AXNT20 KNHC 261010
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
610 AM EDT TUE JUL 26 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 analysis.
Based on 0600 UTC surface analysis and satellite imagery through
A tropical wave is in the eastern Atlantic from 09N-19N with axis
near 22W, forecast to move at 10-15 kt within the next 24 hours.
Scatterometer data show there is a low center associated with the
wave with pressure of 1010 mb. Meteosat composite imagery show
Saharan dry air and dust engulfing the northern wave environment.
A surge of moderate moist air from surface to 850 mb and divergent
flow in the middle to upper levels support an elongated cluster
of moderate to isolated strong convection from 10N-13N between
18W and 25W.
A tropical wave is in the central Atlantic from 09N-18N with axis
near 34W, moving west at 10 kt within the last 24 hours. CIRA LPW
imagery show moderate moist from the surface to 850 mb associated
with this wave and global model guidance show a low at 700 mb
coinciding with the wave axis location. The latest scatterometer
pass show that the low is now reflected at the surface with a
pressure of 1011 mb near 12N34W. Even though there is a divergent
environment at the upper levels, the presence of abundant Saharan
dry air and dust seems to hinder convection at the time.
A tropical wave is in the far eastern Caribbean from 11N-22N with
axis near 63W, moving west at 20 kt within the last 24 hours. The
wave is associated with a surge of moderate moisture from the
surface to 850 mb, which is supporting scattered showers and
tstms across the Virgin Islands, Puerto Rico and adjacent waters.
Isolated showers are possible across the Lesser Antilles and
across the basin E of 67E.
The Monsoon Trough extends across Africa into the east Tropical
Atlantic near 15N17W and then continues to a 1010 mb low near
13N22W to a 1011 mb low near 12N34W SW to 06N48W. The ITCZ begins
near 06N48W and continues west to the coast of Guyana near
07N58W. Aside from the convection associated with the waves,
scattered moderate convection is from 04N-10N E of 30W and from
0N-07N between 30W and 45W.
GULF OF MEXICO...
A broad middle level low centered near 27N92W covers most of the
basin and supports a 1012 mb low over SE Louisiana with an
associated surface trough extending from 30N88W to the low center
near 29N90W to 28N92W. Scatterometer data show S to SW moderate
to fresh winds N of 26N E of the low while surface observations
show moderate to fresh N to NW flow within 90 nm W of the low
center. Instability generated by the middle and surface lows along
with widespread moderate moisture across the basin support
scattered showers N of 23N between 86W and 95W. Clusters of heavy
showers and tstms are just NW of the Yucatan Channel quickly
moving W-NW and extending to the northern Yucatan Peninsula adjacent
waters. Over the eastern Bay of Campeche, a surface trough S of
22N along 92W support isolated showers S of 21N. Scattered showers
and tstms are within 120 nm off the W coast of Florida from 24N to
24N, quickly moving W-NW. Otherwise, weak surface ridging
prevails E of 86W. Expect for the surface low and trough to
dissipate within the next 24 hours.
A broad inverted upper-level trough covers the basin W of 76W
with an embedded W to E elongated low just S of Cuba that
supports isolated heavy showers and tstms over the southern
Island adjacent waters and elsewhere in the NW Caribbean,
including the Gulf of Honduras. A shortwave upper trough is across
the central Caribbean where the remnants of a former surface
trough support passing showers across Hispaniola and the Windward
passage. In the SW basin, the monsoon trough support scattered
showers and tstms within 120 nm of the coast of northern Panama
and Costa Rica. A tropical wave is moving across the E Caribbean where
it generates isolated showers E of 67W. The wave also support
scattered showers and tstms across the Virgin Islands, Puerto
Rico and mainly northern adjacent waters. See the tropical waves
section above for further details. Scatterometer data depict
fresh to strong winds in the south-central basin S of 14N and
moderate trades elsewhere. Showers will continue across Puerto
Rico and will increase across Hispaniola today as the wave
continue to move westward.
A shortwave upper trough is across the central Caribbean where
the remnants of a former surface trough support passing showers
across the Island and the Windward passage. Showers will increase
across Hispaniola today as a tropical wave in the eastern
Caribbean continue to move westward.
Three tropical waves are moving across the basin. Please refer to
the section above for details. A narrow and elongated upper level
trough is in the central Atlc with base extending to 30N between
53W and 59W. The trough aloft supports a dissipating cold front N
of the area with tail extending in the discussion area along
30N58W SW to 28N66W. scattered showers and tstms are within 90 nm
E of the front N of 28N. A broad surface ridge is across the
remainder basin being anchored by a 1030 mb high centered N of
the Azores Islands. Expect for the surface ridge to persist
through the next 24 hours.
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