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000
AXNT20 KNHC 242357 AAA
TWDAT

Tropical Weather Discussion...update to Karl
NWS National Hurricane Center Miami FL
805 PM EDT SAT SEP 24 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 Karl is centered near 33.6N 61.1W at 24/2100 UTC
or about 200 nm east-northeast Bermuda and 865 nm south-
southwest of Cape Race, Newfoundland moving east-northeast at 20
kt. Estimated minimum central pressure is 994 mb. Maximum
sustained wind speed is 55 kt with gusts to 65 kt. Scattered to
numerous strong convection is within 60 nm of a line from 34N60W
to 37N58W with scattered moderate to isolated strong convection
covering the remainder of the area from 33N-38N between 56W-62W.
Please see the latest NHC Forecast/ Advisory under AWIPS/WMO
headers MIATCMAT2/WTNT22 KNHC for more details.

Tropical Storm Lisa was downgraded to Tropical Depression at
24/2100 UTC. Tropical Depression Lisa is centered near 25.3N
39.7W at 24/2100 UTC or about 1000 nm southwest of the Azores
and 1045 nm northwest of the Capo Verde Islands moving northwest
at 10 kt. Estimated minimum central pressure is 1010 mb. Maximum
sustained wind speed is 30 kt with gusts to 40 kt. Lisa is void
of any deep convection. Please see the latest NHC Forecast/
Advisory under AWIPS/WMO headers MIATCMAT3/ WTNT23 KNHC for more
details.

...TROPICAL WAVES...

Tropical wave in the east Tropical Atlantic extends along 29W
from 5N-14N moving west near 20 kt over the past 24 hours. Wave
coincides with a broad 700 mb global model trough and is
embedded within a low amplitude surge of moisture as seen on the
Total Perceptible Water imagery. No associated deep convection
is noted.

Tropical wave in the west Tropical Atlantic extends along 56W/
57W from 11N-21N moving west-northwest near 15 kt over the past
24 hours. Wave coincides with a broad 700 mb global model trough
and is embedded within an isolated surge of moisture as seen on
the Total Perceptible Water imagery. No associated deep
convection is noted. Scattered showers and isolated
thunderstorms are from 18N-21N between 52W-55W.

Tropical wave in the south Gulf of Mexico extends along 95W
south of 20N across south Mexico into the east Pacific region
moving west 5 to 10 kt over the past 24 hours. Wave coincides
with a 700 mb global model trough and is embedded within an area
of moisture as seen on the Total Perceptible Water imagery. No
associated deep convection is noted.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends across Africa into the east Tropical
Atlantic near 14N17W then along 8N27W to 7N38W where the ITCZ
begins and continues along 7N44W 11N56W to over Trinidad.
Clusters of scattered moderate to isolated strong convection are
from 6N-10N between 31W-39W. Clusters of scattered moderate
convection are within 60 nm along the coast of west Africa from
10N-13N, from 4N-7N east of 20W to the coast of Africa, and from
10N-17N between 47W-51W.

...DISCUSSION...

GULF OF MEXICO...

An upper ridge extends from the Caribbean across south Mexico
into the Bay of Campeche near 18N93W to over Texas near Corpus
Christi. An upper low centered over south Alabama extends an
upper trough southeast across the Florida peninsula into the
southwest Atlantic. This is combining to give the Guff westerly
flow aloft. Scattered to numerous showers and isolated
thunderstorms are within 90 nm of a line from 26N90W to inland
over Texas near 29N95W. A weak surface trough in the west
Atlantic extends off the east coast of Florida to along the
Florida Keys generating scattered showers and isolated
thunderstorms inland and from 24N-26N between 80W-83W. A surface
trough inland over the Yucatan peninsula is generating scattered
showers and isolated thunderstorms within 60 nm along the coast
of the Yucatan between 86W-92W. Isolated showers and possible
isolated thunderstorms dot the area across the south/central
Gulf from 22N-25N between 83W-96W. A weak surface ridge covers
the Gulf anchored by a 1018 mb high off the coast of Florida
near 29N85W. Weak high pressure will prevail across the
northeast Gulf through the weekend. A weak cold front will reach
the northwest Gulf Monday night, then stall and dissipate in the
north Gulf through Tuesday night.

CARIBBEAN SEA...

An upper ridge is anchored in the southwest Caribbean near
13N82W and extends an upper ridge axis across Central America
and south Mexico then into the Gulf of Mexico. An upper low is
centered over the Mona Passage near 18N68W extending an upper
trough axis southeast to the Leeward Islands. The remainder of
the Caribbean is dominated by westerly flow aloft. The monsoon
trough extends from over Colombia near 9N76W through a weak 1011
mb low over Panama near 9N79W to across Costa Rica near 10N84W
continuing into the east Pacific region. Scattered showers and
isolated thunderstorms are south of 12N between Colombia and
south Nicaragua. Afternoon showers and thunderstorms have
developed inland over Puerto Rico, Hispaniola, Jamaica, and Cuba
again this evening. Isolated showers and thunderstorms are over
the northwest Caribbean from 17N-22N west of 84W to over the
Yucatan peninsula and includes the Yucatan Channel. Surface
ridge over the west Atlantic will give the south/central
Caribbean moderate to fresh trade winds through Wednesday. A
tropical wave enter the east Caribbean Sunday.

...HISPANIOLA...

Currently scattered showers and isolated thunderstorms prevail
across the island again this evening. Northerly flow aloft will
persist across the island providing moisture and coupled with
the easterly trade winds will bring afternoon/evening showers
and thunderstorms through the Tuesday.

ATLANTIC OCEAN...

The upper low over south Alabama extends an upper trough across
the Florida peninsula near Tampa to Fort Lauderdale into the
southwest Atlantic to near Andros Island in the Bahamas. A
surface trough extends along the east coast of Florida from
31N81W along 27N80W to across south Florida near Fort Lauderdale
generating scattered showers and isolated thunderstorms within
45 nm east of the surface trough and west of the surface trough
to inland over Florida south of 29N. A second upper trough over
the west Atlantic extends along 72W inducing an upper ridge
between the upper troughs. This is responsible for the isolated
showers and thunderstorms within 90 nm of a line from 26N79W to
23N73W. A weak 1017 mb surface high is anchored near 27N75W. A
surface trough extends from southeast of Tropical Storm Karl
near 31N60W along 26N63W to 23N69W with scattered showers and
isolated thunderstorms within 90 nm of a line from 30N59W to
22N63W. The remainder of the Atlantic east of Karl and north of
Lisa is dominated by a surface ridge anchored by a 1025 mb high
near 32N29W. Tropical Storm Karl is expected to continue along a
northeast track becoming a hurricane Sunday afternoon. Tropical
Depression Lisa is expected to continue along a northwestward
track becoming a post-tropical/remnant low later tonight. A cold
front drop south into the central Atlantic Monday and Monday
night becoming stationary Tuesday.

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

$$
PAW