AXNT20 KNHC 241007

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
607 AM EDT Sat Jun 24 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 0600 UTC surface analysis and satellite imagery through 1000 UTC.


A tropical wave is in the E Atlc with axis extending from 17N28W to 05N29W, moving W at 15-20 kt within the last 24 hours. The wave is in a region of favorable to neutral wind shear. However, the CIRA LPW imagery show extensive dry air in the wave environment, which coincide with Meteosat enhanced imagery of Saharan dry air and dust. This is supporting lack of convection at the time.

A tropical wave is in the central Atlc with axis extending from 14N51W to 04N52W, moving W at 15-20 kt within the last 24 hours. The wave is in a region of favorable to neutral wind shear, is in a moderate moist environment with some patches of dry air according to CIRA LPW, and is under a region of upper level divergence. These factors support scattered showers and isolated tstms from 05N to 15N between 48W and 58W.

A tropical wave is in the E Caribbean with axis extending from 15N64W to inland Venezuela, moving west at 10-15 knots within the last 24 hours. The wave is in a region of favorable wind shear. However, extensive intrusion of Saharan dry air and dust in the wave environment hinder convection at the time.


The Monsoon Trough extends from 09N13W to 08N16W. The Intertropical Convergence Zone axis begins near 08N17W and continues to 06N27W, then resumes W of a tropical wave near 05N31W and continues along 03N40W to 05N50W. Aside from the convection associated with the tropical waves, scattered moderate convection is from 03S-07N between 33W-48W. Numerous heavy showers and scattered tstms are off the coast of Africa from 04N-12N E of 17W.



Stable weather conditions are almost basin-wide being supported by surface high pressure extending SW from the W Atlc and dry air subsidence from aloft as indicated by Water Vapor imagery. The ridge supports moderate to fresh E-SE winds across the basin, which are forecast to continue through Sunday. A middle to upper level low centered W of the Yucatan Peninsula is already supporting scattered heavy showers and tstms over the Bay of Campeche with possible gusty winds. The low will move W today and then NW towards Texas adjacent waters generating in its path heavy showers and tstms over the W Gulf this weekend. Otherwise, by tonight into Sunday...a weak frontal boundary is expected to impact the northern waters as it stalls along 30N and dissipates by Sunday night.


An upper level low centered over the E Bay of Campeche continue to support isolated showers over western Honduras and the NW Caribbean W of 85W. Heavy showers continue across Guatemala and Belize associated with a broad area of low pressure in the EPAC with high chances of becoming a tropical cyclone this weekend. A tropical wave is in the SE Caribbean, however lacking convection due to abundant Saharan dry air and dust in the region. The northern portion of this wave is analyzed as a surface trough across the Leeward Islands where it generates isolated showers. Otherwise, fresh to strong winds will continue in the south-central basin, increasing to near gale force on Sunday as the tropical wave moves into this area. Moderate to fresh trades are elsewhere. Little change is expected thereafter for the early portion of next week.


Mostly clear skies prevail across the island as surface ridging to the N across the SW North Atlc remains in place providing mostly fair weather conditions. However, a surface trough moving along the S-SW periphery of the Atlc surface ridge will bring moisture across the region, thus supporting showers across the Island Saturday and Sunday.


An upper level anticyclonic circulation is centered offshore of NE Florida that continues to support a 1021 mb high centered near 30N65W, which is forecast to dissipate tonight. Otherwise, the remainder of the central and eastern Atlc is under the influence of surface ridging anchored by a 1029 mb high centered N of the Azores near 39N27W. There are two tropical waves in the basin. See that section above for further details.

For additional information please visit http://www.hurricanes.gov/marine

$$ Ramos