[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 310002
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT Thu Mar 30 2017

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
2315 UTC.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends from the African coast near 12N17W to
06N18W to 02N20W. The ITCZ extends from 02N20W to the equator at
26W and continues to the coast of South American near 04S39W.
Scattered moderate and isolated strong convection is from the
equator to 04N between 16W-26W.

...DISCUSSION...

GULF OF MEXICO...

As of 30/2100 UTC, a squall line extends from near Pensacola,
Florida to 28N88W to 25N93W. The strongest thunderstorm activity
was N of 28.5N to the Florida coast. A cold front was trailing
the squall line and extended from near Lafayette, Louisiana
through 25N93.5W to the coast of Mexico north of Veracruz.
Earlier scatterometer data indicated northerly winds of 20-25
kt NW of the front. Over the past several hours, winds have
diminished significantly with buoys reporting light and variable
winds of 5-10 kt. Moderate to fresh E to SE winds were noted
over the Gulf N of 25N and east of the squall line. In the upper
levels, an fairly sharp upper level trough extends from a deep
layered cyclone over Missouri southward across extreme western
Lousiana and the NW Gulf with strong upper level subsidence in
its wake. Strong upper level difluence E of the trough over the
NE Gulf of Mexico supported the ongoing squall line in the area.
Satellite derived winds at the upper levels were around 100 kt
in the vicinity of the squall line. The cold front is forecast
to move east along the Gulf coast to the Florida panhandle and
weaken with high pressure settling over the northern Gulf.
moderate to locally fresh SE to S return flow resumes along the
Texas coast by Late Fri.

CARIBBEAN SEA...

As of 30/2100 UTC, the tail end of a weakening stationary front
extended over the Leeward Islands to 15N65W. Scattered low
topped showers are within 60 nm of the front. The remainder of
the Caribbean Sea was governed by a relatively modest surface
pressure gradient with 15-20 kt NE tradewinds noted N of 15N
between 67W and 73W...and E to SE winds of 15-20 kt noted over
the basin W of 85W. lighter winds of 10 kt or so were noted in
between the two areas. Scattered showers were noted over the E
central Caribbean within 60-90 nm of a line from 16N62W to
14N72W. In the upper levels, a broad flat ridge was noted over
the Caribbean with axis along 77W. A shear axis was noted E of
the ridge across the NE caribbean extending to 15N71W. Strong
deep layered subsidence was noted within the shear axis
extending westward over most of the basin. The stationary front
is forecast to dissipate tonight with only a remnant shear axis
remaining into Fri. Little change is expected elsewhere.

...HISPANIOLA...

Patches of broken to locally overcast low and mid clouds were
noted over Hispaniola. The 1200 UTC rawinsonde from Santo
Domingo indicated a modest amount of moisture to 700 MB with a
very strong cap and subsidence above that level. This was
representative of the airmass over the region. :Little change is
expected into the weekend.

ATLANTIC OCEAN...

A cold front is over the W Atlantic from 31N55W to 26N70W where
it transitioned to a weakening stationary front which continued
through 28N75W to 31N80W. Scattered low topped showers were
noted within 60 nm of the front. Further east, another cold
front associated with a strong extra-tropical storm well north
of the area extended from 31N42W and continued to 21N51W, where
it transitioned to a weakening stationary front to 16N62W.
Scattered showers and isolated thunderstorms are noted n of 22n
and within 180 nm E of the front. A 1024 mb high is centered
over the E Atlantic near 33N20W. In the upper levels, an broad
upper level trough is over the central Atlantic N of 20N between
40W-65W supporting the surface fronts. An upstream shortwave
ridge was noted over the western Atlantic with axis along 75W.
The cold fronts are forecast to continue moving east over the
next 24 hours.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Cobb
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