It's that time of the year when the first killing frost/freeze hits central Pennsylvania. Typically, mid-October is when the first killing frost hits although light frosts can occur as early as mid-September.
Some areas of central Pennsylvania did have some frost in late September, but the duration of the frost and the extent of the frost did not kill most garden plants.
The cold air coming for Saturday morning will allow for a longer-duration frost and freeze and will also allow temperatures outside of the towns to dip will into the 20s, if not the teens.
The high pressure system bringing the cold weather originated in northern Canada and will park itself right over central Pennsylvania by Saturday morning. That will promote clear skies and calm winds which is the best setup for what meteorologist call "radiational cooling."
With the cold weather coming, you still have time to protect your plants. Covering them with buckets or blankets will prevent the frost from forming on the plants and may allow your plants to continue until the next threat of frost and freeze comes along.
While prospects for a white Christmas are grim along the I-95 corridor, many communities from the Great Lakes to the Rockies should enjoy the desired snowy scene for the holiday.
The wet weather pattern across the Seattle area will continue through the week, creating poor travel conditions in the region ahead of Christmas Eve and Christmas Day.
People who are dreaming of a white Christmas across the interior Northwest may see their dreams come true this year as another storm impacts the region.
Several fast-moving storm systems will bring windy and wet weather to the British Isles and northern Europe.
A storm bearing strong winds, heavy snow, torrential rain, thunderstorms and fog will converge on the Northeast and Midwest on Christmas Eve and will likely create ground and flight delays.
Kansas City (1961)
16.6" snow, greatest in December.
Elk Park, MT (1983)
Unofficially -64 degrees F. (nation's all time record low is -70 degrees F.).
New Orleans, LA (1989)
1" of snow.