Tropical Weather Discussion
Issued by NWS
AXNT20 KNHC 192225
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
625 PM EDT Sun Mar 19 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
A vigorous middle to upper level low is centered offshore of the
mid-Atlc seaboard near 36N73W that supports a partially occluded
1004 mb low centered near 40N67W. The associated cold front
extends into the discussion area near 32N71W SW to the Florida
peninsula near 27N80W. Near gale to gale force NW winds are
expected in wake of the front tonight through late Monday morning
generally N of 30N between the front and 74W. See the latest NWS
High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC
for more details.
The Monsoon Trough extends from the African coast near 05N09W to
the Equator near 20W. Widely scattered moderate and isolated
strong convection is S of 06N between the Prime Meridian and 11W.
Isolated moderate convection is elsewhere S of 06N between 11W-
17W...and S of 04N between 46W-52W.
GULF OF MEXICO...
Water vapor imagery indicates mostly dry air and stable conditions
over much of the basin as westerly flow aloft continues to
influence the upper level pattern. A middle to upper level low is
centered over the mid-Atlc seaboard and supports a cold front
analyzed across the Florida peninsula and into the Gulf waters
near Fort Myers...continuing to 27N87W then to the SE Louisiana
coast near 29N90W. While the front remains precipitation-free...a
relatively cooler and drier airmass continues settling in across
the eastern Gulf waters and Florida peninsula this evening. The
remainder of the basin is under the influence of a surface ridge
anchored by a 1027 mb high centered near 29N93W. The high is
expected to provide gentle to moderate anticyclonic winds
overnight into Monday as the front drifts SE and exits the region
by late Monday.
Mostly southwesterly upper level flow is noted on water vapor
imagery over much of the Caribbean basin this evening. This
southwesterly flow over western portions feeds NE into a vigorous
middle to upper level low over the SW North Atlc off the coast of
the Carolinas. An embedded mid-level shortwave trough is also
noted in the vicinity of 28N63W that supports a 1016 mb low
centered near 27N69W and the associated stationary front extending
SW to eastern Cuba near 21N77W then to the NE coast of Nicaragua
near 15N83W. Isolated showers continue to focus around the front
occurring generally within 150 nm either side of the boundary. By
Monday the front is expected to become diffuse across the western
Caribbean as the surface low and upper level system move N of the
discussion area into the central North Atlc waters. Otherwise...a
few isolated showers are possible across the central Caribbean in
the vicinity of a surface trough extending from 11N71W to 15N71W.
These showers are expected to continue moving within gentle to
moderate trade winds overnight into Monday.
West-southwesterly flow aloft over the island in addition to a
stationary front analyzed across eastern Cuba is providing for
isolated showers this evening. The front is expected to become
diffuse tonight...however isolated afternoon showers remain
possible on Monday due to the weakened remnant boundary lingering
across the region.
Aside from the Special Features low pressure area and associated
cold front analyzed across the northwestern SW North Atlc
waters...a mid-level shortwave trough is noted on water vapor
imagery in the vicinity of 28N63W supporting a 1016 mb low
centered near 27N69W. The associated stationary front extends
from the low to eastern Cuba near 21N76W with a warm front
extending E-NE from the low to 29N58W then stationary to 32N47W.
Isolated showers are occurring with the stationary front mainly S
of 23N between 71W-78W while scattered showers and tstms are
occurring N of 25N between 55W-67W in association with the warm
front and mid-level shortwave dynamics. This low is expected to
become absorbed by the cold front currently to the NW that will
bring near gale to gale force NW winds to the northern waters
tonight. In addition...northerly winds will filter in across the
remainder of the SW North Atlc through early Monday as high
pressure builds in to the region from the west. The remainder of
the central and eastern Atlc is under the influence of a surface
ridge anchored by a 1028 mb high centered S of the Azores near
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