marine weather discussion NWS National Hurricane Center Miami FL 328 am EST Thu Nov 27 2014
Marine weather discussion for the Gulf of Mexico...Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w...and the SW N Atlantic including the Bahamas.
...Gulf of Mexico...
Model preference: global model consensus
Latest observations indicate winds and seas subsiding rapidly across all but se portions of the basin as front has swept across straits and Gulf of Honduras and 1030 mb high centered over E Mexico ridges NE into Big Bend region. Recent ascat passes showed 20 kt of nly flow streaming through Yucatan Channel..while N of the ridge...wly winds 20-25 kt prevailed from se la ewd to offshore of Mobile Bay...and likely continue into wrn Panhandle waters attm. Seas are likely 6-9 ft se portions with possible Max to 10 ft in Yucatan Channel. Benign secondary frontal boundary to sweep se across N portions today with reinforcing high behind it to restrengthen pres gradient across se portions...while E half briefly lights up 20 to near 25 kt tonight as high shifts E across Gulf coasts states. Winds not expected to diminish below 25 kt in Yucatan Channel until Fri night. High to shift ewd through the weekend and offshore and into Atlc Sat night with ridging SW into Gulf maintaining moderate to fresh anticyclonic flow through Sun night...before easterlies dominate most of basin through first part of week. As high shifts into Atlc Sat evening-night...pres gradient directly to the S will freshen winds through straits and across se portions sun through Mon with seas building to 8 ft in straits during this time.
...Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w...
Model preference: GFS
Cold front has pushed into central Cuba and across the Gulf of Honduras with strong northerly winds driving all the way to the immediate coastal waters of central Honduras per recent ascat passes. In fact...03z ascat passes showed several vectors of gale force winds funneling between roatan and utila in the Bay Islands and am issuing Gale Warning for this area asap. GFS parallel has been hinting at small isolated spots to gale force this afternoon was secondary front sweeps across Gulf of Mexico and tightens gradient NW of frontal boundary...and will leave Gale Warning in effect through 06z tonight to account for this. Seas to build 10-14 ft per model output and some manual editing across this area. Gales may diminish this morning 6-9 hours before this secondary push but lack of obs does not give ME confidence to hoist gale up and down today.
Otherwise...no significant changes to recent guidance trends. Strong northerly winds will persist over the NW Caribbean behind the front through late Fri. Weakened ridging over the central Atlc however will keep relatively lighter winds over the remainder of the area into Sat. This pattern will start to reverse this weekend as high pres over the United States shifts E into the Atlc... allowing trade winds to increase from the tropical N Atlc through the central Caribbean....with Windward Passage and area Lee of Cuba to increase to 20-25 kt sun and Mon. The GFS has been suggesting nocturnal Max winds to gale off Colombia by early Mon as the high shifts directly N of the area...with only 30 kt in the UKMET and ECMWF. However...00z run of operational GFS now showing only 30 kt and only new parallel run of GFS indicating brief gales early Mon...and will hold winds there near 30 kt attm.
...SW N Atlantic S of 31n W of 55w including the Bahamas...
Model preference: global model consensus
Cold front progressing E and se across the area this morning...now extending from 31n71.5w to near mucc in central Cuba. Nwly flow behind front was strong N of 29n earlier tonight...but obs and recent ascat passes show winds generally 15-2- kt behind front...except offshore of extreme S Florida and across The Straits where nly winds area 20-25 kt. Elsewhere...Atlc ridge is retreating to the NE and weakening. However...llvl reflection of TUTT low near 22.5n49w is directly S of Atlc high and producing an area of 25-30 kt winds there 50-52w within a broader area of 20-25 kt stretched E to W across this area. Early evening altimeter pass showed seas 10-12 ft in the area just E of there...and Max seas just downstream likely 13-14 ft. This swell to move W across se waters Fri and into Bahamas and central FL over the weekend.
The cold front is expected to continue east and reach from 31n67w to central Cuba by 00z Fri...while a reinforcing front will move rapidly across the southeastern United States tonight and into the Atlc tomorrow...eventually merging with the previous front Fri. Cold air behind the second front will bring strong NW winds to the waters N of 29n W of 75w again by this afternoon with seas building 8 to 10 ft tonight. The fronts will merge se of Bermuda Fri...reaching from 26n65w to se Cuba...then stall from 25n65w to se Cuba by early Sat. Ridging behind the second front will build off the Carolinas and maintain a band of strong easterly winds across the southern Bahamas and through The Straits of FL sun into Mon. GFS still slightly slower and thus to the W of European models...while gefs very close to Euro models and have used gefs frontal positions from 48 hr and beyond.
.Warnings...Any changes impacting coastal NWS offices will be coordinated through AWIPS 12 planet chat or by telephone:
.Gulf of Mexico... None.
.Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w... .Amz017...Gulf of Honduras... Gale Warning today into tonight.
.SW N Atlantic including the Bahamas... None.
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.Forecaster stripling. National Hurricane Center.