[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251806
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 PM EDT Sat Jul 25 2020

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 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...SPECIAL FEATURES...

Hurricane Hanna is centered near 27.0N 96.7W at 25/1800 UTC,
or 45 nm ENE of Port Mansfield Texas moving W at 6 kt. Minimum
central pressure is 977 mb. Maximum sustained wind speed is 70
kt with gusts to 85 kt. Numerous moderate to strong convection
is noted within 120 nm of the center in the N semicircle and 210
nm southern semicircle. Doppler radar shows an eye diameter of
about 25 nm. A recent observation from a buoy northeast of Hanna
indicated seas are over 20 ft. Hanna could intensify more before
it makes landfall on the coast of southern Texas late this
afternoon. Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and
Forecast/Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more
details.

Tropical Depression Gonzalo is centered near 10.8N 61.9W at
25/1800 UTC or 45 nm NW of Trinidad moving W at 17 kt. Estimated
minimum central pressure is 1010 mb. Maximum sustained wind
speed is 30 kt with gusts to 40 kt. Scattered moderate to
isolated strong convection is observed within 150 nm of the
center in the western semicircle and 45 nm eastern semicircle.
Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and
Forecast/Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for more details.

...TROPICAL WAVES...

An active Atlantic Ocean tropical wave is along 29W from 21N
southward, moving W at 15-20 kt. Some gradual development of
this  system is possible early net week, and a tropical
depression could form in the western tropical Atlantic Ocean
before it reaches the Lesser Antilles. Numerous moderate to
isolated strong convection is from 07N-12N between 24W-37W.

An Atlantic Ocean tropical wave is along 48W from 21N southward,
moving W at 15-20 kt. Isolated moderate convection is within 180
nm of the wave axis from 04N-08N.

A Caribbean Sea tropical wave is along 78W from 21N southward,
moving W at 15-20 kt. Scattered moderate to strong convection is
from 10N-16N between 75W-81W.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of Senegal
near 14N17W to 11N30W to 10N46W. The ITCZ is from 09N51W to
09N57W. Scattered moderate convection is from 08N-14N between
15W-20W.

GULF OF MEXICO...

Outside of the immediate impact area of TS Hanna, generally
moderate SE winds persist across the Gulf. A recent ASCAT pass
shows that winds over 25 kt associated with Hanna were confined
to areas west of 92W and north of 23N, as of 25/1430 UTC. Seas
are less than 6 ft east of 92W. Seas are also less than 6 ft for
areas west of 92W south of 24N. An area of scattered moderate
showers and tstorms is seen from 26N-31N between 87W-91W.

Hurricane Hanna will make landfall along the south Texas coast
late this afternoon. Conditions over the Gulf waters near Texas
will gradually improve Sunday morning. Tropical storm force
winds should end for the Gulf waters by late Sunday morning,
with winds down to 25 kt Sunday afternoon. Seas to 22 ft today
will diminish to 15 ft Sun morning, and to 8 ft by late Sun
afternoon. The pressure gradient between Hanna and a ridge
across the remainder of the Gulf waters will support fresh to
strong SE winds over the western Gulf through Mon.

CARIBBEAN SEA...

Upper level cyclonic wind flow covers the central Caribbean, and
anticyclonic outflow, associated with Hurricane Hanna in the
Gulf of Mexico, covers the NW corner of the basin. Scattered
showers and isolated tstorms are evident near the east coast of
the Yucatan Peninsula, with isolated showers and tstorms south
of Cuba near Jamaica and the Cayman Islands. Scattered moderate
showers and tstorms that may be somewhat associated with T.D.
Gonzalo have streamed out well to the west of Gonzalo's
circulation. This precipitation covers the basin south of 15N
and east of 72W. A recent ASCAT pass shows fresh trades from the
central Caribbean eastward, with moderate trades over the W
Caribbean.

Tropical Depression Gonzalo is forecast to reach near 11N64W
this evening. It should dissipate into an open tropical wave
by late Sunday before it reaches the central Caribbean. The
wave will then continue westward, with strong winds and
enhanced showers. The tropical wave currently along 29W has
a medium chance of developing into a tropical depression by
the middle of next week before it reaches the Lesser Antilles.

ATLANTIC OCEAN...

An upper-level low is centered over the NW and central Bahamas.
The low has a very weak surface reflection to the east, where a
surface trough is analyzed from 29N74W to 23N76W. Numerous
moderate isolated strong convection is seen from 23N-27N between
73W-77W. A broad ridge of high pressure, anticyclonic wind flow
and mostly fair weather span the Atlantic Ocean, north of 24N
and east of 65W.

A ridge will dominate the forecast area, supporting fresh to
occasionally strong winds near Hispaniola and the Windward
Passage at night through Sun. The pressure gradient between the
Atlantic ridge and T.S. Gonzalo currently affecting the Windward
Islands will support fresh to locally strong easterly winds E of
65W through tonight.

$$
Hagen
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