000 AXNT20 KNHC 201726 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 126 PM EDT Sat May 20 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 1715 UTC. ...TROPICAL WAVES... A tropical wave is in the eastern Atlantic with axis extending from 12N25W to 04N27W, moving west at around 10 kt. Based on current SAL analysis from UW-CIMSS, african dust surrounds the wave. As a result, only a few showers are noted near the wave axis. A tropical wave is approaching the Windward Islands. Its axis extends from 15N57W to Guyana near 06N58W, moving west at 10-15 kt. A few showers are noted near the wave axis south of 10N, including parts of northern Guyana. The TPW animation shows a surge of moisture in the wake of the wave axis. A tropical wave is reaching the coasts of the Yucatan Peninsula and Belize, and extends from 20N87W to 12N88W. The wave is moving west at around 15 kt within the last 24 hours. This system remains embedded within an area of deep layered moisture as depicted in the TPW animation. ...ITCZ/MONSOON TROUGH... The Monsoon Trough enters the tropical Atlantic near 08N13W and continues to 07N19W. The ITCZ extends from 07N19W to 07N25W, then resumes west of the above mentioned tropical wave from 06N29W to the coast of Brazil near 02N50W. Isolated moderate convection is noted from 05N-09N between 18W-23W, and within 120 nm north of the ITCZ axis between 30W-34W. ...DISCUSSION... GULF OF MEXICO... High pressure of 1022 mb located near Bermuda extends a ridge across Florida and the SE CONUS into the Gulf of Mexico. The pressure gradient between the ridge and lower pressures across Mexico and the far west Gulf waters supports moderate to fresh E to SE winds across most of the basin. Once again, areas of fog were noted over the NW Gulf under the influence of a SE wind flow. A diffluent pattern aloft is helping to induce some shower activity over the eastern Gulf, particularly from 25N-27.5N between 84W-88W. Fresh to locally strong easterly winds will pulse off the NW coast of the Yucatan Peninsula tonight and Sunday night in association with a thermal trough. This feature will develop during the evening hours over the Yucatan Peninsula before pushing into the SW Gulf each night. The ridge will persist through Sunday with little change in the weather pattern. A weak cold front is forecast to move off the Texas coast by Sunday night. The front will stall and dissipate over the northern Gulf through Tuesday. CARIBBEAN SEA... A tropical wave is approachimg the Windward Islands and a second tropical wave is leaving the basin. Please refer to the TROPICAL WAVE section above for details. High pressure located near Bermuda combined with the Colombian/Panamanian low is supporting fresh to strong trade winds over the east and central Caribbean while moderate to fresh SE winds prevail across the NW Caribbean. This weather pattern will persist on Sunday. Patches of low level moisture, embedded in the trade wind flow, are observed across the region, with the exception of clusters of strong convection over the SW Caribbean, mainly S of 10N. This convective activity is currently affecting parts of Colombia and eastern Panama under the influence of a monsoonal flow from the eastern Pacific. Upper diffluence is also helping to induce this convection. ...HISPANIOLA... Daytime heating, local sea breezes and mountain upslope lifting will combine with available moisture to produce some cloudiness with scattered showers and isolated thunderstorms mainly during the afternoon and early evening hours. ...ATLANTIC OCEAN... High pressure dominates most of the Atlantic Ocean. A 1022 mb high is located near Bermuda while another high pressure center of 1025 mb is near 28N35W. The latter one will remain nearly stationary over the next 24 hours. A surface trough extends from 23N58W to 18N63W. A recent scatterometer pass shows moderate to fresh SE winds on the east side of the trough axis. Scattered showers are also noted mainly ahead of the trough. This feature is ahead of an upper-level trough that extends from 31N57W to the Turks and Caicos Islands. Abundant mid-upper level moisture persists ahead of this upper-level trough forecast to drift eastward. For additional information please visit http://www.hurricanes.gov/marine $$ GR