AXNT20 KNHC 221722
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
122 PM EDT Mon Jul 22 2019
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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.
Based on 1200 UTC surface analysis and satellite imagery through
Showers and thunderstorms have increased in association with an
area of low pressure located near Andros Island in the Bahamas.
While environmental conditions are only marginally conducive for
development, only a slight increase in the organization of this
system could result in the formation of a tropical depression later
today or tonight. Additional development is not anticipated after
that time due to strong upper-level winds. This system now has a
medium chance of tropical cyclone formation during the next 48
hours. The low is expected to move northwestward around 15 mph
today and north-northwestward to northward tonight and Tuesday,
remaining offshore of the east coast of the Florida peninsula.
This system will continue to produce locally heavy rainfall and
gusty winds over portions of the northwest Bahamas through
tonight. Showers and thunderstorms could also spread over portions
of the east coast of the Florida peninsula tonight and Tuesday.
Please see the latest North Atlantic Tropical Weather Outlook for
An eastern Atlantic tropical wave was relocated to near 38W south
of 18N. Scattered showers are noted from 05N to 07N between 37W
A central Atlantic tropical wave is near 48W south of 18N. This
wave is embedded within the middle of a strong outbreak of Saharan
dust, and no convection is present.
A central Atlantic tropical wave is along 57W south of 19N, moving
W around 15 kt. Scattered moderate convection is noted from 06N-
09N between 55W and 61W, including over portions of Suriname and
Guyana. Scattered showers are occurring north of 15N within 60 nm
of the wave axis.
An eastern Caribbean tropical wave is along 68W south of 19N,
moving W around 10-15 kt. The latest radar imagery shows scattered
showers near Puerto Rico behind the wave axis.
The monsoon trough extends from the coast of Senegal near 13N16W
to 11N21W. The ITCZ extends from 11N21W to 08N36W, then resumes W
of a tropical wave from 07N40W to 06N47W. The ITCZ continues W of
another tropical wave from 05N49W to 06N56W. Aside from the
convection previously described, scattered weak convection is
noted within 120 nm of the ITCZ between 24W- 32W.
GULF OF MEXICO...
A weak surface ridge persists over the northern Gulf of Mexico
with axis near 29N. A weak upper-level low pressure centered over
the eastern Gulf is supporting scattered moderate to isolated
strong convection north of 24N and east of 87W. Elsewhere,
scattered moderate convection is occurring from 23N-29N west of
A weak ridge along the northern Gulf of Mexico will weaken
tonight, allowing a cold front to move across the northern half of
the Gulf of Mexico. The front will stall from the Florida Big
Bend to Corpus Christi Tue night and dissipate Wed night. Moderate
to fresh winds will follow the front and prevail mainly across
the NW waters Wed. Otherwise, a surface trough will move off the
Yucatan Peninsula each night, supporting fresh to strong winds
over the eastern Bay of Campeche tonight and Fri night.
Isolated showers and thunderstorms are noted with satellite
imagery and lightning data over the NW Caribbean between Cuba and
the Cayman Islands, as well as south of the Dominican Republic.
Recent scatterometer data shows strong trade winds off the coast
of Colombia, with moderate to fresh trades elsewhere across the
central Caribbean and over the Gulf of Venezuela.
High pressure N of the area will continue to support fresh to
strong trade winds in the south-central Caribbean Sea through Fri,
increasing to near gale force along the coast of Colombia at
night. The high will slightly strengthen on Thu evening, leading
to fresh to strong winds over southern Hispaniola adjacent waters
and the Windward Passage.
Please see the Special Features section above for more information
on developing low pressure over the northern Bahamas.
Elsewhere, a surface trough roughly 500-600 nm east of the Bahamas
is producing scattered moderate convection over the waters from
23N to 27N between 65W and 68W. A high pressure ridge extends
along 29N across much of the northern Atlantic to 1023 mb high
pressure analyzed near 29N62W. Earlier scatterometer data showed a
large area of fresh to strong northerly winds along the African
coast from Western Sahara to Senegal, including Cabo Verde.
A west-northwestward moving trough of low pressure currently over
the Northwest Bahamas continue to generate showers and thunderstorms
for the Bahamas and adjacent waters. The trough will reach the
coast of South Florida tonight along with moderate to fresh winds.
Showers associated with it will continue to affect the Florida
seaboard on Tue. Surface ridging dominating the remainder waters
will move eastward on Tue night enabling a trough to move through
the NW waters early on Wed. Fresh to strong winds are expected
ahead of the trough. Otherwise, east winds will pulse N of
Hispaniola and the approaches to the Windward Passage each night.
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