Portland's January 2004 Snow/Ice Storm - The failure of mesoscale models

The Portland, Oregon Metro area has experienced 4 winters with no significant snow in the lowlands or hard freezing, which is unprecedented even in our mild climate. Arctic air finally surged south on January 3rd, 2004. Forecasts handled the arrival of the cold air well. The arrival of moisture from the Pacific was well forecast too on the 5th.

But the expected one day snow and ice storm turned into a 4 day ordeal for the region. The Portland International Airport was closed for 2 days for the first time in it's history. Blizzard warnings were issued for the eastern parts of the metro area as winds gusted over 70 mph with blowing snow. Over 1" of freezing rain fell in some spots, even to the coastline.

Most distressing to meteorologists was the complete failure of even local mesoscale models to "hang on" to the cold air long enough. Models continually tried to warm the area, but a widespread warm up did not occur until the 9th. The author will show examples of model performance and what local meteorologists have learned from the storm.