Tropical Weather Discussion
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AXNT20 KNHC 201030

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
530 AM EST Mon Nov 20 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 0600 UTC surface analysis and satellite imagery through
1015 UTC.


Strong high pressure behind a cold front over the Gulf of Mexico
is supporting gale force winds S of 21N W of the front. These
winds are forecast to continue through Monday morning. Wave
heights of 8 to 12 ft are expected associated with these winds.
See the latest high seas forecast under AWIPS/WMO headers
HSFAT2/FZNT02 for more details.


The monsoon trough extends from the African coast near 09N13W to
07N20W. The Intertropical Convergence Zone axis extends from
07N20W to 06N34W to 08N42W to the South American coast near
07N58W. Scattered moderate to isolated strong convection is from
03N-08N between 10W-30W. Isolated moderate convection is from
08N-12N between 33W-40W.



As of 0900 UTC, a cold front extends from S Florida near 26N80W
to 23N88W. A stationary front continues to 21N94W to the Bay of
Campeche near 18N94W. Scattered showers are within 15 nm of the
front. A gale is over the SW Gulf S of 21N within 60 nm of the
coast of Mexico. See above. 15-25 kt N winds are over the
remainder of the Gulf. In the upper levels, zonal flow is noted.
Strong subsidence is over the Gulf except along the Texas and
Louisiana coasts. Expect over the next 24 hours for the front to
stall from S Florida to the SW Bay of Campeche, and then begin to
slowly retrograde back N.


A 1008 mb low is centered over the central Caribbean near
15N73W. A surface trough extends NE from the low through the Mona
Passage to the Atlantic near 23N66W. Scattered moderate convection
is near the low from 12N-18N between 68W-71W, to include Aruba
and Curacao. Scattered showers are elsewhere within 180 nm of the
trough axis, to include Puerto Rico and the Virgin Islands. In the
upper levels, an upper level trough is over the NW Caribbean with
axis from E Cuba near 20N74W to the Gulf of Honduras near 16N89W.
Upper level diffluence E of the trough is enhancing the showers
and convection over the central Caribbean Sea. Expect the area of
convection to drift W and persist for the next 24 hours.


Scattered showers are over Hispaniola, and will continue through
Tuesday. Expect convection to build over Hispaniola in the
afternoon and evening hours during maximum heating. Localized
flooding is also possible during this time.


As of 0900 UTC, a cold front is over the W Atlantic from 31N72W
to near Homestead Florida at 26N80W. Scattered showers are within
60 nm of the front. A 1020 mb high is centered over the central
Atlantic near 32N50W producing fair weather. A cold front is over
the E Atlantic from 31N32W to 26N40W to 21N54W. Isolated moderate
convection is within 120 nm of the front. A surface trough is
just E of the Canary Islands from 30N12W to 25N16W. Scattered
showers are over the Canary Islands. Of note in the upper levels,
an upper level trough is over the W Atlantic enhancing the W
Atlantic front. Another upper level trough is over the central
Atlantic with axis from 31N46W to 23N53W. Upper level diffluence
is E of this trough. In addition, a small upper level low is
centered near the Canary Islands at 30N13W.

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