From the VERY latest WRF-GFS model run from the 11 PM AST crunch of global data involving billions if not trillions of calculations, so how bad can it be? We’ll see on the 27th or so (exact timing not so accurate).
Valid at 11 AM AST, January 27th.
In the meantime, the whole pattern causing extreme cold in the eastern half of the US, warmth and drought in the West is truly finished later this month. Soon after the map above, the whole collapses in on itself, as pretty much always happens to extreme patterns like the one we’re having now.
Desert marigold.
Take a look at what our generous mid-November through mid-December rains followed by warmth has done to our wildflower bloom this year. These shots were taken on a group hike into the Tortolita Mountain Park on the 16th, starting from the Ritz-Carlton Hotel and going up to the Wild Mustang Trail. If you want to see a spontaneous eruption of the “Ritz” in Russia1 by a “flash mob” go here. Proves that the world is completely different than it was during the Cold War, and global warming as well. You can see that its not that cold because people are out having a lot of fun and they wouldn’t be if it was really cold. The wildflower shots also suggest global warming has arrived here in Tucson as well, at least this year. They’re still waiting for it to arrive in Wisconsin I think.
Red tipped ocotillos in early to mid-January? Amazing.January 8th, on the way to Romero Pools in Catalina State Park. Never though I would see this so early in January.
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1 Let us not forget that Mr. Cloud-Maven person’s latest book was in Russian. Well, it wasn’t MY book, but all the photos, including the cover one, is from Catalina Cloud Maven! See below:
Published, spring 2013! Taken at Kwajalein Atoll AP, Marshall Islands, 1999.
Warm in the West, COLD in the East. Hasn’t locked in like this over the US since way back in the winters of ’62-63, ’76-77 when old man, “Polar Vortex”, the circulating hub of cold air in Northern Hemisphere winters, lost his way from near the North Pole and drifted down to around Hudson Bay, Canada, a few times, as it is doing at times this winter.
You can read about those January’s, ’63 and ’77 below for those of you who like to reminiscence about severe winters in the East.
You may recall, too, that it snowed in Miami in January 1977, the only time it’s happened. They got pretty excited about it down there, too, as you can see.
That snow in Miami, BTW, occurred pretty much at the height of the global cooling hysteria (hahaha–I like to tease those who think there wasn’t any. But…..we REMEMBER!) Furthermore, one of the great climatologists of the day, Hubert Lamb, from East Anglia University, was even predicting a new ice age dead ahead in the 1970s. Oh, well. I’ve made some pretty bad weather predictions myself.
Fortunately, our current pattern, replicating those old ones, goes to HELL by the end of January, and our chances of rain go way up. Below is the totality of the evidence I am going on for this weather assertion:
Valid at 5 PM, January 28, 2014.
As you can see above, or maybe not, the entire central and eastern Pacific are in complete disarray, and the standing pattern we have now “will not stand” much after this.
Let us compare what we have now, and will have for the next ten days or so, below:
Valid at 5 PM AST, January 23, 2014. Temperature refugees race into Arizona as wave after wave of brutally cold air blasts the eastern half of US leading to an exceptionally moneyful tourist season!
In the first example, very few red and blue contour lines follow the predicted yellow brick road lines. Those red and blue lines are, in general, no where near the actual “control” yellow lines representing an actual prediction for those contours.
In the second example, way out to ten days, the red and blue lines follow the “yellow brick road” ones, meaning the forecast, even that far out, is very robust. So, for another ten days we’ll have our peaceful weather, but watch out toward the end of January. “Change gonna come.”
The End. Might check back when it starts raining….
Not much to say, so will let others speak after showing you this sunset from last evening:
6:01 PM. Best described, due to thickness and coverage, as Altostratus. Note fine virga underneath. It would be a very, very light snow if you were skimming the bottom here. Crystals? Bullet rosettes, natch! Too cold for anything else that had time to grow big enough to fall out.
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About really cold air outbursts as we have had in the East (Great Lakes freezing over, etc.) and global warming…. Let’s see what Mike has to say (gonna be a little technical with a ton of references), but I think you might get SOMETHING out of these.
