The tropics in the Atlantic and East Pacific are likely to remain quiet for the next week or two. Don’t expect the formation of Bret or Beatriz in the near future. Last week, a somewhat favorable Madden-Julian Oscillation (MJO) pattern allowed Tropical Storm Adrian to spin up in the East Pacific. However, the favorable MJO has moved out of the Western Hemisphere, and is heading towards the Indian Ocean and Western Pacific. A favorable MJO pattern is characterized by moist, rising air, allowing developing tropical systems to generate deep convection. An unfavorable MJO pattern is characterized by dry, sinking air, which suppresses thunderstorm development with developing systems. As a result, it is somewhat uncommon to see tropical cyclones develop with an unfavorable MJO, except at peak season.

The CFS and GFS models show the MJO remaining unfavorable for the next 7-10 days, with below average rainfall in much of the basin. However, after that time, near the last few days of May and first few days of June, a more favorable MJO pattern could develop in the Atlantic Ocean. It is still quite far out, but this may be our next opportunity for something with a name to spin up in the Western Hemisphere. We will have to keep watching!

I’ll be back for a daily post tomorrow about my experiences last week visiting the National Hurricane Center’s Hurricane Awareness Tour at Raleigh-Durham International Airport.