Synopsis: the Tropical Atlantic has been pretty quiet since Cristobal but that will likely change over the next few weeks. Below is the Eastern Pacific 5 Day Outlook and as you can see activity is picking up. This kind of activity often foretells future development in the Atlantic but sometimes the East Pacific gets busy and then nothing happens over our way, we'll just have to see.
There is a teleconnection called the Madden-Julian Oscillation (MJO) that circles the global tropics moving to the east. It usually starts in the Indian Ocean, moves east, and then dies out in the Atlantic, although it doesn't always make it all the way to the Atlantic. The MJO is a fairly large area of enhanced convection (stormy weather) that can help kick off tropical development. We need some kind of seed system to get tropical development started and the MJO helps with this. The MJO, and another phenomenon called a Convectively Coupled Kelvin Wave (CCKW, don't worry I really don't understand it either) are responsible for the uptick in activity to our west. This is important because when we see development start in the East Pacific it can give us an idea what may be coming our way in the Caribbean and Atlantic in a few weeks if the MJO continues to the east.
Right now a ton of dust and dry sinking air from the Sahara Desert are preventing tropical development in the Atlantic but it looks like this may subside in the coming weeks. This MJO event doesn't look like it'll be particularly strong when it moves into the Atlantic but it may be enough to kick off tropical development if the dust and dry air settle down. However, if the dust and dry air continue to stream across the Atlantic from the Sahara we probably won't see any development no matter what the MJO does.
Everything continues to point to an active season with above average activity. Several people have mentioned that the tropical wave train coming off Africa is more active than usual for this time of year. Most of the waves are a bit too far south to develop just yet but the signs are there that things could get busy soon. One of the MJO models is forecasting a very active phase of the MJO in the Atlantic for the end of July. I'm not sure how well the models do for the MJO that far out but if that holds there could be trouble in a month.
Another worrisome trend is that steering patterns are such that more storms than normal may get steered toward the US instead of out to sea if the pattern holds. There can be active seasons with an out to sea steering pattern that leads to only a few landfalls. Right now that doesn't look to be the case.
That's all I have for today. We'll just have to keep watching as we get deeper into the season.
Have a great week.
Chris
Weather Nerd Corner
I thought I'd take the opportunity to talk about teleconnections since I brought it up today. "The term "teleconnection pattern" refers to a recurring and persistent, large-scale pattern of pressure and circulation anomalies that spans vast geographical areas." See here for way too much info: https://www.cpc.ncep.noaa.gov/data/teledoc/teleintro.shtml. In much simpler words, just think of a teleconnection as a recurring pattern that we can use to predict the weather when we see that it is occurring or might occur. It is sort of the meteorological equivalent of history repeating itself. The ENSO (El Nino Southern Oscillation) is the most well known teleconnection, and one you've surely heard of.
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