000 AXNT20 KNHC 101028 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 528 AM EST Fri Mar 10 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 1000 UTC. ...SPECIAL FEATURES... A strong pressure gradient will remain in place across the SW Caribbean Sea off the coast of Colombia through the early morning hours on Friday. Thereafter...winds are expected to diminish below gale force as the pressure gradient relaxes. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough axis extends from the African coast near 06N11W to 03N21W. The Intertropical Convergence Zone axis extends from 03N21W to 02N29W to the Equator near 36W. Isolated moderate convection is S of 04N between the Prime Meridian and 26W. Scattered moderate convection is S of 04N between 31W-52W. ...DISCUSSION... GULF OF MEXICO... While upper level ridging prevails over much of the Gulf basin this morning...mid-level energy embedded within weak shortwave troughing over the Rio Grande river valley and coastal Texas is supporting scattered showers and isolated tstms N of 22N W of 90W. Otherwise...the remainder of the basin is under the influence of a surface ridge anchored by a 1022 mb high centered in the NE Gulf near 28N85W. Mostly moderate E-SE winds are expected across the basin Friday with the next weak frontal boundary forecast to skirt the north-central and NE Gulf waters Friday night. Wind are expected to increase out of the N-NE briefly into moderate to fresh breeze levels through Saturday morning. High pressure will then once again influence the basin through the remainder of the weekend. CARIBBEAN SEA... Aside from the near gale to gale force conditions expected through the early morning hours on Friday off the coast of Colombia...two features continue to impact the basin. A surface trough is analyzed across the Gulf of Honduras region from 16N87W to 17N84W providing focus for isolated to widely scattered low-topped showers remaining generally S of 19N between 80W-90W...including interior portions of northern Nicaragua...Honduras...Belize...and Guatemala. Farther east...a shear line extends from the central Atlc to the Lesser Antilles near Dominica then E to 15N72W. Fresh to strong E winds are occurring N of the shear line in addition to isolated showers. Elsewhere moderate to fresh trades prevail and are expected to persist through Saturday. ...HISPANIOLA... Most isolated shower activity lies within the adjacent coastal waters S of the island in the vicinity of a shear line extending along 15N/16N E of 72W. Otherwise...skies are expected to be mostly clear with only a slight possibility of a passing isolated shower. ATLANTIC OCEAN... A broad middle to upper level trough is noted on water vapor imagery in the vicinity of 30N68W supporting a weakening cold front from 32N65W to 30N71W. The remainder of the SW North Atlc is under the influence of two ridges...one anchored by a 1022 mb high centered across the NE Gulf of Mexico near 28N85W and the other a 1028 mb high centered near 29N49W. The stronger ridge to the east across the central Atlc prevails across much of the area...however a shear line extends along 15N/16N W of 48W on the southern periphery of the ridge. Aside from fresh to strong E-NE winds occurring generally S of 22N between 35W-62W...isolated showers are noted within 150 nm either side of the shear line axis. Farther east...a middle to upper level low is centered near 28N30W and supports a 1014 mb low centered near 26N29W with a cold front extending from the low SW to 20N32W to 16N40W to the beginning of the shear line axis near 16N48W. Near gale to gale force conditions are expected to develop generally within 120 nm of the western semicircle of the low as it drifts southeastward and eventually dissipates by late Friday night. Scattered showers and isolated tstms are occurring from 25N-34N between 22W-32W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN