ORLANDO, Fla. – Two tropical waves we’ve been tracking the last several days were designated by the National Hurricane Center as Invests 93L and 94L.
This makes things very interesting. We haven’t had twin tropical cyclones attempting to form so close together in a little while now.
To make matters even more complicated, the pattern over the U.S. and south of where major Hurricane Gabrielle continues to spin is FAR from resolved.
Two systems duking it out in the Atlantic Ocean can lead to some pretty silly things being produced by our computer models. We’re already seeing it.
In terms of our traditional global models, the Euro, the American model GFS, the Canadian, and the German model have all been putting out vastly different results over the last two or so days.
We’re also seeing fairly dramatic adjustments run-to-run. This doesn’t breed much confidence as a forecaster when attempting to predict where a storm could go, let alone trying to piece together the intricate puzzle of what the local environment will look like driving a storm forward.
Let’s begin west to east, as I always say. Over the U.S. we’re monitoring the progression of our next trough, and the first attempt of a fall cold front now that we’re into the calendar season.
Late last week into this weekend prior, the forecast looked like a put-together, deep trough sweeping through the eastern U.S. with the southernmost reach of it coming across our area in Central Florida.
Well, that’s changed.
Looking at the latest guidance as of Tuesday morning, we’re seeing some dispersion in the model solutions, suggesting the northern portion of the trough in the jet stream will continue east moving faster than initially anticipated.
The southern half could break off and leave a piece of spinning energy over the Dixie Alley, Deep South, or Southeast US into this weekend.
If this does occur, that upper level low that’s leftover from the split in the jet stream will make things that much more difficult to predict since models tend to struggle badly with how these cut-off entities behave.
They also have a natural tendency to magnetize tropical features in their immediate vicinity. The early morning run of the European model shows Invest 94L doing as such, coming a bit closer to our east coast and especially the Georgia coastline.
Now, with cut-off lows being tricky to forecast and acting as a way to attract any tropical systems nearby, what adds another layer of mystery are our two invest areas being right up against one another.
They’re practically rubbing elbows, figuratively speaking, when you look at the two of them on satellite.
A phenomena called the “Fujiwhara” effect tends to occur when you have two distinct low pressure centers trying to take up as much local atmosphere as possible.
[WATCH BELOW: Meteorologist Jonathan Kegges discusses the Fujiwara effect]
Kind of like when you’re in a crowded hallway and instead of bumping into the people beside you, you’re left having to maneuver this way and that to go around them.
When you put it all together there’s a lot to resolve before we can truly determine where precisely each of these tropical areas of investigation will. One thing is for certain, while development chances continue to go up, it would behoove all of us in eastern Florida up through the Carolinas to keep checking in with trusted weather sources in the meantime.
Especially for Invest 94L out ahead of the cluster of tropical low pressures, it seems like we’re more poised to see some sort of impacts up the east coast than with what could go on to become future Humberto.
We’ll have to keep watching! And we’ll keep you updated as we learn more information.