Special Feature

Tropical Storm Bertha is centered near 29.4N 88.3W at 22/0900 UTC or about about 45 nm ENE of the mouth of the Mississippi River and 140 nm west-southwest of Panama City Florida, moving W at 4 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Satellite imagery shows that the Bertha remains a heavily sheared system, with its low- level center clearly exposed to the north of its deep convective activity that consists of numerous moderate to strong convection from 26N to 28N between 84W and 88W, and from 25N to 29N between 88W and 92W. Bertha is forecast to continue its current motion through through Fri with a little acceleration. On the forecast track, Bertha will move near or along the northern Gulf Coast during the next couple of days. Bertha is expected to produce total rainfall amounts of 1 to 4 inches with isolated higher totals to 6 inches through Thursday along the central to the western Gulf Coast from western Florida to southern Texas. This rainfall may produce isolated flash flooding, especially in urban areas. Swells generated by Bertha will continue spreading westward along the northern Gulf Coast during the next few days.

Please 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 Two NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details.

Tropical Waves

A far eastern Atlantic tropical wave is west of the Cabo Verde Islands with its axis along 33W from 09N to 19W, moving westward around 20 kt. Dry air surrounds this wave. Only isolated showers are seen near the southern part of the wave between 34W and 35W.

A central Atlantic tropical wave has its axis along 55W from 08N to 24N moving westward near 15 kt. An area of moderate convection is present from 21N to 24N between 51W and 57W. Otherwise, a few showers and thunderstorms are within 120 nm west of the southern part of the wave from 08N to 10N.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic through the coast of Senegal near 14N17W, and continues southwestward to 10N25W and to 08N38W, where it transitions to the ITCZ to the coast of Guyana near 07N58W. Scattered moderate convection is within 60 nm north of the trough between 35W-38W. Similar activity is from 05N to 09N between 29W-34W, and just offshore the coast of Africa from 14N to 18N between 17W-19W.

Gulf Of America

Please refer to the Special Features section for details on Tropical Storm Bertha located about 45 nm ENE of the mouth of the Mississippi River.

Aside from conditions related to Bertha, moderate or weaker winds are noted W of 90W and over the southeastern Gulf waters under a weak ridge.

For the forecast, Bertha will begin top gradually weaken as it moves inland to near 29.4N 89.4W this afternoon, inland to 29.3N 91.4W late tonight, to near 29.3N 93.9W Thu afternoon, then weaken to a remnant low near 29.5N 96.3W late Thu night and dissipate Fri afternoon. Swells generated by Bertha will continue spreading westward along the northern Gulf Coast during the next few days. In the wake of Bertha, weak high pressure centered over the south- central Gulf will be replaced by ridging associated to a new high center that forms over the NE Gulf providing for a light to gentle anticyclonic wind flow pattern across the basin, except for pulsing moderate to fresh winds off the Yucatan Peninsula and near NE Mexico and the Texas coast. These conditions are expected through the weekend.

Caribbean Sea

The pressure gradient between the Bermuda-Azores High and lower pressure over NW Colombia is resulting in fresh to strong trade winds over most of the central and SW Caribbean, including the Windward Passage, and near Cabo Beata, Dominican Republic. Gentle to moderate winds are ongoing in the Gulf of Honduras. Buoy 42058 located near 14N76W continues to report seas of 8 to 9 ft. For the remainder of the basin, winds are moderate or weaker along with slight to moderate seas.

For the forecast, the Atlantic ridge combined with the Colombian low will support fresh to strong winds with moderate to rough seas across the south-central Caribbean through the forecast period. Fresh to locally strong NE to E winds in the Windward Passage will diminish this morning, and may briefly pulse back up tonight. Fresh winds will pulse across the Gulf of Honduras from this afternoon into tonight. Moderate or weaker winds with slight to moderate seas will prevail elsewhere.

Atlantic Ocean

A surface trough extends from near 29N65W to 24N66W and to the Mona Passage. A large area of increasing numerous moderate convection is seen from 22N to 29N between 61W and 71W, and also from 24N to 28N between 47W and 57W. Overnight satellite scatterometer data confirmed the presence of this trough and indicated fresh to locally strong winds on either side of the trough north of about 23N. Otherwise, high pressure dominates the remainder of the Atlantic forecast region supporting mainly gentle to moderate winds, with the exception of fresh to strong north to northeast winds near the Canary Islands, moderate to fresh northeast winds north of the tropical wave near 35W, and fresh to strong northeast winds between Haiti and eastern Cuba, including in the Windward Passage. Seas are generally of moderate state, with locally rough seas east of about 35W as noted in overnight satellite altimeter data passes.

For the forecast west of 55W, the aforementioned surface trough will move westward reaching near 70W by Wed afternoon and to near 75W by Thu morning. Numerous showers and thunderstorms will accompany the trough. Moderate to fresh winds and moderate seas are expected on either side of the trough axis. Fresh to locally strong trade winds are expected offshore Hispaniola, including approaches to the Windward Passage through the forecast period. Moderate or weaker winds along with moderate seas are forecast elsewhere E of the Bahamas through Fri, except S of 23N E of about 77W where mostly fresh trades are expected into Sun.

Posted 3 hours ago by NHC Forecaster Aguirre