[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 241705
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 PM EST Sun Nov 24 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 1200 UTC surface analysis and satellite imagery through
1650 UTC.

...SPECIAL FEATURES...

Tropical Storm Sebastien is near 37.4N 37.0W at 24/1500 UTC,
moving NE at 28 kt. Estimated minimum central pressure is 994 mb
with maximum sustained wind speeds of 55 kt and gusts to 65 kt.
Scattered moderate convection is seen within 60 nm of the center
in the southern semicircle and 300 nm northern semicircle. A
faster NE motion is expected during the next day. On the forecast
track, the center of Sebastien will pass near the western Azores
tonight. A slow decrease in the maximum winds is expected during
the next couple of days. Sebastien is forecast to become post-
tropical by early Monday. The Public Advisories for Sebastien are
available via AWIPS/WMO headers MIATCPAT5/WTNT35 KNHC. The
Forecast/Advisories for Sebastien are available via the AWIPS/WMO
headers MIATCMAT5/WTNT25 KNHC and at www.hurricanes.gov

...TROPICAL WAVES...

An Atlantic Ocean tropical wave has an axis along 46/47W from 13N
southward, moving W at 15 kt. The tropical wave shows up well in
TPW imagery and model diagnostics. Scattered moderate with
isolated strong convection is seen from 05N-11N between 43W-49W.

A Caribbean Sea tropical wave has an axis along 64W from 13N
southward and is moving W at 10 kt. Isolated moderate convection
is from 08N-15N between 58W-70W.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of Sierra
Leone near 08N13W to 06N17W. The ITCZ continues from there to
05N30W to 05N45W, then continues west of a tropical wave from
05N48W to 04N52W. Aside from the convection related to the
tropical waves, scattered to numerous moderate with isolated
strong convection is within 210 nm either side of the ITCZ between
31W-43W. Scattered moderate with isolated strong convection is
also in the far E Atlantic and along the coast of Africa from
03N-09N between 05W-17W.

GULF OF MEXICO...

A cold front extends from near Port Charlotte Florida to 23N91W.
The front continues as stationary to 22N94W to 19N95W. A pre-
frontal trough is about 30-60 nm ahead of the front over Florida
and adjacent waters. A line of showers is over Florida and the SE
Gulf of Mexico along the pre-frontal trough. Isolated showers are
near the stationary front. High pressure is building into the NW
Gulf behind the front. Two surface highs of 1019 mb are over Texas
and NE Mexico, respectively. ASCAT data depicts moderate NW to N
winds behind the front in the eastern Gulf.

The front will reach from Key Largo Florida to the northern
Yucatan Peninsula adjacent waters this evening where it will
stall and weaken through Mon morning. High pressure will build in
the wake of the front, shifting NE of the basin by early Tue. The
next cold front is expected to move into the NW Gulf by Wed
morning, weakening and stalling in the northern Gulf by Wed night.
E to SE flow around high pressure over the Carolinas will dominate
across the Gulf waters Thu and Thu night.

CARIBBEAN SEA...

An upper-level trough axis extends from the Windward Passage to
the Costa Rica/Nicaragua border. A surface trough is seen near the
same area, extending from 19N74W to 14N78W. Isolated showers and
tstorms are near the upper-level trough axis. In the eastern
Caribbean, scattered moderate convection is seen from 13N-15N
between 65W-70W due to a combination of weak upper-level
diffluence and higher moisture content due to a weak tropical wave
approaching the area. The remainder of the Caribbean is relatively
quiet. The latest ASCAT pass shows fresh winds across portions of
the central Caribbean between 71W-75W with moderate winds
elsewhere in the eastern and central Caribbean, to the east of the
surface trough. Gentle winds are in the NW basin.

Gentle to moderate trades will prevail through Mon, increasing to
moderate to fresh outside of the NW Caribbean by Mon evening as
high pressure builds N of the area and low pressure over NW
Colombia deepens. High pressure N of the area will strengthen
afterwards, leading to fresh to near gale force winds in the
south-central and southwest Caribbean from early Tue through Thu.

ATLANTIC OCEAN...

As of 24/1500 UTC, A cold front extends from 32N75W to 29N78W to
near Vero Beach Florida to Port Charlotte. A pre-frontal trough
extends from 28N78W across South Florida to 25N84W. The latest
ASCAT pass from 24/1336 UTC shows gale force winds along the cold
front north of 31N. Near gale SW winds are north of 29N between
73W and the cold front. Strong to near gale W to NW winds likely
extend about 120 nm west of the cold front north of 30N. Fresh
winds to 20 kt extend to the E coast of Florida and to the NW
Bahamas. A line of showers is along the pre-frontal trough.
Scattered moderate convection is within 120 nm ahead of the cold
front north of 28N and east of 76W.

A 1019 mb high is near 20N58W. This high extends a ridge to the
central Bahamas. North of the high, a cold front extends from
32N56W to 31.5N59W. A warm front is from 31.5N59W to 32N61W.
Isolated showers are possible within 90 nm SE of the cold front.
Farther east, a developing cold front is plotted from east of T.S.
Sebastien near 36N37W to 32N38W to 28N42W. A surface trough is
from 28N42W to 18N54W. Scattered moderate showers and isolated
tstorms are along and within 150 nm SE of the developing cold
front and surface trough. An upper-level low is near 24N26W. An
accompanying surface trough lies from 29N25W to 24N26W. Scattered
showers are east of the surface trough axis from 22N-29N between
16W-25W.

The cold front that extends from 32N75W to Vero Beach Florida will
reach from Bermuda to the northern Bahamas to the Straits of
Florida by Mon morning where it will stall and gradually wash out
through Tue. Fresh to near gale force winds are expected on either
side of the front and across the waters N of 27.5N today,
gradually decreasing through early on Mon. High pressure will
build in the wake of the front. Another cold front is forecast to
move across the basin Thu through Thu night with fresh to strong
winds mainly affecting the NE waters.

$$
Hagen
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