Special Feature

Heavy rainfall across the Yucatan peninsula and northern Belize: Broad low pressure is expected to develop over northern Central America and southern Mexico over the next couple of days. The combination of sustained upper-level divergence east of an upper low that is located over the eastern Bay of Campeche, and a tropical wave moving through the Yucatan Peninsula while abundant deep tropical moisture remains in place will provide the potential for heavy rainfall over Belize and the Yucatan Peninsula into Sat. Increasing deep convection is presently over the eastern section of the Yucatan Peninsula and over eastern Belize. The heaviest rainfall may be as high as 6 to 8 inches over this 48 hour period, primarily across northern Belize and southern part of the Mexican state of Quintana Roo. Rainfall of up to 2 to 4 inches is possible across eastern Campeche and eastern Yucatan states as well. Localized flooding is possible. Please refer to local meteorological agencies for further guidance.

Tropical Waves

A far eastern tropical wave has its axis along 20W from 02N to 12N, moving westward near 10 kt. Scattered moderate convection is within 60 nm west of the wave from 07N to 10N.

A central Atlantic tropical wave has is axis near 47. 5W from 05N to 15N, moving westward at 10 to 15 kt. Only isolated showers are seen within 60 nm either side of the axis from 05N to 08N.

A tropical wave has entered the eastern Caribbean, with its axis near 62W. It is moving westward around 15 kt. Scattered moderate to isolated strong convection is within 120 nm east of the wave from 10N to 12N, and within 60 nm west of the wave from 10N to 11N to 12. 5N. Isolated, small showers and thunderstorms are ahead of the wave from 13N to 14N between 63W and 65W.

Another eastern Caribbean tropical wave has its axis near 67W, moving westward at about 15 kt. No significant convection is occurring at the present time with this wave.

A tropical wave was added to the 12Z analysis over the Yucatan Peninsula along a position from 21. 5N87W to 18N90W and to 13N92W as suggested to some extent in long-term satellite imagery and mildly in model guidance. This feature is one of the factors contributing to the heavy rain event described above under the Special Features section. Upper-level divergence from an upper-level low that is west of the Yucatan Peninsula is helping to sustain clusters of scattered moderate to isolated strong convection over the eastern portions of the Yucatan Peninsula and Belize. Similar convection is noted from from 21. 5N to 24N between the western tip of Cuba and 89W. Environmental conditions are forecast to be only marginally conducive for development before the system moves inland over eastern Mexico late Sat or on Sun.

Monsoon Trough Itcz

The monsoon trough axis extends off the coast of Africa near 15N17W and extends southwestward to 08N21W and to 05N30W, where it transitions to the ITCZ to 05N35W to 04N42W and to 05N40W. Scattered moderate convection is within 120 nm north of the trough between 20W-23W, also within 60 nm north of the trough between 24W-26W, between 27W-30W and also between 34W-38W. Scattered moderate to isolated strong convection is also seen from 04N and 09N between 11W-18W.

Gulf Of America

Please see the Tropical Waves sections for information on convection north of the Yucatan Peninsula.

Weak Atlantic ridging stretches westward from the western Atlantic to just inland the northern Gulf coast as an upper-level low is identified to be over the eastern Bay of Campeche. Recent Ascat satellite data passes indicate mostly gentle to moderate east to southeast winds across the basin, except for fresh southeast winds over the central portions. Seas are in the 4 to 6 ft range between the northwest Yucatan Peninsula and the Texas coast, and 2-4 ft elsewhere.

For the forecast, weak ridging will extend from the western Atlantic across the north-central Gulf into early next week. Farther south, weak low pressure will develop over southern Mexico and northern Central America today, then move into the the Bay of Campeche this evening. The low pressure will then move northwestward toward the coast of Tamaulipas state in northeast Mexico through Sat night. The gradient between the low pressure and the high pressure over the northeast Gulf will support a plume of fresh to strong southeast winds and moderate to rough seas from the northwest Yucatan peninsula to the coast of Texas through at least Sat night. The low pressure will be accompanied by numerous showers and thunderstorms across the western Gulf. Winds and seas will diminish early next week after the low pressure moves inland and weakens.

Caribbean Sea

Please see the Special Feature section regarding the potential for heavy rainfall and localized flooding in the Yucatan peninsula and in northern Belize into Sat.

The pressure gradient between western Atlantic high pressure and relatively lower pressure in the western Caribbean is generally allowing for fresh to strong southeast winds to exist in the northwestern part of the sea. Seas with these winds are 6 to 9 ft in southeast swell. The gradient between the same high pressure and relatively lower pressure in northern Colombia is maintaining fresh to strong trades in the south-central section of the basin along with seas of 6 to 8 ft. Latest scatterometer satellite data passes indicate mostly gentle to moderate trades elsewhere. Seas are 4 to 6 ft elsewhere. Clusters of scattered moderate to isolated strong convection are just inland and along the coasts of the Yucatan Peninsula and Belize. This activity is to the east of a tropical wave that is over the Yucatan Peninsula.

Atlantic Ocean

A 1016 mb low is analyzed near 26N61W, with a trough extending south-southwestward to 23N63W and to 22N70W. Another trough extends from the low to 29N60W while a stationary front is anaylzed from 29N60W to 29N61W, where it transitions to a cold front to northeast of the area at 31N47W. Scattered showers and thunderstorms are seen from 25N to 28N between 53W and 58W. Isolated showers and thunderstorms are elsewhere north of 22N between 50W and 65W. Farther north, a surface ridge extends from 1025 mb high pressure center that is northeast of Bermuda near 35N58W west-southwestward to across northern Florida. Farther east, another surface ridge extends from a 1030 mb high pressure center near the Azores Islands southwestward to 31N31W and continues to near 25N55W. Latest scatterometer satellite data passes reveal light to gentle winds west of and along the ridge axis. Seas are 4 to 5 ft over these waters. The scatterometer satellite data passes reveal mostly moderate to fresh northeast winds south of the ridge axis, where seas are 6 to 7 ft.

For the forecast west of 55W, the aforementioned 1016 mb low centered near 26N61W will dissipate as it moves northeast of the area through this evening. A ridge will extend westward along roughly 29N and remain in place through early next week. This pattern will support gentle to moderate breezes across the basin, except moderate to fresh winds off Hispaniola starting Fri night.

Posted about 1 hour ago by NHC Forecaster Aguirre