By Rod Hill on 2010-01-21
The barometric pressure Thursday at PDX dropped to 28.90" of mercury. This is the 6th lowest in the record books. The lowest recorded pressure is 28.56" back in 1880. Medford as seen their lowest pressure this week in recorded history! The 500 mb heights continue to be very low - near 520. This is a reading typically associated with a deep low and an arctic jet flow. Yet, as you know we continue to be very mild with highs in the 50s! It is this "unbalance" of the air mass that is producing great instability, gusty to strong winds and the other day, lots of lightning at the coast. A VERY STRONG JET STREAM continues to hit California. The golden state has had heavy rain all week and even a tornado in southern California. The heavy rain to our south and the much stronger storm centers have played a part in our mostly dry weather here in the north. Look for the weather pattern to stabilize and be a little more"normal" next week.
By the way, the low upper level pressure heights usually associated with cold air is the reason I was big on projecting low snow levels this week. I was wrong. All we got was a little wind, a few lightning strikes and a big batch of not much!
Changing Weather A Week Away