HS 101

marine weather discussion NWS TPC/National Hurricane Center Miami FL 200 PM EST Sat Nov 07 2009

Marine weather discussion for Gulf of Mexico...Caribbean Sea and southwest north Atlc S of 31n

Gulf of Mexico... a very tight pres gradient remains across the Gulf between Tropical Storm Ida S of the area and strong high pres to the N-NE. As a result strong easterly winds persist across all Gulf zones except the far NW portion. Buoy observations continue to show NE-E winds in the range of 20-25 kt with gusts around 30 kt over the se and S portions including The Straits of Florida and waters near the Florida Keys. Cman station plsf1 W of the Dry Tortugas has been reporting E winds of 30 kt gusts to 33 kt for the past few hours. A 1216 UTC Quikscat pass also showed numerous 30 kt wind barbs over the se-S Gulf. In addition a ship with caller ID "wkpf" near 25n85.5w reported NE winds of 30 kt at 18 UTC. The persistent and large easterly fetch of these winds have resulted in building seas up to 13 ft over the central portion of the middle Gulf...with 8-12 ft seas in the majority of the remainder of the Gulf...except the far NW and N waters where of 4-6 ft seas are prevalent.

The parent high center will shift to the E off the U.S. Mid- Atlantic coast and the ridge over the Gulf Coast states weakening. Tropical Storm Ida is projected to continue to move to the N-NW over or just to the east of the Yucatan Peninsula through the Yucatan Channel on sun...entering the middle/se Gulf waters by sun evening. Ida has the potential to reach minimal hurricane strength as it approaches the Gulf...although it is then expected to weaken and transition into an extratropical system Mon through Tue once it encounters strong SW winds and as a strong upper level trough and attendant cold front move into the Gulf from the south central U.S. States. Once extratropical transition occurs storm force winds will still be possible over the middle Gulf...with gale conditions also possible over the NE Gulf by late Tue into Wed. Meanwhile the weak area of low pres in the Bay of Campeche will drift to the N-NW and eventually merge with the approaching trough/front with some of its moisture and energy potentially being advected into the circulation of Ida.

SW N Atlc S of 31n and W of 65w a weakening cold front from 24n65w to 23n74w will stall out and become nearly stationary tonight before dissipating on sun. A tight pres gradient will exist between high pres just N of the area and Tropical Storm Ida. In addition very cold air aloft will move over the warm SW N Atlc waters. The combination of these factors will result in increasing NE-E winds over the majority of the waters today through Mon night. Latest wavewatch builds seas up to 13 ft E of the Bahamas by Mon. Large NE swells will propagate W through the Bahama passages today through Mon with seas expected to build quite rapidly over the Gulf Stream waters. The high will weaken significantly and shift off to the the E Mon night through Wed as the circulation of Ida moves closer to the E Gulf waters with a deep upper level trough and sfc cold front approaching the se U.S. Coast. Seas will briefly subside with winds diminishing Tue night into early Wed. Expect another strong northerly wind surge behind the next cold front by Wed continuing through the end of next week. As a result building northerly swell will also return and propagate through the waters by mid to late week.

Caribbean and tropical N Atlantic W of 55w... Tropical Storm Ida has strengthened to 60 kt with gusts to 75 kt and it has the potential to reach minimal hurricane status before in departs the NW Caribbean waters and moves into the S Gulf waters. Ida is forecast to track towards the Yucatan Channel reaching near 20.3n 85.5w by Sun morning...and then across the Yucatan Channel or just over the NE Yucatan Peninsula through early sun evening. With Ida increasing to a 60 kt tropical storm seas have quickly built. Buoy 42056 approximately 120 nm to the N-NW of Ida is up to 11 ft as of 18 UTC. The 12 UTC run of the nah wavewatch peaks seas at 30 ft in the Yucatan Channel by 00 UTC Mon. Meanwhile light to moderate trades will prevail across the remainder of the Caribbean. Seas over the northern portion of the tropical N Atlc are expected to build up to 6-9 ft in long period northerly swells Sun night through Mon and possibly up 11 ft Mon night through Tue. NE swells will also build seas up to 8 ft through the Atlc passages Mon night through Wed. Seas will subside by late Wed through Thu...then will build again by the end of the week as a new set of building northerly swell arrives.

Warnings...

Atlc... .None.

Caribbean... .Amz082...Tropical Storm Warning N of 17n W of 82w...

Gulf of Mexico... .Gmz084 and gmz086...Tropical Storm Warning expected Sun night through Wed S of 28n between 84w and 91w... .Gmz084...Gmz080 and gmz086...Storm Warning expected Mon night through Wed N of 26n between 84w and 91w... .Gmz086...Gale Warning expected Wed through Thu N of 26n W of 82w...

$$ forecaster lewitsky