresh and with seas 5-8 ft. Saharan Air and suspended
dust dominate much of this area producing hazy skies. West of
60W, moderate SE to S winds prevail with seas 2-4 ft. Southerly
low level flow across the far eastern Gulf of Mexico, Florida and
the Bahamas has advected moisture northward this afternoon, and
has erupted into scattered moderate to strong convection from 24N-
29N west of 71W, and supported by upper-level divergent flow.

For the forecast west of 55W, a surface ridge along about 28N
will lift north to 30N through tonight and strengthen. This
pattern will support mainly gentle to moderate breezes across the
region through early next week, except for moderate to fresh winds
north of Hispaniola starting tonight.

$$
Stripling
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