marine weather discussion NWS National Hurricane Center Miami FL 226 PM EDT Wed Aug 20 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: latest GFS blended with previous official. Nwps used for wave parameters. High confidence.
The northern extension of a tropical wave over the Western Bay of Campeche will move inland Mexico this afternoon. A ridge extends from FL Bay to the NW Gulf Coast with a high pres center along the ridge near 27n87w. The high will gradually shift NW along the ridge to the N-central Gulf on Thu and Thu night...then shifting NW over la on Fri with a ridge extending se to the se Gulf waters. The high will shift se along the ridge and back over the NE Gulf over the weekend into early next week.
Variable 5-10 kt winds expected over the NE Gulf waters till Fri ...Then light and variable conditions developing again on Fri night and Sat. Expect se-S 10-15 kt return flow across the W-central and NW waters around the W periphery of the ridge through Thu night...except increasing briefly to 15-20 kt during the late night hours. The gradient will gradually relax Fri through Mon.
S of 23n...expect an evening enhancement of 20-25 kt NE winds along the W coast of the Yucatan Peninsula this evening and again on Thu evening with the most significant event tonight. These 20-25 kt conditions will spread W along 22n gradually becoming E to se late tonight...and diminish to se at 20 kt near 22n94w by sunrise Thu. The Thu evening event will dampen quickly to E at 10-15 kt by sunrise Fri. As stated previously...beginning Fri evening the locally enhanced evening winds will set up an inverted trough over the Eastern Bay of Campeche during the late night hours. The trough will shift W across the central Bay of Campeche during each morning...and lose identity during the early afternoon hours.
...Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w...
Model preference: latest GFS blended with previous official which consisted of a GFS/ECMWF blend for day 4 and 5. Nwps used for wave parameters. Low-Med confidence.
Fresh easterly trades will continue across the central Caribbean through early Fri with the maximum affected area occurring during the late night hours. Tropical low pres continues near 11n53w but remains disorganized for the time being. Latest NHC/wpc guidance favors the low tracking northwesterly...with the potential for tropical cyclone formation. The grids have been adjusted in the medium range periods to account for shift in the track of the low or possible tropical cyclone slightly to the N from the ones shown in previous grids. This was based on the NHC/wpc midday coordination. Presently...a surface low center is expected to move into the tropical Atlc waters near 13n55w late tonight with 20-25 kt winds within about 240 nm over the NE semicircle. The area of enhanced winds will increase to 20-30 kt...and shift to over the N semicircle as the low continues to near 14n59w on Thu evening...to near near 15n64w early on Fri...near 16n68w on Fri evening...then begin to accelerate in forward speed as tracks more to the NW reaching a psn to just S of central Hispaniola early on Sat. The low will or possible tropical cyclone is then forecast to approach the eastern part of Cuba early sun...and continue NW through The Straits of Florida thereafter. Interaction with the larger islands will of course play a major part in the organization of this tropical low...and mariners should expect frequent adjustments to the ndfd grids...text and graphics over the next week.
...SW N Atlantic including the Bahamas...
Model preference: latest GFS blended with previous official which consisted of a GFS/ECMWF blend for day 4 and 5. Nwps/mww3 used for wave parameters. Low-Med confidence due to tropical low.
A ridge will persist near 27n through Thu night...then shift N to 28n Fri through Mon. Expecting SW 10-15 kt conditions N of the ridge...except diminishing some W of 73w over the weekend...and into Mon.
Easterly trades from the ridge axis S to along 22n are expected to continue at 5-10 kt. To the S of 22n moderate 10-15 kt trades are expected...except for 15-20 kt conditions along the N coast of Hispaniola till late Fri when the effects of a tropical low shifting W across the norther Caribbean will begin to spread across the waters S of 21n. Much uncertainty for the 3-6 day forecast at this time as model guidance continues to vary.
.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... none.
.SW N Atlantic including the Bahamas... None.
*For detailed zone descriptions please visit: http://www.NHC.NOAA.Gov/abouttafbprod.Shtml#owf
Note: gridded marine forecasts are available in the National digital forecast database (ndfd) at: http://www.NHC.NOAA.Gov/marine/grids.Php
For additional information please visit: http://www.Hurricane warnings.Gov/marine
.Forecaster Aguirre. National Hurricane Center.