AXNT20 KNHC 250012
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE MAY 24 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
Based on 1800 UTC surface analysis and satellite imagery through
Tropical wave extends from 04N05W to 12N04W moving W at 10 kt.
the wave coincides with an amplified 700 mb trough between the
Prime Meridian and 08W. Largely remaining across inland west
Africa...scattered strong convection extends from 06N to 12N
between 07W and 10W.
Tropical wave extends from 02N32W to 10N31W moving W at 15 kt.
The wave coincides with weak 700 mb troughing between 28W and
36W. Widely scattered moderate convection associated with the
wave is from 03N to 05N between 31W and 33W.
Tropical wave extends from 02N55W to 09N54W moving W at 15 kt.
The wave coincides with a subtle mid-level 700 mb trough and
associated relative vorticity aloft in the vicinity of the wave
axis near 05N. No significant convection is associated with the
Tropical wave extends from 04N77W to 13N77W moving W at 10-15 kt.
The wave is located within the southwestern periphery of a mid-
level ridge anchored over the SW North Atlc waters near
21N65W and broad mid-level troughing between 70W and 82W.
Scattered moderate to strong convection is mainly over Panama
ahead of the tropical wave axis.
The Monsoon Trough extends from the African coast near 08N13W to
05N21W. The Intertropical Convergence Zone axis extends from
05N21W to 03N35W to the coast of South America near 04N51W.
Scattered moderate isolated strong convection is within 90 nm
either side of the axis between 18W and 29W.
GULF OF MEXICO...
The Gulf basin is under the influence of upper-level NW flow
which is providing a mostly stable environment aloft. A small
but vigorous upper level vortmax is sweeping SE across the Florida
panhandle into the base of a sharp amplifying upper level trough
over Florida...Cuba and the western Bahamas. At the surface,
a ridge is anchored by a 1022 mb high centered near Charleston, S.C.
with primarily light to moderate E-SE surface winds E of 90W and
moderate to occasional fresh SE surface winds W of 90W.
This general synoptic pattern is expected to persist through Friday
with little variation expected.
The axis of a sharp amplifying mid-to upper level trough extends from
Florida across Cuba to a base near 16N77W. The trough appeared to be
assuming a negative tilt with time with increasing diffluent flow over
eastern Cuba and the north-central Caribbean. This flow aloft coupled
with diurnal heating and orographic lift resulted in scattered strong
thunderstorms over Cuba...Jamaica and adjacent waters. At the surface,
the pressure gradient between a ridge anchored across the central Atlantic
and lower pressures over northwestern South America is resulting in fresh
to strong trades across the basin with the strongest winds occurring across the
south-central portion of the basin between 65W and 76W. 1326 and 1418
UTC ASCAT passes indicated 20-25 knot winds in the same area described.
As the ridge is forecast to remain nearly stationary over the next 24 hours,
then begin to gradually shift west, the gradient across the Caribbean will
relax by Thursday with more moderate trades.
The axis of an amplifying and more negatively-tilted upper level trough along
77W/78W is providing an increasingly diffluent mid-to upper level diffluent
environment over the island. However, scattered strong thunderstorms have
so far developed around the island. The 12Z rawindsonde from Santo Domingo
suggested an unstable environment, one conducive for deep convection with
precipitable water values around 2.00 inches and the presence of an upper level
jet streak....75-80 KT. This overall upper level diffluent pattern is expected to become
further enhanced as a mid-to upper level low cuts off over the Bahamas. This
increases the likelihood of scattered thunderstorms and potentially locally heavy
An elongated middle-to upper level low is centered offshore of New England
with troughing dipping southward over much of the SW North Atlantic. The
base of the trough was becoming more amplified and negatively tilted with time
with increasing upper level diffluence over the SW North Atlantic from 22N to
30N between 65W and 73W. At the surface, a dissipating stationary front extended
from 32N67W to the northwest Bahamas. An inverted trough was developing from
27N68W to 22N71W beneath the area of enhanced diffluent flow. Scattered
moderate isolated strong thunderstorms were developing within 240 NM east
of the inverted trough. This trough is forecast to develop further and move WNW
over the next few days. For additional information please refer to the Graphical
Tropical Weather Outlook at www.hurricanes.gov.
Elsewhere, a 1022 mb high is centered across South Carolina and will slide
offshore by Wednesday continuing the gradual clearing and fair weather conditions
expected west of the front. Finally...a 1032 mb high is centered near 34N45W
across the central Atlantic that is providing relatively tranquil conditions E of 60W.
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