Tropical Weather Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

484
AXNT20 KNHC 181005
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
605 AM EDT Wed Oct 18 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
0915 UTC.

...TROPICAL WAVES...
A tropical wave extends from 06N59W to 15N59W moving W at 10-15
kt. The wave coincides with shortwave 700 mb troughing between
56W-61W and a maximum in 850 mb relative vorticity along the wave
axis near 10N. Scattered moderate convection is from 08N-13N
between 52W-61W.

A tropical wave extends from 08N66W to 17N66W moving W at 10-15
kt. The wave coincides with shortwave 700 mb troughing between
64W-68W and a maximum in 850 mb relative vorticity along the wave
axis near 15N. Isolated moderate convection is from 11N-18N
between 62W-69W.

A tropical wave extends from 06N83W to 16N83W moving W at 10-15
kt. The wave coincides with subtle 700 mb troughing over the SW
Caribbean Sea. Dry NE to E flow aloft is noted on water vapor
imagery on the southeastern periphery of an upper level ridge
anchored near 17N80W. Scattered moderate and isolated strong
convection is from 06N-14N between 76W-85W.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 07N12W to
07N20W. The Intertropical Convergence Zone axis extends from
07N20W to 09N26W to 06N38W to 07N54W. Scattered moderate
convection is from 05N-12N between 22W-43W.

...DISCUSSION...

GULF OF MEXICO...
A stationary front extends from the southern Florida peninsula
near 26N81W westward to 27N90W then curves SW to 23N94W to the
coast of southern Mexico near 18N94W. The front is supported aloft
by a middle to upper level trough progressing eastward over the
offshore waters of the far northwestern SW North Atlc waters this
morning. Most convection...scattered showers and isolated
tstms...are occurring across eastern portions of the basin S of
28N E of 87W...including the southern Florida peninsula. Other
isolated showers and tstms are occurring across the SW Gulf S of
22N between 91W-95W in the vicinity of the front. The front is
expected to drift SE through the next couple of days and gradually
become diffuse by Wednesday night. Fresh to strong N-NE winds
will prevail through Wednesday night and then weaken slightly
into moderate to occasional fresh through early Thursday. Surface
ridging is expected to remain in place across the SE CONUS the
remainder of the week.

CARIBBEAN SEA...
An upper level anticyclone is centered over the western Caribbean
near 17N80W and is providing mostly dry air aloft between 70W-
80W. Scattered showers and strong tstms are occurring S of 14N W
of 79W in association with a tropical wave along 83W. Widely
scattered showers and isolated tstms are also N of 16N W of 84W.
Farther east...another tropical wave along 66W is providing for
widely scattered showers and tstms between 62W-67W...while a
third tropical wave remains to the E of Windward Islands along
59W. The third wave carries more active convection that is
expected to impact the Lesser Antilles Wednesday through early
Thursday. Elsewhere...moderate to fresh trades prevail and are
expected to persist through Wednesday...gradually increasing
across the eastern and central Caribbean by Wednesday night as
the pressure gradient strengthens.

...HISPANIOLA...
A narrow upper level trough axis extends along 69W over the island
between two upper level anticyclonic circulations...one centered
near 18N64W and the other centered over the western Caribbean Sea
near 17N80W. Most of the island is under fair skies this morning.
Looking ahead...a tropical wave will skirt S of the island
Wednesday night and bring a higher potential for shower and tstm
activity through Thursday night.

ATLANTIC OCEAN...
A stationary front extends from 32N70W SW to the southern Florida
peninsula near 26N80W and continues to slowly drift eastward. The
front is supported aloft by a middle to upper level trough axis
extending from over the offshore waters of the Carolinas
southwestward to over the NE Gulf of Mexico waters. Scattered
showers and isolated tstms are occurring primarily N of the front
and W of 76W south of the front. A pre-frontal surface trough is
analyzed from 25N71W to 32N65W and continues to provide focus for
widely scattered showers and isolated tstms from 22N-32N between
59W-67W. The remainder of the central and eastern Atlc are under
the influence of a surface ridge anchored by a 1029 mb high
centered near 33N37W.

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

$$
HUFFMAN




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.