Tropical Weather Discussion
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AXNT20 KNHC 122337

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
636 PM EST Sun Nov 12 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
2245 UTC.

The Intertropical Convergence Zone axis extends from the African
coast near 08N13W to 09N35W to 08N51W to 06N58W. Scattered
moderate convection is from 03N-12N between 24W-46W.


An upper level trough extends over the Gulf basin this evening
from over northern Florida SW to over the SW waters near 21N93W.
Mid-level shortwave energy is noted over the north-central waters
in the vicinity of 29N91W progressing eastward and supporting a
surface trough extending from SE Louisiana near 29N89W to 22N91W.
Widely scattered showers and isolated tstms are occurring N of 27N
between 85W-90W...and within 75 nm either side of the surface
trough axis S of 27N. Farther east...this area of convection
merges with shallow widely scattered showers occurring generally
N of a shear line analyzed across the Florida peninsula from near
Jupiter to near Sarasota and into the NE Gulf near 28N85W. The
shear line is expected to slowly dissipate through Monday night as
stronger NE winds weaken. Elsewhere moderate to fresh NE winds
prevail and are expected through Tuesday night into Wednesday.

Middle to upper level divergence prevails over the NW Caribbean
and Yucatan peninsula this evening generating a broad area of
scattered to numerous showers and scattered strong tstms from
14N-22N between 76W-90W...including Cuba...Jamaica...Belize...and
portions of the Yucatan peninsula. South of this feature...a 1007
mb low and associated surface trough analyzed from 17N83W into the
low then along the Costa Rica and western Panama coast to 09N82W
is providing focus for scattered showers and tstms from 08N-14N
between 76W-86W. This entire area of the western Caribbean and
portions of Central America remain on the northwestern periphery
of an upper level ridge anchored over northern South America near
06N70W. Farther east...generally moderate to fresh trades persist
and are expected through Tuesday night. Isolated showers and tstms
are embedded within the trades N of 16N between 64W-76W.

Scattered showers and isolated tstms continue across the island
this evening as the region remains within westerly flow aloft.
Although only marginally divergent aloft...low-level moisture
convergence is maximized across the region within E-SE trades.
This overall pattern will persist through Tuesday.

A stationary front extends across the SW North Atlc from 32N59W
W-SW to 28N70W where it becomes a shear line to the Florida
peninsula near Jupiter. A pre-frontal surface trough is analyzed
to the SE of the front from 24N62W to 30N57W. While widely
scattered showers are occurring generally within 150 nm N of the
shear line...low-level moisture convergence SW of the surface
trough and a favorable divergent environment aloft are generating
scattered showers and isolated tstms from 18N-26N between 50W-
77W. To the east...a 1013 mb low is centered near 30N34W with a
surface trough extending from the low to 26N32W to 22N34W. The
system is supported aloft by a broad middle to upper level low
centered near 30N35W. Widely scattered showers and isolated tstms
are noted near the low center from 29N-36N between 26W-37W.
Additional scattered showers and isolated tstms are occurring
farther south from 12N-25N between 25W-40W.

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