National Weather Service United States Department of Commerce

Showers and Thunderstorms in the Southwest and Ohio Valley; Mountain Snow in the Northeast

Showers and thunderstorms, along with high-elevation snow, will begin to develop over parts of the Southwest late tonight and is expected to continue through Wednesday morning. Mountain snow over parts the Northeast will continue through Tuesday. A few strong to severe storms and heavy rainfall are possible across portions of the Lower Ohio Valley Tuesday. Read More >

When you woke up this morning, you noticed that the ground and especially the pavement was wet. So you would have concluded that it rained last night. However, if you had a rain gage, you would have seen that it was bone dry. Where did the water come from?

The record breaking warm air mass with brisk southerly breezes was the key. Temperatures overnight were near record levels and the dew point was only about 5 degrees cooler. This meant that the pavement was cooler than the dew point, so dew formed. Normally, in this situation dense fog would have formed like it did earlier this week. However, the southerly winds were too strong to let that happen, and in fact, dried out many elevated surfaces. Thus, mainly the pavement was wet.

Above is a photo of the NWS driveway taken this morning. You can see the wet pavement including some small puddles toward the right. The shrub on the left was dry. 

Numerous temperature records will be broken today, both warm minimums as well as warm maximums.