AXNT20 KNHC 211052
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
552 AM EST Tue Feb 21 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
A broad area of low pressure across the western North Atlc is
forecast to strengthen during the next 24 to 36 hours and extend a
cold front into the discussion area near 32N53W by 22/0000 UTC
generating near gale to gale force SW winds N of 29N between 50N
and 52W. The gale force conditions are expected to move N of the
area by 23/0000 UTC. See latest NWS High Seas Forecast under
AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details.
The Monsoon Trough extends from the African coast near 08N13W to
04N18W. The Intertropical Convergence Zone axis extends from
04N18W to the Equator near 27W and along the Equator to 38W.
Scattered moderate convection is S of 05N between 26W-34W...and S
of 06N between 48W-52W.
GULF OF MEXICO...
A sharp middle to upper level trough is noted on water vapor
imagery over the central CONUS with trough axis dipping southward
over the western Gulf waters and NE Mexico. The troughing
supports a 1010 mb low centered across east-central Arkansas near
35N91W with a cold front extending S-SW to 30N90W to 20N96W.
Scattered showers and widely scattered tstms are occurring N of
24N between 87W-93W largely enhanced by strong middle to upper
level diffluence. Otherwise...the eastern half of the basin is
under the influence of a surface ridge anchored by a 1024 mb high
centered across the Carolinas. Mostly clear skies prevail across
the Florida peninsula...however middle to upper level cloudiness
and moisture is noted across the eastern Gulf as the upper level
trough and front approaches from the west. Looking ahead...the
cold front is forecast to move into the eastern Gulf by late
Tuesday night into Wednesday and gradually weaken into a surface
trough. A secondary boundary...currently a cold front analyzed
across central Texas...is expected to emerge off the Texas and
Louisiana coasts Tuesday and quickly merge with the other
weakening front lingering across the eastern Gulf. As this
occurs...a broad area of low pressure is forecast to develop on
Wednesday across the NE Gulf waters and drift eastward across the
Florida peninsula into the SW North Atlc waters by Friday into
Overall the Caribbean basin remains under fairly tranquil
conditions this morning with the exception of the northeastern
waters. An area of low pressure N-NE of Puerto Rico centered near
24N64W extends a cold front to 20N64W to 17N68W. Low-level
moisture convergence within southerly winds focused along a
surface trough analyzed from 19N64W to 13N66W is generating
widely scattered showers and isolated tstms E of 66W...and within
60 nm either side of the cold front. Otherwise...dry and stable
air aloft coupled with gentle to moderate E-NE winds are
prevailing and expected to persist through Tuesday night. By
Wednesday...a cold front is expected to move across the central
Gulf of Mexico and reach the Yucatan Channel region and NW
Caribbean waters introducing another round of fresh to occasional
strong W-NW winds.
Isolated showers are expected as a cold front is analyzed to the
SE of the island. Persistent northerly winds will continue to feed
Atlc moisture across northern portions of the islands that will
result in these showers through Wednesday afternoon.
A broad area of low pressure is noted across the SW North Atlc
focused on a 1010 mb low centered near 24N64W. The associated
cold front extends S to 20N64W to 17N68W. Scattered showers and
tstms are occurring to the E of the low from 18N-30N between 52W-
63W. The low is forecast to continue moving eastward and merge
with a cold front dropping into the discussion area from the
NW...currently analyzed from near 32N62W to 28N70W. The entire
system will move into the central Atlc waters by Tuesday night
into Wednesday producing the Special Features near gale to gale
force conditions mentioned above. Otherwise...the remainder of the
SW North Atlc is under the influence of a surface ridge anchored
by a 1024 mb high centered across the Carolinas. The ridge will
slide offshore through Wednesday. Finally...the remainder of the
eastern Atlc is under the influence of another surface ridge
anchored by a 1031 mb high centered NE of the Azores near 44W19W.
The ridge axis extends SW from the high to 32N31N to 17N43W.
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