Sometimes we can clearly see that there will be fog forming, because the “Dew Point” is high enough and temperatures are falling…so that they become the same number. Then there is fog. And, that would not be a bad thing overnight. Fog would act as a thin blanket to keep temperatures from bottoming out and producing a killing freeze.
The coldest temperatures will occur between 4 AM and 8 AM, but some orchards may see freezing temperatures as early as 2 AM. Orchards perched on the hillsides tend to fair better under these circumstances, because they are slightly above the inversion, and sit in slightly warmer air…plus air tends to move downhill…so these orchards often will have a light wind in the early morning hours coming down from the hills and the mountains.
Clear skies are the biggest concern overnight. Several hours of clear skies would put temperatures on the lower end of the low temperature scale. What we don’t need is a cold night like we had on April 16, 2009; when it was 28.
Pears are in danger at 29 or colder. Stone fruits are susceptible to damage between 30 and 31 degrees. So, it is going to be a “Nail-biter” tonight.
There will be warmer temperatures over the next week. A slight chance for a shower will develop Friday afternoon…with snow levels above 6,000 feet. Then sunny weather with highs in the 70’s and lows in the 40’s will settle in for next week!