Monsoon Trough/ITCZ

The monsoon trough axis extends passes off the coast of Africa near 14N17W and continues southwestward to 07N23W, where overnight scatterometer data indicates that it transitions to the ITCZ and continues to 04N30W to 02N40W and to near 00N48W. Scattered moderate to isolated strong convection is within 60 nm north of the ITCZ between 26W-30W. Scattered moderate convection is seen within 120 nm north of the ITCZ between 32W-35W and within 60 nm north of the ITCZ between 37W-40W. Similar convection is from 01N to 04N between 45W and the coast of Brazil.

Gulf Of Mexico

A stationary front extends from near Fort Myers, Florida to the central Gulf near 27N90W and to inland Texas near Corpus Christi. A mid-level shortwave trough lifting northeastward over southeastern Texas is acting on the stationary boundary leading to the development of scattered showers and thunderstorms over the waters within about 120 nm east of South Texas and northeastern Mexico. This activity is quickly moving east-northeastward. Isolated showers and thunderstorms are elsewhere north of 26N and west of 93W. The remainder of the basin is under a weak pressure pattern, typical for this time of year. Fresh easterly winds and seas of 3-4 ft are occurring off the Yucatan Peninsula. Mostly moderate east to southeast winds and seas of 4 to 5 ft are north of 27N and west of 90W. Gentle to moderate easterly winds and 2-4 ft seas are over the rest of the western half of the Gulf of Mexico. Elsewhere, light to gentle winds and slight seas prevail.

For the forecast, the eastern portion of the front will slowly move southeastward and extend from the Straits of Florida to the central Gulf this morning, where it will stall again and weaken with its remnants lifting back N as a warm front through Sun night. Moderate to fresh return flow will dominate for the end of the weekend into early next week, with another front or trough possibly impacting the western Gulf Mon night. High pressure should rebuild across the basin mid-week, with moderate to fresh SE-S winds, locally strong. Meanwhile, haze due to agricultural fires in Mexico continues across most of the western Gulf and Bay of Campeche. Fresh to strong winds will pulse near the Yucatan Peninsula each evening through the period.

Caribbean Sea

A weak pressure gradient prevails across the Caribbean and maintains moderate trade winds over most of the basin. The exception is the Gulf of Honduras, where fresh to strong east to southeast winds remain rather persistent there as seen in an overnight ASCAT pass. Seas are slight to moderate across the basin, with peak seas to 6 ft in the Gulf of Honduras.

Rather stable atmospheric conditions under a broad anticyclone aloft prevail across most of the basin west of 75W, except in the far southwestern part of the basin where scattered showers and thunderstorms are noted and in the far northeast part of the basin, where lingering moisture is evident along with some degree of atmospheric instability present there. The eastern segment of the east Pacific monsoon trough reaches eastward into the southwestern Caribbean and into northern Colombia helping to sustain the aforementioned shower and thunderstorm activity. Isolated showers are over some sections of the eastern Caribbean. This activity may increase to that of the scattered type today over some areas, including islands, of the northeast part of the basin as mid to upper-level atmospheric conditions become more favorable for the enhancement of convective activity.

For the forecast, high pressure over the central Atlantic will support strong to near gale east to southeast winds near the Gulf of Honduras, moderate to fresh winds in the south-central and in the southeastern Caribbean, with gentle to moderate winds elsewhere into the upcoming week. The pressure gradient will tighten early next week, with fresh to strong trade winds expected in the south-central and in the northwestern Caribbean, and moderate to fresh trade winds elsewhere. Seas will build next week as a result of the increasing winds. Meanwhile, haze due to agricultural fires in Central America continues across some areas of the northwestern Caribbean.

Atlantic Ocean

A cold front is analyzed from 31N67W to 27N73W and to the northern Bahamas, where it transitions to a stationary front to inland South Florida near Palm Beach. A pre-frontal trough extends from 31N65W to 26N72W. Satellite imagery shows scattered showers and isolated thunderstorms from 26N to 29N between the trough and 66W. Moderate to fresh southwest winds are east of the front to 60W and north of 27N. Seas with these winds are 5 to 7 ft. To the southeast of the trough, another trough is analyzed from 24N60W to the Mona Passage. Isolated showers are along and near the trough. Scattered showers and thunderstorms moving quickly eastward are noted from 20N to 24N between 57W and 61W. Mostly gentle east to southeast winds are east of this trough to near 59W. Another area of scattered showers and thunderstorms that is moving eastward at a pretty fast pace is to the north, from 24N to 31N between 54W and 57W. Both areas of shower and thunderstorm activity are underneath upper-level diffluence found on the SE side of a broad mid-upper level trough that covers a good portion of the western Atlantic.

The remainder of the basin is dominated by a broad 1029 mb high pressure system centered to the southwest of the Azores. The pressure gradient between this ridge and relatively lower pressures in northwest Africa result in fresh to strong northerly winds north of 15N and east of about 30W, with the strongest winds off Morocco. Seas in the area described are in the 6 to 8 ft range. Elsewhere, moderate or weaker winds and moderate seas are prevalent.

For the forecast W of 55W, the aforementioned cold front will reach from near 31N64W to vicinity of the Florida Keys by early this afternoon, then from 31N59W to the central Bahamas early Mon, dissipating from 28N55W to 23N70W early Tue. High pressure will build in behind the front for the start of next week. Fresh to strong southerly winds and building seas are forecast offshore N Florida by mid-week ahead of another possible cold front. That front may reach from near 31N76W to 27N80W by early Thu.

Posted 5 hours ago by NHC Forecaster Aguirre