July 19, 2023
It has been almost a month since my last weather update. The tropics have been quiet (other than Don way out in the Atlantic) and while the weather in the Southeast has been notable at times I wouldn't have been telling you anything you didn't already know.
I've been wanting to write a tropical weather update as there has been much discussion but with activity being low in the Atlantic I thought I'd wait until there was something less speculative to discuss (as there is today). The yellow area on the 7-Day Outlook below is a tropical wave that has a 20% chance of development according to the National Hurricane Center. Various models and ensembles have been suggesting this wave might develop around early next week as it approaches the Lesser Antilles and this is what the NHC forecast is indicating. Right now it's too far out in time to be concerned about but it may be something to start paying more attention to in a week's time. In the short term at least it's going to be battling some adverse conditions as it moves west but that may change some by the weekend.
The real item I've wanted to discuss is what to expect for the rest of the season. Without going into too many details there are conflicting indications (and ideas) of what is in store for the rest of the season. On the one hand, the presence of a developing El Nino usually suppresses hurricane activity. On the other hand, virtually the entire North Atlantic is much warmer than average (see below). The thinking is that this additional heat may offset some of the negative impacts of El Nino. This has been reflected in some long term models as well as some seasonal forecasts. Colorado State University has increased its forecast for the season to "average" activity, up from the below average forecast they predicted in the spring. Other forecasters and groups have done the same with some even expecting an above average season. With that said there are still quite a few forecasters who either expect El Nino to still dominate and suppress activity or who are more in a "wait and see" frame of mind. As a somewhat subjective general consensus, average to below average activity from here on out seems reasonable at this point but that could go the other way.
Another factor in this that I've read about is that even though El Nino is evident in sea surface temperatures the atmosphere hasn't fully responded yet. My understanding is this is why we in the Southeast are alternating between several days of rainy and stormy weather followed by hot and dry and then back again as the atmosphere transitions to a more El Nino like state (which would be a little cooler and more rainy for us than a normal summer). The bottom line is we don't know what the rest of the season holds, but I wanted to discuss this briefly because there are some people who are expecting a lot of activity and you might see some of this on social media. They may be correct but we shouldn't be preparing any differently regardless of what the seasonal forecasts are saying because there is always the possibility that any given location may be impacted by a storm.
That's it for today. I'll send another update early next week if development chances increase for the wave in the Atlantic.
Chris
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