[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 012331
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
730 PM EDT Fri Sep 1 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 1800 UTC surface analysis and satellite imagery through
2245 UTC.

...SPECIAL FEATURES...
Hurricane Irma is centered near 18.8N 39.1W at 01/2100 UTC or
about 1300 nm E of the Leeward Islands moving W at 11 kt.
Estimated minimum central pressure is 964 mb. Maximum sustained
wind speed is 105 kt with gusts to 130 kt. Numerous moderate is
within 75 nm of center. Scattered moderate is elsewhere from
16N-22N between 35W-43W. See the latest NHC Forecast/Advisory
under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details.

...TROPICAL WAVES...
A tropical wave extends from 07N25W to 17N26W moving W at 10-15
kt. The wave coincides with 700 mb troughing between 19W-29W and a
maximum in 850 mb relative vorticity lagging behind the wave in
the vicinity of a 1013 mb low centered along the monsoon trough
near 09N22W. Scattered moderate convection is from 06N-14N between
23W-30W.

A tropical wave extends from 10N57W to 21N55W moving W at 5-10
kt. The wave coincides with 700 mb troughing between 52W-59W and
continues to interact with an upper level low and associated
troughing to the N-NE near 24N54W. Isolated moderate convection is
from 17N-22N between 55W-61W.

A tropical wave extends from 10N86W to 20N86W moving W at 10-15
kt. The wave coincides with subtle 700 mb troughing on the
southwestern periphery of a mid-level ridge anchored over the SW
North Atlc near 29N73W. Scattered moderate convection is from
10N-17N between 81W-87W...including inland portions of Nicaragua
and Honduras.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 12N17W to
07N26W then resumes near 14N42W to 13N53W. Isolated moderate
convection is from 06N-13N between 36W-47W.

...DISCUSSION...

GULF OF MEXICO...
Water vapor imagery indicates a middle to upper level trough
extending from over the Ohio River valley and southern Mississippi
River valley to a base over the NW Gulf near 26N94W. The troughing
supports a cold front extending across western Georgia and SE
Alabama...across the western Florida panhandle near 31N87W to
29N90W. A pre-frontal surface trough extends from 30N86W to
26N89W. East of the upper level troughing...upper level divergence
is maximized over the eastern Gulf this evening and along with the
boundaries mentioned above are generating scattered to numerous
showers and scattered tstms N of 23N between 80W-89W...including
portions of the Florida peninsula. Upper level divergence is also
maximized over the SW Gulf and along with a surface trough from
19N94W to 25N96W...these features are providing focus for
scattered showers and tstms S of 25N between 86W-98W...including
much of the Yucatan peninsula and southern Mexico. Otherwise...
outside of ongoing convection...mostly light to moderate weak
anticyclonic flow is noted as a weak ridge axis extends across the
Florida Straits through 26N90W to Texas coast near Galveston Bay.

CARIBBEAN SEA...
A tropical wave is moving across the NW Caribbean and portions of
Central America providing scattered showers and tstms across the
NW waters and interior portions of Nicaragua and Honduras this
evening. Most of the activity remains W of 80W and is expected to
move west of the area by Saturday night. A few isolated showers
and tstms are occurring N of 16N between 75W-80W due to a
weakening upper level low centered near 20N80W. Farther east...
drier air aloft and mostly fair conditions prevail this
evening within moderate to fresh trades. An approaching tropical
wave currently along 56W will impact the Lesser Antilles on
Saturday with increase cloudiness and a greater chance for
isolated showers and tstms. Looking beyond this weekend
however...Hurricane Irma looms across the central tropical Atlc
and is forecast to approach 60W Tuesday night into Wednesday.

...HISPANIOLA...
Mostly fair weather and clear skies prevail this evening across
the island as dry air aloft moves in over the region. The
overall dry weather pattern is expected to persist the next
couple of days.

ATLANTIC OCEAN...
A middle to upper level trough is progressing over the mid-Atlc
and SE CONUS regions this evening supporting a fairly divergent
environment across the far western SW North Atlc waters this
evening. Scattered showers and tstms are occurring generally N of
25N W of 79W...including interior portions of Florida...
Georgia...and the Carolinas. Otherwise...a pair of 1020 mb highs
centered near 25N72W and 31N70W are providing for fair conditions
this evening. Farther east...an upper level low is centered near
24N54W and supports a stationary front extending from 32N53W SW to
27N60W to 26N67W. While isolated showers are occurring within 60
nm either side of the boundary...upper level divergence between
the upper level low and an upper level anticyclone centered near
31N62W is generating an area of scattered showers and isolated
tstms from 19N-27N between 55W-65W. Lastly...Hurricane Irma
remains on the southern periphery of a ridge anchored by a 1029 mb
high centered E of the Azores near 39N24W.

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

$$
HUFFMAN
This weather bulletin was brought to you by:
www.nashvilleweather.net