[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 162328
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
728 PM EDT Tue May 16 2017

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.

...TROPICAL WAVES...

A tropical wave is over the central tropical Atlantic with axis
extending from 07N31W to 01N32W, moving westward at 15 kt. The
wave has a subtle signal in satellite imagery, but still appears
in model diagnostics. Saharan dry air and dust in the wave
environment limits convection to isolated showers within 90 nm
either side of its axis.

A tropical wave is over the western tropical Atlantic with axis
extending from 09N52W to 00N51W, moving westward at 15 kt. The
wave continue to be difficult to locate in satellite imagery, but
still appears in model diagnostics. Unfavorable wind shear, dry
air and dust in the wave environment inhibits convection at this
time.

A tropical wave extends from the south-central Caribbean near
13N70W to inland Venezuela and eastern Colombia near 03N71W.
Unfavorable wind shear across this region of the Caribbean limits
convection to isolated showers S of 12N between 66W and 72W.

...ITCZ/MONSOON TROUGH...

The monsoon trough crosses the western African coast near 08N13W
to 06N21W. The ITCZ begins near 06N21W and extends to 03N29W,
then resumes west of a tropical wave near 03N34W to the Souith
American coast near 00N49W. Aside from the convection related to
the tropical waves, scattered showers are within 120 nm of the
ITCZ between 21W-30W.

...DISCUSSION...

GULF OF MEXICO...

As of 16/2100 UTC, a 1022 mb high is centered off the coast of
South Carolina near 33N72W. 10-15 kt E winds are over the E Gulf
of Mexico, while 20-25 kt SE winds are over the Gulf. Radar
imagery shows scattered showers over the SE Gulf, S Florida, and W
Cuba. The remainder of the Gulf has fair weather. In the upper
levels, an upper level ridge is over the W Gulf with axis
extending from Baton Rouge Louisiana to Tampico Mexico. An upper
level trough is over the E Gulf with axis from Fort Pierce Florida
to Roatan Honduras. Strong subsidence is over the entire Gulf.
Expect over the next 24 hours for scattered showers to persist
over the S Florida, the Straits of Florida, and W Cuba.

CARIBBEAN SEA...

As of 16/2100 UTC, a 1009 mb low is centered near the Cayman
Islands at 20N82W. A surface trough extends S from the low to
the SW Caribbean near 13N80W. Scattered showers are within 210 nm
E of the trough axis. Further S, the monsoon trough is over
Panama and Costa Rica with scattered moderate convection. 15 kt
tradewind flow is over the central and eastern Caribbean E of 78W.
In the upper levels, an upper level trough is over the W
Caribbean. Upper level diffluence E of the trough axis is
producing scattered moderate to isolated strong convection over
the central Caribbean between 71W- 77W. A tropical wave is over W
Venezuela and N Colombia producing showers. See above. Expect the
surface trough to remain over the W Caribbean for the next 24
hours with showers. Also expect the upper level trough to remain
quasi-stationary over the next three days. This will lead to the
continuation of showers for the north-central Caribbean.
Hispaniola, E Cuba and Jamaica will receive numerous showers with
the potential for flooding and mud slides.

HISPANIOLA...

Scattered showers are over most of Hispaniola mostly due to upper
level diffluence. Expect thunderstorms to form again during max
heating Tuesday afternoon and evening. The upper level diffluent
flow aloft will remain nearly stationary for the next three days,
thus there is a risk for flooding and mud slides.

ATLANTIC OCEAN...

A 1022 mb high is centered over the W Atlantic near 33N72W. A
cold front is over the W Atlantic from 31N59W to 26N70W. Widely
scattered moderate convection is within 240 nm SE of the front. A
1030 mb high is over the central Atlantic near 37N35W. A
dissipating cold front is over the E Atlantic from 31N25W to
26N33W. Scattered showers are within 60 nm of the front. In the
tropics two tropical waves are noted. See above. Of note in the
upper levels, upper level diffluence is over the W and Central
Atlantic enhancing convection from the S Bahamas to the Central
Atlantic. Likewise upper level diffluence is over the E Atlantic
producing scattered showers over the Canary Islands. Expect over
the next 24 hours for the W Atlantic front to move E with
continued convection. Also expect the W Atlantic front to fully
dissipate.

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

$$
Formosa
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