Q -- What weakened Hurricane Isabel before it reached State College?
A -- While Hurricane Isabel may have left some parts of the East Coast a disaster, it barely affected State College as it passed through the region.
AccuWeather senior meteorologist Alex Sosnowski attributes Isabel's lack of force to cooler, churned up water in the Atlantic Ocean and a pocket of dry air as it neared the coast.
When hurricanes and tropical storms travel across the water, they thrive on the warm, moist air of the oceans. Hurricane Fabian, which followed a similar path over some of the Atlantic before Isabel, churned up the waters, which produced cooler than normal air as Isabel worked it's way up the coast. A drop of only a few degrees in sea surface temperature can greatly effect storm intensity.
A warm pocket of dry air off the coast was drawn into the storm's circulation and worked to further weaken Isabel.
In addition to these factors, once a storm hits land, it continues to lose strength, as the source of the warmer, moist air is no longer underneath it, Sosnowski said.
He attributed Isabel's further lack of strength in the area to the jet stream.
"It is typical for these storms to weaken as they are drawn into the jet stream and begin to accelerate across land," he said. "And we can't gauge how quickly this will happen."
While few effects besides the occasional fallen branch could be seen here at Penn State, some areas on hilltops saw substantial wind gusts. So when trees and branches fell, crews already on alert were able to clear them fairly quickly.
While State College saw little of Hurricane Isabel, areas in eastern North Carolina and southeastern Virginia saw extreme winds. Tidal flooding was also reported as winds pushed waters northward through the Chesapeake and Delaware bays.
According to Sosnowski, a trough of low pressure in the Midwest acted as a vacuum and drew the storm up the coast. Once the storm hit land, the jet stream worked to move it across southwestern Pennsylvania toward the Great Lakes.
The last storm to have an impact similar to Isabel was Hurricane Hugo, which followed a very similar path in 1989.
So far, 2003 has been an average year in terms of the number of hurricanes, but there is still potential for an above-average year -- the peak season for these storms doesn't end until mid-October, with the official end of hurricane season on Nov. 30.
When asked about the decisions of many area schools and businesses to close prematurely, Sosnowski said, "It should always be safety first. I don't know what they do to make their decisions, but trees falling and live wires over roads are a concern. I can't say that I blame them for closing."
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