marine weather discussion NWS TPC/National Hurricane Center Miami FL 130 PM EST Tue Jan 06 2009

Marine weather discussion for Gulf of Mexico... Caribbean Sea and southwest north Atlc S of 31n W of 55w.

Gulf of Mexico and Atlantic... a longwave trough over the plains will pass E through the Gulf of Mexico on Thu and into the SW N Atlc by Fri. The associated surface cold front is expected to generate winds to gale force ahead of it over the SW N Atlc zone N of 29n on Wed/Thu. The models are in reasonable agreement with the strength and timing of this cold front...but appear to be running slightly weak with the strength of the southerly flow ahead of the cold front. The 1238 UTC Quikscat pass shows winds into the 25 to 30 kt range here while the 35 km resolution GFS does not generate wind that strong until 0000 UTC. Even the 20 km NAM is weaker than Quikscat and several surface observations ahead of the front are reporting. Therefore...bumped the winds up slightly ahead of the cold front into the forecast period. Believe the winds will get to gale force as the front emerges off the FL/GA coast Wed afternoon through Thu.

A second cold front will push southeastward into the northern Gulf of Mexico over the weekend. With the steering flow becoming more zonal across the central and eastern U.S. On Fri/Sat...the models are having a hard time agreeing on the strength and timing of the cold front over the Gulf. The GFS and NOGAPS solutions are generally faster to carry the leading edge of the front eastward through the Gulf than the UKMET and ECMWF. Given the trend in the forecast for more zonal flow...think the UKMET and ECMWF may be too slow. Do not have a good reason to stray from the GFS.

Caribbean... the southern end of the cold front currently over the Gulf of Mexico is expected to pass through the Yucatan Channel tomorrow and dissipate over the NW Caribbean Thu. Winds over the NW Caribbean are already beginning to turn more southerly ahead of the cold front and are expected to turn more N of E as the front passes through...but considering this is a relatively weak front once it reaches the Caribbean...winds are not expected to exceed 25 kt due to the frontal passage. Winds over 25 kt are being reported near the coast of Colombia according to the 1428 ascat pass...and winds are expected to remain above 25 kt here through the period due to the pressure gradient between low pressure over South America and mean high pressure N of the Caribbean centered near 25n.

Atlantic... none.

Caribbean... none.

Gulf of Mexico... none.

Forecaster schauer Clark. Tropical Prediction Center.