By Rod Hill on 2010-12-01
As promised Tuesday's storm was a wet one! Tillamook had more than 2.00" of rain, Salem had over an inch, PDX .84" and Timberline picked up 18" of snow! The Portland rain total closed November at 6.63" for the month, more than inch above the average of 5.61 inches. Not a "super" wet month, but our trend of above normal precipitation that began in September continues. Total precipitation since September 1st is 12.84", which is 121% of normal!
As you may know, December is the start of meteorological winter. (Yes, meteorologists have their own seasons - it's an ego thing!) All outlooks call for above normal precipitation through at least February. Temperatures are expected to be near normal for December and slightly below in January and February. La Nina, which began back in June will likely continue into the early spring months. Slightly more than 50% of forecast models project La Nina conditions will continue to strengthen through the month of December. If correct, January and February could be very active months! At present, Pacific ocean temperatures in the equatorial belt off of south America, average 3-5 degrees F below normal, which is considered to be a STRONG LA NINA and continues to have the possibility of being one of the strongest in the last 60 years. Strong La Nina's are associated with wet, cool and very active winters across the Northwest. It is interesting to note that the heaviest moisture so far in terms of departure from normal has been across central California, Nevada, Idaho and Montana. La Nina's typically produce a moisture bulls-eye over the Northwest. However, so far, this event has produced a deep trough to our south, which has supported heavier amounts south and east of our region. If the flow pattern changes, we will really get wet!
Snow Reports