AXNT20 KNHC 250534
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
134 AM EDT SUN SEP 25 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 0000 UTC surface analysis and satellite imagery through
Tropical Storm Karl is centered near 35.0N 58.0W at 25/0300 UTC
or about 378 nm east-northeast of Bermuda, moving northeast at 25 kt.
Estimated minimum central pressure is 992 mb. Maximum sustained
wind speed is 55 kt with gusts to 65 kt. Scattered to numerous
strong convection prevails north of 34N between 50W-58W. Please
see the latest NHC Forecast/ Advisory under AWIPS/WMO headers
MIATCMAT2/WTNT22 KNHC for more details.
Post-Tropical Cyclone Lisa is located at 25/0300 UTC near 25.8N
40.8W at 24/2100 UTC or about 1108 nm northwest of the Cabo Verde
Islands moving northwest at 11 kt. Estimated minimum central
pressure is 1011 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.
A tropical wave in the east Tropical Atlantic extends its axis from
14N33W to 04N33W, moving west near 20 kt over the past 24 hours.
This wave coincides with a 700 mb trough noted in model guidance
and is embedded within a surge of moisture as seen in TPW
imagery. No associated deep convection is noted.
A tropical wave in the west-central Tropical Atlantic extends its
axis from 21N57W to 12N57W, moving west near 15 kt over the past
24 hours. The wave coincides with a 700 mb trough depicted in
model guidance and is embedded within an surge of moderate moisture
as seen in TPW imagery. No associated deep convection is
associated to this feature at this time.
A tropical wave extends from the southern portion of Mexico into
the EPAC waters from 19N95W to 09N96W. This wave is moving west at
about 5-10 kt over the past 24 hours. A 700 mb trough is depicted
by global guidance near this area and abundant moisture is noted
in TPW imagery. Isolated moderate convection prevails in the
wave's environment mainly between 94W-101W.
The Monsoon Trough extends across Africa into the east Tropical
Atlantic near 14N17W to 07N33W to 07N40W. The ITCZ begins near
07N40W to 07N50W to 10N61W. Scattered moderate convection is
06N-11N between 34W-41W.
GULF OF MEXICO...
An upper-level low centered over south Alabama extends its trough
across the eastern Gulf waters east of 90W. At the surface; a
surface ridge extends across the basin anchored by a 1017 mb high
near 28N86W. A thermal surface trough is moving across the Bay of
Campeche from 22N90W to 17N92W. Scattered moderate convection is
observed along this trough and in its vicinity between 89W-94W.
Scatterometer data depicts a gentle to moderate anticyclonic flow
prevailing over the Gulf waters. Expect for the surface ridge to
prevail across the basin within the next 24 hours. A weak cold
front will reach the northwest Gulf by late Monday, then stall
and dissipate in the northern Gulf by Tuesday.
A diffluent flow aloft is supporting cloudiness and a shower
activity across the western Caribbean mainly west of 80W. The
Monsoon Trough extends along 10N between 76W-83W supporting
scattered moderate convection over the southern Caribbean waters.
A 1010 mb surface low centered near 09N79W accompanies the trough
with convection. Scatterometer data depicts moderate to fresh
trades across the basin except south of 15N between 68W-75W where
fresh to strong winds prevail. Little change is expected within
the next 24 hours. A tropical wave will approach from the east
with isolated showers affecting the Lesser Antilles by late Sunday.
Isolated showers prevail across the island at this time. Northerly
flow aloft will persist across the island providing moisture and
coupled with the easterly trade winds will enhance afternoon/evening
showers and thunderstorms through the Tuesday.
Karl, Lisa, and two tropical waves are moving across the basin.
Please refer to the section above for details. A stationary 1018
surface high is located north of the Bahamas near 28N77W. To the
east; a surface trough extends from 21N68W to 30N59W. Isolated
convection is observed along this boundary. The remainder of the
basin is under the influence of a surface ridge anchored by a pair
of 1027 mb highs centered near 32N30W and 38N25W. Expect for Karl
to continue moving northeast becoming a hurricane by Sunday.
Lisa is expected to continue moving northwestward while weakening.
A cold front drop south into the central Atlantic on Monday
enhancing convection, then becoming stationary by Tuesday.
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