Home


000
AXNT20 KNHC 010007
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT WED AUG 31 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...

Hurricane Gaston is centered near 35.6N 46.5W at 01/0000 UTC or
about 870 nm west of Faial Island in the central Azores and
about 950 nm west of Lajes Air Base in the Azores moving
northeast at 16 kt. Estimated minimum central pressure is 969
mb. Maximum sustained wind speed is 90 kt with gusts to 110 kt.
Scattered moderate to isolated strong convection is within 150
nm of the center in all quadrants. See latest NHC Forecast/
Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for
more details.

Tropical Storm Hermine is centered near 25.5N 87.4W at 01/0000
UTC or about 290 nm south-southwest of Apalachicola, Florida and
about 290 nm southwest of Tampa, Florida moving north-northeast
at 7 kt. Estimated minimum central pressure is 1001 mb. Maximum
sustained wind speed is 45 kt with gusts to 55 kt. Scattered to
numerous strong convection is within 30/45 nm of a line from
25N87W to 23N89W. Scattered moderate to isolated strong
convection covers the Gulf east of a line from Apalachicola,
Florida along 26N89W to 19N93W including portions of Florida,
Cuba and the Yucatan peninsula. See latest NHC Intermediate
Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC
and the full Forecast/Advisory under the AWIPS/WMO headers
MIATCMAT4/WTNT24 KNHC for more details.

Tropical Depression Eight is centered near 36.3N 71.9W at
31/2100 UTC or about 185 nm east-northeast of Cape Hatteras
North Carolina and 1050 nm west-southwest of Cape Race
Newfoundland moving northeast at 14 kt. Estimated minimum
central pressure is 1010 mb. Maximum sustained wind speed is 25
kt with gusts to 35 kt. Scattered moderate convection is sheared
to the northeast of the center, from 35N-37N between 70W-71W.
See latest NHC Intermediate Public Advisory under AWIPS/WMO
headers MIATCPAT3/WTNT33 KNHC and the full Forecast/Advisory
under the AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more
details.

...TROPICAL WAVES...

Tropical wave in the east Atlantic extends along 29W from 10N-
20N with a 1012 mb low along the wave near 13N29W. Wave and low
are moving west 10 to 15 kt over the past 24 hours. Wave
coincides with a well defined global model 700 mb trough and is
embedded within a surge of deep moisture as seen on the Total
Precipitable Water imagery. Scattered moderate to isolated
strong convection is within 90 nm of the low over the northwest
quadrant.

Tropical wave in the central Atlantic extends along 43W/44W from
8N-19N moving west at 15 to 20 kt over the past 24 hours. Wave
is embedded within a weak surge of moisture as seen on the Total
Precipitable Water imagery. No associated showers or deep
convection.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends across Africa into the east Tropical
Atlantic near 21N17W through the 1012 mb low along the wave near
13N29W 8N35W to 7N41W where the ITCZ begins and continues along
10N55W to South America near 9N61W. Scattered moderate to strong
convection is inland over west Africa from Guinea to Mauritania
and within 90 nm along the coast from 7N-11N and 75 nm along the
coast from 16N-21N. Clusters of scattered moderate to isolated
strong convection are within 120 nm south of the ITCZ between
47W-57W and within 210 nm north of the ITCZ between 48W-56W.

...DISCUSSION...

GULF OF MEXICO...

The primary concern this evening is Tropical Storm Hermine
moving through the Gulf of Mexico. See Special features above.
An upper low is in the west Gulf near 25N93W while an upper
ridge is over Mexico anchored near 24N103W. This is creating a
diffluent environment along the west Gulf coast to generate
scattered showers and isolated thunderstorms from 23N-27N west
of 95W. A large upper ridge covers the remainder of the Gulf as
well as the activity in the east Gulf being associated with
Tropical Storm Hermine. The current forecast track takes
Tropical Storm Hermina across the Florida panhandle near the Big
Bend Region late Thursday night then continues northeast inland
along the coastal plains of Georgia and the Carolinas.

CARIBBEAN SEA...

The upper ridge associated with Hermine covers the Caribbean
west of 75W with a second upper ridge anchored in the central
Atlantic covering the east Caribbean east of 67W. Wedge between
these upper ridges is an elongated upper low centered along the
north coast of Hispaniola near 20N71W and extends south into the
Caribbean waters. The northerly upper level flow over the west
Caribbean combined with the southerly surface flow is generating
isolated showers and thunderstorms dotting the west Caribbean
north of 14N west of 76W. The upper low is generating scattered
showers and isolated thunderstorms inland over Hispaniola west
of 71W. The easterly trade winds over the east Caribbean are
generating isolated showers and possible isolates thunderstorms
from 12N-16N east of 67W to over the Lesser Antilles. Fresh to
strong trade winds are across the south-central Caribbean
through Friday.

...HISPANIOLA...

An upper low remains along the north coast of Hispaniola near
20N71W with scattered showers and isolated thunderstorms west of
71W. The upper low will track westward becoming an open trough
through Friday. Afternoon/evening showers and thunderstorms
could develop across the island through Friday.

ATLANTIC OCEAN...

Hurricane Gaston moving through the north-central Atlantic and
Tropical Depression Eight moving off the coast of North Carolina
are the primary concerns for the Atlantic basin this evening.
See Special features above. Scattered to numerous showers and
isolated thunderstorms are northwest of a line from West Palm
Beach Florida to beyond 32N74W due to the outflow from Tropical
Storm Hermine in the Gulf of Mexico. An elongated upper trough
is in the east-central Atlantic extending from 15N55W to 32N4!
supporting a surface trough that extends from 22N52W to 16N53W.
This surface trough is along the leading edge of large area of
of Saharan dust and dry air that extends east to the coast of
Africa. this is limiting shower activity associated with this
surface trough as well as the two tropical waves. The remainder
of the Atlantic is dominated by a surface ridge that is anchored
by a 1028 mb high just south of the Azores and extends a ridge
axis through 32N35W south of Hurricane Gaston along 26N48W to a
1019 mb high near 25N61W continuing to 28N76W. Tropical Storm
Hermine is expected to track inland along the southeast CONUS
Friday and Saturday. This will generate strong southerly winds
off the northeast Florida coast with seas building to 10 ft
Thursday and Friday.

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

$$
PAW

Home