NHC Tropical Weather Discussion (Atlantic) NHC Atlantic Tropical Weather Discussion
NHC Tropical Weather Discussion (Atlantic)
NHC Atlantic Tropical Weather Discussion
AXNT20 KNHC 281754
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
154 PM EDT Tue Mar 28 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 1200 UTC surface analysis and satellite imagery through
A middle to upper level shortwave trough is observed on water
vapor imagery supporting a 1004 mb low centered near 25N65W. Near
gale to gale force winds are occurring in the northern semicircle
of the low within 240 nm of the center. The low is forecast to
move E-NE through Thursday with near gale to gale force winds
rotating around its center. By Thursday evening...the low will
have moved N of the discussion area. Please 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 06N11W SW
to 02N17W to 01N24W. The Intertropical Convergence Zone axis
extends from 01N24W to 02N36W to 0N50W. Scattered moderate
convection is within 150 nm north of the ITCZ. Scattered to
isolated strong convection is 120 nm either side of the monsoon
trough. Numerous moderate to strong convection is from 04S to 04N
E of 05E and from 01N to 05S between 05W and 14W.
GULF OF MEXICO...
Middle to upper level ridging prevails over the Gulf with water
vapor imagery indicating relatively dry and stable air. Dry air is
also at the lower levels as indicated by CIRA LPW, which is
supporting fair weather conditions. Generally, low pressure
continues to dominate the western basin while ridging extends
from the SW Atlc waters across Florida into the eastern Gulf.
This synoptic pattern provides gentle to moderate return flow E of
90W and moderate to fresh SE flow W 90W. Winds in the western
basin will increase tonight to fresh to strong ahead of the next
cold front to emerge the coast of Texas Thursday morning. Fresh to
strong winds will prevail in the vicinity of the front as it moves
E-SE across the Gulf through Saturday.
West-southwesterly flow aloft prevails over the Caribbean basin
this morning with mostly dry and stable conditions noted on water
vapor imagery. CIRA LPW and water vapor imagery also show very
dry conditions in the low and middle levels across the central and
western Sea, which is favoring fair weather conditions there.
However, over the eastern basin there is abundant moisture being
advected from the tropical Atlantic. This moisture supports
shallow convection mainly across western Puerto Rico and the Mona
Passage. With the Special Features low pressure area located N of
Hispaniola and Puerto Rico...the pressure gradient remains fairly
weak and results in gentle to moderate trades. This overall wind
pattern is expected to persist through Thursday with the exception
of occasional fresh E-SE winds across the Gulf of Honduras.
Otherwise...little change is expected through the remainder of the
Dry and stable air aloft prevails within southwesterly flow
aloft...however a surface trough extends southward from the
Special Features low to the northeast coast of the Island. Low-
level moisture convergence in the vicinity of the surface trough
may enhance isolated showers across this portion of the Island
later today. As the low pressure area moves E-NE during the next
24 hours...conditions will trend drier tonight into Wednesday.
The primary focus for the SW North Atlc is the Special Features
low pressure area centered on a 1004 mb low near 25N65W. A warm
front extends E-NE from the low to 29N60W to 26N54W and provides
much of the lift generating scattered showers and isolated tstms
N of 26N between 48W-63W. The remainder of the SW North Atlc is
under the influence of a surface ridge associated with a 1018 mb
high centered near 31N76W. Farther east across the central
Atlc...a middle to upper level low is centered over the north-
central Atlc that supports a dissipating stationary front
extending from 30N32W to 30N50W. The remainder of the central and
eastern Atlc is under the influence of a surface ridge.
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