All Eyes Along East Coast Watching Cristobal

Third Named Storm of the Atlantic Season Forms on Saturday; Bringing Rain To Turks and Caicos

In what has been a dull season by recent standards in the Atlantic, the fourth tropical cyclone and third named storm of the season, Tropical Storm Cristobal, is departing from the waters near the Southeastern Bahamas and Turks and Caicos Islands. The fact that Cristobal has even gotten to this point is a testament to its fortitude. The question is will it ramp up into the season’s third hurricane, and more importantly, will it impact anywhere along the East Coast of the United States. The answer to the latter question is not likely.

The storm originally formed modestly off the West African coast last week, and pushed its way westward. It was a fairly impressive tempest upon arrival in the Eastern Atlantic, but the waters and atmosphere there have not been kind to nurturing Cape Verde Storms this season. The combination of dry air over much of the Tropical Atlantic Ocean this season as well as hostile upper level winds have made it difficult for storms to fire up. Tropical Depression #3 and Hurricane Bertha encountered these difficulties. Bertha was able to withstand it to become the season’s second hurricane in early August.

The models from last week were hinting though that Cristobal would form. It took a bit of time, but things are slowly beginning to come together for the storm. Some northwesterly shear has been the hindrance so far, but that is forecast to slacken within the next 72 hours. Combine that with the presence of adequate sea surface temperatures (around 29 degrees C), and we could be seeing a hurricane by Tuesday or Wednesday. The latest intensity model forecast from the National Hurricane Center indicates that Cristobal will be just below minimal hurricane strength in 48 hours, a hurricane within 72 hours, and an 80 mph hurricane in 4 days.

Bryan Norcross of The Weather Channel had a good breakdown of the storm on Saturday night with several players in the environment that could play a role in the future course of the storm. One is the subtropical ridge in the Atlantic, which is driving the storm westward. Another one is a trough that is draped just to the north of the storm off the east coast of North Carolina of the United States. These two players will continue to battle for a bit and Cristobal will be slugging through the Bahamas for the next couple days. The trough off the Carolinas is then forecast to move to the Northeast, Cristobal will try to take advantage of the gap between the trough and the ridge, and turn towards the coast, but a second trough is supposed to move across the United States, and kick the storm away from a US coastal impact.

There is some disagreement among the models, but they are generally in agreement with the American (GFS) model and the European (ECMWF) model. Timing and speed is the key difference. According to the 5:00 PM Sunday afternoon discussion from the National Hurricane Center, the GFS solution has the system moving more slowly and lags behind the other models by about 500 nautical miles within 5 days. Overall though, Cristobal’s forecast track appears to be heading in the same direction as Bertha’s earlier this month. The NHC guidance has the storm pushing northward, and between the U.S. East Coast and Bermuda, and then turning out to sea.