Four areas to watch, one may approach the southern Mid-Atlantic?

Good evening.

It’s a busy night in the tropics as four systems are currently floating around the Atlantic. We have been tracking 99L all week in frustration as it continues to struggle, but its time may be coming. Fortunately, it is no threat to our area. Likewise, Gaston – about to become a hurricane officially (based on best track and satellite data) – should remain far from our shores. Two new systems have our attention, however. Models are actually in good agreement all the way around for all the systems, at least for track.

Current satellite image of the broader Atlantic (image from NHC/NCDC) annotated showing current systems as of 8:45 pm EDT August 27, 2016.

Current satellite image of the broader Atlantic (image from NHC/NCDC) annotated showing current systems as of 8:45 pm EDT August 27, 2016.

Hurricane Gaston

The long awaited strengthening of Gaston is underway, and it has clearly intensified today. At the last advisory it was still a tropical storm with 70 mph sustained winds, but new satellite imagery and best track data suggest that Gaston has intensified and is once again a hurricane. At this time, sustained winds are estimated around 85 mph. Continued intensification is likely through tomorrow or Monday, and I personally believe Gaston will become a major hurricane by then. Eventually, cooler waters will allow it to weaken and begin to lose tropical characteristics. It is no threat to land.

Disturbance/Invest 99L
Model suite based on interpolated 12Z and 18Z runs for the future track of 99L. Most runs and ensembles (throw out the BAMs) recurve it into the NW Florida coast. (SFWMD)

Model suite based on interpolated 12Z and 18Z runs for the future track of 99L. Most runs and ensembles (throw out the BAMs) recurve it into the NW Florida coast. (SFWMD)

All week this has been our primary focus. The NHC has increased the probability for development up to 50%, which might be a bit conservative. Models are in good agreement now that it will turn towards the northwestern Florida coast, somewhere between Tampa and Panama City Beach. Hence Scenario 3 from Thursday’s post appears to be the probable end result (not 100% certain though!) It should quickly go out to sea afterward as the ridge to the north breaks down – hence it will likely not be a threat to the Northeast or Mid-Atlantic.

18Z HWRF August 27, 2016 model run for late Wednesday afternoon (5:00 am EDT). 99L becomes a powerful hurricane (likely Hermine, possibly Ian) making landfall near Tampa Bay as a Category 3 or 4 storm. This is unlikely.

18Z HWRF August 27, 2016 model run for late Wednesday afternoon (5:00 am EDT). 99L becomes a powerful hurricane (likely Hermine, possibly Ian) making landfall near Tampa Bay as a Category 3 or 4 storm. This is unlikely.

Conditions are somewhat more favorable for development now, but not completely ideal, which makes the HWRF run (above) seem very far-fetched. I estimate that 99L will become a tropical depression or tropical storm by Monday, and MAYBE a low-end hurricane before landfall, but I have a hard time believing the most aggressive models. But that is just me.

Disturbance/Invest 91L

This new system, partially due to the remnants of Fiona although a new circulation appears to have formed instead, is currently located southwest of Bermuda. It is on a westward trajectory towards the coast of North Carolina. Poorly organized, the NHC only gives this low a 30% chance of development, which is probably accurate. If this wants to become a tropical cyclone, it most likely has to become one by late tomorrow or early Monday, since shear increases starting Monday and water becomes cooler after that as well. Most models do little with this system.

In terms of impact, regardless of development most of the impact will likely be offshore. Some rainfall and breezy to windy conditions are possible in the Outer Banks of North Carolina and perhaps in the Virginia Capes, but it shouldn’t spread inland. Rough seas and rip currents are concerns for beaches. Overall, even if this becomes a named storm, it should not amount to much.

Next system off Africa

This is at least 10 to 12 days from any land but an early heads up is warranted. Since a few ultra long range models show this low developing into a powerful hurricane and approaching (or even reaching) the east coast, the hype machine may turn on over the coming days. In my view, it is too far-fetched to even bother posting the solution. We shouldn’t worry too much yet as a lot can happen in that time frame. I will focus more on this once it gets into the forecast range (about 6 to 8 days out). It is currently off Africa and the NHC has tagged it with a 40% chance of development within 5 days. It will likely be classified as Invest 92L in the next couple days.

Conclusion

These are busy times and the media hype machine may go into overdrive next week and into the Labor Day weekend if current trends hold. There are multiple areas to watch, although there are no significant imminent threats to our area. We need to remember to keep our sources to the best meteorologists available. One low could bring rain and wind to a few areas in the Mid-Atlantic, but should not be a significant weather maker for our region overall. Then we wait for the following system – cautiously.

No matter what, now is not the time to overreact. Models are not gospel, and they aren’t even reliable until we get to about a week out. While the Southeast could experience more severe weather, even there uncertainty is very high in terms of potential impacts – follow your local meteorologists on social media for the latest and stay tuned to local weather offices and outlets. Enjoy the week ahead if you are in the Mid-Atlantic or Northeast, just keep an eye on the tropics.

Forecaster Craig Ceecee – @Ceecee_Wx

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