TD 4 Forms, Saffir-Simpson Scale

The system that was the subject of the last blog post has taken its first step to becoming a major player in the weather during the next 7-14 days. The system has become a tropical depression, the weakest classified tropical system. Winds are currently sustained at 35 mph. As you can see below, the system is still a very long ways from land. Based on historical data of storms that form in that area, the projected path looks fairly consistent. However, those projections can change in a hurry, so don't put too much stock in them until the system evolves more.


So of course, the next questions are: How strong will this become and where will it head? Neither of those questions can be answered for sure yet; its still a very young system, being upgraded just today. However, I do think there is a good bet it will become a hurricane, possibly a "major" one. Some of the "experts" from Accuweather.com have been saying Florida looks like a prime target. But in reality, its impossible to tell with any degree of certainty.

Wait a second...a "major" hurricane? What does that mean? Since hurricane season is heating up, its a good time to review the "Saffir-Simpson Scale," which is used to measure hurricanes based on wind speeds. There are 5 categories of hurricanes, 1 being the weakest, 5 the most powerful and rarest. Anything with a category 3 or higher is considered a "major" hurricane. Here is the complete scale, just focusing on categories and wind speeds:

• Category 1: Winds between 74-95 mph
• Category 2: Winds between 96-100 mph
• Category 3*: Winds between 111-130 mph
• Category 4*: Winds between 131-155
  
• Category 5*: Winds over 156 mph

*Denotes a major hurricane

Now, these winds are sustained winds. Sustained winds are a 1-minute average. Individual gusts within the hurricane can far exceed the sustained wind speeds.

Keep checking back for updates on TD-4, which will like be named either "Dean" or "Erin" depending on another area of disturbed weather in the Western Gulf of Mexico.

Vigorous Tropical Wave Needs Watching

For days now, models have been saying a tropical wave would develop into a hurricane and churn across the Atlantic. Friday, the system in question came off the coast of Africa as a vigorous tropical wave. This wave has stayed healthy in its first 36 hours over water and could become a tropical depression as soon as this afternoon or evening. Conditions look favorable and the models still agree that this should become a hurricane. The thing the models haven't been agreeing on is where this will go, ranging from Mexico to Maine. Most times with storms that form where this one is, it is somewhere between Florida and Virginia that gets hit. Of course, it is way way way too soon to tell where it will go. The storm is still 10-14 days away from the United States coast. I will be posting updates through the week, so stay tuned!