Tropical Weather Discussion
Issued by NWS
AXNT20 KNHC 220004
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT MAY 21 2016
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
Tropical wave extends from 03N38W to 08N35W moving W at 15 kt.
The wave coincides with a mid-level 700 mb trough and associated
positive relative vorticity in the vicinity of the wave axis.
Both the CIRA layer precipitable water imagery from the surface
to 850 mb and the Saharan Air Layer imagery show dry air in the
northern wave environment, which is in part is hindering
convection at the time.
Tropical wave extends from 08N53W to 03N55W moving W at 10 kt.
This wave coincides with a weaker 700 mb trough across Suriname
and adjacent coastal waters. Moderate moisture from the surface
to the middle levels along with a diffluent environment aloft
support isolated showers in the vicinity of the wave.
The Monsoon Trough extends from the African coast near 07N12W to
04N24W. The Intertropical Convergence Zone axis extends from
04N24W to 04N30W to 06N35W. It then resumes west of a tropical
wave from 04N39W to 03N51W. Scattered moderate convection is
from 02N to 11N east of 20W.
GULF OF MEXICO...
A cold front extends across the SE CONUS and transitions to a
stationary front from 30N87W to 29N92W. Shallow moisture over
the western Gulf advected from the Caribbean by SE flow support
scattered showers within 90 NM either side of the front.
Otherwise...the remainder of the Gulf is under the influence of
gentle to moderate anticyclonic flow associated with a ridge
anchored by a 1017 mb high over the NE basin near 28N87W. The
high will dissipate by early Sunday morning while the front
transitions into a cold front to move across the eastern Gulf
and the Florida Peninsula the remainder Sunday through Monday
The surface pressure gradient across the Caribbean Sea remains
relatively strong due to a nearly stationary ridge anchored
across the central Atlc and lower pressure noted across northern
South America. The gradient is resulting in fresh to strong
trades across the central and eastern basin with winds strong to
near gale force within close proximity to the coast of Colombia.
Strong high pressure persisting over the Atlantic will allow for
this winds to remain in place through at least late Monday.
Otherwise...an upper level trough is noted on water vapor
imagery across the eastern Caribbean with axis along 67W. East
of the axis in the region of maximum lifting
dynamics...scattered showers and tstms are occurring across the
Windward Islands S of 15N east of 63W. Diffluence aloft along
with moisture inflow from the tropical Atlantic support showers
along Cuba and central Hispaniola.
A diffluent environment aloft between a short-wave trough over
the SW N Atlantic waters and NW flow from a ridge over the
western Caribbean along with moisture inflow from the tropical
Atlantic support showers across central Hispaniola. These
conditions are forecast to persist through the remainder
A middle to upper level trough over the eastern CONUS extending
to W Atlantic waters W of 70W support a surface trough from
30N76W to 25N80W that enhances scattered moderate convection and
isolated thunderstorms N of 25N W of 72W. Farther east...a deep
layered low centered over the central North Atlc supports a cold
front analyzed from 30N58W to 29N61W where is becomes stationary
to 30N67W. Otherwise...the remainder of the central and eastern
Atlc is under the influence of a surface ridge anchored by a
1025 mb high centered near 29N34W.
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