000 AXNT20 KNHC 221030 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 630 AM EDT Mon May 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. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...TROPICAL WAVES... A tropical wave came off the west African coast earlier this morning. The wave axis extends from 12N18W to 04N18W and is embedded in a neutral to favorable wind shear environment and abundant low level moisture is present according to CIRA LPW imagery. Water vapor imagery show the way is under a col or divergent environment aloft that supports scattered moderate convection from 04N-15N between 16W-24W. A tropical wave is in the central Atlantic with axis extending from 12N35W to 04N36W, moving west at 10 kt within the last 24 hours. The wave is in a region of unfavorable wind shear and most of the wave environment is covered by Saharan dry air and dust, which is hindering convection at the time. A tropical wave is in the central Caribbean with axis extending from 18N67W to inland Venezuela near 11N69W, moving west at 15-20 kt within the last 24 hours. Similar to the wave in the central Atlantic, the wave environment is characterized by unfavorable wind shear, which support the lack of deep convection at the time. ...ITCZ/MONSOON TROUGH... The Monsoon Trough enters the tropical Atlantic near 09N13W and continues to 07N16W. The ITCZ extends from 06N23W to 05N33W, then resumes west of a tropical wave at 06N38W to the coast of Guyana near 07N58W. Scattered moderate convection is from 03N-07N between 07W-14W and from 04N-13N between 43W-60W. ...DISCUSSION... GULF OF MEXICO... Mosaic Doppler Radar and satellite imagery show numerous heavy showers and tstms are in the north-central and northwest Gulf ahead of a stationary front that extends along the coast of Texas. Moisture inflow from the Caribbean by SE wind flow and upper level diffluence between a ridge covering the western Gulf and the trough that support the front support this convection N of 23N W of 90W. Gusty winds to near 30 kt are seen per buoy observations near the convective activity over the NW Gulf. A thermal trough is over the Bay of Campeche extending 24N92W to 17N93W lacking convection, however it supports fresh E-SE winds within 90 nm off the western Yucatan Peninsula. Otherwise, scatterometer data show mainly gentle to moderate return flow in the basin, except for the NE gulf where variable gentle to light winds are observed. The front will continue to stall through tonight when it will transition to a weak cold front to merge with a stronger cold front that will exit the coast of Texas early Wednesday morning. CARIBBEAN SEA... Convection in the SW Caribbean has significantly reduced due in part to unfavorable wind shear across the region, however upper level divergence prevails and along with shallow moisture support scattered to isolated showers S of 12N and within 90 nm off the coast of Nicaragua. The pressure gradient between strong high pressure in the Atlantic and lower pressure across the southern basin continue to support fresh to strong winds off the Colombia coast S of 13.5N between 70W and 76W. Latest scatterometer data indicate the presence of moderate trades across the remainder basin and fresh easterlies in the Gulf of Honduras. Otherwise, a tropical wave lacking convection is entering the central Caribbean. For further details see the tropical waves section. The wave will move into the SW Caribbean Monday night and Tuesday while a new tropical wave enters the eastern basin Wednesday. ...HISPANIOLA... Daytime heating, local sea breezes and mountain upslope lifting will combine with available moisture to produce scattered showers and isolated thunderstorms mainly during the afternoon and early evening hours the next two days. ...ATLANTIC OCEAN... Surface high pressure prevails in the SW N Atlc being anchored by a 1021 mb high near 30N70W that is forecast dissipate tonight. In the central Atlc, a surface trough extends from 26N52W to 20N63W. Isolated showers are within 60 nm either side of the trough N of 25N. A broad surface ridge covers the remainder central and eastern Atlc with the center of high pressure being located near 28N31W, which is forecast to dissipate tonight. A cold front will enter the north central Atlc waters this evening. Otherwise, surface high pressure will dominate elsewhere. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos