Cold air is threatening the Pear Crop tonight, but it appears that temperatures will remain above critical levels. Clouds are moving from the Pacific into Western Oregon…with will help to insulate and keep temperatures from dropping, plus, some fog may form, with also will help to keep temperatures from falling.
However, the air is still cold for this time of the year, so a Freeze Warning has been issued.
But, how cold will it get? Looking at the cloud cover, the dew point (which is the temperature at which fog forms) and evaporation (warming effect), I have come up with a projected low of 32 at the Medford Rogue Valley International Airport.
Based on the formula I use, the worst case scenario would be 29, if skies clear and fog does NOT form. Realize a couple of things.
1) The low temperature is taken at 4 and 1/2 feet above the ground.
2) The actual ground temperature can be 3 to 4 degrees colder than what we would call the “official low”.
3) Many areas around the Rogue Valley, The Applegate Valley, the Illinois Valley, the Sams Valley…and other Western Valleys (west of the Cascades) have microclimates that are colder than the Medford Airport. Some locations can be more than four to six degrees colder. Other locations, where orchards are placed on hillsides and where the air movement is more persistent can be two to five degrees warmer than the Medford Airport.
I will keep an eye on this all evening, and update as necessary. Also, tune in tonight at 11 PM for the latest information on the FREEZE WARNING.