AXNT20 KNHC 171030
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
630 AM EDT Tue Sep 17 2019
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 0600 UTC surface analysis and satellite imagery through
Hurricane Humberto is centered near 30.6N 74.3W at 17/0600 UTC or
495 nm W of Bermuda moving ENE at 7 kt. Estimated minimum central
pressure is 966 mb. Maximum sustained wind speed is 80 kt with
gusts to 100 kt. Numerous strong convection is from 29N- 32N
between 73W-76W. Scattered moderate convection is seen stretching
down to the Bahamas, from 23N-34N between 70W-73W. Humberto is
expected to gradually increase forward speed through early
Thursday. On the forecast track, the center of Humberto is
expected to approach Bermuda Wednesday night. Some strengthening
is forecast during the next 36 hours and Humberto is expected to
become a major hurricane by Tuesday night or Wednesday morning.
Please read the latest NHC forecast/advisory under AWIPS/WMO
headers MIATCMAT4/WTNT24 KNHC, or at the website hurricanes.gov
for more details.
A 1009 mb surface low is centered near 13N44W or about 870 nm E
of the Lesser Antilles. A tropical wave extends from 02N-19N along
the low. Scattered moderate to isolated strong convection is from
11N- 14N between 43W-46W. This system has changed little in
organization since yesterday, but conditions are still expected to
be conducive for the formation of a tropical depression during the
next day or so while the system moves slowly northwestward to
west-northwestward. There is a high chance of tropical cyclone
formation within the next 48 hours.
An eastern Atlantic tropical wave with axis along 32W S of 18N, moving
W at 10 kt. Scattered moderate to isolated strong convection is
noted from 13N- 16N between 30W-34W. Scattered showers and
thunderstorms are also seen near the wave from 04N- 06N between
See section above for information on the tropical wave along 43W.
An eastern Caribbean tropical wave with axis along 68W S of 19N,
moving W at 20 kt. Scattered moderate convection is seen in the
northern portion of the wave from 14N-19N between 66W-68W.
A central Caribbean tropical wave with axis along 77W S of 17N,
moving W at 15 kt. Scattered thunderstorms are noted over the
northern portion of the wave, affecting Jamaica and adjacent
The monsoon trough extends from the coast of Mauritania near 18N16W
to 13N28W to the low near 13N44W to 08N50W. The ITCZ begins near
08N50W to the coast of Guyana near 07N59W. Aside from the
convection already discussed in the Tropical Waves section above,
scattered showers and thunderstorms are in the vicinity of the
monsoon trough and the eastern portion of the ITCZ between 14W-
GULF OF MEXICO...
A 1009 mb low is located in the NW Gulf of Mexico near 28N96W
with a trough extending along the low from 23N96W to 30N94W.
Scattered moderate convection is noted near the low from 26N- 30N
between 93W- 97W. Some slight development is possible before the
system moves inland along the northwestern Gulf coast Tuesday
night. Regardless of development, this system is expected to
produce locally heavy rainfall and possible flash flooding along
portions of the central and upper Texas coastal areas later this
week. This system has a low chance of development in the next 48
Numerous strong convection is seen moving along the southern Bay
of Campeche, S of 19N between 93W-94W. Scattered showers with
isolated thunderstorms are also seen in the eastern Bay of
Campeche near the Yucatan coast from 19N-21N and E of 92W. There
is also a trough analyzed along 92W. Upper level ridging is seen
in the eastern basin with a 1014 mb surface high near 29N86W.
Latest scatterometer data depicts light winds across the basin,
and gentle to moderate winds near the low pressure area in the NW
Weak surface low pressure off the coast of Texas will move inland
through late today. High pressure will build over the north
central Gulf tonight, supporting gentle to moderate winds through
mid week, except for moderate to fresh winds off the west coast of
Yucatan at night. The high pressure will dissipate later in the
week in advance of a weak cold front that is forecast to move
across the eastern Gulf of Mexico then stall and dissipate over
the southeast Gulf Friday into Saturday. Fresh winds and building
seas will follow the front over the eastern Gulf Friday into
Refer to the Tropical Waves section above for details on the two
tropical waves currently over the Caribbean.
Scattered showers and thunderstorms are seen moving across the
Lesser Antilles from 10N-17N between 60W-65W. Additionally,
isolated thunderstorms are moving across the NW Caribbean from
16N-21N between 79W-89W. Numerous strong convection is moving off
the Colombian coast, enhanced by the eastern Pacific monsoon
trough, from 09N- 11N and E of 77W. Latest scatterometer data
depicts light to gentle trades across the basin, with moderate to
fresh winds are noted in the Gulf of Honduras and the Gulf of
Moderate to fresh trade winds will dominate much of the basin.
Long period northerly swell will starting pushing through the
Atlantic Ocean passages today. A tropical wave over the western
Caribbean Sea will move west of the basin through mid week.
Scattered thunderstorms and gusty winds accompany a second
tropical wave currently in the eastern Caribbean that will move
across the central Caribbean Sea Wednesday and Thursday, and
through the western Caribbean Sea Friday and Saturday. A low
pressure center developing east of the area will move toward the
Atlantic Ocean offshore waters of the Leeward Islands by late
Thursday and Friday, possibly as a tropical cyclone.
Refer to the sections above for details on Hurricane Humberto and
the tropical waves moving across the basin.
A 1019 mb surface high is over the central Atlantic near 30N51W.
Scattered thunderstorms are also seen in the central Atlantic from
27N-31N between 57W-60W. To the east, a cold front enters the
discussion area near 31N31W to 29N34W, then stalls from 29N34W to
25N53W. Scattered showers are noted along the front.
Northerly swell will follow across the open waters in the wake of
Humberto. Looking ahead, a low pressure center developing
tropical Atlantic will move toward waters off the Leeward Islands
by late Thursday and Friday, then north of the Virgin Islands by
Saturday, possibly as a tropical cyclone.