If you read NWS discussions for the U.S. you can see they divided the continent into sections for their forecasts as seen in the feature graphic.
This is from the NOAA short range discussion for this week:
The short range period begins in a relatively quiet weather pattern across much of the lower 48 as sprawling surface high pressure dominates resulting in below average temperatures from nearly coast to coast. The greatest departures from normal on Tuesday will be from the Great Basin to the Midwest/Appalachians where afternoon highs of 10 to 20 degrees below early December normals are expected. This shifts into the Eastern states by Wednesday, with the Southwest and Central U.S. seeing a warm-up to near or slightly above average temperatures.
The surface high is located over Oklahoma and Kansas and as you can see there are no storm systems or low pressure systems anywhere in the U.S.. High- and low-pressure systems evolve due to interactions of temperature differentials in the atmosphere, temperature differences between the atmosphere and water within oceans and lakes, the influence of upper-level disturbances, as well as the amount of solar heating or radiationized cooling an area receives.
Pressure systems cause weather to be experienced locally. Low-pressure systems are associated with clouds and precipitation that minimize temperature changes throughout the day, whereas high-pressure systems normally associate with dry weather and mostly clear skies with larger diurnal temperature changes due to greater radiation at night and greater sunshine during the day.
Over the past few weeks we have seen our weather influenced by cold air moving in from Canada. Most of the storm systems have been moving through the Ohio Valley to the south of Michigan on up to New England. It is my thinking we will see this pattern change next week sometime as we get into a warmer pattern with a west to east flow influencing the weather across the northern plains and Michigan. I will get into this in my Thursday winter update post.
We may see some sun today which will be a welcome change before the clouds move back in and chances of lake effect snow increases for the lakeshore counties off and on through the rest of the week. Not expecting much as the air is dry due to the high pressure influence. Daytime temps will be at or below freezing with nighttime temps around 20 to the upper teens.
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