000 AXNT20 KNHC 221633 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1233 PM EDT Wed Mar 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 1200 UTC surface analysis and satellite imagery through 1515 UTC. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 07N12W to 02N22W. The Intertropical Convergence Zone axis extends from 02N22W to the Equator near 26W. Scattered moderate and isolated strong convection is S of 07N between 09W-20W. Scattered moderate convection is S of 03N between 20W-33W...and S of 02N between 40W-52W. ...DISCUSSION... GULF OF MEXICO... NW flow aloft prevails over the Gulf providing dry air and stable conditions that filter to the surface in the form of a ridge anchored by a 1021 mb high centered near 27N90W. The ridge extends eastward very narrowly across the southern Florida peninsula and Florida Keys into portions of the SW North Atlc. Gentle to moderate anticyclonic winds accompany the ridge as noted on recent ASCAT data. The high is forecast to remain nearly stationary across the central Gulf waters with little change in the overall wind pattern through late Wednesday night. By Thursday...the ridge will weaken slightly and merge NE with a eastern CONUS high pressure system. E-SE winds are forecast to increase into fresh to strong levels Thursday night into Friday as an area of low pressure develops across the Front Range and central Plains. CARIBBEAN SEA... Broad upper level troughing is noted on water vapor imagery over the NW Caribbean while southwesterly flow aloft to the east of the troughing prevails over the central and eastern Caribbean. Dry and stable air overall is providing for a lack of any significant deep convection and mostly tranquil surface conditions this afternoon. A few areas of isolated showers however are noted on satellite imagery across the far southwestern waters S of 17N W of 80W...including inland portions of Honduras...Nicaragua...and Costa Rica. A frontal boundary terminates N of Hispaniola near 20N72W and is providing isolated showers across the island adjacent coastal waters N of 17N between 70W-77W. Otherwise...moderate to occasional fresh trades prevail and are expected to persist through Thursday night. ...HISPANIOLA... The tail end of a warm front extends from the central Atlc near 23N62W SW to the northern coast of Hispaniola near 20N71W. Low- level moisture convergence associated with the front continues to provide focus for isolated showers generally N of 17N between 70W-77W...including portions of the adjacent coastal waters. The front is expected to gradually lift northward and become absorbed by a cold front expected to impact the SW North Atlc waters by Thursday. Any lingering remnant boundary or surface troughing will provide a slight probability of isolated shower activity through the remainder of the week. ATLANTIC OCEAN... Broad middle to upper level troughing is noted on water vapor imagery over the SW North Atlc generally W of 65W in response to a middle to upper level trough progressing over the NE CONUS. A shortwave mid-level trough is noted in the vicinity of 33N74W supporting a 1008 mb low centered near 34N75W. The associated cold front extends westward to the coast of South Carolina with scattered showers and tstms occurring N of 31N between 73W-76W. Farther east...another middle to upper level trough axis extends N of 32N along 42W over the central North Atlc. The associated cold front extends to 32N47W then becomes stationary into the discussion area SW to 23N62W then transitions into a warm front to the Turks and Caicos islands and the northern coast of Hispaniola near 20N71W. Scattered showers and isolated tstms are occurring N of 29N within 150 nm E of the front. Similar convection is occurring along and N of the warm front from 20N-25N between 63W-73W. Finally...the remainder of the eastern Atlc is under the influence of another surface ridge anchored by a 1035 mb high centered N of the Azores near 40N28W. A dissipating cold front extends across far NW Africa near 32N09W to 30N18W to 32N30W. Little sensible weather is occurring with this cold front. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN