Special Feature

Tropical Storm Bertha is centered near 29.4N 87.2W at 21/2100 UTC or 90 nm WSW of Panama City Florida, moving NW 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 again, with bursts of deep convection displaced to the south by strong northerly shear. The convection consists of numerous moderate to scattered strong convection covering the waters from 27N to 29N between 86W and 88W. Scattered moderate to isolated strong convection is noted elsewhere from 26N to 28N between 87W and 92W. On the forecast track, Bertha will move near or along the northern Gulf Coast during the next couple of days or so. Little change in strength is expected tonight, and gradual weakening is forecast Wednesday through Friday. Bertha is expected to produce total rainfall amounts of 2 to 4 inches with isolated higher totals around 6 inches through Thursday along the central Gulf Coast from western Florida into southern Louisiana. 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. 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 32W from 05N to 19W, moving W at 15 to 20 kt. Dry air surrounding the wave is precluding any convection near it at this time.

Another tropical wave is along 47W from 09N to 21N, moving W at 10 to 15 kt. Convection is limited near the wave axis.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic through the coast of Senegal near 14N17W, and continues southwestward to 10N25W and to 08N35W. The ITCZ extends from 08N35W to the coast of Guyana near 07N58W. Scattered moderate convection is from 04N to 09N between 29W and 40W. Similar convective activity is noted over northern Guyana.

Gulf Of America

Please refer to the Special Features section for information on Tropical Storm Bertha located in the NE Gulf. The most recent scatterometer data indicate that the fresh to strong southerly winds associated with the periphery of Bertha extend eastward reaching the west coast of Florida, including the Tampa Bay area, N of 25N. Moderate or weaker winds are noted W of 90W and over the southeastern Gulf waters under a weak ridge.

For the forecast, Tropical Storm Bertha is near 29.4N 87.2W at 5 PM EDT, and is moving northwest at 5 kt. Maximum sustained winds are 50 kt with gusts to 60 kt, and the minimum central pressure is 995 mb. Bertha will weaken slightly as it moves toward southeast Louisiana overnight, reaching 29.6N 87.9W by Wed morning, 29.5N 89.3W by Wed afternoon, and 29.3N 91.4W by Thu morning. Bertha will weaken further as it moves along the coast of Louisiana, reaching 29.4N 93.4W Thu afternoon, then moving inland and weakening to a tropical depression near 29.8N 95.6W by Fri morning. The remnant low of Bertha will continue inland reaching 30.3N 97.6W by Fri afternoon. Bertha will dissipate Sat afternoon. Swells generated by Bertha are affecting portions of the Gulf coast of Florida and are likely to spread westward during the rest of the week. Elsewhere, weak high pressure over the western Gulf will dissipate by midweek. After midweek, Atlantic high pressure will extend westward to the central Gulf following Bertha.

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 indicates seas of 8 to 9 ft. 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 29N58W to 19N63W. A large area of showers and thunderstorms is associated with this trough. This convective activity is affecting mainly the waters from 22N to 29N between 55W and 70W. Scatterometer data confirmed the presence of this trough and provided observations of fresh to locally strong winds on either side of the trough N of 23N. High pressure dominates the remainder of the Atlantic forecast region supporting mainly gentle to moderate winds, with the exception of fresh to locally strong N to NE winds between the Canary Islands, moderate to fresh NE winds N of the tropical wave located near 32W, and moderate to fresh winds offshore Haiti and eastern Cuba, including approaches to the Windward Passage. Seas are generally moderate, with locally rough seas E of 35W based on altimeter data.

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. 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, 44 minutes ago by NHC Forecaster Gr