000 AXNT20 KNHC 082357 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 757 PM EDT Mon May 8 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...TROPICAL WAVES... A tropical wave is over the central tropical Atlantic with axis extending from 01N38W to 09N35W, moving westward at 15 to 20 kt. CIRA LPW imagery show moderate to high moisture in the wave low level environment, however it is embedded in an unfavorable wind shear environment, which is limiting the convection to isolated showers within 90 nm either side of its axis. A tropical wave is over the western tropical Atlantic with axis extending from 01S54W to 10N53W, moving westward at 15 to 20 kt. This wave continue ill-defined. However, some signature remains in infrared satellite imagery and in model fields. Convection associated with this wave is inland South America. ...ITCZ/MONSOON TROUGH... The monsoon trough crosses the western African coast near 08N13W and extends to 06N16W. The ITCZ begins near 06N16W and continues along 02N26W to 01N36W, then resumes west of a tropical wave near 00N40W and extends to the South American coast near 01S46W. Aside from convection associated with the tropical wave, scattered moderate convection is from 02S-07N between 24W-30W. Numerous strong convection is off the coast of Liberia with embedded scattered tstms from 04N-07N between 10W-12W. ...DISCUSSION... GULF OF MEXICO... Fair weather and very stable conditions prevail across the basin being supported by middle to upper level ridging and surface high pressure being anchored by a 1018 mb high centered off the Florida Panhandle coast near 29N86W. Water vapor and CIRA LPW imagery show dry air nearly basin-wide, which is allowing for clear skies. Except for east of 87W where winds are from the N-NE, moderate return flow dominates elsewhere. Except for a thermal surface trough projected for the Bay of Campeche the next three days, surface ridging will prevail elsewhere. CARIBBEAN SEA... A middle to upper level trough over the W Atlc extends S to a base over the Central Caribbean. East of it, middle to upper level ridging generates a diffluent wind environment that along with shallow moisture across the region support scattered to isolated showers E of 80W. A surface pre-frontal trough is over Hispaniola where heavier showers and isolated tstms are observed. Showers will continue for the north-central and northeast Caribbean through Wednesday as the front N of the area moves east-southeast along with the surface trough. ...HISPANIOLA... Scattered showers and isolated tstms continue over the island due mostly to prefrontal activity. This activity is forecast to continue through Wednesday. ATLANTIC OCEAN... Former cold front in the SW N Atlc has stalled from 30N64W to 24N68W to 22N70W. A diffluent environment between the upper trough that support the front and ridging to the right continue to support scattered moderate convection N of 20N between 58W and 68W. This front is forecast to transition back to a cold front tonight. A weakening cold front is on the NE Atlc extending from 30N20W to 22N34W lacking significant convection. This second front is forecast to dissipate within 24 hours. The remainder basin is being dominated by surface ridging and fair weather conditions. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos