Sunday, March 20, 2016

The air is dry. The dew point map at the bottom of the entry shows an interior USA with very little water vapor.

The Weather Channel
Current Temperature Map
20 March 2016
1445 GMT

The swing in temperatures over the USA today is absolutely ridiculous, with the exception of Florida because it is surrounded by ocean on three sides.

The Weather Channel
Current Temperature Map
20 March 2016
2345 GMT

The change in temperature over southern California and Arizona is astounding.
March 20, 2016
By Kristina Pydynowski, Senior Meteorologist

A portion (click here) of the southern United States will face the return of severe thunderstorms and flooding downpours at midweek.
The severe weather will erupt as a cold front slices into the surge of warmth set to bring a dramatic upswing in temperatures during the first half of this week.
The warmth will erase the frost and freeze threat closing out the weekend.

Without water vapor the change in temperature is rapid. Water vapor is the buffer that provides for comfortable climate. The olive green color over most of the USA is near the 'very dry' side. The coastal areas of comfortable, but, not very humid at all.