[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260559
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
158 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 0000 UTC surface analysis and satellite imagery through
0515 UTC.

...SPECIAL FEATURES...
Hurricane Harvey is centered near 28.2N 97.0W at 26/0600 UTC or
about 5 nm N of Rockport Texas and about 40 nm S of Victoria
Texas moving NW at 5 kt. Estimated minimum central pressure is
942 mb. Maximum sustained wind speed is 110 kt with gusts to 135
kt. Numerous moderate and isolated strong convection is within 90
nm of center. Scattered moderate convection is elsewhere from 26N-
31N between 91W-99W. 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 11N30W to 22N28W moving W at 10-15
kt. The wave coincides with amplified 700 mb troughing between
18W-32W. Infrared satellite imagery shows the presence of Saharan
dust surrounding the wave environment N of the monsoon trough
axis. Isolated moderate convection is from 15N-18N between 22W-
26W.

A tropical wave extends from 09N44W to 19N44W moving W at 5-10
kt. A weak 1012 mb low is analyzed along the wave axis near 15N
and is providing focus for isolated moderate convection from 14N-
18N between 44W-50W.

A tropical wave extends from 10N92W to 19N88W moving W at 10-15
kt. Global model guidance suggests subtle 700 mb troughing and a
maximum in 850 mb relative vorticity S of 18N between 88W-94W
moving over portions of Central America and the East Pacific
waters. Scattered moderate and isolated strong convection is from
11N-20N between 87W-97W.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 18N16W to
13N33W to 15N45W. Widely scattered moderate convection is from
04N-08N between 02W-15W...and from 06N-10N between 37W-52W.

...DISCUSSION...

GULF OF MEXICO...
The primary concern for the Gulf of Mexico is Hurricane Harvey
that has made landfall this evening. Harvey remains on the
western periphery of an upper level ridge anchored near 28N89W
that extends influence over the Lower Mississippi River valley
southward over the central and eastern Gulf...including the
Florida peninsula. The ridging also extends influence over the SW
Gulf and central Mexico. To the east of Harvey...upper level
divergence associated with the ridging supports a 1012 mb low
centered N of Tampa Bay near 28N82W. A surface trough extends N
from the low to near Jacksonville and SW from the low across Tampa
Bay to 26N86W. The low along with the boundaries in place and
upper level divergence are generating scattered showers and tstms
generally E of 87W...including portions of the Florida peninsula.
As Harvey impacts the NW Gulf waters and coastal Texas through
the upcoming weekend...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 widely scattered showers and isolated tstms occurring
N of 17N between 77W-86W...and across interior portions of Central
America S of 17N W of 85W. Otherwise...farther east...much of the
central and eastern Caribbean are under dry air aloft and mostly
fair conditions at the surface this evening. However...a weak
surface trough currently along 59W is expected to move westward
across the Lesser Antilles later tonight into Saturday bringing
possible isolated showers to the eastern waters E of 66W.
Finally...moderate to fresh trades prevail and this overall
synoptic pattern is expected to persist through the weekend into
Monday.

...HISPANIOLA...
Mostly clear skies prevail this evening 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 evening generating scattered
showers and tstms remaining W of a line from 32N68W to the coast
of central Cuba near 22N78W. Water vapor imagery also indicates
longwave 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 34N73W to coastal
Georgia near 32N81W to the Florida panhandle. Farther east across
the remainder of the central and eastern Atlc...ridging prevails
anchored by a 1029 mb high centered W-NW of the Azores near
41N39W.

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

$$
HUFFMAN
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