000 AXNT20 KNHC 161035 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 635 AM EDT Mon Oct 16 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 1015 UTC. ...SPECIAL FEATURES... A low pressure system located about 100 miles northeast of the Turks and Caicos Islands is gradually becoming better defined. Associated thunderstorm activity has increased and become a little better organized this morning, and gale-force winds have been occurring in squalls northeast of the center. Some development of this low will be possible during the next day or so while it moves generally northward over the western Atlantic. However, upper- level winds are expected to become unfavorable for tropical cyclone formation by late Tuesday, and the system is likely to merge with a front and become extratropical on Wednesday. There is a medium chance of tropical cyclone formation within 48 hours. As of 1500 UTC a cold front extends from the Florida Panhandle near 31N86W to the NW Gulf of Mexico near 26N94W to Tampico Mexico near 21N98W. The front will stall from Tampa Bay to the western half of the Bay of Campeche early Tue. A tight pressure gradient and cool dry air associated with the front will allow N winds funneling along the coast of Mexico to reach minimal gale force from Tampico to Veracruz Monday into late Tuesday, with seas reaching 8 to 14 ft. ...TROPICAL WAVES... A tropical wave is in the central Atlantic with axis extending from 15N46W to 04N48W, moving W at 20 kt. The wave is in an area of moderate moisture as noted on SSMI TPW imagery. The wave is in a distinct surface trough, and a weak 700 mb trough. Clusters of scattered moderate convection are from 08N-13N between 44W-50W. A tropical wave is over the central Atlantic with axis extending from 17N54W to 07N56W, moving W at 15 kt. The wave is in an area of moderate moisture as noted on SSMI TPW imagery. The wave is in a distinct surface trough, and a weak 700 mb trough. Scattered moderate convection is from 10N-15N between 51W-58W. A tropical wave is over the central Caribbean with axis extending from 21N73W to 10N74W, moving W at 15-20 kt. The wave is in an area of abundant moisture as noted on SSMI TPW imagery. The wave is in a distinct surface trough, and a distinct 700 mb trough. Isolated moderate convection is over Haiti, and S of Jamaica. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 12N16W to 11N23W. The Intertropical Convergence Zone axis extends from 11N23W to 07N33W to 08N47W. Aside from the convection associated with the tropical waves, widely scattered moderate convection is S of the monsoon trough from 05N-10N between 10W-20W. Widely scattered moderate convection is within 90 nm of the ITCZ between 33W-43W. ...DISCUSSION... GULF OF MEXICO... As of 1500 UTC, a cold front is over the N Gulf of Mexico extending from the Florida Panhandle to Tampico Mexico. See above. 20-30 kt north winds are north of the front. Scattered moderate to isolated strong convection is within 90 nm of the front. A surface trough is over the W Gulf from 26N91W to 21N91W. Scattered moderate to isolated strong convection is within 90 nm of the trough. In the upper levels, the base of a large trough is over Texas supporting the cold front. An upper level ridge is over the Gulf of Mexico with axis along 88W. Upper level diffluence E of the upper trough is enhancing the convection over the W Gulf. Gale force winds will develop between the front and the E coast of Mexico today. See special features above. Expect the cold front in 24 hours to extend from Tampa Florida to the western Bay of Campeche with convection. CARIBBEAN SEA... A tropical wave is over the central Caribbean. See above. The eastern extent of the E Pacific monsoon trough is over Costa Rica and Panama. Scattered moderate convection is over the SW Caribbean from 07N-11N between 76W-80W. Widely scattered moderate convection is along the coast of Nicaragua from 11N-14N between 80W-85W. Of note in the upper levels, a small upper level high is centered over the Windward Islands near 15N60W. Another small upper level high is centered over the Yucatan Peninsula near 18N88W. Expect the central Caribbean tropical wave to produce additional convection over the next 24 hours. ...HISPANIOLA... Presently isolated convection is over Haiti due to a tropical wave. Expect more scattered showers and isolated moderate convection over the next 24 hours, especially in the afternoon and evening hours. ATLANTIC OCEAN... A 1011 mb low is centered N of Hispaniola near 23N70W. A surface trough extends N from the low to 29N71W. Scattered moderate to strong convection is from 20N-27N between 65W-70W. See above. A 1029 mb high is centered over the central Atlantic near 35N43W. Elsewhere, the tail end of a cold front is producing scattered showers over the Canary Islands. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa