000 AXNT20 KNHC 050521 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 121 AM EDT Thu Jul 5 2018 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...SPECIAL FEATURES... A tropical wave extends along 38W from 03N-15N with a small area of low pressure located near 10.5N38W. Satellite images indicate that the shower activity associated with these features remains well organized, and a tropical depression could form at any time soon. This disturbance is forecast to move westward or west- northwestward at 15 to 20 mph over the tropical Atlantic Ocean. However, in a few days, the upper-level winds are forecast to become unfavorable, and the system is expected to degenerate into a trough of low pressure before it approaches the Lesser Antilles. Currently, the Tropical Weather Outlook gives this system a high chance of tropical cyclone formation through 48 hours. A recent scatterometer pass indicates fresh to strong winds in the NW quadrant of the low center. ...TROPICAL WAVES... Another tropical wave is along 46W from 03N-15N. This wave shows up well in the moisture product and is surrounding by African dust. Isolated moderate convection is noted where the wave encounters the ITCZ. A tropical wave is moving across the central Caribbean. Its axis is along 71W, and extends from Hispaniola to near Lake Maracaibo in western Venezuela. Convection is limited near the wave's axis with only isolated showers and tstms. This system will reach the western Caribbean Thu and move west of the area by Sat. A tropical wave is approaching the Yucatan Peninsula. Its axis is along 87W crossing the Gulf of Honduras and northern central America. A cluster of moderate to isolated strong convection is behind the wave's axis over Nicaragua and NE Honduras. Scattered showers with embedded tstms are noted over the remainder of Nicaragua and parts of Costa Rica. This wave is forecast to move west of the area tonight. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through the W coast of Africa near 13N17W then continues to 09N35W. The ITCZ extends from 07N39W to 06N56W. Aside from the convection associated with the tropical waves, scattered moderate convection is seen from 05N-10N between 22W-30W, and from 02N-07N between 33W-45W. ...DISCUSSION... GULF OF MEXICO... Scattered showers and tstms are noted over Florida and the eastern Gulf, particularly N of 24N E of 91W. This convective activity is the result of a surface trough, interacting with an upper-level trough that extends from the NE Gulf to the central Bay of Campeche. Convection has also flared-up over the Yucatan Peninsula just ahead of the trough aloft. The surface trough has moved from the Florida Peninsula into the eastern Gulf. A recent ASCAT pass shows the trough axis along 84W. The trough will move westward across the northern Gulf waters, reaching the Texas coast Fri night. Plenty of moisture will remain in place across the northern Gulf, and the Gulf Coast States in association with this trough through Fri. this will keep the likelihood of showers and tstms mainly during the afternoon and evening hours. A thermal trough will move westward off the Yucatan Peninsula each evening, and enhance nocturnal winds over the SW Gulf through Sun. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean Sea. Please, see the TROPICAL WAVES section for details. Recent scatterometer data provide observations of fresh to strong winds across the east and central Caribbean while an altimeter pass indicates seas near to 11 ft across the Caribbean waters S of Haiti. Gentle to moderate winds are over the NW Caribbean, including the Yucatan Channel. Fresh to strong trades are expected across much of the area S of 18N and E of 83W through at least Fri. Winds will reach near gale force near the coast of Colombia, mainly at night through Fri night. ATLANTIC OCEAN... Showers and thunderstorms located a few hundred miles to the SW of Bermuda are associated with a weak trough of low pressure. This system appears to be less organized, and the potential for a tropical depression to form is diminishing. However, environmental conditions are still conducive for some development before the end of the week, while the system moves west- northwestward and then northward between Bermuda and the east coast of the United States. The disturbance is then forecast to interact with a frontal system on Sunday, which should limit any additional development. This system has now a low chance of tropical cyclone development based on latest Tropical Weather Outlook. Two tropical waves are between the coast of west Africa and the Lesser Antilles. Please, see the TROPICAL WAVES section for details. The remainder of the Atlantic forecast area is under the influence of ridge anchored by a 1031 mb high pressure centered W of the Azores near 36N36W. Moderate to fresh trades are noted along the southern periphery of the ridge. As the high pressure builds westward across the western Atlantic through the weekend, winds N of Hispaniola will pulse to strong each afternoon and evening the remainder of the week. For additional information please visit http://www.hurricanes.gov/marine $$ GR