With the eastern Pacific quieting down, the Atlantic basin has become active, with Tropical Depression Two forming over the tropical Atlantic yesterday. The depression rapidly intensified into a tropical storm quickly after formation, and is now a Category 1 hurricane on the Saffir-Simpson Hurricane Wind Scale (SSHWS). Beryl is a tiny hurricane over the tropical Atlantic, and is likely to impact the Lesser Antilles as at least a tropical storm on Sunday night. In addition to Beryl, Invest 96L over the western subtropical Atlantic is likely to develop into a tropical depression into the next day or two and could pass very close to the United States east coast early next week.

Beryl becomes an uncommon July hurricane, expected to approach Lesser Antilles late this weekend

As of 11:00 a.m. EDT Friday, Hurricane Beryl was centered near 10.7°N 46.5°W, and was moving westward at about 15 mph. Maximum sustained winds were 70 knots (80 mph), with an estimated minimum pressure of 994 mb. Beryl is a tiny hurricane, with a very small eye surrounded by a ring of deep convection. Models did not predict the rapid intensification of Beryl, which was only a 30 knot (35 mph) tropical depression at this time yesterday. Since Beryl is a very small storm, it is more likely to have quick changes in intensity. Beryl could reach Category 2 status over the next day or so before wind shear begins to quickly increase as it nears the Lesser Antilles. Beryl is currently located over marginally warm sea surface temperatures of about 27°C (80.6°F), and in a low wind shear (less than 10 knots) environment, but this shear is expected to increase to over 20 knots (25 mph) in about 48 hours. The current National Hurricane Center (NHC) forecast predicts Beryl will still be a hurricane when it approaches the Lesser Antilles late Sunday, however, it is also possible that shear could quickly weaken Beryl to a poorly organized tropical storm by that time. It has becoming increasingly likely that Beryl will remain a weak tropical storm as it enters the eastern Caribbean, and Beryl or its remnants (likely to be weak by that time) is likely to be near Hispaniola by Tuesday. It should be stressed that confidence in Beryl’s intensity forecast is very low. Regardless, residents of the central Lesser Antilles should closely monitor Beryl, as some of these areas are still recovering from Hurricanes Irma and Maria last September. Tropical Storm and/or Hurricane Watches will likely be issued soon.

Beryl is the first July hurricane to form in the Atlantic basin since Arthur in 2014, and the first July Atlantic hurricane to form in the Main Development Region (MDR) since Bertha in 2008. Normally, strong development in the deep Atlantic tropics this early would be an indicator of a very active season. However, this does not appear likely to be the case this season, since a weak to moderate El Niño event is likely to emerge later this year and the Atlantic sea surface temperature anomaly pattern is not typically one associated with active hurricane seasons. Regardless, the formation and rapid intensification of Beryl in the deep tropics makes the expectation of a below average season questionable.

96L likely to develop into a tropical depression soon, could pass close to the U.S. East Coast next week

A well-defined area of low pressure (Invest 96L) located southeast of North Carolina is gradually becoming better organized, and shower and thunderstorm activity has increased today. As of 12:00 UTC Friday, Invest 96L was located near 31.5°N 73.1°W, and was drifting slowly northwestward. Maximum sustained winds were 30 knots (35 mph), with an estimated minimum pressure of 1016 mb. Since 96L is already well-defined, it is not far off from becoming a tropical depression, and will likely be classified as one very soon. NHC gives 96L a 70 percent chance of development within 48 hours, and an 80 percent chance of development within 5 days. If 96L becomes a tropical storm it would be named Chris. Originally, models predicted that 96L would be quickly swept out to sea on Sunday and that little development would occur. Steering currents are expected to be weak, which could cause 96L to stall and move little over the next several days. Models have quickly changed to a different solution this morning, with the GFS, ECMWF and UKMET models all predicting 96L to meander near the coast of North Carolina. The GFS and UKMET are more aggressive, developing 96L into a hurricane well east of the Outer Banks by next Wednesday. The 00Z ECMWF model was weaker and kept 96L a tropical storm. Most likely, the steering pattern will keep 96L close to the shore or possibly offshore,and it is unlikely that 96L will be steered well inland. The 12z Friday run of the SHIPS model indicated that environmental conditions were favorable for development, with wind shear expected to remain less than 15 knots for the next 5 days and that 96L would remain over water temperatures above 28°C (82.4°F), though mid-level relative humidity values were expected to only be around 45-55 percent. This dry air may slow development. Rainfall from 96L is likely to reach the Carolinas by Sunday or Monday, regardless if development occurs. Residents of the Carolinas and the mid-Atlantic U.S. coast should closely monitor 96L over the next several days.

I will be back with another post about Beryl and 96L tomorrow. The Atlantic could be on its way to having simultaneously active tropical cyclones in July for the first time since 2011.