Tropical Weather Discussion
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AXNT20 KNHC 200606

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 AM EDT Wed Sep 20 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 0000 UTC surface analysis and satellite imagery through
0545 UTC.


At 20/0600 UTC, major Hurricane Maria was located near 17.6N 65.1W
or about 15 nm west-southwest of Saint Croix, and 75 nm southeast
of San Juan, Puerto Rico. The present movement of Maria is west-
northwest at 9 kt. The estimated minimum central pressure is 910
mb. Maximum sustained winds are 145 kt with gusts to 175 kt, a
Category 5. Numerous strong convection is within 90 nm of the
center. Scattered moderate convection is elsewhere within 180 nm
of the center. The eye of Maria will cross Puerto Rico today
Wednesday, and pass just north of the northeast coast of the
Dominican Republic tonight and Thursday. Please see the latest
NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT5/WTNT35
KNHC for more details.

At 20/0600 UTC, Tropical Storm Jose was located about 175 nm
south of Nantucket Massachusetts near 38.2N 70.5W, moving
northeast at 8 kt. The estimated minimum central pressure is 973
mb. Maximum sustained winds are 60 kt with gusts to 75 kt.
Scattered moderate convection lays on the NW quadrant of the storm
from 37N to 41N between 70W and 73W. The center of Jose is
expected to pass well to the east of the New Jersey coast today,
and pass offshore of southeastern Massachusetts Thursday. Please
see the latest NHC Forecast/Advisory under AWIPS/WMO headers
MIATCMAT2/WTNT22 KNHC for more details.


A 1008 mb low in the central Atlc, or the remnants of former
tropical cyclone Lee, are located near 17N44W. Showers and
thunderstorms have increased near the low pressure area and gale-
force winds are already in the E quadrant of the low...within 75
nm of the center. Numerous moderate/isolated strong convection is
mainly to the north of the low from 16N to 20N between 41W and
45W. An increase in the organization of the deep convection would
result in the regeneration of Lee as it moves northward over the
central Atlantic Ocean. There is a medium chance for tropical
cyclone re-development within the next 48 hours.


A tropical wave is in the E Atlc with axis extending from 18N25W
to 06N26W, moving west at 20 kt. The wave is mainly within a
region of abundant low to middle level moisture as shown by CIRA
TPW imagery. However, enhanced IR imagery show intrusion of Saharan
dry air and dust to the W environment of the wave. This is
limiting the convection to scattered moderate from 07N to 14N
between 24W and 30W.

A tropical wave is over the western Caribbean with axis
extending from 21N85W to 09N86W, moving west at 20 kt. CIRA TPW
imagery indicates the presence of dry air in the wave environment
that along with strong subsidence from aloft, and strong vertical
wind shear support lack of convection in the far NW Caribbean W of


The monsoon trough extends southwest from the African coast near
13N17W to 10N27W to 07N34W. The ITCZ extends from 07N34W to 08N43W
to 08N50W. Aside from the convection associated with the tropical
wave, scattered moderate convection is from 04N to 10N between
30W and 40W.



Weak surface ridging prevails over the Gulf of Mexico basin with
light and variable winds over most of the basin with the
exception of moderate locally fresh SE winds within 90 nm of the
coast of Texas. Ridging aloft over the entire Gulf along with dry
air subsidence continue to support clear skies, except for
scattered showers and tstms over the E Bay of Campeche associated
with the proximity of a tropical wave that already moved over the
EPAC waters S of Mexico. Winds will shift from SE to E Thursday


Category 5 Hurricane Maria is moving across the northeast
Caribbean waters and is expected to reach southeastern Puerto Rico
this morning. The eye of Maria then will cross Puerto Rico during
the day, and pass just north of the northeast coast of the
Dominican Republic Wednesday night and Thursday. See the special
features section for further details. Low level wind convergence
east of a tropical wave in the western Caribbean is producing a
large area of scattered showers and isolated tstms in the SW
Caribbean from S of 15N W of 77W. Expect the wave to continue
moving west with convection mainly east-southeast of the wave
axis. Scatterometer data shows mainly light to gentle trade winds
west of 71W, with the remainder of the basin N of 15N experiencing
cyclonic winds associated with Hurricane Maria. Fresh to locally
strong winds are off the Nicaragua coast associated with the
aforementioned convection.


Isolated showers are in the Windward Passage and southern Haiti
adjacent waters. Mostly fair weather prevails across the island.
Weather conditions will deteriorate across the Island starting
Wed morning associated with the outer rainbands of Hurricane
Maria moving across Puerto Rico. These showers will increase as
the system moves WNW very close of the Island on Thu.


Please refer to Special Features section for more information on
Hurricanes Maria and recently downgraded Tropical Storm Jose.
There is a gale warning associated with the remnants of former
tropical cyclone Lee along with strong convection. See gale
warning section above. A surface trough over the central Atlantic
extends from 32N41W to 30N42W to 25N44W. Scattered moderate
convection is observed east of the trough north of 23N between
38W-44W. The remainder of the basin remains under the influence of
a broad surface ridge centered north of the area.

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