Crown Weather posted this morning:
Tropical Weather Discussion
Issued: Monday, June 21, 2010 800 am EDT/700 am CDT
Tropical Cyclone Development Likely In The Western Caribbean Late This Week Or This Weekend (Now Invest 93-L): This week I will be watching the Caribbean Sea extremely closely for the potential of tropical cyclone development. It appears that this development will come from the combination of an area of disturbed weather in Venezuela and the tropical wave that is now located in the eastern Caribbean. It also appears that what is left of Invest 92-L will help to set up this possibility by lowering air pressures in the western Caribbean. So, the combination of all of this may cause a tropical cyclone to form later this week in the western Caribbean.
Satellite imagery this morning showed numerous shower and thunderstorm activity over the eastern Caribbean that is associated with a tropical wave in that area. This disturbance will push westward reaching the western Caribbean by about Wednesday or Thursday. Environmental conditions are forecast to be favorable from the western Caribbean northward into the Gulf of Mexico from late this week through this weekend. The European, Canadian and NOGAPS models all agree that a tropical cyclone will form in the western Caribbean as we head into Thursday or Friday. The European model is by far the strongest of the model suite and I spit my coffee out when I saw it! The European model forecasts a major hurricane making landfall on the northern Gulf coast next Wednesday. On the other hand, the GFS model shows very little, if any tropical cyclone formation in the next week or so. With that said, the GFS model is forecasting favorable environmental conditions late this week through this weekend and into next week.
There are a few things I want to point out:
The first is that even though the European model is forecasting a major hurricane early next week in the Gulf of Mexico; it does not mean it will actually happen. The European model sometimes (not often) ramps storms up too much and also there is no tropical cyclone to speak of yet. For the time being, this is just an extremely frightening possibility, but it is not a certainty.
The second is that the European model should also be taken seriously as it has been THE BEST model in the Atlantic Basin for the last 3 years. The European model has been far and none the king in correctly forecasting tropical systems in the Atlantic Basin. With that said, like I said in my first point, the European model is not infallible and it may end up being wrong.
So, the key question of the morning is which model guidance will be correct?? The European and Canadian model’s forecast of a significant tropical cyclone in the Gulf of Mexico or the GFS model’s forecast of nothing forming over the next 7 to 10 days.
The reason for the change in the forecast track from the Canadian and European models is that they are now forecasting that the ridge of high pressure in the southeastern United States may break down somewhat this weekend into next week, instead of holding strong. This would cause a southeasterly wind flow from the Caribbean into the Gulf of Mexico and potentially steer a tropical system from the Caribbean northward into the Gulf of Mexico.
So, bottom line is that the chance for tropical cyclone development in the western Caribbean late this week into this weekend is increasing and I would put the chance of this occurring at 50 percent. This increase in probability of formation is due to the fact that we have an active disturbance in the eastern Caribbean, forecast favorable environmental conditions in the western Caribbean and an upward motion pulse of the Madden Julian Oscillation now moving into the Atlantic. So, I think it’s fairly likely that we will see our first named storm, Alex, by this weekend.
Right now, I am focused much more on development possibilities rather than any track forecasts. Once a system does form, we can try and pin down a forecast track. So, all interests in the western Caribbean and the Gulf of Mexico, including the entire US Gulf coast should keep an eye on this. Obviously, I will be monitoring things very closely and will keep you all updated.
The next tropical weather discussion will be issued by 7 am EDT/6 am CDT Tuesday morning.