[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 190929
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Thu Nov 19 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 0600 UTC surface analysis and satellite imagery through
0830 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: Strong autumn high pressure will
continue to build southward across the Gulf of Mexico behind a
stationary front that extends from western Cuba to across the
Yucatan Channel and to the northern Yucatan Peninsula. The high
pressure will continue to create a very tight gradient between it
and the front leading to strong northeast winds. Frequent gusts to
35 kt may occur in the southeast Gulf including the Straits of
Florida until around sunrise. Very hazardous conditions can be
expected between the wind waves against the flow of the Gulf
stream through the Straits of Florida, and due to a southeast
swell propagating through the Yucatan Channel. Seas will be
highest in the Straits of Florida today, 10-16 ft. Please read
the latest NWS High Seas Forecast issued by the National Hurricane
Center at website https://www.nhc.noaa.gov/text/ MIAHSFAT2.shtml
for more details.

Caribbean Gale Warning: The same conditions that are occurring in
the southeastern Gulf of Mexico are extending into the northwest
Caribbean N of 20N. Frequent gusts to gale force will be possible
there until around sunrise. Large and hazardous seas will be
possible near the Yucatan Channel as fresh northerly wind waves
mix with southeast swell. Please read the latest NWS High Seas
Forecast issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

Atlantic Gale Warning: A cold front is stalling from 31N56W to
north-central Cuba. Scattered moderate and isolated strong
convection is noted within 180 nm either side of the front east of
65W, with scattered moderate convection noted within 60-90 nm
either side of the front west of 65W. Strong high pressure
continues to build in behind the front supporting strong northeast
winds. Frequent gusts to gale force are forecast from 22N-27N and
west of the front today, and then from 22N-27N between the front
and the Bahamas tonight. Large and hazardous seas are possible in
the gulf stream between the Bahamas and Florida through the
Straits of Florida, with large fresh seas also developing NE of
the Bahamas through the end of the week in the continued northeast
flow. Please read the latest NWS High Seas Forecast issued by the
National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...TROPICAL WAVES...

The axis of a tropical wave is along 45W/46W from 15N southward,
moving westward around 10 kt. Nearby convection is primarily
associated with the ITCZ and is described in the section below.

The axis of a tropical wave is along 65W from near the Virgin
Islands southward to across central Venezuela, moving westward at
10-15 kt. Associated convection has dissipated during the past
several hours.

The axis of a tropical wave is along 76W from near eastern Jamaica
to western Colombia, moving westward around 10 kt. Associated
convection is over western Colombia.

...MONSOON TROUGH/ITCZ

The monsoon trough axis extends from the coast of Africa near
07N12W to 06N15W. The ITCZ axis extends from 06N15W to 02N30W to
02N45W, then resumes west of a tropical wave near 05N47W to
06N53W. Scattered moderate and isolated strong convection is
noted from 03N-10N between 33W-56W.

GULF OF MEXICO...

See the Special Features section for details on a Gale Warning in
effect in the southeast Gulf of Mexico.

High pressure is northeast of the basin over the Carolinas.
Outside of the gale conditions described above, moderate to fresh
E-SE flow and seas of 6-9 ft in NE swell are noted north of 22N
and west of 90W, with fresh to strong NE flow and 7-10 ft seas in
NE swell elsewhere.

Winds and seas will diminish through late Sat across the basin.
Looking ahead, a weak cold front will move into the northwest Gulf
and stall late Sun through Mon.

CARIBBEAN SEA...

See the Special Features section for details on a Gale Warning in
effect for the northwest Caribbean N of 20N.

Elsewhere, a 1011 mb low pressure area is noted in the southwest
Caribbean north of the Panama Canal near 11N80W. Scattered
moderate and isolated strong disorganized convection is noted
within 180 nm in the southeast semicircle of the low. Development,
if any, of this system is expected to slow to occur during the
next several days while it drifts west-southwestward or westward
across the southwestern Caribbean Sea. Regardless of tropical
cyclone formation, areas of heavy rain are possible during the
next several days from Nicaragua southward across Central America
and into Colombia. These rains could cause new flooding concerns,
especially across previously inundated areas. Please read the
latest Tropical Weather Outlook issued by the National Hurricane
Center at website www.nhc.noaa.gov/text/MIATWOAT.shtml for more
details.

Scattered moderate convection is noted in the Gulf of Honduras
extending southeastward to offshore of Honduras and Nicaragua.
Additional scattered moderate convection is noted in the central
Caribbean between 68W-72W due to a mid-to-upper level trough.
Moderate to fresh trades and seas of 4-6 ft are noted east of 72W,
with mainly moderate trades W of 72W, except moderate to fresh
south of 18N.

The fresh to strong winds in the northwest Caribbean will
gradually diminish this weekend. Moderate to fresh trades will
prevail across the remainder of the basin through the weekend,
weakening some early next week as the pressure gradient slackens.

ATLANTIC OCEAN...

See the Special Features section for details on a Gale Warning in
effect for the waters from 22N-27N west of a stalling cold front.

Southeast of the stalling cold front described above, mainly
moderate to fresh trades prevail, except fresh to strong south of
14N east of 55W, and south of 29N east of 45W. Seas are 6-10 ft
in mixed swell with the highest seas noted where the fresh to
strong winds are.

The stalling cold front mentioned above will completely stall and
weaken today, then lift NW and dissipate through Fri. High
pressure northwest of the front will continue to support fresh to
strong NE-E winds through Fri. Conditions will gradually improve
this weekend as the pressure gradient slowly relaxes.

A non-tropical area of low pressure could form between the
Bahamas and Bermuda by early next week. The system could gradually
develop subtropical characteristics through the middle of next
week while it moves northeastward. Please read the latest Tropical
Weather Outlook issued by the National Hurricane Center at
website www.nhc.noaa.gov/text/MIATWOAT.shtml for more details.

$$
Lewitsky
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