The overall forcast picture for Tropical Storm Katia is beginning to take on a focus that contains good news for Tampa Bay and Florida. While the 5 day forecast projects a course just north of west, noted hurricane expert and Weather Underground founder Dr. Jeff Masters has been looking a bit deeper into some of the more arcane data that’s not generally available or easily understood by non-experts to come up with some interesting and somewhat reassuring opinions.
In his daily commentary, Masters points to what’s called the GFS “ensemble” computer projection that generated the spaghetti chart that accompanies this story. “The ensemble prediction was done by taking a lower-resolution version of the GFS model and changing the initial distributions of temperature, pressure, and humidity randomly by a few percent to generate an ensemble of 20 different computer projections of where Katia might go. The operational (highest-resolution) version of the GFS model (white line) is usually more accurate, but the ensemble runs give one an idea of the uncertainty in the forecast.” A glance at the chart shows that while there is considerable uncertainty about Katia’s ultimate destination, Florida is not in the picture.
Masters also mentions that history is on Tampa Bay’s side when it comes to figuring out where Katia might go a historical chart by a Florida State University scientist has some good news as well. “Dr. Bob Hart’s Historical Tropical Cyclone Probability web page shows that tropical storms in Katia’s current position have a 19% chance of hitting North Carolina, a 16% chance of hitting Canada, an 11% chance of hitting Florida, and a 47% chance of never hitting land.”
While the indications are that Katia is not going to threaten Florida and may not even hit the eastern U.S. the 2011 hurricane season has a long way to go. Masters notes that this season is comparable to the busiest season in history. “A typical hurricane season has just 10 – 11 named storms, so we’ve already had a whole season’s worth of storms before reaching the half-way point. At this rate, 2011 will see 25 named storms, making it the 2nd busiest season on record, behind 2005.”
So even if Katia turns into a non-event, there’s reason to believe there are more storms to come and as forecasters like to remind everyone, “all it takes is one.”
To see Jeff Masters complete blog entry click here. To see the latest official report on Katia from the National Hurricane Center, click here.