Special Features

Tropical Storm Alberto is centered near 21.9N 95.3W at 19/2100 UTC or about 150 nm east of Tampico, Mexico moving west- southwest at 8 kt. The estimated minimum central pressure is 995 mb, and the maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas are up to 19 ft, with the radii of seas 12 ft or greater extending within 420 nm of the center in the NE quadrant and within 390 nm of the center in the NW quadrant. Satellite imagery shows numerous moderate to strong convection in wide banding features that extend along and to well inland the coast of Mexico from 18N to 22N between 92W and 98W and from 22N to 26N between 95W and 100W. Numerous moderate to isolated strong convection is the the north from 26N to 20N between 96W and 100W.

Alberto is forecast to resume a westward motion soon and continue for the next day or so. On this track, the center of Alberto is expected to reach the Gulf coast of Mexico early Thu. Some slight strengthening is possible this evening or tonight before the center of Alberto reaches land. Weakening is expected once the center moves inland, and Alberto is likely to dissipate over Mexico Thu or Thu night. Alberto is expected to produce rainfall totals of 5 to 10 inches across northeast Mexico into South Texas. Maximum totals around 20 inches are possible across the higher terrain of the Mexican states of Coahuila, Nuevo Leon, and Tamaulipas. This rainfall will likely produce considerable flash and urban flooding along with new and renewed river flooding. Mudslides are also possible in areas of higher terrain across northeast Mexico. The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The deepest water will occur along the immediate coast near and to the north of the landfall location, where the surge will be accompanied by large and dangerous waves. Storm surge will raise water levels by as much as 1 to 3 feet above normal tide levels along the immediate coast of northeastern Mexico in areas of onshore winds north of where the center makes landfall. Near the coast, the surge will be accompanied by large and destructive waves. Please consult products issued by your local National Weather Service forecast office, and read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Alberto NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details.

Gale Warning E of 35W: Strong high pressure that is currently north of the Azores will shift southeastward through late Fri. A tightening of the pressure gradient between the high pressure and relatively lower pressures in West Africa will support gale- force (Force 8 on the Beaufort Wind Scale) with severe gusts for the marine zone of AGADIR beginning at 12Z on June 20 and lasting to 00Z June 21th according to the METEO-FRANCE High Seas warning issued at 1905Z today. Please read the latest High Seas Forecast issued by Meteo-France for more details at website https://wwmiws.wmo.int/index.php/metareas/display/2

Tropical Waves

A far eastern Atlantic tropical wave has its axis along 24W from 05N to 18N. It is moving westward at 10 to 15 kt. Scattered showers are within 180 nm east of the wave from 13N to 19N and within 60 nm west of the wave from 06N to 12N.

An eastern Atlantic tropical wave has its axis along 40W from 04N to 17N, moving westward at around 15 kt. Scattered showers and isolated thunderstorms are within 120 nm east of the wave from 09N to 11N and within 60 nm west of the wave from 10N to 11N.

A central Atlantic tropical wave has its axis along 55W south of 16N, moving westward at 10 to 15 kt. This wave originated in the mid-latitudes and moved southward to become embedded within the tradewind easterlies. As typical for these types of tropical waves that originate in the mid-latitude, it is embedded within dry air so there is no significant convection noted at this time. An ASCAT pass nicely depicted the shift from northeast to southeast of moderate wind speeds across the wave axis. Weakening scattered showers are within 60 nm either side of the wave axis from 08N to 10N.

A central Caribbean tropical wave has its axis along 74W/75W south of 19N to inland eastern Colombia, moving westward at 5 to 10 kt. Isolated showers and thunderstorms are within 60 nm either side of the wave from 11N to 13N.

Monsoon Trough/ITCZ

The monsoon trough passes through the coast of Africa across northwest Guinea near 11N14W and continues to 10N24W. The ITCZ extends from 10N24W to 09N40W to 07N45W to 08N53W and to the coast of Guyana near 07N58W. Scattered moderate convection is within 120 nm south of the ITCZ between 29W and 34W and within 60 nm north of the ITCZ between 34W and 39W.

Gulf Of Mexico

Please read the Special Features section for information on Tropical Storm Alberto and its impacts. Alberto is the main feature over the basin.

Aside from impacts discussed above, a tight gradient between high pressure centered over the southeastern U.S. And Tropical Storm Alberto is supporting strong to near-gale force easterly winds over the Gulf waters west of 87W, with fresh to strong winds east of 87W, including the Yucatan Channel. Latest buoy observations show seas in the range of 9 to 14 ft north 24N and west of 87W. Seas of 6 to 9 ft are south of 24N and west of 87W, including the Bay of Campeche. Seas of 6 to 8 ft are east of 87W.

