Matthew’s Forecast Track Returns To Being Complicated
Remember the forecast for Matthew that I was talking about the past couple of days? Things have become a little more complicated again. More on that in a moment.
Hurricane Matthew
5:00 AM EDT on October 05, 2016
Location 21.1 N -74.6 W
Winds: 125 mph Gust: 155 mph
Pressure: 962 mb
Category: 3
Moving: N at 10 mph
Matthew is a category 3 hurricane with winds at 125 mph with gusts to 155 mph. Hurricane Matthew took a hit from its trip through Haiti and Cuba. It held strong but ultimately weakened somewhat over the past 24 hours. It remains a category 3 hurricane so I use the word “weakened” lightly in this situation. The center of the storm is now exiting the coast of Cuba and in a few hours the bulk of the storm should be clear of Cuba.
Matthew will then enter a region that is very favorable for tropical cyclone intensification. It will take Matthew 24 hours to recover and organize its core once again. We could see Matthew return to category 4 status over the next 48 hours as it passes over the Bahamas. A hurricane warning has gone up for all the islands in the Bahamas as most of the island chain will experience Hurricane Matthew over the next 48 hours. Given little land interaction with the core of the storm, this storm will pass through the like they aren’t even there. If you live in this area and can leave, do so. If you can’t leave, prepare for major hurricane conditions and stay safe.
Beyond that the forecast track seemed so much easier to forecast. We had a setup that made perfect sense all we needed to do it tidy up some of the margins and we would have a good understanding of what was going to happen. Or so we thought.
Yesterday I misjudged the Euro model’s solution as an outlier, question its handling of the trough over the central US. I felt that it forecast the trough way too weak. I took a glance at the 18Z GEFS solutions and began to lean towards the Euro solution. I began to question my earlier assumption the Euro could be wrong. When I woke up this morning, I found that the 00Z and 06Z GFS operational model and half the ensemble members leaning towards that same solution.
So lets take a closer look as to why the forecast philosophy changed so much so quickly:
The forecast still calls for a strong ridge to the east which will still bring the center of the storm very close to the Florida east coast. It will begin rounding the western edge of the ridge as the trough approaches the eastern CONUS. This is where the models begin to diverge. Like before the Euro showed the trough being much weaker and much flatter that previous forecast model solutions before it. The storm will also be much slower than previous models showed previously. These two factors combine will lead to Matthew missing the trough which was suppose to take the storm to the northeast just of the southeast coast and then out to sea.
After missing the trough the storm will begin moving east off the Georgia/South Carolina coast as the ridge over the Atlantic begins to weaken and a ridge behind the trough over the US will begin to build in north of the storm. As the ridge builds in the storm is expected to slow and get trapped under this ridge to the north. On Monday, the ridge will strengthen and begin to force Matthew south and southwest in response. After this the models diverge on whether to steer Matthew on this course moving back towards south Florida or take it on a full loop and back out to sea. During this time the storm will be weakening so if it does somehow make it back to Florida next week, we shouldn’t have to deal with a strong hurricane this time.
Matthew is forecast to be a strong category 2 or 3 as it approaches the coast of Florida. Even if the storm does not make actual landfall, hurricane conditions are expected along the coast and as well as some areas inland. Tropical storm force winds will extend out further than that some areas in central Florida could also see some of the action.
It is worth noting that the 00Z CMC model does not show this change in its solution, keeping on its original track up the coast and off the North Carolina coast out to sea.
There is still plenty of time to get this forecast wrong again and I encourage all of those on the southeast coast to pay close attention to this storm. This forecast is fairly new and its unknown if this forecast will occur given all the model’s changes over the past few days. Honestly, I’m still not convinced that the trough will be that weak so I will be interested to see if this holds up.
I want to emphasize this again. Do not count on one more more models to be an accurate forecast or an official forecast. Consult the NHC’s official track and make sure you make your decisions based on the information you receive from them, the NWS, and local authorities. This forecast represents my opinion and may not be the opinion of the NHC.
By the way, Tropical Storm Nicole is still out there. She does not pose a threat to land any time soon so she might not get the attention that Matthew is getting.
I will update with any new information around lunch today and provide a full discussion later this afternoon. Have a great Wednesday!
Update: The 12Z GFS model run is similar to the previous two runs showing a weaker trough, slower forward speed of Matthew, and a strong ridge building over the Gulf States. The weaker trough and slower speed means the trough will not pick up the storm while it is along the east coast. Instead the ridge will push it away from the South Carolina coast. This is where things get complicated. High pressure will advance north of the storm will build southeastward causing the storm to turn southwestward towards the Florida coast again. It is uncertain at this time to accurately predict how all of these interactions are going to affect the storm. The GFS and Euro are hinting at this solution while the NAM and CMC are still up the coast and off North Carolina. The difference between the two are how strong the trough is as it moves east and how strong the ridge is after the troughs passage.
I know this update has a lot in it and I will provide a more detailed discussion later this afternoon when I have more time.