Special Feature

Tropical Storm Bertha is centered near 29.4N 87.7W at 22/0300 UTC or 110 nm WSW of Panama City Florida, moving W at 5 kt. Estimated minimum central pressure is 995 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Peak seas are near 15 ft on the E semicircle of the center. Bertha remains a sheared tropical storm. The low-level center is exposed, with bursts of deep convection displaced to the SW semicircle by strong shear. The convection consists of numerous moderate to scattered strong convection covering the waters from 24N to 29N between 86W and 93W. Bertha is moving toward the west near 6 kt, and a generally westward motion is expected Wednesday through Friday. On the forecast track, Bertha will move near or along the northern Gulf Coast during the next couple of days. A gradual weakening trend is forecast to begin on Wednesday. Swells generated by Bertha will continue spreading westward along the northern Gulf Coast during the next few days. These swells are likely to cause life- threatening surf and rip current conditions. Please consult products from your local weather office. 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 tropical wave is W of the Cabo Verde Islands with axis along 33W from 09N to 19W, moving W at 15 to 20 kt. Dry air in the wave environment is limiting convection to scattered moderate from 11N to 15N between 25W and 31W.

A tropical wave is along 50W from 08N to 22N, moving W at 10 to 15 kt. Convection is limited to isolated showers within 240 nm west of the wave axis.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic through the coast of Senegal near 14N17W, and continues southwestward to 10N28W and to 08N38W. The ITCZ extends from 08N38W to the coast of Guyana near 07N58W. Aside from the convection associated with the tropical waves, scattered moderate convection is from 06N to 14N between the coast of W Africa and 19W. Similar convective activity is noted from 03N to 09N between 29W and 43W.

Gulf Of America

Please refer to the Special Features section for information on Tropical Storm Bertha located in the NE Gulf.

Tropical Storm Bertha is near 29.4N 87.7W at 11 PM EDT, and is moving west at 5 kt. Maximum sustained winds are 50 kt with gusts to 60 kt, and the minimum central pressure is 995 mb. South of the sheared convection from Bertha, a weak ridge S of 25N and anchored by a 1015 mb high near 23N91W dominates the southern half of the Gulf waters. The gradient of pressure between the ridge and a surface trough inland Yucatan, supports moderate to fresh NE to E winds in the Bay of Campeche. Over the NW Gulf, moderate to strong SW to W winds associated with Bertha are present, being the strongest winds near 90W or south of Louisiana. In the Florida Straits, winds are moderate from the SE. Otherwise, S of 26N and W of 92W, seas are slight.

For the forecast, Bertha will begin to gradually weaken as it moves to near 29.4N 88.6W Wed morning, then inland to near 29.4N 90.2W Wed evening with maximum sustained winds 40 kt gusts 50 kt. Bertha is forecast to weaken to a tropical depression near 29.3N 95.0W Thu evening, move inland to near 29.5N 97.0W Fri morning, and dissipate Fri evening. 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. This should hold 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. Moderate to fresh winds are also ongoing in the Gulf of Honduras. Seas over these waters are moderate, except rough offshore Colombia. For the remainder of the basin, winds are moderate or weaker, 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. During the same period, fresh to locally strong NE to E winds are expected in the Windward Passage through Wed night. Fresh winds will pulse across the Gulf of Honduras through Wed night as well. Moderate or weaker winds with slight to moderate seas will prevail elsewhere.

Atlantic Ocean

A surface trough extends from near 28N61W to 24N64W and to Puerto Rico. A large area of showers and thunderstorms is associated with this trough, affecting mainly the waters from 20N to 29N between 55W and 70W. Aside from the convection, the trough is bringing moderate to fresh winds to the same region E of the Bahamas. The Bermuda-Azores ridge dominates the remainder of the Atlantic forecast region supporting mainly moderate to locally fresh easterly winds, with the exception of fresh to locally strong N to NE winds in the vicinity of the Canary Islands, and in the approaches to the Windward Passage. Seas are generally moderate across the tropical and subtropical waters.

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 1 hour, 35 minutes ago by NHC Forecaster Ramos