Watching tropical storm Isaac: what does it mean for the RNC?

http://www.guardian.co.uk/world/us-news-blog/2012/aug/22/tropical-storm-isaac-rnc

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The worlds of politics and weather are combining as tropical storm Isaac is expected to turn into a hurricane and hit Florida in time for the Republican national convention next week. Let's first talk about Isaac, and then we'll look at the websites where you and I can follow storms for the upcoming season.

Right now, Isaac is 140 miles east of Guadeloupe, and could strengthen into a hurricane by Thursday. Hurricane watches are out for the Dominican Republic, Puerto Rico and the Virgin Islands.

The National Hurricane Center's five-day tropical storm wind probabilities page illustrates the where Isaac should be turning next.

The NHC currently puts the probability of tropical storm winds hitting Tampa in the next 5 days at 10% to 20%. That may seem low, but that is about as high as you will get this far out. The probability will go up as confidence in the storm track does.

The NHC current forecast track gives reason to believe the probability will go up in Tampa.

As you can see, the NHC believes the most likely path puts Isaac over the Gulf of Mexico south of Naples, Florida at 8am on Monday. Forecast maximum wind speeds are 80mph, good enough for a level 1 hurricane.

But let's get into some more details.

First, note that there is still a wide range in where Isaac could go. Right now the NHC has a track of anywhere well to the east to well to the west of Florida. The error cone is there because there is a spread in the hurricane models.

I won't bore you with all the reasons for these track differences, but it mostly has to do with how the models view mid-level ridging in the northern Gulf of Mexico. The stronger (weaker) the ridge, an area defined by high pressure, the harder (easier) time the storm, an area of low pressure, will have at strengthening and coming north.

Second, the winds are forecast to be fierce, but nothing historic. It is not wise to mess with a hurricane, but 80mph is different from the 125mph with which Katrina hit New Orleans. Indeed, the probability that Isaac is not a hurricane (maximum winds of 74mph or greater) on Monday morning is 70%.

The sort of damage one expects from a category 1 – minor home damage, tree branches down, and power outages – is not likely something that would postpone a convention for any long stretch of time. Isaac's interactions with islands of the Caribbean combined with its relatively weak standing at the moment is not going to allow for major strengthening.

Third, the timing for Isaac is Monday, not later in the week. Hurricanes can meander and the time for Isaac to hit near Tampa is uncertain. Yet, we have a pretty good handle that Monday seems a lot more likely than any other day during the week. In fact, the GFS already has Isaac well past Tampa by 8am on Monday.

Hurricane damage such as downed trees and power outages can last until well after the storm has passed. A category 1 hurricane's winds are, however, less likely to have longer lasting effects. Rains can certainly create longer-term flooding problems. At this point, the rain forecasts are pointing towards some flooding, but not biblical-style problems.

So what does this all mean for Isaac and the RNC right now?

Isaac certainly threatens Florida. The timing of the storm is such that a delay in the start of convention is a possibility. The storm's strength and timing do not at this point suggest that Paul Ryan's nomination as vice-president on Wednesday or Mitt Romney's nomination on Thursday are likely to be interrupted by Isaac.

But of course, storm tracks do change. That's why it's important to stay on top of the latest information. To do so, you can visit following websites, which are for pro and rookie alike.

National Hurricane Center

This should be the first stop for anyone. You get the latest up-to-date conditions, official government storm track, and forecast probabilities. You can go in-depth with the forecast or stay simple with the storm advisory among other tools.

Weather Underground Tropical

Easy to use, this site has it all. Scroll down the page a little, and you'll find all sorts of satellite imagery, buoy data, actual computer models and instructions on how to use them, and long-range hurricane forecasts.

My Fox Hurricane

I'm just not sure there is a site that has more visualizations in such a little space. With radars, models, ocean temperatures, and a lot more, you can quickly know what is going on without being a pro. Plus, there are many Florida specific images that will come in handy with Isaac.

Storm Adivsory

This site isn't flashy, but it does two things very well. You get a nice aggregated list of all articles having to do with hurricanes. You also get have a tremendous visualized storm archive. If you want to know how any track or speed of a current storm compares with ones form the past, this site is perfect.

American Weather Forum

Want to interact with weather diehards? Go here. Weather enthusiasts from Maine to Florida gather to discuss the latest trends in weather. Professional meteorologists are known to post among the amateurs. If you don't know very much, it's probably best to learn more before posting.

You can use Isaac as a test run for these websites in what promises to be an exciting year in the Atlantic.