Tropical Storm Bertha crossed the Lesser Antilles island chain into the Caribbean Friday afternoon. At 8:05 p.m. Eastern Daylight time Friday, the National Hurricane Center placed the center of Bertha 352 miles southeast of San Juan, Puerto Rico. Movement was a brisk 21 knots to the west-northwest. Highest sustained winds are reported at 50 miles an hour, 100 to 150 east-northeast of Bertha's center.
The official track posted by the NHC shows Bertha following a northwesterly course between Puerto Rico and Hispaniola, and then brushing the southern tip of the Bahamas on Sunday, before starting a northeasterly turn on Monday. That course would leave it off the U.S. East Coast. The less reliable 5 day forecast puts Bertha in the mid-Atlantic by Wednesday afternoon.
In his Friday afternoon forecast discussion, NHC forecaster Jack Beven says the storm's overall lack of organization and several other factors should keep Bertha from getting much stronger. “Bertha continues to experience about 15 knots of southwesterly verticalwind shear, and a combination of water vapor imagery and microwave total precipitable water shows abundant dry air near the storm. The forecast track calls for Bertha to interact with one or two upper-level troughs during the next 48 hours or so, which should cause some shear and dry air entrainment to continue.”
Reports out of the Caribbean from Caribbean News Now dot com indicate that Bertha is causing some unpleasant conditions across parts of the Leeward Islands which make up the northern part of the Lesser Antilles, but no signs of any great hazards. The biggest problem might be localized flooding with 1 to 3 inches of rain expected in the northern Leewards and up to 10 inches possible in the southern parts of Puerto Rico.
For those American readers just interested in the bottom line: Bertha continus to pose no direct threat to the U.S. East Coast. Perhaps even better news is that NHC forecasters do not expect any further tropical cyclones to develop over the weekend.