Lead Forecaster Daniel Crawley
Tropical Weather is something that we have not had to worry about lately across the majority of the US coastal regions. After getting three named systems in the first five weeks of the 2022 Atlantic Hurricane Season, we have gone another six weeks with no additional systems in the basin.
Looking at the Water Vapor image from early Tuesday morning, the Atlantic Basin remains quiet on August 16th. A weak system related to a decayed cold front tried its best to develop into a tropical depression in the Western Gulf of Mexico this past weekend. Fortunately it ran out of time moving into Deep South Texas before being classified. Meanwhile if you look at the MDR (Main Development Region) there are some large areas of dry mid/upper level air and that is a good deterrent to tropical cyclone development.
The inactive tropical activity is not just limited to the Atlantic Basin. The entire Northern Hemisphere is running low on ACE (Accumulated Cyclone Energy) for Mid-August. The Atlantic is running at less than 20 percent for the season and the Hemisphere is at roughly 62%.
With that said, Mid August is when the frequency of tropical genesis in the Atlantic Basin really begins to ramp up. September 10th is recognized as the peak of the season in the Atlantic Basin. So we are heading to what should be the most active time of the year.
Looking at some of the global teleconnections and climate indices, we are currently sitting in a neutral phase so-to-speak. The MJO (Madden-Julian Oscillation) was updated on Monday and it shows the MJO currently in the null phase. However over the next two weeks the MJO may work into a more supportive phase for tropical activity. The confidence on this is not very high due to the fact that all summer long the MJO projections have been too aggressive compared to verification.
Another factor that can impact development in the MDR is the amount of Saharan Dust existent in the Atlantic Basin. Compared to earlier in the summer the Saharan Dust is not as prevalent across the tropics…here’s a look at the projections for dust over the next 10 days…
Global computer models and ensembles have been void of guidance of obvious tropical development in recent weeks but the long range is finally showing hints of life specifically in the Main Development Region as we head toward the end of the month.
By the middle of next week there are indications of a potent tropical wave that could emerge off Africa. With a broad Atlantic Ridge in place, this would lead to something gradually getting its act together.
Once we get to Day 12, which would be next Sunday (August 28th), ensembles have various low positions out in the middle of the Atlantic Basin with a lead disturbance possibly trying to develop somewhere in the Caribbean to north of Hispanola.
So, don’t be surprised if the tropics finally wakes up from its extended slumber. Given how frontal boundaries have been dropping into the Southeast US, we can’t rule out another attempt at homegrown development as well in the Gulf or off the East Coast.
One final map to look at is the 15-Day precipitation anomaly for the entire Atlantic Basin. While there are no obvious precip tracks across the region, there is a general abundance of moisture in the Caribbean over the next two weeks…we shall see!