AXNT20 KNHC 111130

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
630 AM EST Tue Dec 11 2018

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 1115 UTC.


...Atlantic Gale Warning...

A cold front from 33N73W to 30N79W will sweep E across the northern Atlantic waters Tue. Gale-force winds are expected with this front north of 29N between 63W-73W Tue evening into early Wed morning, along with seas of 12-15 ft. Please read the latest High Seas Forecast under AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details.


The monsoon trough extends from the coast of Liberia near 07N11W to 04N21W. The ITCZ continues from that point to 02N30W to 00N40W to the coast of Brazil near 00N49W. Scattered moderate convection is noted south of 05N between 04W-20W. Scattered moderate/isolated strong convection is seen south of 06N between 31W-49W. Scattered showers and thunderstorms are also just off the coast of French Guiana from 04N-07N between 50W-55W.


A 1031 mb high pressure is centered over Louisiana and east Texas. The high extends a surface ridge across the entire Gulf. An upper-level trough over the eastern U.S. extends southward over the northern Gulf of Mexico. Broken low-level stratocumulus cover the eastern and southern Gulf. The northwestern Gulf has cleared out. The surface high pressure will continue to prevail over the basin through midweek. The next cold front will move into the NW Gulf Thu, quickly reaching the eastern Gulf late Thu night, then pushing SE of the basin Fri night. Strong winds will follow the front, possibly reaching gale force Thu night into Fri over the NW Gulf.


In the northwest Caribbean, a cold front extends from central Cuba near 22N78W to 20N82W to the N coast of Honduras near 16N87W. A surface trough is located east of the front from eastern Cuba near 21N77W to 15N81W. Broken clouds and isolated showers cover the entire western Caribbean Sea west of a line from 21N78W to 18N81W to 12N82W. Water vapor imagery shows relatively dry air in the eastern and central Caribbean, especially east of 76W and south of 16N. Puerto Rico radar shows isolated trade wind showers over and south of the island.

Fresh to strong trade winds will prevail in the S central Caribbean through Sat night, pulsing to near gale off the coast of Colombia at night. The front from central Cuba to the N coast of western Honduras will reach from near the Windward Passage to eastern Honduras by tonight, where it will stall and dissipate through Thu. Fresh to strong winds will prevail behind the front this afternoon through early Wed. Another cold front will enter the NW Caribbean Fri afternoon, dissipating over the NW Caribbean through Sat night.


A cold front extends over the west Atlantic from 32N62W to 27N70W to the central Bahamas near 24N75W to central Cuba near 22N78W. Scattered showers and isolated thunderstorms are noted from 24N- 28N between 68W-71W, and north of 30N between 57W-63W. These two clusters of showers are oriented parallel to the front about 30 to 90 nm east of the front. A second cold front extends from a 1004 mb low near 33N73W to 30N79W. Broken clouds and isolated showers cover much of the western Atlantic from the first front westward. The weather is relatively quiet across the remainder of the basin, with a 1027 mb high analyzed near 27N44W. The surface ridge extends from this high westward to N of Puerto Rico.

The cold front from 32N62W to central Cuba will shift E across the basin through Wed. The second cold front will move across the northern waters Tue, with the two boundaries merging by Wed. Gale force winds are expected Tue evening into early Wed with the second front N of 29N between 63W-73W. Return flow will dominate the area for the end of the week, with another potentially strong cold front impacting the NW portion of the Atlantic forecast area by late Fri.

For additional information please visit http://www.hurricanes.gov/marine

$$ Hagen