A Mega Front

Low pressure moving northeast through Ontario is dragging a cold front to its south that is openning the doors to a major arctic blast in the upper plains with record low temperatures. Out ahead of it, surface temperatures are approaching record highs. In fact, some places approach both within a 24 hours period. Here is the daily climate summary for Ottumwa, IA for December 14, 2008:

Actual...           Record...
MAXIMUM 61 1157 AM  62 1908 
MINIMUM 3 1159 PM  -10 1989 

That's a 58 degree drop in just 12 hours.

Taking a look at temperatures across the nation this morning, you can see the contrast: 50's and 60's east of the boundary, and temperatures below zero, as low as -30, west of the boundary.



The cold front will lose some strength as it heads east, and it will stall south of the region tomorrow. The cold air mass will not be quite as intense in the east, but will be enough to keeps temperatures about 5 degrees below the normal for this time of year.