ABNT20 KNHC 171705
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sat Aug 17 2019
For the North Atlantic...Caribbean Sea and the Gulf of Mexico:
A surface trough is producing a band of cloudiness and showers
extending from the northeast Gulf of Mexico northeastward across the
coasts of Georgia, South Carolina, and North Carolina. The shower
activity is currently most concentrated near a small area of low
pressure located along the trough near the South Carolina coast.
Tropical development of this system, if any, is likely to be slow as
the disturbance moves northeastward along the eastern coast of the
United States with increasing forward speed during the few days.
Regardless of development, the disturbance is forecast to produce
heavy rainfall along with a threat of flash flooding in that region.
Please see products from your local National Weather Service office
or the Weather Prediction Center's Excessive Rainfall Outlook for
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.
AXNT20 KNHC 171736
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
136 PM EDT Sat Aug 17 2019
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
An Atlantic Ocean tropical wave is along 27/28W, from 19N
southward, moving W around 15 kt. Numerous moderate to isolated
strong convection is from 05N-09N between 22W-36W.
A tropical wave is near the Lesser Antilles along 60/61W from
05N-18N moving W at 15-20 kt. Scattered moderate convection is
seen from 11N-15N between 55W-62W including over portions of the
Windward Islands. Expect enhanced showers and tstorms across the
Lesser Antilles and eastern Caribbean through the remainder of
A Caribbean Sea tropical wave is along 83W, from 21N southward,
moving W around 15 kt. Scattered moderate convection is within 30
nm W and 210 nm E of the wave axis from 10N-17N. The southern
portion of this convection is being enhanced by the East Pacific
monsoon trough. Expect the wave to produce enhanced rains over
Central America and the Yucatan Peninsula through early Sunday.
The monsoon trough passes through the coastal areas of Mauritania
near 17N16W to 09N29W to 08N40W. The ITCZ extends from 08N40W to
06N57W. Aside from the convection mentioned in the Tropical Waves
section, no other significant convection is seen.
GULF OF MEXICO...
Disorganized cloudiness and showers over the NE Gulf of Mexico
are associated with a weak surface trough. Some of this activity
may contain gusty winds causing locally rough seas. Scattered
showers and tstorms are seen north of 24N east of 90W to include
the Florida Big Bend area. Upper-level ridging covers the western
Gulf. However, scattered showers and isolated tstorms are found
within 90 nm of the Louisiana and upper Texas coasts. An E-W
stationary front just inland from the northern Gulf Coast over the
southeastern U.S. will continue to be a source of moisture that
will bring showers and tstorms to the northeastern Gulf through
the weekend. Moderate to fresh southwest winds are expected over
the NE Gulf through Sun evening.
A tropical wave over the western Caribbean will bring enhanced
showers and tstorms to the southern Gulf from east to west late
tonight through early Monday. Fresh to strong winds will pulse
over the western Yucatan Peninsula adjacent waters through Mon. A
stronger tropical wave will move from the western Caribbean Sea
to the south central Gulf on Wednesday, accompanied by ample deep
moisture. Otherwise, high pressure will build westward across the
area through Wed night.
Two tropical waves are affecting the Caribbean Sea. See the
Tropical Waves section above for details.
Scattered showers and isolated tstorms are noted across the
north-central Caribbean Sea north of 16N between Puerto Rico and
Jamaica, including Hispaniola. The moisture that is producing
this activity appears to be related to a surface trough over the
Atlantic that extends northward from 19N65W. The latest ASCAT
pass from late Saturday morning shows strong east to southeast
winds in the northwest Caribbean from 16N-21N between 84W-86W.
A tropical wave with axis near 83W will move across the rest of
the western Caribbean through this evening. The passage of the
wave along with high pressure north of the area will continue to
support fresh to strong winds over the southwest Caribbean through
tonight, and over the NW Caribbean through Sun. Fresh to strong
winds will resume over the south-central Caribbean on Sun evening
being supported by the passage of a tropical wave that is currently
located across the Lesser Antilles.
A surface trough located near the coasts of Georgia and southern
South Carolina is producing disorganized showers and tstorms.
Tropical development of this system, if any, is expected to be
slow to occur while it moves northeastward at 5 to 10 mph near the
coasts of Georgia, South Carolina, and North Carolina during the
next couple of days. There is a low chance of tropical cyclone
formation during the next 48 hours.
A surface trough extends from 31N63W to 20N65W. Scattered showers
and tstorms are seen from 25N-30N between 55W-65W. Isolated
showers and tstorms are elsewhere from 23N-31N between 54W-70W. A
surface trough from 29N37W to 22N35W is producing cloudiness and
possible isolated showers within 60 nm of the trough as it moves
westward. A 1025 mb surface high near 33N47W is producing surface
ridging across the remainder of the basin. In the eastern Atlantic
offshore Morocco and near the Canary Islands, strong to near gale
force NE winds are expected now through Monday.
The Atlantic ridge dominates the forecast area in the western
Atlantic. The ridge axis is forecast to lift northward by Mon
night. The trough from 31N63W to 20N65W will track westward across
the eastern and central forecast waters this weekend and over the
western part of the area Mon before moving inland across Florida
on Tue. The gradient between the high pressure and the tough will
maintain mainly gentle to moderate east to southeast winds north
of 22N, and moderate to fresh east winds south of 22N through most
of the forecast period. Fresh to locally strong winds will pulse
at night between the Turks and Caicos Islands and Hispaniola