For the North Atlantic, Caribbean Sea and the Gulf of Mexico:

Tropical cyclone formation is not expected during the next 5 days.

Posted 2 hours ago by NHC Forecaster Forecaster Cangialosi

Special Features

Heavy Rainfall over Central America and SE Mexico: A broad area of low pressure centered just off the Pacific coast of eastern El Salvador has produced periods of heavy rain during the past 24 hours (20/1800 UTC to 21/1800 UTC) over portions of northern Costa Rica, Nicaragua, Honduras, coastal El Salvador and southern Guatemala, as indicated by a 24-hr infrared satellite loop. The current satellite imagery shows scattered to locally numerous moderate to strong convection extending from central Guatemala east and southeastward across Honduras, Nicaragua, and covering much of the southwest Caribbean south of 15N and west of 80W. Other scattered moderate and isolated strong convection is occurring over land across Costa Rica. Over the next 4 days or so (through Wed 25 May), additional periods of moderate to heavy rain, with locally heavy to extreme rain, are expected over portions of western Panama, Costa Rica, Nicaragua, southern Honduras, El Salvador, southern Guatemala and the Mexican state of Chiapas. There is potential for localized areas of flash flooding and mudslides, especially across mountainous terrain. This is a slow moving weather system. High atmospheric moisture content is expected over the area for the next several days. Please refer to products issued by your local or national meteorological agency for more information.

Tropical Waves

A tropical wave is in the Atlantic with axis along 56W-57W, from 14N southward, moving west at 15-20 kt. Scattered moderate convection is noted near the ITCZ from 05N-09N between 50W-58W.

Monsoon Trough/ITCZ

The monsoon trough extends from the Senegal coast near 14N16.5W to 06N26W. The ITCZ continues from 06N26W to 04.5N35W to 07N54W. Scattered to numerous moderate to strong convection is noted from 03.5N-101N between the coast of Africa and 20W, while scattered moderate to strong is noted further west, from 05N to 07N between 20W and 29W. Scattered moderate convection is occurring N of the ITCZ from 06N to 09.5N between 36W and 50W.

Gulf Of Mexico

An upper-level trough extends from Mississippi southward to the southeast Gulf of Mexico. Upper-level diffluence on the east side of the upper trough is supporting numerous moderate and scattered strong convection covering the NE Gulf of Mexico, north of 25N and east of 90W. Gusty winds and frequent lightning are occurring with these thunderstorms. GOES-16 infrared imagery depicts cloud tops as cold as -76 deg C. A recent satellite altimeter pass from 21/1630 UTC showed seas of 7 to 8 ft off the coast of central Texas. Fresh SE winds and seas of 5-7 ft prevail elsewhere across the basin W of 90W, while fresh to strong winds are across much of the eastern Gulf between 85W and 90W, where seas are estimated to be 7-9 ft. Smoke from agricultural fires over Mexico continues to spread northward and is producing hazy skies across the western Gulf west of 93W off Mexico and southern Texas.

For the forecast, the area of strong thunderstorms over the NE Gulf of Mexico is expected to linger into the evening hours and slowly migrating W toward the north-central Gulf. Fresh to strong southeast winds along with rough seas will prevail from the south-central Gulf to the northwest Gulf into Sun between high pressure over the western Atlantic and broad low pressure over southern Mexico and northern Central America. Winds and seas will diminish Sun into Mon as the low pressure weakens, except for pulses of fresh to strong winds off the north coast of the Yucatan Peninsula, mainly at night. Looking ahead, a ridge will build from the western Atlantic across the northern Gulf through mid- week, supporting fresh southeast return flow over the western Gulf.

Caribbean Sea

The eastern periphery of a broad cyclonic circulation over Central America, combined with the east Pacific monsoon trough, is combining to produce scattered to numerous deep convection across the southwest Caribbean, described above. Cloudiness with possible isolated showers prevails elsewhere over the NW Caribbean to the west of Jamaica. Mainly fair weather is found over the eastern and central Caribbean, east of 77W, due to subsidence from mid-level ridging over the area. A recent ASCAT satellite data pass showed fresh to strong E to SE trades over much of the central and western Caribbean. Moderate E trades cover the eastern basin. Seas of 7 to 10 ft are likely occurring over the far NW Caribbean to the Yucatan Channel. Seas of 7-10 ft are over the waters in between Colombia and Jamaica, while 3-5 ft seas prevail across the E basin.

For the forecast, broad low pressure over Central America will persist through Sun as high pressure builds over the western Atlantic. This pattern will support fresh to strong east to southeast winds and rough seas over the central and northwest Caribbean through Sun. Winds and seas will start to diminish across the basin early next week as the pressure gradient relaxes.

Atlantic Ocean

A surface ridge extends east to west from a 1027 mb high pressure near 33N28W to 27N44W, while a second high of 1027 mb is centered near 32N69W and extends to the coast of Georgia. This ridge is maintaining light to gentle winds north of 24N between 40W-75W, with 3-4 ft seas. A recent ASCAT satellite wind data pass shows moderate to fresh SE winds from north of Hispaniola through the Old Bahama Channel to South Florida. Currently, seas near the Windward Passage are likely 4 to 5 ft, while 3 to 4 ft seas prevail over the remainder of the western Atlantic. A couple of weak surface troughs over the central Atlantic are inducing some scattered showers north of 23N between 38W-53W. Recent ASCAT data showed fresh trades north of the ITCZ to 16N between 40W and 60W, where seas are likely 5 to 7 ft. Moderate trades and 5-6 ft seas are elsewhere from the ITCZ to 20N between 30W- 60W. Fresh NNE winds and 5-7 ft seas prevail north of 20N between the coast of Africa and 21W.

For the forecast west of 55W, the high pressure ridge along 32N will strengthen some through the weekend, then weaken next week. The associated pressure gradient will allow for mainly gentle to moderate winds across the region through the period, except for pulsing moderate to fresh east winds north of Hispaniola through late Sun. Moderate northeast swell may impact the waters east of 60W and north of 25N Sun through Tue. The swell is expected to subside Tue night into Wed.

Posted 1 hour, 58 minutes ago by NHC Forecaster Stripling