Hurricane Joaquin Forecast Is Complex, East Coast Needs To Monitor Closely

Anytime you have the slightest possibility that a tropical storm or hurricane is going to impact the United States in any way, you’re going to hear about it all over the news media, social media, and everywhere else. In this case, it is good to get people prepared along the East Coast, but I want to break down what’s going on and show you why this forecast is complex. Hopefully this article clears up many of the questions that you may have, despite the current uncertainty.

Current Details On Hurricane Joaquin:

As of 8 pm ET, Hurricane Joaquin has 105 mph sustained winds and is moving to the southwest at 8 mph. A change in direction to the north should occur in a couple of days, but how quickly that occurs will be one of the determining factors as to whether or not this hurricane eventually hits the East Coast or turns northeast out to sea. Keep in mind that I said it’s one of the determining factors; there are other factors I’ll get into in a minute.

One Of Two Scenarios Could Play Out:

The region off the Southeast U.S. coast is the area that I have been monitoring most closely this season, and I even specifically talked about how that region would have a higher probability of seeing some tropical mischief this year. The waters are very warm, and given the right environmental conditions to go along with it, rapid development can occur. In other words, Hurricane Joaquin is in a favorable area for development so further intensification is likely.

When a tropical system develops into a hurricane, the mid and upper-level wind patterns have a much bigger influence on the path the storm takes. This isn’t as much the case with a weaker tropical system. I generally look at the 500 mb pressure level (which is approximately 18,000 ft above the surface) to try to determine where a hurricane like Joaquin will be steered. It seems like a simple concept, but you have to know where your troughs/ridges are going to be located and the timeframe. Also, you have to know when and how much these wind patterns will influence the storm. If this doesn’t make sense, I’m going to start showing you a few maps to clear this up.

A trough is going to continue to dig into the southeastern United States and strengthen as it begins to take on a northwest to southeast orientation. This building trough is eventually going to try to pull Joaquin northward and if it makes the connection, Joaquin could majorly impact somewhere along the East Coast. There is currently a ridge located west of the storm over Florida, so you’re getting that clockwise-flow around that ridge that’s causing Joaquin to currently meander. Once that breaks down and the trough in the Southeast U.S. starts trying to pull this hurricane north, it’ll make that change in direction. If you’re a visual person, the maps below will clear all of this up.

One reason this gets complex is because the models vary on the exact timing on all of this. The European model is much slower (it has Joaquin meandering longer) causing it to entirely miss the trough connection. It tries, but a ridge begins building to its east over the open waters of the Atlantic. This would steer the storm away from the United States.

GFS Joaquin solution

Euro Joaquin solution

The GFS model is much quicker with all of this. It pulls the hurricane up faster, makes the connection with the trough, and a ridge to the hurricane’s northeast helps to steer Joaquin right into the East Coast somewhere along North Carolina/Virginia and has the storm riding up the coast. This would be a very bad scenario, not just because of the very strong winds but the excessive flooding potential.

WPC’s 3 Day Rainfall Forecast:

East Coast flooding

Putting All Of This Together:

The European model is taking Joaquin away from the U.S. while the GFS model has the worst-case scenario. Generally, the European model performs much better than the American models, but right now, I’m actually leaning towards this storm making the connection with the trough and impacting somewhere along the East Coast. However, I will admit that I am uncertain about this. The reason I showed you the two scenarios is because each scenario is very viable and realistic. This shows you why meteorology is so complex, and why timing and the placement of troughs and ridges can be the determining factor between a hurricane slamming the East Coast or not being an issue at all.

So, I’m going to keep a close eye on this. I laid out the meteorology, and while I hate to admit it, there will be some nowcasting involved with this forecast over the next couple of days simply because of these complexities.

If you’re along the East Coast, you need to prepare. It’s much better to be over prepared than not prepared at all. In the meantime, I’ll get all of the details ironed out over the next couple of days.