Gordon hits the Azores, 94L, 95L, and 96L all worth watching - 8/20/12
Good morning everyone and welcome to my tropical weather update for Monday, August 20th, 2012. The tropics are responding to the time of year with having 3 different systems to watch out in the Atlantic not including, Hurricane Gordon, which managed to make a rather unexpected run at Category 3 status, peaking at 110mph, just shy of becoming a major hurricane as it approached the Azores. Gordon is similar, in many ways to it's predecessor - Hurricane Gordon in 2006. That system also brought tropical storm force winds to the Azores. However the Azores is used to these kind of systems in the winter bringing howling rains and is not a real threat for serious damage as it is now down to tropical storm status.
Figure 1. Hurricane Gordon at peak intensity.
Disturbance Invest 94L a threat to develop into Isaac
Yet another confusing and hard to understand situation is developing in the Atlantic. In a seemingly repeat of the events that spawned Ernesto, we are now facing a similar situation, a disorganized tropical wave with so-so model support and a lot of dry air. That is Invest 94L currently located out in the tropical Atlantic. However, I do not think 94L will in the long run become another Hurricane Ernesto, rather I think there's a chance that it could be a threat to islands and even the United States. The GFS and European models have all backed off on an intense system in the short term, this is thanks to the amount of forward speed 94L is having to deal with. Buoy data shows that 94L indeed has a closed circulation. The NHC is giving 94L an 80% of becoming a tropical cyclone in the next 48 hours.
Figure 2. Latest satellite image of Invest 94L.
I believe that 94L will probably become Tropical Storm Isaac sometime in the next 72 hours, and that the European model is wrong in suggesting that this won't even become a tropical cyclone. This is one of those times where you simply can't look at the models for your predictions. It's mid to late August, there's a tropical wave out in the Atlantic with low shear and working out dry air out of its system. That alone is good enough reason to believe it has a chance to develop.
Figure 3. Latest intensity model predictions.
The GFS is saying that 94L will develop but will not become a major threat until it reaches the Gulf of Mexico. I will be honest, I believe the HWRF/CMC/UKMET seem to have the better handle with this system in terms of short term intensification. The pattern in place does not support 94L becoming a Caribbean cruiser as there is a weakness at ~60W, so I do not believe that it will track all the way to the Yucatan. Eventually, I believe it will head north some.
Figure 4. Latest 'Spaghetti' model track for Invest 94L.
Invest 95L a threat to develop in the Gulf of Mexico
Associated with the remnant area of low pressure from Helene, which briefly developed between blog posts in the Gulf of Mexico and quickly moved inland, 95L has developed in the Gulf of Mexico. Little movement is expected, though I expect that the general path will be NE as there is a weak trough draped out over the Gulf that is helping to give this system some 'juice' so to speak. 95L has little to no model support with the exception of some of the FIM and GFS ensemble members. The NHC is giving 95L a 30% chance of developing into a tropical cyclone over the next 48 hours. Heavy rain should be expected over the Gulf and Texas during that timeframe.
Figure 5. Latest satellite image of Invest 95L.
Invest 96L could slowly develop over the next few days.
Our final area of interest is Invest 96L currently located south of the Cape Verde islands. Satellite reveals a disorganized wave but with less dry air than what 94L had to deal with. Model support is very limited about this system, and it appears this system will probably be similar to the invest that spawned TD7 - eventually Helene - which also had no model support. I do not expect major development in the next 24-48 hours. The National Hurricane Center is currently giving this low a 20% chance of development.
Figure 6. Current satellite image of Invest 96L.