Rain and cold foretold for Catalina on Saturday as big, long-foretold storm bops Cal then moves on to AZ

Things are falling into place.  Remember the spaghetti from a week or more ago, in which it was clear, or at least at attempt was made to explain to both readers of this blog,  that a large trough was almost certainly going to be along the Cal coast?  We intuited that from the lack of spread in some contours in that “spaghetti” plot along the West Coast some week or more in advance.

Well, that trough is truly turing out to be a behemoth, a gigantosaurus for April.  The people of California are going to be very excited today and tomorrow about cold, showery weather, mountains of snowfall in the mountains, maybe a funnel cloud or two in the Sac or San Joaquin Valleys.  Here is that trough as shown on today’s 5 AM AST 500 millibar map from the U of WA weather department, the one prophesized with high confidence so long ago:

However, for many days after that, the models did not think the rain in Cal was going to get here.  Of course, still being in the cool season, our rain is nearly all dependent on whether the jet stream in the middle levels (500 millibars or about 18,000 feet above sea level) is able to be over or especially,  south of us here in Catalina.

But lately, in the forecasts, been shifting the jet southward and rain has started to show up in two or more recent model runs, always a good thing.  You may also remember that in our spaghetti plots back a week ago, it was not clear in the models where the Cal trough was going to go after it bashed the West Coast.  Hence, while things were clear for Cal (actually, they were going to be cloudy and rainy), they weren’t so clear for here until lately.

From the U of WA, this for Saturday morning (colored splotches denote where the model thinks precip has fallen in the prior 3 h); below, the jet stream at 500 mb from IPS Meteostar for the same time.

Yesterday’s clouds

In case you missed them….   Cumulus and Stratocumulus, punctuated with a splash of Cirrus fibratus undulatus (Cirrus with rolls, showing something akin to swells in the ocean in the atmosphere).  The wind at Cirrus level in that shot is blowing from left to right.   No ice falling out in Cu and Sc; too warm at cloud top.  Only about -5 C (23 F) or warmer.

The End.