Hazardous Conditions: Autumn

• Autumn is a transitional season of extremes. Dry summer-like conditions may extend well into October, but it is also not unusual for southward incursions of the Polar Front Jet to bring autumn storms, particularly toward the end of October.

• Rainfall fluctuates considerably from year to year, varying from 0.0 inches in some years to as much as nine and one half inches in others. Average rainfall increases from 0.63 inches in September to more than 3.0 inches in October.

• Temperatures vary widely from lows in the 40's to highs above 100°F.

• Thunderstorm activity more than doubles from September to October and as many as eight thunderstorm days have been recorded during October.

• The winter frontal passage pattern is usually well established by the end of October. Normally, once the first frontal passage is experienced, the winter pattern is in control and the winter frequency of frontal passage is quickly established. Winter type wind, wave, visibility, thunderstorm and precipitation characteristics are also quickly established.