[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 052320
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
720 PM EDT Thu Oct 5 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.

...SPECIAL FEATURES...

Tropical Storm Nate is centered near 14.9N 84.3W at 05/2100 UTC
or about 35 nm west-northwest of Puerto Lempira Honduras, moving
north-northwest at 9 kt. Estimated minimum central pressure is
1000 mb. Maximum sustained wind speed is 35 kt with gusts to 45
kt. Scattered to numerous moderate and scattered strong convection
is from 11N-22N between 73W-86W. See the latest NHC Intermediate
Public Advisory under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC and
the full Advisory/Forecast under AWIPS/WMO headers
MIATCMAT1/WTNT21 KNHC for more details.

...TROPICAL WAVES...

A tropical wave extends its axis from 15N33W to 09N36W, moving
west at 10-15 kt. The wave has remained low-amplitude since
emerging off the African coast several days ago. An ASCAT pass
this morning indicated fresh to strong low-level cyclonic winds
focused around the wave's axis with strong to near gale force
southerly winds noted south of the ITCZ. Scattered moderate
convection is from 07N-14N between 28W-40W.

A tropical wave extends its axis from 18N41W to 09N48W, moving
west at 10-15 kt. The wave coincides with troughing at 700 mb
between 40W-50W. Isolated moderate convection is from 10N-14N
between 45W-53W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 08N13W to
07N18W. The ITCZ extends from 07N18W to 09N35W to 11N47W. Besides
the convection associated with the tropical waves, no significant
deep convection is occurring at this time.

...DISCUSSION...

GULF OF MEXICO...

North-northeasterly flow aloft persists over most the basin this
between an upper-level anticyclonic circulation centered over
northern Mexico and Texas, and an upper-level low centered over
the Yucatan peninsula with a sharp trough axis extending to the
Florida Big Bend region. The troughing supports a 1006 mb low
centered across the Florida Straits near 24N83W. A surface trough
extends to the south across western Cuba and to the northeast to
near central Florida and then into the west Atlantic. Scattered
moderate convection is observed along and south of the trough
affecting the central and southern portions of the Florida
Peninsula, the Florida Straits and Keys, and adjacent Gulf waters
south of 27N and east of 84W. The remainder of the basin is under
the influence of relatively drier northeasterly flow aloft and
fresh to strong easterly winds on the southern periphery of
surface ridging anchored across the southeast CONUS. The low and
associated trough are expected to move westward into central Gulf
waters by Friday with convective precipitation impacting much of
the Florida peninsula and eastern two-thirds of the Gulf through
Friday night into Saturday. By early Saturday, Tropical Storm
Nate is forecast to have emerged into the south-central Gulf
waters.

CARIBBEAN SEA...

The primary focus remains across the western Caribbean and
Central America is Tropical Storm Nate. Please refer to the
section above for details. In addition, a surface trough embedded
within a low pressure centered over the Florida Straits extends
across western Cuba into the Caribbean waters. This feature is
also enhancing convection across the area west of 80W. To the
east, a surface trough extends from the northern coast of Puerto
Rico near 18N66W to across the Atlantic waters providing focus for
scattered showers and thunderstorms across the island and adjacent
waters. This activity is supported aloft by an upper-level low
centered near 12N64W, and associated upper-level trough that
extends north to over Puerto Rico. Outside of the influence of
Tropical Storm Nate, moderate to occasional fresh trades prevail
east of 72W.

...HISPANIOLA...

Currently skies remain mostly fair across the island. Surface
troughing to the east is approaching the Mona Passage region and
an upper-level trough currently over Puerto Rico will introduce
scattered showers and thunderstorms late tonight into Friday to
the area.

ATLANTIC OCEAN...

South-southwesterly flow prevails over the west Atlantic with a
favorable upper-level divergent environment generally west of 70W
enhancing scattered to numerous showers and thunderstorms
occurring mainly north of 26N. This activity is focused east of a
surface trough analyzed across the Florida peninsula from
offshore of Jacksonville near 29N81W to 30N80W. To the east,
remnant energy from a weakened tropical wave is analyzed as a
surface trough extending from Puerto Rico near 19N67W to 26N61W.
Scattered showers and thunderstorms are occurring from 20N-24N
between 57W-65W. This activity links up with the western extent
of a stationary front that enters the discussion area near 32N38W
to 24N56W. Scattered showers and thunderstorms are occurring
within 150 nm either side of the front. Elsewhere, a broad
surface ridge anchored by a 1020 mb high centered near 24N30W
prevails across the eastern Atlantic.

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

$$

ERA
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