Extreme Cold/Wind Chill in Northern Grafton, New Hampshire

During the early morning on the 24th temperatures plunged below zero. Strong cold air advection allowed mechanical mixing to occur through the night. Sustained winds of 15 to 20 mph, and frequent gusts even higher, led to wind chills of 25 to 40 below zero.

During the afternoon on the 23rd a cold front crossed the Northeast. Later that evening a strong, secondary cold front crossed the region with heavy snow showers and bitterly cold temperatures. Widespread temperatures below zero and gusty winds were observed by the morning of the 24th. Key messages: dangerous wind chills, business closures.