Winter Storms Not Predictable Like Hurricanes

El Nino sends out strong signals influencing the weather, he said, affecting tropical weather systems. But the system does not affect extra-tropical conditions, which are defined as weather patterns above 30 degrees North latitude and below 30 degrees South latitude.

Modelers, he said, are concerned with the probability of events over an extended period of time determined after running numerous historical storm events through computer simulation modeling scenarios.

AIR's own winter outlook, due out in the first quarter of 2005, will be based on the probability of severe winter storms in an average year over the long term. AIR is a subsidiary of Jersey City-based Insurance Services Office Inc.

Mr. Dailey said research is continuing among others to produce models that would be predictive of storms similar to what is done during the hurricane season, but AIR is not looking to do such predictions until they become more reliable.

The National Oceanic and Atmospheric Administration winter outlook, covering the next three months, sees cooler-than-average temperatures in much of the East, Mid-Atlantic and South.

Warmer-than-average temperatures are expected in Alaska, Hawaii, and the West. Below-average temperatures are possible in the Mid-Atlantic Coast states, the Southern Ohio Valley, the Tennessee Valley, the Southeast, lower Mississippi Valley and eastern sections of Texas.

Wetter-than-average conditions are predicted from New Mexico through Texas and southern Oklahoma to Louisiana.

The Ohio Valley and the Northwest should see drier-than-average conditions this winter. Below-average precipitation is expected in Washington and Oregon, from the Great Lakes to the Tennessee Valley and in Hawaii.

Temperatures in the mid-U.S. running up into New England could be about average, while precipitation through most of the U.S. and Alaska could fall into the average range.

NOAA said the forecast could translate into improvements in the drought conditions in some parts of the Southwest and possible worsening dryness in the Northwest and Ohio Valley regions.

Forecasters say a weak continuation of an El Nino event in the Pacific is responsible for the weather. It is expected to continue into early 2005

While winter is designated as beginning on Dec. 21, when the noontime sun is farthest south in the sky in the Northern Hemisphere, NOAA said the weather season begins Dec. 1 with the onset of winter-like conditions in much of the U.S.