2007 Hurricane and Tropical Storm Forecasts

Most of the well-known forecasters have weighed in with their 2007 forecasts now, so let’s take a look at what is being predicted.

• NHC/NOAA Hurricane forecast summary:
13 to 17 tropical storms
7 to 10 of them becoming hurricanes.
75% chance of above normal hurricane activity according to the NOAA’s NHC.

Other people are predicting:
• William Gray from Colorado State predicts 17 named storms with 9 hurricanes.
• AccuWeather calls for 13-14 tropical storms with 9 becoming hurricanes.
• Tropical Storm Risk (back in March) expected to bring 17 tropical storms, of which nine will strengthen into hurricanes.

Essentially all within the same ball-park.

What does this MEAN? It means that the experts think that we’ll have a busy season – we may or we may not, see below. So what should you do now? You have two choices: prepare now and be ready if a hurricane hits your area or don’t prepare and have no options. Preparation is a pretty simple matter when you have time to prepare, so the smart choice is to be ready.

In our view, these forecasts are an educated guess based on statistical analysis of previous seasons as applied to current seasons’ weather patterns. There is currently no magic box (or even sophisticated computer program) that can provide an accurate forecast for the number of storms. That said, the annual predictions are a worthwhile exercise in order to advance our knowledge. Studying current weather patterns, comparing these patterns with previous years, and then attempting to forecast based on the intersection between the two advances our knowledge incrementally and advancing knowledge is very worthwhile.

When the actual number of storms falls near the long term average, the forecasts are general correct since the forecasters generally end up predicting trends near the average while adjusting for various well known factors. The way forecasting works (usually) is you start with a long term average as your prediction and then you adjust it up or down based on various factors. For example, El Nino or La Nina’s presence or lack thereof will cause forecasters to adjust their predictions up or down. Patterns over the Atlantic, dust or lack of dust from Africa work similarly. Sea surface temperatures impact the forecasts also. It is merely a matter of how much each factor will impact storm formation and whether the impact will be up or down.

Let’s recall previous year predictions compared with the actually events. Please remember, the forecasters do their best with the knowledge they have.

2006 ended with 10 named storms (one between Alberto and Beryl that was unnamed during the season and only identified in the post-season analysis).
CSU had predicted 17 storms
AccuWeather: 6 tropical cyclones (3 major) will strike US coast (none did), with a total number “above average”
NHC/NOAA predicted:
* 13-16 named storms (hurricanes and tropical storms)
* 8-10 of which will become hurricanes
* 4-6 of which will be major hurricanes (category 3 or higher)

In summary, the number of storms was well below predictions.

Actual: 28 tropical storms, 15 hurricanes, 7 major
CSU’s May forecast, predicted 13 named storms for 2005, which was obviously well off.
NOAA: 12-15 Storms, 7-9 hurricanes, 3-5 of them major

In short, the number of storms greatly exceeded pre-season predictions.

Actual: 15 storms, 9 hurricanes, 6 major
NOAA: 12-15 Storms, 6-8 hurricanes, 2-4 major
CSU: 14 storms, 8 hurricanes, 3 major (May 2004 forecast)

The number of storms in 2004 fell in the average range and consequently pre-season predictions were quite accurate, only fall well below actual numbers in the “major storms” category.