Hurricane Center - Atlantic

Tropical Outlook

altantic tropical storm outlook
Atlantic Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Tuesday August 22 2017

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Satellite images indicate that an area of low pressure over
the Yucatan Peninsula, associated with the remnants of Harvey, has
become better defined during the day.  Environmental conditions are
conducive for development when the system moves over the Bay of
Campeche tonight, and a tropical depression is expected to form over
the southwestern Gulf of Mexico on Wednesday or Thursday, and move
in the general direction of the Texas coast on Friday.  Interests in
northeastern Mexico and along the Texas coast should monitor the
progress of this system, as it could produce storm surge and
tropical storm or hurricane force winds along portions of the Texas
coast, and very heavy rainfall across portions of central and
eastern Texas from Friday through the weekend. Please refer to
products from your local National Weather Service office for more
information on this system.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...near 100 percent.

A large area of disorganized showers and thunderstorms over the
Bahamas is associated with a trough of low pressure.  Any
development of this system during the next few days should be slow
to occur while it moves northwestward or northward near Florida and
the adjacent waters. Environmental conditions could become a little
more conducive for tropical or subtropical development by the
weekend when the system begins to move northeastward over the
western Atlantic.  Regardless of development, very heavy rain and
flooding is possible over portions of the Florida peninsula during
the next few days.  Please refer to products from your local
National Weather Service office for more information on this system.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...30 percent.

Forecaster: Eric Blake, National Hurricane Center

For detailed analysis see the Atlantic Tropical Weather Discussion.

Sea Temperatures

sea temperatures

sea temperatures north atlantic

sea temperatures south atlantic

Tropical Discussion

Atlantic Tropical Weather Discussion
...UPDATED NWS National Hurricane Center Miami FL
157 PM EDT Tuesday August 22 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.

Updated to include Gale Warning conditions in Special Features section

Based on 1200 UTC surface analysis and satellite imagery through 1615 UTC.

Active Storms
A tropical wave extends from 14N89W to 24N88W moving NW at 10-15 kt. The remnant circulation of Harvey continues to be analyzed as a 1010 mb low along the wave axis near 19N89W with scattered moderate convection occurring from 19N-24N between 84W-89W. Widely scattered moderate convection is elsewhere from 16N-27N between 84W-92W. The low pressure area along the wave is forecast to emerge off the coast of the Yucatan peninsula tonight with environmental conditions favorable for development across the SW Gulf of Mexico through Thursday. Largest impacts at this point will be the expected rainfall and strong convection today across the Yucatan peninsula and adjacent coastal waters through this evening. By Thursday...regardless of tropical cyclone development...gale force winds are expected across portions of the Gulf of Mexico waters from 21N-25N between 90W-94W. See latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC and the Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more details.

Tropical Waves / Developing Storms

A tropical wave extends from 15N31W to 24N27W moving W at 15-20 kt. The wave coincides with an amplified 700 mb between 23W-37W with a maximum in 850 mb relative vorticity to the immediate west of the wave axis that remains largely associated with a 1012 mb low centered near 15N32W. Scattered moderate convection is from 11N-16N between 25W-31W.

A tropical wave extends from 08N72W to 17N72W 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 across the central Atlantic waters. The wave is expected to move across the central Caribbean Sea and portions of Venezuela through tonight and across the SW Caribbean Sea on Wednesday. Scattered moderate convection is from 14N-17N between 69W-74W.

Monsoon Trough And Intertropical Convergence Zone - ITCZ
(The ITCZ is also known by sailors as the doldrums)
The monsoon trough extends from the African coast near 14N17W to 17N24W then resumes near 14N32W to 08N43W to 08N49W. The Intertropical Convergence Zone axis extends from 08N49W to 10N57W. Scattered moderate and isolated strong convection is from 06N-14N between 12W-20W. Widely scattered moderate convection is within 120 nm either side of a line from 11N31W to 06N39W to 06N46W.

Discussion: Gulf Of Mexico
An upper level low is centered over the western Gulf near 27N92W and continues to support isolated showers and tstms occurring primarily N of 23N between 87W-96W. Some of the convection within the southeastern periphery of this area begins to fall under the influence of a tropical wave and the remnant low of Harvey mentioned in the Special Features section above. The northern extent of the wave extends along 89W with the 1010 mb low centered across the Yucatan peninsula near 19N89W. Scattered showers and tstms are occurring S of 27N between 85W-91W in association with the wave. Otherwise...ridging to the N remains anchored across the SE CONUS with a 1019 mb high centered across the Lower Mississippi River valley. Light to moderate easterly winds prevail mainly N of 22N. This overall synoptic pattern is expected to persist until tonight when the Special Features low pressure area emerges off the coast of the Yucatan peninsula and into the SW Gulf waters where environmental conditions are favorable for development of a tropical cyclone later this week.

Discussion: Caribbean Sea
The Special Features tropical wave is mentioned above...however scattered showers and isolated tstms continue to impact the NW Caribbean and portions of Central America as the low pressure area analyzed along the wave axis moves NW into the Gulf of Mexico waters by tonight. Low-level convergence is maximized along a line from near 18N86W offshore of Honduras southward along coastal Nicaragua to 11N84W. Another tropical wave is across the central Caribbean and continues to support scattered showers and tstms from 14N-17N between 69W-74W. The wave is expected to reach Central America by Thursday. Otherwise...moderate to occasional fresh trades are expected through Thursday night.

Discussion: Hispaniola
A tropical wave continues to skirt south of the island this afternoon with convection remaining generally S of 17N at this time. Otherwise...skies are mostly clear with fair conditions expected through Wednesday as dry air and subsidence prevails aloft over the region.

Discussion: Atlantic Ocean
The SW North Atlantic is under the influence of a weak upper level low near 28N79W and an inverted upper level trough extending from the low to 23N78W. The troughing supports a surface trough extending from the Florida Straits near 24N81W to 30N77W with scattered showers and isolated tstms occurring from 21N-31N between 73W-81W...including the Bahamas and the adjacent coastal waters. Farther east...water vapor imagery indicates a middle to upper level trough progressing over the central North Atlantic waters in the vicinity of 38N61W supporting a cold front extending from 33N60W to 32N65W then stationary to the W-NW to 33N70W. Scattered showers and tstms are occurring N of 26N between 59W-66W and falls on the northwestern periphery of an upper level low centered near 26N58W. While the upper level low is enhancing convection south of the also supports a surface trough extending from 15N59W to 22N57W to 27N59W within the eastern periphery of the upper level feature. Scattered showers and tstms are occurring primarily E of the surface trough from 22N-30N between 51W-56W. Finally...a dissipating cold front bridges the subtropical ridge across the eastern Atlantic with the front extending from 32N31W to 28N37W to 29N43W. Isolated showers are possible within 60 nm either side of the front.

Forecaster: Marshall Huffman, National Hurricane Center