000 AXNT20 KNHC 040604 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT Wed Oct 4 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 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...SPECIAL FEATURES... A 1007 mb low in the SW Caribbean centered near 11N81W is showing signs of organization. Clusters of scattered moderate to isolated strong convection are within 90 nm of the low center. Environmental conditions are favorable for development, and this system is expected to become a tropical depression within the next two days. This disturbance should move north-northwest into the NW Caribbean Sea then reach the southern Gulf of Mexico by this weekend. This system will likely produce heavy rains over portions of Central America during the next few days. There is a high chance of tropical cyclone formation in the next 48 hours. A gale warning is in effect for the western Atlantic north of the Bahamas. Scatterometer data showed a large area of 25-30 kt winds east of the Florida peninsula, with a narrow band of winds more than 30 kt from 30N75W to the Florida coast near Melbourne. Expect frequent gusts to 35 kt through mid-day due to a tight pressure gradient. Frequent gusts to gale force are also expected in the NE Gulf of Mexico. Scatterometer data at 0325 UTC showed a large area of 25- 30 kt winds west of the Florida peninsula to near 88W. ...TROPICAL WAVES... A tropical wave in the central Atlantic extends from 17N35W to 08N38W moving W at 15-20 kt. The wave remains low amplitude and coincides with modest troughing at 700 mb. Satellite TPW imagery indicates this wave is embedded in an area of deep moisture. Scattered moderate isolated strong convection is from 09N-14N between 35W-40W. Scattered showers are elsewhere within 180 nm of the wave axis. A tropical wave in the E Caribbean extends from 23N61W to 09N62W moving W at 10-15 kt. The wave coincides with broad 700 mb troughing and continues to interact with an upper-level low centered near 16N61W. Divergent upper-level winds on the east side of the upper low are supporting widely scattered moderate convection over the Atlantic from 11N-22N between 57W-62W. A tropical wave in the W Caribbean extends from 23N81W to 12N83W moving W at 10-15 kt. The wave is moving into an area of strong northerly upper level winds associated with an anticyclone near 27N98W. Scattered moderate and isolated strong convection is from 16N-23N between 75W-81W. ...ITCZ/MONSOON TROUGH... The monsoon trough is along the African coast between 16W-18W. The Intertropical Convergence Zone axis extends from 09N18W to 08N49W to 11N60W. Besides the convection associated with the tropical waves, scattered moderate to isolated strong convection is along the coast of W Africa from 09N-13N between 40W-48W. ...DISCUSSION... GULF OF MEXICO... A gale warning for frequent gusts to 35 kt is in effect for the NE Gulf. See above. Surface ridging over the northern Gulf is creating a tight pressure gradient with 20-30 kt winds likely during the next 24 hours. A surface trough is over the SW Gulf of Mexico from 24N99W to 17N94W. Scattered moderate convection is within 90 nm of this trough. In the upper levels, a small upper level high is centered over the S Texas near 28N96W. A good amount of upper level moisture is along the Texas and Mexico coasts. Expect over the next 24 hours for convection with wind gusts to advect over S Florida. Also expect the surface trough to persist over the Bay of Campeche with convection. CARIBBEAN SEA... A tropical wave with an trailing low in the SW Caribbean has a high chance is tropical cyclone development. See above. In addition, the eastern extent of the E Pacific monsoon trough extends from S Guatemala to N Costa Rica to N Colombia. Scattered moderate to isolated strong convection is over all of Central America S of 20N. Otherwise, 10-20 kt tradewinds are over the Caribbean. ...HISPANIOLA... Hispaniola is between tropical waves. Skies remain mostly fair, with some showers are over the southern part of the island. ATLANTIC OCEAN... A gale warning is in effect east of Florida. A surface trough extends from the N Bahamas near 26N78W to central Cuba near 21N80W. Scattered moderate to strong convection is within 240 nm E of the trough axis. Squalls associated with the trough will produce locally heavy rainfall and strong gusty winds over portions of the Bahamas and southern Florida the next couple of days. Elsewhere, a stationary front extends from 30N50W to 26N74W. Widely scattered moderate convection is within 120 nm of the front. Broad surface ridging extends SW from a surface high centered over the Azores near 40N26W. The ridging dominates the Atlantic N of 22N and E of 45W. For additional information please visit http://www.hurricanes.gov/marine $$ Mundell