Despite the official start of hurricane season starting less than three weeks ago, we are watching two tropical waves in the Atlantic basin, one of which may eventually impact the United States. These two tropical waves (dubbed 92L and 93L) have been monitored for development by the National Hurricane Center (NHC) for several days now. Of the two, 93L located in the Western Caribbean Sea has the best chance of developing while 92L, located east of the South American continent, is running out of time to develop. June and July are often quiet months across the Atlantic with hurricane most development occurring between mid-August and mid-October.
NOAA infrared satellite image of 92L and 93L in the Atlantic basin.
The first tropical wave is 92L which is located southeast of the Windward Islands. Many tropical waves emerge off the coast of Africa over the course of hurricane season. However development in the eastern and central Atlantic typically occurs later in the year. Conditions are not typically favorable for development in June. Many tropical waves like 92L will go on to develop in the Pacific ocean. In their latest outlook, the NHC gives a 50% chance of development for 92L over the next five days though the true window of development is much shorter. Some of our computer models continue to show development but I believe it is unlikely it will become a named storm. I give 40% odds of 92L becoming a tropical depression and 10% odds of it becoming a named storm.
NOAA visible satellite image of tropical wave 92L.
The other tropical wave has a much greater chance of development but it is still not a sure thing. The tropical wave called 93L is located off the coast of Central America. It continues to produce an area of heavy showers and thunderstorms bringing significant rainfall to the region. This system is expected to drift north over the next few days with development expected in the Gulf of Mexico early next week. The Gulf of Mexico is one of the main areas we watch for tropical cyclone development in June and the NHC gives 80% odds of development over the next five days. Regardless of development, this system could be a heavy rain maker for parts of the Southeastern United States. I put 75% odds of 93L becoming a tropical depression and 60% odds of it becoming a named storm. Should either tropical wave become a named storm, it will be given the name Bret.
Locations of all June tropical storms in our hurricane database.
You may be wondering why the next named storm would start with a B and not an A. The reason why is because hurricane season already started back in April! Our season started early for the third year in a row with the development of Arlene. Prior to 2003, no known tropical storms have existed in the Atlantic basin. This all changed when Tropical Storm Ana formed near Bermuda. Both of these rare early season storms did not form from tropical waves but from a non-tropical system that moved off the eastern United States. Many early and late season storms develop this wave becoming cut off from the main flow long enough to develop tropical characteristics. The unusual formation of Arlene was preceded by an even rarer event when Hurricane Alex formed in January in the far northeastern Atlantic. Whenever a storm forms early, many wonder if that indicates an active season but there is no correlation between early season storms and overall tropical activity.