[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131012
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sun Dec 13 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
0930 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: A strong cold front will move into
the NW Gulf tonight. Behind the front, northerly gale force winds
are expected to develop over sections of the western and SW Gulf
Mon through Mon evening, with strong north winds elsewhere over
the western Gulf. Seas are forecast to reach 12 ft in the SW Gulf.
Winds and seas will decrease Tue as high pressure moves over the
area. Please read the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the coast of Sierra Leone
near 08N13W to 06N21W. The ITCZ stretches from 06N21W to 04N38W
to 03N51W. Scattered moderate to strong convection is within 150
nm S of the trough east of 21W, and from 02N-09N between 28W-41W.
Scattered moderate isolated strong convection is noted from 05.5N-
11N between 42W-58W.

GULF OF MEXICO...

A cold front extends from the entrance to Mobile Bay to the mouth
of the Mississippi River, then become a warm front to southeast
Texas. A pre-frontal trough extends from Pensacola Florida to
27N92W. Widely scattered light to moderate showers are along and
within 90 nm south and east of the front east of 93W. The front
will lift northward and inland later this morning. A surface
trough is over the Yucatan Channel along 86W and south of 24N,
with isolated showers to the east of it over the SE Gulf of
Mexico. High pressure ridging stretches from the north central
Atlantic to northern Florida and weakly into the NE Gulf. Gentle
SE to S winds are over the Gulf east of 90W while, moderate to
fresh SE to S winds prevail west of 90W.

A significant cold front will move into the NW Gulf early
tonight, then cross much of the basin Mon into Tue. Strong N winds
will spill behind the front, and gales will develop over parts of
the W and SW Gulf Mon into Mon evening. Please see the Special
Features section above for details on the Gale Warning in the
western Gulf. Winds and seas will decrease Tue as high pressures
builds in. The next front will move into the western Gulf Tue
night.

CARIBBEAN SEA...

Upper-level ridging covers the western Caribbean and Central
America. An upper-level trough axis extends from near 30N60W to
the eastern Caribbean Sea. At the surface, a trough is over the
Yucatan Channel, with isolated to scattered light to moderate
showers extending east of the surface trough from western Cuba
to the Cayman Islands. Isolated light trade wind showers are
over the eastern Caribbean. Dry air is over the central and SW
portion of the basin. Overnight ASCAT data showed fresh trades
over the south-central Caribbean from 10.5N-16N between 70W-78W.
Within that area, there are strong trades near the coast of
Colombia from 11N-14N between 71W-75W. Moderate tradewind cover
the remainder of the Caribbean.

Strong NE winds will pulse nightly into Mon along the Colombian
coast. High pressure will weaken across the western Atlc early
Mon through Wed and yield a weakened wind flow across the entire
basin. A weakening cold front is forecast to move slowly SE
across the Yucatan Channel and western Cuba late Thu through Fri.

ATLANTIC OCEAN...

A cold front enters the area through 32N33W and extends to
28N42W, where it transitions to a stationary front to 27N49W,
where it then becomes a shearline to 23N62W. Overnight ASCAT data
showed strong northeast to east winds north of the front and
shearline to 30N, between 42W-60W, where seas were 10-12 ft.
Scattered moderate to strong convection is seen from 20N-25N
between 50W-61W. This convection is being enhanced by an upper-
level trough axis that stretches from near 30N60W to the eastern
Caribbean. Eslewhere across the eastern waters, moderate to large
NW swell dominates the area N of 20N and E of 66W, where seas are
8-12 ft.

In the western Atlantic, a surface trough is just east of
northern Florida, and another surface trough extends N from the
SE Bahamas to 27N. Isolated showers are north of 26N and west of
70W. West of 73W, SE winds are moderate. Fresh E winds are
between 63W-73W. A 1032 mb high is north of the front near
35N53W and extends a ridge southwest to north Florida.

The fresh E winds between 63W-73W will diminish early this
morning as the high pressure building into the area weakens and
slides east. Ahead of the next cold front, strong SW winds will
develop Mon offshore the N Florida coast. This front will move
into the NW waters Mon afternoon and stretch from Bermuda to
south-central Florida along 27.5N Tue morning before stalling.

$$
Stripling
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