What a superb rain that was last night. It just kept coming until finally we piled up an astounding-to-me 0.53 inches by 4 AM this morning. The regional rain reports from around Tucson can be found here. As you will see, the upper regions of the Catalina Mountains got around an inch (1.22 inches at CDO wash at Coronado Camp now). Mt. Lemmon probably got a little more, but the record says “0.00” due to snow at that elevation. This is a substantial boost for our emerging spring desert vegetation after our four week drought. This is so much better than that near rainless January of last year! Looking at some of the statewide precip reports, it looks like the Catalina area and the Cat Mountains got more than anywhere else. Lucky us.
If you would like to relive yesterday, at least in clouds, go here to the U of AZ time lapse. One of the things you will see later in the day are Altocumulus lenticularis clouds over the Catalinas. You will see their upwind edges spurt upwind (seem to go the “wrong way”, against the wind) as the lifted air got more moist, one of the tricks that these clouds can pull. You will see quite a panoply of clouds in this movie, from Stratocumulus, Altocumulus, Altostratus (dead gray and smooth higher layer), Nimbostratus (when the rains come) along with some mammatus formations. Hmmmph. There’s that “m-word” again, the one I used so many times yesterday. Wonder what’s going on?
“But wait, there’s more!”
If you call now (well, actually if you continue reading) you’ll find that a few more hundredths of rain are possible this morning before about 8 AM AST, AND, (We interrupt this blog for an important message: “hey”, just started raining again now at 5:03 AM! Yay!)
all of the model runs are indicating rain again on the 22-23rd timeframe; even the “pernicious” 00 Z run from the 5 PM AST global data. (I have questioned that output of late, rationally or irrationally, because it kept drying the State of Arizona out whilst the model runs before and after that time, foresaw precip in spades in the State.
Here is a sample of the IPS Meteostar renderings of what happens in our rain window of the 22-23rd according to our latest model run, one from 11 PM AST data. Note green areas of precip in the 6 h ending at 5 AM AST, Jan 23rd. This is pretty satisfying since another good rain will keep us on track for a great spring bloom.
On other fronts…
While I could go on to talk about all sorts of things due to the ambiguity of the subtitle phrasing above, I will actually only talk about weather fronts, not this or that.
The coming floods in northern Cal-Oregon still on track. Storms break through from the Pacific “under” the Bering Sea “blocking” high, one that diverts the potent Asian jet stream that comes into the Pacific into two branches, one of which is forced southeastward in the central Pacific where water temperatures are warm. (Just heard some rain on the roof again. What a nice sound that is!) The other branch goes deep into the Arctic and merges with the southern branch in the eastern Pacific after it turns southward over AK.
Those warmer storms, heavy with semi-tropical rain clouds, race to the West Coast once the southern jet breaks through the weakening southern part of the blocking high. And once that jet stream has broken through, its days before things change, so the duration of rain adds to the colossal totals certain to occur now. In a ten day span, beginning tomorrow, the peak totals in this event will likely exceed 30 inches of rain.
Here is the current weather map (5 AM AST today) from the University of Washington that illustrates the odd flow pattern developing now from the central Pacific to the western US. The block is developing from a ridge in the eastern Pacific now (evidenced by the lack of green contours in it) that extends from the tropics all the way to the Bering Sea! It will fracture in its southern portion tomorrow. It has overextended its “reach”, in a manner of speaking, at this point, and will fail just like a dam break and all those clouds to the west of it will flood eastward. Its a pretty exciting thing for us precipophiles.
One particularly bruising storm, one the size of Asia practically, with “tentacles” from the Aleutian Islands to Minnesota, was shown to develop in this series of storms battering the West Coast in the European model run by Environment Canada based on last night’s data.
I show this output below because you RARELY see a low whose circulation is this big, at least one of the biggest I have ever seen, portrayed on a weather map (upper right panel). The map below showing this colossal low is valid for the evening of Jan. 21st. The entire West Coast would be battered by this bruiser.