AXNT20 KNHC 282354
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Wed Oct 28 2020
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 1800 UTC surface analysis and satellite imagery through
Hurricane Zeta is moving ashore across Southeast Louisiana, and
is centered near 29.2N 90.6W at 2100 UTC ,or 65 nm SSW of New
Orleans, moving NNE at 21 kt. Estimated minimum central pressure
is 970 mb. Maximum sustained wind speed is 95 kt with gusts to
115 kt. Numerous strong convection is within 90 nm of the center
in the W semicircle and within 45 nm east semicircle. Numerous
moderate and scattered strong convection is elsewhere within 180
nm of the center in the NE quadrant, 150 nm SE quad, 90 nm SW quad
and 120 nm NW quad. Isolated moderate convection is elsewhere
within 210 nm of the center in the N semicircle and 180 nm S
semicircle. Zeta will race across the New Orleans metro area in
the next few hours and then move across eastern Lake
Pontchartrain, Lake Borgne and then enter the Mississippi coast
later this evening, then move across the southeastern and eastern
United States on Thursday. Very high waves and hurricane force
winds will continue over the north-central Gulf of Mexico east of
the mouth of the Mississippi River through this evening before
diminishing overnight and early Thu morning. Zeta is expected to
bring life-threatening storm surge and hurricane force winds to
portions of the SE Louisiana coast during the next few hours and
to the Mississippi and Alabama coasts through late this evening.
Please read the latest High Seas Forecast issued by NHC at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for marine impacts.
Please read the latest NHC Forecast/Advisory and Public Advisory
on Zeta at www.hurricanes.gov for more details.
A tropical wave has been added to the analysis along 49W from
03N-16N, moving W at 15 kt. Scattered moderate convection is
within 180 nm east of the wave axis from 06N-12N, and within 360
nm west of the wave axis from 09N-15N. Strong winds continue east
of the wave axis from 10N-14N.
An Atlantic Ocean tropical wave is along 60W from 04N-17N, moving
W at 15-20 kt. A mid to upper level trough is located just to the
northwest of this tropical wave. Scattered moderate to strong
convection is noted from 09.5N-16N between 56W-60W. Strong winds
are behind the wave axis from 12N-15N. Expect an enhancement of
showers along with gusty winds over the Lesser Antilles this
evening through early Thursday as the wave enters the Caribbean
and interacts with the upper trough. Enhanced rainfall is
possible in Puerto Rico Thursday through Friday, and in Hispaniola
Friday through Saturday.
A Caribbean Sea tropical wave is along 76/77W from 05N-21N,
moving W at 15-20 kt. Isolated showers and mild thunderstorms dot
the waters within 120 nm of the wave axis.
The monsoon trough extends from the coast of Guinea near 09.5N14W
to 08N18W. The ITCZ continues from 08N18W to 06N36W to 07N47W,
then resumes W of a tropical wave from 10N51W to 11N58W. Isolated
moderate convection is from 03N-08N between 05W-22W. Scattered
moderate convection is from 03N-07N between 28W-38W. Scattered
moderate and isolated strong convection is from 03N-08N between
07W and 17W, and from 02.5N-10N between 30W and 46W. within 180
nm north of the ITCZ between 51W-55.5W.
GULF OF MEXICO...
Please see the Special Features section above for details on
Hurricane Zeta entering the Southeast Louisiana coast.
A cold front continues across the western Gulf of Mexico and has
dammed up along the western periphery of Zeta, from near the
Texas-Louisiana border to 24N93W to the southern Mexico coast near
20N97W. Near gale force NW winds are occurring behind this front
from 25N-28.5N off the central Texas coast to 94W. Strong NW
winds are elsewhere behind the front. The front will cross the
Gulf of Mexico after Hurricane Zeta moves well inland tonight.
The front will then reach from the Florida Big Bend to the NW
Yucatan Peninsula by late Thu. By late Fri, the front will move
southeast of the area. Strong northwest winds behind the front
will diminish to fresh speeds Thu through Fri. High pressure will
build in behind the front through the weekend, with winds
diminishing and seas subsiding throughout. A strong reinforcing cold
front will cross the area Sun and Sun night followed by fresh to
strong N to NE winds.
A mid to upper-level trough extends from the Anegada Passage SW to
the A-B-C Islands. A tropical wave approaching the Lesser
Antilles will enter the eastern Caribbean tonight. The
combination of the upper trough and the tropical wave will produce
a significant enhancement of showers and tstorms across the
Lesser Antilles and eastern Caribbean through Thursday. Strong E
winds are expected behind the tropical wave. As the wave crosses
the central Caribbean Fri through Sat, gusty winds along with
showers and tstorms will continue to accompany the wave,
particularly over the Greater Antilles.
Isolated showers and tstorms are seen over the central Caribbean
in association with a tropical wave along 76/77W. This wave will
move across the western Caribbean Thu through Fri.
Elsewhere scattered showers along the coast and just inland
between Tulum, Mexico and Belize City, Belize have shifted inland
across the Yucatan Peninsula. Scattered moderate o strong convection
is seen over Panama, Costa Rica, Nicaragua and Honduras in
association with the east Pacific monsoon trough, and broad
cyclonic circulation south of Zeta. The latest ASCAT pass shows
fresh NE to E winds over the NE Caribbean north of 15N and east of
73W. Fresh E winds are south of Cuba and north of the Cayman
Islands. Mainly moderate winds prevail elsewhere.
A third tropical wave will enter the eastern Caribbean early Sat
and reach the central Caribbean by late Sun. This wave will also
contain numerous showers and tstorms and be followed by fresh to
strong east winds.
A surface ridge extends from a 1022 mb high pressure near 32N27W
to a 1020 mb high pressure near 30N61W to the coast of Georgia.
Light to gentle winds prevail from 27N-32N between 40W-82W. Fresh
trades are farther south from 19N-25N between 50W-82W. Strong
trades are occurring in the tropical Atlantic over much of the
area from 10N-19N between 41W-59W.
A mid to upper level trough resides over the central Atlantic
near 60W from 30N southward to the NE Caribbean. Scattered
showers and isolated thunderstorms are from 16-26N between 53W-
63W. No major areas of shower activity are seen across the
remainder of the basin.
Moderate to fresh winds are expected south of 27N through Thu
night. A cold front will move off the SE U.S. coast Thu night with
strong SW winds ahead of it, north of 29N. These winds will
spread east as the front reaches a line from Bermuda to the SE
Bahamas to central Cuba this weekend and stalls. Strong N winds
are possible behind the front north of 29N this weekend. The
northern part of a tropical wave will move across the waters just
north of the Leeward and Virgin Islands this afternoon and north
of Puerto Rico Thu night, followed by fresh to strong east winds.
Scattered showers and tstorms will impact most of the eastern
Greater Antilles and also the southeastern Bahamas from Thu night
into the weekend.