Computer models have been used in weather forecasting since the 1960s, but they are becoming more numerous and more sophisticated. They predict track, intensity and in some cases the effects of tropical storms. There are two basic types. It suggests a storm will move a certain way because similar storms in similar circumstances behaved that way. This kind of model is relied on most often when the storm is far from land and data is scarce.
Some models combine both types of data, but none is perfect and all require interpretation.
At present the results are considered research product and are not made public. FSU and the hurricane center use some of the same models, and researcher Eric Williford said he, too, has concerns about the reliability of the model that predicted Harvey's sharp turn. Therefore, Williford said, although FSU super ensemble predicted Harvey's turn, he would not have had much confidence in it. Pasch said a better organized storm probably would have behaved more in accordance with the models. A shallower flow, like the one from the northwest, can then have more influence.