Lengthy Period of More Seasonable Weather In SightMarch 24th, 2014 at 9:33 pm by Don Paul under 4 Warn Weather
The first 3 days and nights of this work week we’ll still be stuck with harsh cold and true arctic air. But that all changes beginning Thursday. The northern/polar branch of the jetstream will be changing to a much lower amplitude flow, losing its connection with arctic air and bringing mainly Pacific air across the lower 48. This does not equate to mid-spring warmth in the mean, but it does mean there will be no true arctic blasts in the foreseeable future. During this time, the northern branch will be active, sending frequent short waves with their warm fronts and trailing cold fronts across the northern tier of the US. That will probably bring more frequent rounds of precipitation, and more frequent ups and downs with our temperatures. However, the downs will not be AS down. The cold fronts will bring cooler air masses rather than harsh cold. The warm fronts, of course, will bring periods of above average temperatures as well. In the mean, we’re looking at a more seasonable pattern. It’s not “June Is Busting Out All Over”, but it will have to do until the real thing comes along.
We’ll have to monitor area streams and creeks on Friday with the potential for moderate rainfall accompanying seasonably mild temperatures. There continue to be some ice jams in place.
We’re still in neutral ENSO conditions and should be for some months to come, with a slightly greater than 50% probability of el nino developing toward or during the summer. In my view, it’s not possible to know the amplitude of this possible el nino this far in advance. I’ve previously written its development would have little impact around here during the summer. The probability of neutral ENSO conditions shrinks into the 40-45% range by mid/late summer, and la nina drops to under 10%. Currently, there are early signs of a developing el nino with SSTs and near sfc Pacific tropical temps beginning to rebound, with cool anomalies at those latitudes restricted to the far eastern Pacific.