Tropical Weather Discussion
Issued by NWS
AXNT20 KNHC 200520
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
120 AM EDT Thu Apr 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
As of 20/0300 UTC, the center of Subtropical Depression ONE is
near 33.2N 39.3W. The subtropical depression is moving north at
10 knots. The estimated minimum central pressure is 996 mb. The
maximum sustained wind speeds are 30 knots with gusts to 40 knots.
Scattered moderate convection prevails north of 30N between 30W-
41W. Please read the PUBLIC ADVISORIES about Subtropical
Depression ONE under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC for
more details. FORECAST/ADVISORIES about Subtropical Depression ONE
are issued under the AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC.
The Monsoon Trough extends across the western Africa coast from
09N14W to 04N17W. The Intertropical Convergence Zone continues
from 04N17W to 02N36W to the South American coast near 02S43W.
Scattered moderate convection is from 02S-05N between 15W-37W.
GULF OF MEXICO...
Broad surface ridging prevails across the Gulf of Mexico. An
upper-level low is centered over the western Gulf near 21N92W.
Upper-level diffluence to the east of the low is supporting
scattered showers over the Yucatan Peninsula and channel mainly
south of 23N between 84W-90W. Scatterometer data depicts gentle to
moderate easterly winds across the basin. Expect over the next 24
hours for little change over the surface pattern, while in the
upper levels the low over the western Gulf will drift east to the
south central portion of the basin.
Gentle to moderate tradewinds prevail over most of the Caribbean
Sea with the exception of the central portion of the basin
between 69W-74W where moderate to fresh winds were reported. These
winds are also affecting the Windward Passage. A diffluent flow
prevails across the western Caribbean supporting scattered
showers mainly west of 75W. Scattered moderate convection is
observed over portions of Central America in the proximity of a
surface trough that extends over the EPAC. Portions of Costa
Rica and Panama are affected by this activity as well as their
adjacent waters south of 12N between 80W-84W. Expect little
change over the next 24 hours.
Abundant cloudiness and isolated showers are over the island at
this time. Expect over the next 24 hours for scattered showers to
advect over the island from the east with the tradewind flow.
Also, expect scattered moderate convection to form due to local
The Subtropical Depression One is over the central Atlantic.
Please refer to the section above for details. A broad surface
ridge is over the west Atlantic. A cold front extends from 31N49W
to 27N54W to 31N72W with isolated showers. Further east, a 1017 mb
surface high is centered near 25N26W. Scatterometer data depicts
fresh to strong northerly winds mainly north of 27N between 33W-
57W. Another area of fresh easterly winds prevails across the
Bahama Islands south of 24N between 72W-80W. Expect over the next
24 hours for the Subtropical Depression to move N while dissipating.
Little change is expected elsewhere.
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