NWS National Hurricane Center Miami FL
1205 UTC Thu Sep 12 2024
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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.
Based on 0600 UTC surface analysis and satellite imagery through=20
0720 UTC.
...SPECIAL FEATURES...
Tropical Storm Francine is centered near 30.9N 90.1W at 12/0900
UTC or 50 nm N of New Orleans Louisiana, moving NE at 10 kt.
Estimated minimum central pressure is 992 mb. Maximum sustained
wind speed is 40 kt with gusts to 50 kt. While the system is=20
inland and weakening some remnant related seas remain over a=20
portion of the north-central Gulf waters, with seas up to 13 ft in
the SE quadrant near the coastal waters just southeast of SE=20
Louisiana per an in-situ observation BBXX. Some scattered moderate
convection is over water, north of 28N and east of 90W. A turn
toward the north-northeast and north is expected during the next=20
day or so, with some decrease in forward speed. On the forecast=20
track, the center of Francine will move over central and northern=20
portions of Mississippi through early Fri. Continued weakening is
forecast, and Francine is expected to become a tropical=20
depression this morning and degenerate to a post-tropical cyclone=20
today. Francine will continue to bring heavy rainfall and the=20
risk of flash and urban flooding, along with river flooding,=20
across portions of the Lower Mississippi Valley, Tennessee Valley,
and the Southeast. Locally considerable flash and urban flooding=20
is possible today and tonight over portions of central and=20
northern Alabama and the Florida Panhandle. Swells generated by=20
Francine ill continue to affect much of the northern Gulf coast=20
through today. These swells are likely to cause life-threatening=20
surf and rip current conditions. Please consult products from your
local weather office.
Tropical Depression Seven is centered near 17.3N 33.0W at
12/0900 UTC or 520 nm W of the Cabo Verde Islands, moving WNW at
15 kt. Estimated minimum central pressure is 1007 mb. Maximum
sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are
currently around 11 ft. Scattered moderate convection is noted=20
within 45 nm in the N semicircle, and 90 nm in the S semicircle,=20
as well as in bands, between 90 nm and 240 nm in the E semicircle,
and between 120 nm and 600 nm in the SW quadrant. A west-
northwest to west motion at a slower forward speed is anticipated=20
over the next few days. Gradual strengthening is forecast during=20
the next 48 hours, and the depression could become a tropical=20
storm later today.
Please read the latest HIGH SEAS FORECAST issued by the National=20
Hurricane Center at website -=20
https://urldefense.com/v3/__https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml__=
;!!DZ3fjg!5eRqiJCniI6oGycZZncqhrUG6GM3ZeraCpwex1Pw0sBz9tb-gV0RLU522qlXKJdyR=
vtflDVrbA202FO5TecRxQZCAjI$ and the latest
Francine and Seven NHC Forecast/Advisory and Public Advisory at=20
https://urldefense.com/v3/__http://www.hurricanes.gov__;!!DZ3fjg!5eRqiJCniI=
6oGycZZncqhrUG6GM3ZeraCpwex1Pw0sBz9tb-gV0RLU522qlXKJdyRvtflDVrbA202FO5TecRr=
ud37gY$ for more details on both systems.
Eastern Atlantic Gale Warning: Meteo-France is forecasting gale-=20
force winds in their Agadir marine zone to end at 12/09 UTC with=20
accompanying seas of 9 to 12 ft. Refer to the Meteo-France High=20
Seas Warning listed on the website=20
https://urldefense.com/v3/__https://wwmiws.wmo.int/index.php/metareas/affic=
he/2__;!!DZ3fjg!5eRqiJCniI6oGycZZncqhrUG6GM3ZeraCpwex1Pw0sBz9tb-gV0RLU522ql=
XKJdyRvtflDVrbA202FO5TecR7uQq-10$ for more=20
details.
...TROPICAL WAVES...
A tropical wave is in the central Caribbean Sea near 71W from
central Hispaniola southward to NW Venezuela, moving westward at
around 10 kt. Some isolated showers and thunderstorms are noted
north of 15N between the wave and 76W, with deep convection also
noted over NW Venezuela west of the wave.
=20
A tropical wave is in the far NW Caribbean Sea and Gulf of
Honduras near 87W from just offshore Belize southward across
portions of Honduras and through the Gulf of Fonseca, moving
westward at around 10 kt. No deep convection is noted over the NW
Caribbean.
...MONSOON TROUGH/ITCZ...
The monsoon trough axis enters the Atlantic at the coast of Africa
from 15.5N17W to near the Cabo Verde Islands at 15.5N22W, then is
disrupted by Tropical Depression Seven and continues southwest of
Seven from 12N36W to low pressure, AL92, near 15.5N48.5W to low=20
pressure, AL93, near 15.5N55.5W. No ITCZ axis is analyzed in the=20
Atlantic Ocean. Other than the convection associated with Tropical
Depression Seven discussed above, and Atlantic Invests AL92 and=20
AL94 discussed above, no other deep convection is present near the
monsoon trough.
...GULF OF MEXICO...
