[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 122339
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT MON SEP 12 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 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...SPECIAL FEATURES...

Tropical Storm Ian is centered near 22.9N 50.7W at 12/2100 UTC
or about 940 nm east-southeast of Bermuda moving north-northwest
at 11 kt. Estimated minimum central pressure is 1007 mb.
Maximum sustained wind speed is 35 kt with gusts to 45 kt.
Please see the latest NHC forecast/advisory under AWIPS/WMO
headers MIATCMAT5/ WTNT25 KNHC for more details. Numerous strong
convection is within 60 nm of a line from 25N47W to 23N49W.
Scattered moderate to strong convection covers the remainder of
the area from 22N-27N between 45W-52W.

...TROPICAL WAVES...

Tropical wave in the east Tropical Atlantic extends from 21N24W
along 16N26W to 10N26W moving west-northwest near 10 kt over the
past 24 hours. Wave coincides with a 700 mb trough based on the
global models and is embedded within a high amplitude surge of
moisture as seen on the Total Precipitable Water Imagery. Small
clusters of scattered moderate to isolated strong convection are
within 280 nm east of the wave.

Tropical wave in the central Tropical Atlantic extends along
35W/36W from 6N-13N moving west 10 to 15 kt over the past 24
hours. Wave is to the west of a 700 mb low based on the global
models and is embedded within a low amplitude surge of moisture
as seen on the Total Precipitable Water Imagery. No associated
deep convection.

Tropical wave, previously associated with Tropical Storm Ian,
extends from 16N52W to 9N55W moving west near 10 kt over the
past 24 hours. Wave coincides with a 700 mb trough based on the
global models and is embedded within a surge of moisture that
trails from Tropical Storm Ian, as seen on the Total
Precipitable Water Imagery. No associated deep convection.

Tropical wave in the Caribbean extends along 88W/89W south of
20N across Central America continuing into the east Pacific
region moving west near 10 kt. This wave is moving over the
Yucatan and Central America and is not producing any shower
activity in the Caribbean waters.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends across Africa into the east Tropical
Atlantic near 17N16W and continues along 15N22W 8N37W to 8N40W.
The remainder of the monsoon trough and the ITCZ are being
disrupted by Tropical Storm Ian. Clusters of scattered moderate
to isolated strong convection are from 8N-13N between 17W-21W,
from 6N-11N between 25W-33W, and from 4N-9N between 38W-44W.

...DISCUSSION...

...GULF OF MEXICO...

A broad upper trough over the eastern CONUS dips south over the
Gulf of Mexico supporting surface trough that extends from
29N90W along 26N89W to a 1013 mb low near 24N87W. Scattered to
numerous showers and isolated thunderstorms are within 180 nm
east and 120 nm west of the surface trough. An upper ridge is
anchored over Mexico extending a ridge axis across the northwest
Caribbean then across west Cuba into the west Atlantic. Isolated
showers and thunderstorms are south of 25N between 82W-86W and
south of 22N between 86W-91W. Afternoon scattered showers and
isolated thunderstorms that developed inland over the Florida
peninsula are moving into the Gulf coastal waters. This is
leaving the west Gulf with fair weather this evening. A weak
surface ridge extends from over the southeast CONUS into the
northwest Gulf of Mexico anchored a 1025 mb high over
Pennsylvania. The upper trough will weaken through Tuesday night
as the surface trough drifts west-northwest through Wednesday
night.

...CARIBBEAN SEA...

An upper ridge anchored over Mexico covers the west Caribbean
west of 80W. A cutoff upper low is centered south of Haiti near
16N73W covering the central Caribbean. A second upper ridge,
associated with Tropical Storm Ian extends across the west
Tropical Atlantic over the Windward Islands to northeast
Colombia. This is creating a diffluent environment across the
west Caribbean to generate clusters of scattered showers and
isolated thunderstorms north of 16N to over the Greater Antilles
west of 74W including Cuba, Jamaica, and into the Yucatan
peninsula and Channel. Afternoon showers and thunderstorms have
developed inland over central Hispaniola. The monsoon trough
extends from a 1011 mb low along the coast of Colombia near
11N74W then along 10N78W then across Nicaragua into the east
Pacific region near 12N84W generating scattered showers and
isolated thunderstorms south of 12N to inland over Colombia
between 73W-76W and south of 11N to over Panama and Costa Rica
between 78W-83W. The tropical wave will exit the Caribbean basin
overnight tonight.

...HISPANIOLA...

Afternoon scattered showers and isolated thunderstorms have
developed over the central portion of the island this evening.
The cutoff upper low will persist through midweek. This could
continue to bring showers and thunderstorms to the island,
especially in the afternoon and evening hours through Wednesday.

...ATLANTIC OCEAN...

An upper ridge axis extends from the northwest Caribbean across
Cuba along 26N79W to beyond 32N76W. Beneath this upper ridge is
a newly developed 1011 mb low at 12/2100 UTC near 26N79W with a
surface trough extending from 28N78W through the low to 24N78W.
An elongated narrow upper low is centered near 27N58W then
extends an upper trough through 22N74W to the Turks and Caicos.
Difflunce between these upper features is generating scattered
showers and isolated thunderstorms from 24N-31N west of 75W to
over the Florida peninsula. The remainder of the Atlantic, west
of 55W, east of 45W, and north of Tropical Storm Ian is
dominated by a surface ridge anchored by a 1021 mb high in the
west Atlantic near 33N72W and a 1021 mb high near 31N42W. The
surface trough over the Bahamas will move west-northwest through
the remainder of the Bahamas then over Florida through Tuesday
night. The surface ridge over the west Atlantic will persist
through the end of the week.

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

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