Monsoon Trough Itcz

The monsoon trough enters the Atlantic along the coast of Sierra Leone near Freetown, then continues SW to near 06N15W. The ITCZ extends westward from 06N15W across 02N30W to NE Brazil near 00N50W. Scattered moderate to isolated strong convection is observed near the ITCZ from 01N to 04N between 21W and 35W.

Gulf Of America

A stationary front extends across the northern Gulf waters, from the western Florida Panhandle to 28N91W and to the central coast of Texas. Scattered showers are seen near this boundary. Otherwise, a surface ridge dominates the remainder of the Gulf region supporting a gentle to locally moderate wind flow. Seas are generally 2 to 4 ft, except 1 to 2 ft offshore Florida.

For the forecast, the aforementioned stationary front will linger across the northern Gulf through Sat morning before it lifts back N as a warm front ahead of a strong Arctic cold front Sat afternoon. The cold front is expected to approach the Texas coast early on Sat, then stall as low pressure that forms near the southern Texas coast rides up along it through Sat night. This will tend to then drag the front SE across the entire basin Sun through Mon evening. Strong reinforcing Arctic high pressure behind the front is expected to produce near gale force winds across NW portions of the Gulf Sun and Sun night, and possible gale conditions over the offshore waters of Tampico Sun night into Mon, then over the waters offshore Veracruz on Mon and Mon night. There is some potential for winds in the NW Gulf to at times reach gale force on Sun.

Caribbean Sea

The most recent scatterometer pass shows fresh to strong trades over the south-central Caribbean due to the pressure gradient between the Atlantic high pressure and the Colombian/Panamanian low. Seas are 5 to 8 ft with these winds. Moderate to fresh winds and moderate seas are noted elsewhere across the eastern and central Caribbean, including the Windward Passage. Gentle to moderate winds and slight to moderate seas prevail across the NW part of the basin. Patches of low level moisture, embedded in the trade wind flow, are moving across the area producing isolated to scattered passing showers.

For the forecast, broad central Atlantic high pressure will maintain mostly fresh trades over the eastern and central Caribbean as well as the Tropical N Atlantic waters through early next week, while winds pulse to fresh to strong speeds at night offshore Colombia through Sun, then to near gale force afterward into midweek. Large E swell over the Tropical N Atlantic will slowly subside through the weekend, but remain around 8 ft through early next week. A cold front will enter the NW Caribbean late Mon and begin to stall from eastern Cuba to the Gulf of Honduras by late Tue into Wed. Strong northerly winds will follow the font before slowly diminishing to moderate to fresh speeds Wed.

Atlantic Ocean

A weak low of 1017 mb is located near 26N74W, with a trough extending SW to the NW Bahamas, and another trough running NE from the low to near 31N72W. Scattered showers and thunderstorms are E of the low and trough from 27N to 30N between 70W and 74W. Farther E, a cold front crosses the Canary Islands from E to W. High pressure of 1031 mb located SW of the Azores near 34N33W dominates the remainder of the forecast region. Under this weather pattern, fresh to strong NE winds are noted from 10N to 20N E of 30W, including the Cabo Verde Islands, and from 07N to 25N between 30W and 50W. Seas of 8 to 11 ft are within these winds based on altimeter data. Fresh winds are occurring on the Atlantic side of the Leeward Islands with seas of 8 ft in NE swell. Moderate or weaker winds and moderate seas prevail elsewhere. A band of transverse high clouds associated with very strong southwesterly winds aloft extends from NE South America all the way to W Africa.

For the forecast west of 55W, fresh to strong S to SW winds will develop over the NW forecast waters Sun night through early Mon in advance of a strong Arctic cold front that is expected to move offshore northeastern Florida early Mon. Winds to near gale force will be just N of the area early on Mon. The front may be attended by a few thunderstorms as it reaches from near 31N70W to the NW Bahamas and Straits of Florida early Mon evening, from near 31N56W to the SE Bahamas and eastern Cuba Tue evening, then weaken as it reaches from near 31N50W to 27N60W and stationary to the SE Bahamas and eastern Cuba by late on Wed. Fresh to strong northerly winds and rough seas are expected W of the front Mon afternoon through Tue, becoming mostly fresh NE winds on Wed within about 180 nm NW of the frontal boundary.

Posted about 2 hours ago by NHC Forecaster GR