Tropical Storm Franklin quickly intensified to the first hurricane of the 2017 Atlantic hurricane season on Wednesday afternoon over the western Bay of Campeche. Franklin’s strengthening into a hurricane on August 9 is just one day ahead of the climatological average date of the first hurricane – August 10. Franklin is expected to make landfall during the next few hours in the Mexican state of Veracruz, and Hurricane Warnings are in effect from Puerto de Veracruz to Cabo Rojo.

Hurricane Franklin likely to make landfall during the next few hours in Veracruz

Hurricane Franklin was strengthening quickly earlier this evening, but has likely peaked in intensity as it nears landfall in Veracruz. As of 10:00 p.m. CDT (11:00 p.m. EDT) Wednesday, Hurricane Franklin was centered near 20.2°N 96.1°W, and was moving westward at about 13 mph. Maximum sustained winds were 75 knots (85 mph), with an estimated minimum pressure of 985 mb, based on data from an Air Force Hurricane Hunter aircraft. Franklin likely reached its peak intensity a few hours ago, when the aircraft recorded surface winds near 80 knots (90 mph) with an estimated minimum pressure of 981 mb. However, the pressure has since risen to 985 mb while the flight-level winds have decreased slightly. Although an eye has not been easily visible in satellite imagery, it has been visible in microwave imagery. Franklin is likely to maintain a similar intensity for the next few hours or so before weakening begins after landfall. Conditions are likely already beginning to deteriorate along the eastern coast of Veracruz as Franklin nears landfall.

Immediately after landfall, Franklin is expected to begin to weaken quickly as it interacts with the mountainous terrain, and is likely to dissipate by tomorrow evening, if not sooner. However, the mid-level energy of Franklin is likely to cross over the Eastern Pacific, where a new tropical cyclone could form. The National Hurricane Center (NHC) gives Franklin’s remnants a 10 percent chance of development within the next 48 hours, and a 30 percent chance within the next five days. However, any redevelopment in the Eastern Pacific is likely to be short-lived, since environmental conditions are expected to become unfavorable by early next week. The next name on the Eastern Pacific naming list is Jova.

99L becoming better organized, could develop over next few days

Invest 99L, a trough of low pressure located northeast of the Lesser Antilles, has become a little better organized today, with a possible tight low-level circulation briefly visible on satellite imagery.  As of 00:00 UTC Thursday, Invest 99L was centered near 18.4°N 57.8°W, and was moving west-northwestward. Maximum sustained winds were 25 knots (30 mph) with an estimated minimum pressure of 1013 mb. NHC gives 99L a 20 percent chance of development within the next 48 hours, and a 50 percent chance within the next five days. Deep convection has developed over the center of 99L, but cloud tops have warmed a little during the past hour or so. At present, 99L is not far off from the level of organization needed to be classified as a tropical depression, but it is unlikely that the current convection will persist. However, if the convection does persist, 99L could develop into a tropical depression as soon as tomorrow. An ASCAT pass captured part of 99L this evening, but showed that the circulation of 99L may not be as well defined as seen on visible.

There is modest model support for 99L’s development. The 12z Wednesday UKMET model run developed 99L into a tropical depression by early next week before quickly dissipating. The 12z Wednesday ECMWF model run came in much weaker and now only barely develops 99L into a weak tropical storm at most, instead of the hurricane it developed on earlier runs. EPS ensemble support also came in much weaker than previous runs. The 12z Wednesday CMC model run showed development as well. The 18z Wednesday GFS model run continued to show no development, and GEFS members were also not optimistic on development. Regardless, 99L will need to be watched for development. It does not appear likely that 99L will make landfall along the United States East Coast, but some high surf is a possibility if development occurs.

Low pressure area near the Bahamas not likely to develop

The NHC has also included another system in its Tropical Weather Outlook, but it is not likely to develop. A trough of low pressure located over the Bahamas is producing disorganized showers and thunderstorms. NHC gives this system a 10 percent chance of development, both within 48 hours and five days. No reliable global models develop this system, and I would personally be quite surprised to see it develop.

I will be back tomorrow for a post on Franklin, as well as 99L and the Bahamas system.