[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 102315
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat Oct 10 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
2300 UTC.

...TROPICAL WAVES...

A tropical wave has its axis along 40W from 02N-17N, moving
westward at 15-20 kt. Scattered moderate to isolated strong
convection is noted on either side of the wave axis from 08N-16N
between 37W and 43W. Slow development of this system could be
possible later this weekend or early next week while the wave
continues moving westward. Upper-level winds are forecast to
become unfavorable for further development by the middle of next
week. This system has a low chance of tropical cyclone formation
within 48 hours and through 5 days.
Please read the latest NHC Tropical Weather Outlook at
https://www.nhc.noaa.gov/text/MIATWOAT.shtml for more details.

Visible satellite imagery suggests that the tropical wave now
located along 70W is farther E along 66W, where a well defined
inverted-V pattern is noted. This wave should be re- located on
the next surface map. The wave combined with a diffluent pattern
aloft is supporting shower and thunderstorm activity over Puerto
Rico, the US/UK Virgin Islands and regional waters.

Another tropical wave is over western Caribbean with axis along
82W south of 20N. It is moving westward at 15 kt. The wave is
helping to induce scattered showers and thunderstorms over the
Cayman Islands.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic Ocean just N of Dakar,
Senegal and drops southwestward to near 08N24W. The ITCZ
continues from 08N24W to 06N38W to 10N52W to 12N60W. Scattered
moderate convection is within about 90 nm S of the ITCZ between
40W-51W, and from 10N-13N between 57W-60W.

GULF OF MEXICO...

Delta becomes a non-tropical low and the heavy rain threat
continues. At 10/2100 UTC, Post-Tropical Cyclone Delta is
centered near 33.7N 90.0W or 70 nm WSW of Tupelo Mississippi
moving NE at 10 kt. Estimated minimum central pressure is 998 mb.
Maximum sustained wind speed is 25 kt with gusts to 35 kt. Flood
and Flash Flood watches remain in effect for portions of the
Mid-South of United States and areas in and near the southern
Appalachians. Weakening is forecast during the next 36 hours, and
Delta's surface low is expected to dissipate across West Virginia
late Sunday night. Future information on this system can be
found in Public Advisories issued by the Weather Prediction
Center at http://www.wpc.ncep.noaa.gov.

Now that Delta has moved inland and continues to pull farther
away from the Gulf waters, relatively weak high pressure from
the western Atlantic has settled in over the area. However, the
most recent scatterometer data showed moderate to locally fresh
winds across the NW and north-central Gulf. Similar wind speeds
are also noted over the eastern Gulf between Delta and the
Atlantic ridge. Lines of showers, with embedded thunderstorms in
a SE wind flow are seen on Mosaic Doppler Radar across the
eastern Gulf, Florida and the waters E of Florida.

An upper-level low is helping to induce convection over the
Yucatan Peninsula.

Weak high pressure will continue to build across the area into
early next week producing mainly light to gentle winds. A cold
front will move into the northern Gulf of Mexico Mon night and
quickly dissipate over the northern Gulf on Tue. High pressure
will follow the front.

CARIBBEAN SEA...

A couple of tropical waves are moving across the Caribbean Sea.
Please, see the Tropical Waves section for details. Low-topped
trade wind showers are seen elsewhere across the basin.

Fresh trade winds over the south-central Caribbean will pulse to
strong speeds at night through Mon. Gentle to moderate trade
winds elsewhere will change little through the period. Seas will
be in the slight range, except for moderate seas in the south-
central Caribbean into next week. A strong tropical wave may
bring higher winds and building seas to the Atlantic waters east
of the Leeward Islands Tue through Thu.

ATLANTIC OCEAN...

The southwest periphery of high pressure centered well north of
the area near 38N57W extends south-southwestward toward the
Bahamas and Florida. The pressure gradient between the high
pressure and Delta is allowing for fresh southeast winds to
occur N of 30N W of 78W. These winds will diminish to moderate
speeds Sun as Delta pulls farther to the northeast.

A stationary front extends from 31N50W to 26N60W. A trough ahead
of it is along a position from 26N56W to 20N63W and to just
northeast of Puerto Rico. A cluster of moderate to isolated
strong convection is near the southern end of the trough axis
covering the waters from 19N-21.5N between 62W-66.5W. Another
trough is analyzed from 28N42W to 17N44W. Scattered showers are
near the northern end of the trough axis. The remainder of the
Atlantic is under the influence of a 1036 mb high pressure
located NE of the Azores. The pressure gradient between the high
and lower pressures over W Africa is resulting in moderate to
fresh N-NE winds across the Canary Islands and over the waters N
of the Cabo Verde Islands to about 22N.

As for the forecast, high pressure over the northern and central
waters will begin to shift east-northeast tonight through Mon
ahead of a cold front that will move off the SE U.S. coast Tue.
This front will weaken and stall from Bermuda into the Central
Bahamas for mid week.

$$
GR
This weather bulletin was brought to you by:
www.nashvilleweather.net