Yes, if you’re from Seattle or the west side of the Cascade Mountains of the Pacific Northwest, you are going to feel especially at home today. Its dark, even with the sun up, low ceilings and visibility, steady light rain mixed with snow, temperatures in the mid 30s to low 40s, well, that’s home in January. And, here is that “home” right here in Catalina, AZ, for us to experience again! Cloud type? Nimbostratus, often with an underlay of….Stratocumulus and Stratus fractus clouds to kind of provide that ragged, dark and gloomy, splotchy look.
As you may have experienced this morning, an extremely sharp cold front came through with a spectacular drop in temperature and a windshift at 6:30 A. M. The temperature dropped from the upper 40s down into then upper 30s in only about 20 minutes, which it pretty unusual. Along with the that temperature drop, the rains came in the “frontal band”, now totaling 0.80 inches here since the first period of rain began late yesterday afternoon (local weather station data here). (BTW, this station’s wind data are averaged over 10 min, and gusts are 1 min averages. Multiply gusts by about 1.5 to estimate the velocity of the strongest, few second duration puffs.)
This storm, still in progress, brings the Catalina rainfall for December up to 1.93 inches. Normal, based on a 31 year record provided by the folks at Our Garden here in Catalina, is 1.44 inches. So with this storm, we have exceeded the normal AND crushed the monthly NOAA prediction of well below normal precip this month. Yay! Such predictions are partly derived from the effects of the strong La Nina now in progress-note colder than normal water along the Equator in the eastern and central Pacific. La Ninas normally hedge the climate of the SW toward drought, and so this has been a great December if droughty conditions materialize later in the winter. The December US-wide precip prediction, FYI: (I should acknowledge a bias here: I am overjoyed when droughty forecasts fail but also overjoyed when wet ones verify.)