000 AXNT20 KNHC 052319 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 619 PM EST Sun Mar 5 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... ...Caribbean Gale Warning... A strong pressure gradient between a high pressure anchored across the southeast CONUS and lower pressure analyzed across northwestern South America will support near-gale to gale force winds each night and early morning within about 90 nm of the northwest coast of Colombia. These conditions will continue through Wednesday night. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...Florida Straits/Windward Passage Gale Warning... Strong high pressure is centered across the southeast CONUS and continues to build in across the Florida Straits region behind a cold front analyzed from 26N56W to the eastern coast of Cuba near 21N74W. Near-gale to gale-force east winds will continue across the Straits and are expected to persist through early Monday. As the front moves east of the Windward Passage region by tonight into early Monday...near-gale to gale-force northeast winds are expected through the Windward Passage and adjacent Caribbean Sea waters. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 07N12W to 00N23W. The Intertropical Convergence Zone extends from 02N23W to 03S42W. Isolated showers are observed within 100 nm on either side of the ITCZ mainly west of 35W. ...DISCUSSION... GULF OF MEXICO... A mid to upper-level shortwave trough is noted on water vapor imagery over the west Gulf waters and eastern Texas. While no lower-level or surface feature has materialized across this area, isolated showers are occurring between 88W-94W. Elsewhere, the southwestern periphery of a surface ridge prevails across the remainder of the basin anchored by a 1039 mb high centered across Virginia and North Carolina. Fresh to strong easterly winds are prevailing across the basin except over the Florida Straits (see section above for details). These conditions will to continue through Monday. Winds will gradually diminish through early Tuesday from west to east as the high center moves eastward into the west Atlantic region. CARIBBEAN SEA... Aside from the near-gale to gale-force winds forecast off the coast of Colombia during the next few days, the Caribbean is under the influence of dry and stable air aloft, along with fairly tranquil conditions at the surface. A few quick-moving isolated showers are possible across the Lesser Antilles, Puerto Rico, and Hispaniola as low level moisture continues to be transported by the fresh to strong trades. These conditions are expected to prevail through early Friday. The high pressure will be anchored across the west Atlantic region for much of the week ahead. ...HISPANIOLA... Water vapor imagery depicts strong subsidence over the island with west-southwesterly flow aloft. Low-level moisture transported by trade wind flow is supporting isolated showers this afternoon across the island and adjacent coastal waters. A cold front lies to the N along 21N/22N and will reach the island by tonight increasing the northeast winds into fresh to strong levels. These winds are forecast to persist through Wednesday night. ATLANTIC OCEAN... A cold front extends across the west/central Atlantic from 31N50W to 20N74W. A strong high pressure is building in the wake of the front centered over the North Carolina/Virginia boundary. The pressure gradient in the area is strong enough to support gale- force winds currently occurring across the Florida Straits area and soon to begin in the Windward Passage. Refer to the section above for details. To the east of the cold front, a pre-frontal trough extends from 25N57W to 20N63W. No significant convection is related to the trough at this time. The remainder of the basin is under the influence of a surface ridge anchored by a 1028 mb high centered near 34N22W. South of this feature, an upper-level low is reflected at the surface as a trough that extends from 28N29W to 22N30W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA