[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201112
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
612 AM EST Wed Nov 20 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 0600 UTC surface analysis and satellite imagery through
1100 UTC.

...SPECIAL FEATURES...

Tropical Storm Sebastien is near 21.0N 61.0W at 20/0900 UTC, or
about 205 nm NE of the northern Leeward Islands. Sebastien is
moving NW at 7 kt. The estimated minimum central pressure is 1002
mb. Maximum sustained winds are 45 kt with gusts to 55 kt.
Numerous moderate with scattered strong convection extends outward
to 240 nm in the SE quadrant. Scattered moderate convection is
elsewhere within 300 nm in the SE quadrant. Sebastian will turn
to the north today and move to near 23N 61W tonight. The cyclone
is forecast to become extratropical Thu night as it reaches near
29N 54.5W. Some strengthening is forecast through Thursday.
Sebastien is expected to become absorbed by a cold front on
Friday. The Public Advisories for Sebastien are available via the
WMO header WTNT35 KNHC and the AWIPS header MIATCPAT5. The
Forecast/Advisories are available via the WMO header WTNT25 KNHC
and the AWIPS header MIATCMAT5.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 42W from 12N southward,
moving W at 10-15 kt. Isolated moderate convection is from 07N-11N
between 38W-45W.

A Caribbean Sea tropical wave is along 72/73W from 09N-20N, moving
W at 5-10 kt. No significant deep convective precipitation is
apparent with this tropical wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of southern
Sierra Leone near 07N12W to 05N19W. The ITCZ continues from 05N19W
to 04N26W to 07N33W to 07N40W. Scattered moderate convection is
seen from 07N-13N between 27W-38W, and from 03N-09N between 10W-
15W.

GULF OF MEXICO...

A 1019 mb surface high is near 28N89W. Weak surface ridging and
relatively dry air cover most of the basin. The latest ASCAT pass
shows that gentle to moderate anticyclonic winds cover the basin.

High pressure over the central Gulf will shift east today. Fresh
SE return flow will intensify over the NW Gulf tonight and Thu
ahead of a cold front moving into Texas. The front will move into
the NW Gulf Fri night, followed by fresh N winds. The front will
weaken and stall along 24N Sun through Mon.

CARIBBEAN SEA...

A surface trough extends from the Turks and Caicos Islands through
the Windward Passage to near Jamaica. Isolated moderate convection
is near the trough axis. Isolated showers are also present in the
western Caribbean from 10N-20N between 81W-85W in an area of
slightly higher moisture content. The latest ASCAT pass shows
moderate N winds from 12N-21N between 78W-83W. Fresh NE winds will
prevail across most of the western Caribbean through Fri morning,
with highest winds expected in the Windward Passage.

ATLANTIC OCEAN...

A cold front passes through 32N70W to 28N72W to 25N79W. A pre-
frontal surface trough is from 29N69W to 24N72W. Another trough
extends from 23N70W to the Windward Passage. Isolated moderate
convection is from 26N-29N between 65W-68W and from 20N-24N
between 69W-72W. The latest ASCAT pass shows strong W winds
northwest of the cold front, north of 28N between 72W-80W.

In the far NE portion of the area, a cold front extends from
32N15W to 28N24W. Fresh N winds are north of the front. Surface
ridging dominates elsewhere, anchored by a 1026 mb high near
31N41W.

The cold front from 32N70W to 25N79W will quickly move across the
northern waters through tonight, with fresh to strong NW winds
developing behind the front. High pressure will build across the
northern waters Thu through Sat.

$$
Hagen
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