Please refer to the Special Features section for information on
inland Tropical Storm Francine.
A front has retreated slightly northward over the NE Gulf
extending from northern Florida to along the Panhandle toward
Biloxi, Mississippi. Some nearby convection is present as
described with Francine. Weak troughing extends in the wake of
Francine from south-central Louisiana to near 22N94W. Gentle to
moderate winds are present away from the outer influence of
Francine with fresh to strong winds lingering north of 27N between
86W and 92W. Remnant seas of 8 to 12 ft are offshore SE Louisiana,
Mississippi and the western Florida Panhandle, with 4 to 7 ft seas
elsewhere north of 24N. Seas are 2 to 4 ft in W to NW swell
elsewhere.
For the forecast, Francine will weaken to a remnant low near
32.6N 89.8W this afternoon, move to 34.4N 90.1W Fri morning,=20
35.1N 90.3W Fri afternoon, and dissipate Sat morning. Remnant=20
outer winds and seas will diminish and subside over the Gulf=20
through tonight, with westerly swell impacting the eastern Gulf=20
through tonight. High pressure will become established over the=20
north-central Gulf this weekend, with rather tranquil conditions=20
expected throughout the basin.
...CARIBBEAN SEA...
Refer to the Tropical Waves section for information on a tropical
wave over the Gulf of Honduras and Central America, and another
tropical wave moving into the Central Caribbean.
A fairly weak pressure pattern persists across the basin with
mainly gentle to moderate winds. Seas are 2 to 4 ft in the central
and eastern Caribbean, and 1 to 3 ft elsewhere.
For the forecast, a tropical wave over the NW Caribbean and Gulf=20
of Honduras will exit the basin later today. Another tropical wave
extending from central Hispaniola to NW Venezuela will move=20
across the basin through the next few days. Moderate to locally=20
fresh winds will pulse at times offshore of eastern Honduras,=20
while moderate to locally fresh winds pulse in the south-central=20
Caribbean through the beginning of next week. Mainly gentle to=20
moderate trades will prevail otherwise. Slight to moderate seas=20
will prevail across the waters through the next several days.=20
...ATLANTIC OCEAN...
Please see the Special Features section for details on Tropical=20
Depression Seven in the far eastern Atlantic.
A front that has been lingering over portions of the SW N Atlantic
for many days did manage to make some southward progress early but
is stalling again from near 31N73W to near Cape Canaveral,
Florida. Early scatterometer data showed fresh to strong NE to E
winds with 6 to 8 ft seas north of the front. Widely scattered
showers and isolated thunderstorms are noted across much of the
waters north of 24N and west of 55W. More concentrated activity is
from 19N to 23N between 60W and 65W due to a mid to upper level
trough.=20
A weak low is analyzed near 30N52W with some showers around the
low. This low is helping to disrupt the typical Atlantic ridge
with mainly gentle to moderate winds found across the waters north
of 25N between 35W and the stalling front. Seas across these same
waters are mainly 3 to 5 ft, except higher closer to 35W and
closer to the front. Moderate to fresh trades are found from 15N
to 25N due to the influence of the ridge to the north and lower
pressures to the south, with seas of mainly 5 to 7 ft. Winds=20
north of 19N between the coast of Africa and 35W and moderate to=20
fresh, except fresh to strong north of 20N between Africa and 21W.
Seas are 6 to 9 ft there. Near and south of the Cabo Verde=20
Islands, weak ridging is developing in the wake of the formation=20
of Tropical Depression Seven with gentle to moderate winds and 4=20
to 6 ft seas.
To the south, two areas of low pressure continue to be analyzed
along the monsoon trough. The western low, Invest AL94, is located
near 15.5N55.5W at 1010 mb. This low has scattered moderate=20
convection within 60 nm of the low, mainly in the west semicircle.
Winds are around 20 kt with seas around 6 ft. The eastern low,=20
Invest AL92, is located near 15.5N48.5W at 1009 mb. Earlier=20
scatterometer data depicted that the low is opening up to a=20
trough, however some 20 to 25 kt winds and seas to 8 ft are found=20
on the north side. Scattered moderate convection is noted within=20
75 nm of the remnant center.
For the forecast west of 55W, a stationary front extending from=20
near Bermuda to 1012 mb low pressure near 30N72W to near Cape=20
Canaveral, Florida will linger through early morning with fresh to
locally strong winds and seas up to 8 ft north of it. Widely=20
scattered showers and isolated thunderstorms will prevail across=20
much of the waters north of 25N through at least today. The front=20
will retreat northward as a warm and stall along 31N through the=20
end of the week. In a few days, a non-tropical area of low=20
pressure could form along the residual frontal boundary.=20
Thereafter, some subtropical or tropical development is possible=20
during the early part of next week while the system drifts to the=20
north or northwest. This system has a low chance of tropical=20
cyclone formation through the next 7 days. Regardless of=20
development, increasing winds and building seas will impact the=20
waters near 31N by the end of the weekend into early next week.=20
Gentle to moderate winds and slight to moderate seas will prevail=20
otherwise.
$$
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