AXNT20 KNHC 251204

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
704 AM EST Sun Feb 25 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 1145 UTC.


A rapidly intensifying low pressure system over the north-central Atlantic supports a cold front N of the area that will enter forecast waters along 31N42W to 29N49W to 28N57W tonight. A strong pressure gradient between this broad low and surface ridging to the west will lead to the development of gale-force winds north of 30N east of the front. Gale conditions are forecast to prevail through Tuesday. For more details, refer to the NHC High Seas Forecast under AWIPS/WMO Headers MIAHSFAT2/FZNT02 KNHC.


The monsoon trough enters the eastern Atlantic near 05N09W and continues to 02N22W. The ITCZ extends from that point to the coast of Brazil near 01S46W. Scattered moderate convection is noted from 0N-05N between 0W-22W. Numerous strong convection is N of the 02S E of 0W. Scattered moderate to isolated strong convection is at the western end of the ITCZ from 3S to the Equator W of 40W.



Fair weather prevails across the basin due to a very dry airmass at low and middle levels of the atmosphere, as indicated by GOES-16 water vapor imagery. CIRA microwave imagery at the lower levels show patches of shallow moisture advecting to the northwest Gulf, which is supporting dense fog north of 27N and west of 91W. A broad area of high pressure over the western Atlantic extends across the basin supporting moderate to fresh southeast flow across the basin. By early Monday, a cold front is forecast to move over the northwestern waters from Louisiana to Brownsville, Texas to inland northeast Mexico. By Monday afternoon, the front is forecast to extend from the Florida Panhandle to 27N94W to inland NE Mexico and then it will stall before it lifts northward along the Gulf coast through Tuesday night. Scattered showers will accompany this boundary.


Water vapor imagery from GOES-16 show deep layer dry air across the Caribbean, which is supporting fair weather across most of the basin. Scattered showers are noted across the Greater Antilles generated by shallow moisture transported by moderate to fresh trades. Latest scatterometer data depicts locally strong winds within 90 nm of the coast of Colombia increasing to near-gale force at night. Sea heights are highest near the coast of Colombia, reaching 12 ft at times. Looking ahead, winds and seas are expected to gradually lessen by this morning as the high pressure system north of the area weakens.


Gale-force winds are forecast to develop over northeast Atlantic waters by Sunday night/Monday morning. See the Special Features section above for further details. A broad surface ridge prevails across the west and central Atlantic anchored by a 1026 mb high near 31N69W and a 1025 mb high near 31N57W. Fresh to locally strong east winds are noted in the approaches of the Windward Passage and the eastern Great Bahama Bank. To the east, a low pressure system over the northeast Atlantic continues to support a cold front that enters the area of discussion near 31N22W to 22N30W to 19N40W then weakens to 19N45W. Another piece of it was analyzed as a surface trough that extends from 22N51W to 26N56W. Little change is expected over the remainder of the basin during the next day or two as the high pressure system remains nearly- stationary and weakens.

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