For the forecast, Tropical Storm Alberto will move to near 22.0N 97.0W late tonight with maximum sustained wind speed 40 kt gusts 50 kt, then move inland and weaken to a tropical depression near 22.1N 100.9W Thu afternoon and dissipate Fri morning. Another broad area of low pressure is forecast to develop over the southwestern Gulf of Mexico this weekend. Environmental conditions are expected to be conducive for gradual development of this system through early next week while it moves slowly west-northwestward or northwestward.

Caribbean Sea

A tight gradient between the broad cyclonic circulation associated to Tropical Storm Alberto and high pressure ridging that stretches southward from the southeastern U.S. To Florida and western Cuba is supporting fresh to strong southeast winds over the northwestern Caribbean west of about 83W. Seas over this section of the sea are in the 7 to 10 ft range as indicated by buoy 42056 located at 20N85W. Moderate to fresh southeast winds are between 81W and 83W. Moderate to fresh trade winds are east of 78W as seen partial ASCAT satellite data passes over that part of the sea, and gentle to moderate trade winds are elsewhere. Seas elsewhere across the basin are in the range 3 to 5 ft, except for slighter lower seas of 2 to 4 ft are over the waters from 15N to 18N between 72W and 80W and south of 11N west 80W. Higher seas of 6 to 8 ft are from 15N to 20N between 80W and 85W and 6 to 9 ft in the Gulf of Honduras. A very unstable atmospheric environment in place, mainly a result of a broad upper-level low that is north of the basin near the central Bahamas has assisted in the development of numerous moderate to isolated strong convection south of 15N and west of 74W to inland some sections of Nicaragua, Costa Rica and Panama. Similar convection is from just north of the Gulf of Honduras to 20N and west of 86W to just inland the Yucatan Peninsula and Belize. Other scattered moderate to isolated strong convection is increasing over most of Cuba and Jamaica. Scattered clusters of showers and thunderstorms are increasing over some areas of Hispaniola and south of Puerto Rico to near 16N. Isolated showers and thunderstorms are elsewhere east of 83W and north of 18N west of 81W.

For the forecast, the fresh to strong southeast winds and rough seas over the NW Caribbean will diminish to moderate to fresh speeds and moderate seas from Sat afternoon through Sun night. Moderate to fresh trade winds will continue across the eastern and central Caribbean through Sat, pulsing to strong speeds over the south-central basin tonight through Fri night. Winds across these two regions will diminish to gentle to moderate speeds Sun.

Atlantic Ocean

A surface trough extends from near 30N70W to low pressure of 1014 mb (Invest-AL92) near 26N71W and to near 22N71W. Scattered moderate convection lifting northward is seen from 26N to 29N between 69W and 71W. Similar convection also lifting northward is from 19N to 25N between 63W and 68W, from along the coast of Hispaniola north to 22N between 70W and 72W and west- southwest of the Bahamas to along the central and western coasts of Cuba and extending out over the Straits of Florida. Scattered moderate convection moving quickly westward is noted from 26N to 29N west of 78W, including the NW Bahamas and inland some areas of the Florida peninsula. This activity is being further enhanced by an upper- level low observed to be near 25N79W. A stationary front enters the area through 31N52W and continues to 29N62W and to 28N69W. The pressure gradient between these features and high pressure to the north is inducing fresh to strong northeast to east winds north of a line from 30N60W to 29N70W to 26N74W and to Palm Beach, Florida as depicted in ASCAT satellite data passes over these waters and in buoy observations. These winds are producing seas in the range of 8 to 12 ft, with buoy 41047 located at 27.5N 71.5W reporting combined seas of 12 ft. Elsewhere north of 20N, winds are mainly gentle to moderate in speeds with seas in the range of 4 to 6 ft. Moderate to locally fresh winds are over the tropical Atlantic with seas of 4 to 6 ft. The main exception is in the vicinity of the tropical wave in the eastern Atlantic, where fresh to locally strong winds, and seas of 8 to 9 ft prevail.

For the forecast west of 55W, in reference to the aforementioned surface trough that extends from near 30N70W to low pressure of 1014 mb (Invest-AL92) near 26N71W and to near 22N71W, environmental conditions are marginally conducive for some gradual development of this system during the next few days while it moves westward or west-northwestward. The system is forecast to approach the coast of the southeastern U.S. By Fri. Regardless of development, fresh to strong northeast to east winds and rough seas to 12 ft will continue over the waters north of 26N through Thu. High pressure north of the area and associated ridging will dominate the region afterwards, generally supporting gentle to moderate east to southeast winds for the next few days.

Posted 4 hours ago by NHC Forecaster Aguirre