Invest 97 has strengthened enough for the National Hurricane Center to name it Tropical Storm Karen. That makes it the eleventh named storm of the 2013 season. Predicting where Karen is going to go and how strong it will get are proving difficult for forecasters. For now the National Hurricane Center's forecast shows Karen coming ashore near Destin, in the heart of the stretch of Florida's panhandle known as the "Emerald Coast" as a tropical storm on Saturday.
However, Weather Underground founder Dr. Jeff Masters cautions in his Wednesday afternoon blog entry that the official forecast is a compromise between the different tracks generated by two usually reliable sets of computer programs. "The models are split into two camps for Karen's track. The European, UKMET, and GFDL models have Karen making landfall over Central or Eastern Louisiana. These models keep Karen relatively weak, resulting in a path that follows the low-level winds more to the west, where there is more dry air and higher wind shear. The GFS model and HWRF model keep Karen stronger, and predict a landfall in the Western Florida Panhandle."
Masters also notes that forecasters are a long way from being able to accurately predict how strong a storm will get, but for the sake of comparison shows how the 2009 storm Hurricane Ida fizzled into an extratropical storm just before it hit land, because of a combination of a low pressure trough, cooler water and high wind shear.