Atlantic Tropical Weather Discussion (Text)

AXNT20 KNHC 211659

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1259 PM EDT Mon Aug 21 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 1200 UTC surface analysis and satellite imagery through 
1615 UTC.

A tropical wave extends from 09N82W to 21N82W moving W-NW at 
15-20 kt. The remnant circulation of Harvey continues to be 
analyzed as a 1008 mb low along the wave axis near 16N82W with 
scattered to numerous moderate and scattered strong convection 
occurring from 15N-21N between 80W-87W. Scattered moderate
convection is elsewhere from 15N-22N between 79W-88W. Regardless 
of development...the wave will continue across the NW Caribbean 
Sea waters and portions of Central America through tonight into
early Tuesday morning and move across the Yucatan peninsula 
Tuesday. Largest impacts at this point will be the expected 
rainfall and strong convection the wave and low pressure area will
generate across interior portions of eastern Honduras... 
Guatemala...Belize...southern Mexico...and the Yucatan peninsula 
Monday night into Tuesday. In addition to the expected 
rainfall...a higher probability of flash flooding and mudslides 
will be an ongoing hazard across this region early in the week.

A tropical wave extends from 10N26W to 22N24W moving W at 15-20
kt. The wave coincides with an amplified 700 mb trough that has
emerged off the West Africa coast between 18W-31W with a maximum
in 850 mb relative vorticity along the wave axis. A 1010 mb low
precedes the wave centered near 13N29W. Scattered moderate
convection is noted from 12N-18N between 19W-23W...and within 90
nm either side of a line from 13N21W to 09N32W.

A tropical wave extends from 06N62W to 16N60W moving W at 20-25 
kt. The wave has continued a westward motion after energy
fractured to the N and is now associated with a surface trough and
upper level low in the vicinity of 25N53W. The wave is expected to
move across the Caribbean Sea and portions of Venezuela through
Tuesday increasing cloudiness and convective precipitation.
Currently no significant deep convection is occurring across the
eastern Caribbean Sea...however isolated showers are noted S of
17N between 61W-68W. 

A tropical wave extends from 11N93W to 20N83W moving W at 15-20 
kt. Most influence associated with the wave is located in the East
Pacific waters...however the wave is the focus for isolated
showers and tstms across the SW Gulf of Mexico S of 22N W of 94W.

The monsoon trough extends from the African coast near 10N29W to 
07N43W. The Intertropical Convergence Zone axis extends from
07N43W to 08N50W. Widely scattered moderate convection is from 
03N-09N between 33W-45W.


An upper level low is centered over the central Gulf near 26N89W 
and continues to support isolated showers and tstms occurring
primarily N of 22N between 83W-91W. Farther west across the
remainder of the basin...a weak surface trough has formed across
the SW Gulf analyzed from 20N95W to 25N97W. This troughing is
providing focus for isolated showers and tstms from 19N-26N
between 93W-98W. Otherwise...ridging to the N across the SE CONUS
is providing light to moderate easterly winds. This overall
snyoptic pattern is expected to persist until Tuesday night into
Wednesday when the special features low pressure area emerges off
the coast of the Yucatan peninsula and into the SW Gulf waters.

Two tropical waves continue moving across the basin this 
afternoon and are highlighted above. One of these waves is the 
special feature wave containing the remnant circulation of 
Harvey. Scattered to numerous showers and scattered strong tstms 
are occurring across the area from 15N-22N between 79W-88W. This 
wave will cross Central America through tonight and the reach the
Yucatan peninsula by late tonight into Tuesday morning. Farther
east...another tropical wave is analyzed across the Lesser
Antilles and portions of the far eastern Caribbean. Isolated
showers associated with this wave and inverted upper level 
troughing between 72W-75W are occurring generally between 61W-73W.
Finally...moderate to occasional fresh trades are expected through

Daytime heating...local sea breezes...and mountain upslope 
lifting will combine with an inverted upper level trough extending
from over the SE Bahamas to western Hispaniola and produce widely 
scattered showers and tstms across the island mainly during the 
afternoon and evening hours this afternoon. An approaching 
tropical wave currently along 62W is expected to skirt south of
the island on Tuesday night into Wednesday.

The SW North Atlc is under the influence of an inverted upper 
level trough extending from 28N77W to over the Windward Passage
region near 20N74W. The troughing supports a surface trough
extending from 23N74W to 29N71W with scattered showers and
isolated tstms occurring from 24N-30N between 69W-78W. 
Otherwise...the remainder of the SW North Atlc falls within the 
influence of a surface ridge anchored by a pair of 1024 mb highs 
centered near 31N65W and 32N72W. Farther east...an upper level low
is noted on water vapor imagery near 27N57W with a surface trough
analyzed from 18N54W to 26N50W. Scattered showers and tstms are
occurring from 21N-30N between 48W-55W.

For additional information please visit 


Standard version of this page

Alternate Formats
About Alternates - E-Mail Advisories - RSS Feeds

Cyclone Forecasts
Latest Advisory - Past Advisories - About Advisories

Marine Forecasts
Latest Products - About Marine Products

Tools & Data
Satellite Imagery - US Weather Radar - Aircraft Recon - Local Data Archive - Forecast Verification - Deadliest/Costliest/Most Intense

Learn About Hurricanes
Storm Names Wind Scale - Prepare - Climatology - NHC Glossary - NHC Acronyms - Frequently Asked Questions - AOML Hurricane-Research Division

About Us
About NHC - Mission/Vision - Other NCEP Centers - NHC Staff - Visitor Information - NHC Library

Contact Us

NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
Privacy Policy
About Us
Career Opportunities
Page last modified: Monday, 21-Aug-2017 16:59:43 UTC