[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261205
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
804 AM EDT Sat Aug 26 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 0600 UTC surface analysis and satellite imagery through
1015 UTC.

...SPECIAL FEATURES...
Hurricane Harvey is centered near 28.7N 97.2W at 26/1200 UTC or
about 15 nm WSW of Victoria Texas and about 80 nm SE of San
Antonio Texas moving NNW at 5 kt. Estimated minimum central
pressure is 975 mb. Maximum sustained wind speed is 70 kt with
gusts to 85 kt. Numerous moderate and scattered strong convection
is occurring in the NE semicircle within 180 nm and the SE
semicircle within 90 nm of the center. See latest Intermediate
Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and
the full Forecast/Advisory under AWIPS/WMO headers
MIATCMAT4/WTNT24 KNHC for more details.

...TROPICAL WAVES...
A tropical wave extends from 14N27W to 25N23W moving W at 5-10
kt. The wave coincides with amplified 700 mb troughing between
17W-30W. Infrared satellite imagery shows the presence of Saharan
dust surrounding the wave environment N of the monsoon trough
axis. No significant deep convection is associated with the wave
at this time.

A tropical wave extends from 11N44W to 17N46W to 23N47W moving W
at 5-10 kt. A weak 1011 mb low is analyzed along the wave axis
near 15N and is providing focus for widely scattered moderate
convection from 15N-18N between 45W-51W.

A tropical wave extends from 11N92W to 18N91W moving W at 10-15
kt. Global model guidance suggests subtle 700 mb troughing and a
maximum in 850 mb relative vorticity S of 17N between 89W-94W
moving over portions of Central America and the East Pacific
waters. Scattered moderate and isolated strong convection is from
10N-20N between 91W-98W.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from 18N23W to 14N27W to 11N40W to
11N50W. Scattered moderate convection is from 03N-11N between
03W-17W. Widely scattered moderate convection is from 06N-11N
between 37W-51W.

...DISCUSSION...

GULF OF MEXICO...
The primary concern for the Gulf of Mexico is Hurricane Harvey
that has made landfall and continues impacting SE Texas this
morning. Harvey remains on the western periphery of an upper
level ridge anchored over the central Gulf near 27N89W. The ridge
extends influence over the Lower Mississippi River valley...the
central and eastern Gulf...including the Florida peninsula...and
portions of the SW Gulf waters. To the east of Harvey...upper
level divergence associated with the ridging supports a 1012 mb
low centered NE of Tampa Bay near 28N82W. A surface trough
extends N-NE from the low to near Jacksonville and W-SW from the
low across Tampa Bay to 27N87W. The low along with the boundaries
in place and upper level divergence are generating scattered
showers and strong tstms from 24N-28N between 81W-85W...with
widely scattered showers and isolated tstms occurring elsewhere E
of 86W. As Harvey impacts the NW Gulf waters and coastal Texas
through the weekend into early next week...the troughing and
weaker low pressure across the eastern Gulf waters and Florida
peninsula are expected to maintain unsettled conditions across the
region as the low moves NE into the SW North Atlc waters through
Sunday night.

CARIBBEAN SEA...
Much of the NW Caribbean and portions of Central America are under
the influence of NW flow aloft and an overall divergent pattern
supporting isolated showers and tstms occurring N of 17N between
77W-88W...and across interior portions of Central America S of
16N W of 86W. Otherwise...farther east...much of the central and
eastern Caribbean are under dry air aloft and mostly fair
conditions at the surface this morning. However...a weak surface
trough currently along 60W/61W is expected to move westward
across the Lesser Antilles this morning and into the eastern
Caribbean with isolated showers occurring E of 69W. Finally...
moderate to fresh trades prevail and this overall synoptic pattern
is expected to persist through Monday.

...HISPANIOLA...
Mostly clear skies prevail this morning across the island with
these overall conditions expected to persist through the weekend.
Isolated afternoon showers and tstms are possible across western
Hispaniola with maximum daytime heating and instability...along
with local sea breeze effects.

ATLANTIC OCEAN...
Upper level ridging and an overall divergent upper level pattern
prevails over the SW North Atlc this morning generating scattered
showers and tstms remaining W of a line from 32N62W to 26N75W to
the coast of central Cuba near 22N77W. Water vapor imagery also
indicates long wave upper level troughing offshore of the eastern
CONUS with the base of this trough remaining generally N of 34N.
The trough supports a stationary front extending from 34N70W to
coastal Georgia and South Carolina near 32N81W to the Florida
panhandle. An upper level low is centered near 29N46W and supports
a surface trough analyzed from 27N54W to 31N49W. Isolated showers
and tstms are occurring from 28N-32N between 42W-54W. The
remainder of the central and eastern Atlc is under the influence
of a surface ridge anchored by a 1027 mb high centered W-NW of the
Azores near 39N39W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
HUFFMAN
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