819
AXNT20 KNHC 021754
TWDAT
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
1700 UTC.
...SPECIAL FEATURES...
The low pressure in the northwest Caribbean has organized into
Tropical Depression Twenty-Five. T.D. Twenty-Five is centered
near 18.3 84.9W as of 02/1800 UTC, or about 175 nm SE of Cozumel
Mexico, moving NW at 7 kt. Estimated minimum central pressure is
1005 mb. Maximum sustained wind speed is 30 kt with gusts to 40
kt. Scattered moderate to strong convection is seen within 270
nm of the center in the northern semicircle and 210 nm southern
semicircle, including over northern Honduras, the east coast of
the Yucatan Peninsula, the Yucatan Channel and western Cuba. The
depression is forecast to strengthen to a tropical storm before
moving near or over the northeastern Yucatan Peninsula on
Saturday. The cyclone may emerge into the south central Gulf of
Mexico Sunday or Monday, before shifting westward across the
southern Gulf. This slow-moving tropical cyclone is expected to
bring heavy rain that could result in life-threatening flash
flooding over portions of the Yucatan Peninsula, far western
Cuba, and well away from the center in the Mexican states of
Campeche, Tabasco, and northern Chiapas, as well as northern
portions of Central America. Seas will build over the far
northwestern Caribbean and Yucatan Channel through Saturday
night, and in the south-central Gulf through early next week.
Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and the Forecast/
Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for
more details.
...TROPICAL WAVES...
An Atlantic Ocean tropical wave is along 37W from 18N southward,
moving W at 10-15 kt. Scattered moderate and isolated strong
convection is within 180 nm either side of the wave axis from
05N-15N.
A Caribbean Sea tropical wave is along 66/67W from 19N
southward, moving W at 10-15 kt. Scattered moderate to isolated
strong convection is within 270 nm W and within 90 nm E of the
wave aixs from 08N-18N. Additional convection occurring farther
east over the Windward and Leeward Islands is partially due to a
moist environment caused by the tropical wave, but also due to
enhanced upper-level diffluence to the SE of an upper-level
trough N of Puerto Rico. This tropical wave has a low chance of
tropical cyclone formation over the next 5 days as it continues
W through the Caribbean.
...MONSOON TROUGH/ITCZ...
The monsoon trough passes through the coastal sections of Senegal
near 14N17W to 10N25W. The ITCZ continues from 10N25W to 09N33W,
and from 07N40W to 06N56W. Scattered moderate convection is noted
near the ITCZ between 28W-33W. Similar convection is along and N
of the ITCZ between 40W-54W.
GULF OF MEXICO...
A stationary front extends from southwest Florida near 26N81W to
22N88W. A dissipating stationary front is analyzed from 22N88W
over the NW Yucatan Peninsula to the eastern Bay of Campeche near
19N92W. Scattered moderate convection is noted within 120 nm of
the front. A recent ASCAT pass indicates strong N to NE winds
over much of the south-central Gulf to the north of the front and
west of 85W. Locally near gale force winds are offshore the NW
coast of the Yucatan Peninsula. Fresh to strong NW to N winds are
also evident over the far southwest Gulf of Mexico, south of 20N.
Farther north, a reinforcing cold front is moving through the
northern Gulf, stretching from near Crystal River Florida near
28.5N83W to 26N94W to the Texas coast near 27N97.5W to 28N100W.
Fresh to locally strong NE winds follow the reinforcing front.
The stationary front from southwest Florida to the western
Yucatan Peninsula will slowly dissipate today. The reinforcing
front over the northern Gulf will move across the northeast Gulf
today, eventually stalling and dissipating across southern
Florida and the southeast Gulf through Sat. Tropical Depression
Twenty-Five is forecast to emerge north of the Yucatan Peninsula
into the far southern Gulf of Mexico Sunday or Monday as a
tropical storm, increasing winds and seas across the southern
Gulf. Please see the special features section above for more
details on T.D. Twenty-Five.
CARIBBEAN SEA...
Convection in the NW Caribbean is due to Tropical Depression
Twenty-Five. Please see the Special Features section above for
details. Convection between 60W-73W is due to the tropical wave
in the eastern Caribbean. A broad mid to upper trough north of
Puerto Rico is providing divergent flow aloft on the southeast
periphery of the upper trough, and this is enhancing the shower
and thunderstorm activity over the eastern Caribbean near and
east of the tropical wave along 66/67W. See the tropical waves
section above for more details.
A recent ASCAT pass shows fresh to strong winds across much of
the eastern and central Caribbean, especially from 15N-18N
between 63W-75W and from 11N-15N between 65W-70W. Gusty winds
associated with T.D. Twenty-Five cover the NW Caribbean. Light
to gentle winds are noted in the far SW Caribbean south of 14N
west of 76W. Recent altimeter passes indicate that seas are
5 to 8 ft in the central Caribbean.
Tropical Depression Twenty-Five is forecast to strengthen to a
tropical storm near 20N87W Sat morning, move inland to near
21.5N87.5W Sun morning, to near 22N88W Mon morning, and to near
21.5N 90.5W early Tue. Elsewhere, fresh to strong trades are
expected over the eastern and central Caribbean through Sun
night as a tropical wave moves westward through the Caribbean.
The tropical wave in the eastern Caribbean has a low chance of
developing into a tropical cyclone during the next 5 days. Winds
and seas will subside Mon and Tue across the basin.
ATLANTIC OCEAN...
A cold front extends from 32N74W to 30N76W. The front continues
as stationary from 30N76W to Ft. Lauderdale Florida to 24N85W.
The front is under a sharp upper ridge extending to the northeast
of the broad upper anticyclone covering T.D. Twenty-Five in the
northwest Caribbean. Convergent southeast flow into the front
along with divergence along this upper ridge is supporting
clusters of showers and thunderstorms along and within 120 nm of
the front. A recent ASCAT pass shows fresh S to SW winds within
120 nm east of the front, north of 28N. Gentle to moderate winds
are observed elsewhere over the waters north of 23N and west of
65W. Moderate to fresh trade winds and 5 to 7 ft seas are south
of 23N. A reinforcing cold front extends from 32N79W to St.
Augustine Florida to Crystal River Florida. No significant
precipitation is noted with the reinforcing front.
For the forecast west of 65W, the stationary front will gradually
dissipate through late today. The reinforcing cold front will
stall from near 31N79W to central Florida by Sat afternoon, and
then retreat northward as a warm front on Sun. Meanwhile, the
Bermuda High north of our area and lower pressure in the NW
Caribbean associated with T.D. Twenty-Five will support moderate
to fresh trades south of 22N, occasionally pulsing to strong
north of Hispaniola during the overnight hours through Sun night.
Looking ahead, a third weak front will move over the Atlantic
waters east of NE Florida late Sun and dissipate by early Tue.
Farther east, 1033 mb high pressure is centered near 41N38W. A
weak surface trough is noted along 41W from 23N-31N. Scattered
showers and tstorms with this trough are seen from 27N-32N
between 38W-45W. Fresh to locally strong E winds persist near the
trough north of 27N, but winds and seas are expected to subside
later today. Generally moderate trades persist farther south into
the tropics between 40W-58W, with 5 to 7 ft seas. Fresh to strong
NE winds with 6 to 9 ft seas are noted off North Africa.
$$
Hagen
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