Check here and here. Awards? Too numerous to mention. And he may be the most disinterested person you will ever meet in the current “climate wars” surrounding the issue of anthropogenic global warming1. I don’t mean by “disinterested” that he is bored with his work (haha) but rather that he refrains from axe grinding, stays aloof from the emotions and partisanship that we see so much of in that domain. HELL, I get mad myself sometimes.
Enjoy, if you can.
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Sorry to say there’s no rain in the computer outputs here for another 15 days. Pattern of warm and dry in the West, cold in the East continues to dominate computer forecasts.
The End.
1Fueled in particular these days by the halt in the rise in the earth’s temperature over the past 15 years or so when it was predicted it would continue rising GRADUALLY by our best computer models.
I think its pretty plain to see in the NOAA spaghetti plot below that our first rain in January will just about be here in a week. Looking forward to an upcoming pattern change, with two troughs zooming into AZ in the week-to-two-week period.
Valid for 5 PM January 9, 2014. Can you find Arizona here? Hope so.
This is the first mod crunch I have seen in more than a week that had ANYTHING in the way of rain, even out to 15 days, in southern AZ. While forecasts of precip here this far out are like water on a desert highway in summer, will bet overall pattern of cold in the Midwest and East will be changing into one of cold in the West, beginning in the Pac NW a few days into January.
Valid January 9th, at 5 PM AST. Green areas are where mod thinks its rained/snowed during the prior 12 h. Blue is extra heavy precip. This from yesterday’s global data at 5 PM AST.
Why even bother mentioning this when its so far away in model terms?
Below, an arrow has been placed where a very cold upper trough will be starting to make its debut in the Pacific NW, and subsequently extrude southward along the West Coast and or Great Basin area, affecting Arizona by the 8th-10th. Because its ONLY 216 h out, and the wiggly lines are fairly clustered in the central Pac to the western US, seems like this trough will surely be there in the Pac NW, at least to start out with.
Sure hope this works out for us. Desert greening up nicely, but need more to keep up prospects of a great wildflower bloom later.
NOAA ensembles of spaghetti, valid on January 5th.
Thought the overall clearing that occurred at around 8 PM yesterday afternoon was going to be much earlier. So kind of disappointed there, as all of us weatherfolk are when things don’t go right. I thought I was going to see some nice small to moderate Cu amid big sunbreaks during the afternoon. Instead, that incoming Altocu-Stratocu deck from a mostly wasted Pac NW storm had more in it than it looked like on the sat images. That’s what passed over and occluded the forecast. Still, there was quite an afternoon clearing at one point, if a brief one….. So, I guess I was partly right after all.
3:15 PM. Giant clearing passes over Oro Valley and Catalina as clouds begin to breakup. (Photo not zoomed or cropped at all in a cheap attempt to exaggerate a clearing?) ((By putting a question mark, I am not actually lying right out.))
On the other hand, I do get to report a trace of rain in the past 24 h today, which is always good. Hope you saw it, too, to put a bright spot on an otherwise dismal day.
That incoming deck that piled on top of the residual Stratocu here that was topping Samaniego Ridge, was cold enough to produce virga, and some it fell into the clouds below which allowed it to reach the ground rather than dry up.
Also, some of those lower clouds built upward into that higher deck and developed ice, one produced quite a shaft briefly on the Catalinas. That was the surprise of the day, since it appeared to be too stable for that kind of development.
Mods had no rain around here, too, so they’re a little red-faced, as well.
Here are a few other shots from your cloud day:
8:51 AM. This is a common cloud scene that we have here when moist air is being lifted up as it approaches the Catalinas and moves upward in the slot between those mountains and the Tortolitas. The back edge, shown here, is moving toward you, but either never gets here, or takes a lot longer than it should. The reason is that cloud is forming on the back edge. Sometimes when this happens and you see a big clearing that you think will get to you and it doesn’t, its called a “sucker hole.”
10:57 AM. Here, with Big Blue, I was thinking that the clouds were breaking up, and it was going to be nice, scattered Cumulus, day, and the forecast I made early yesterday morning would turn out to be one of the great ones of our time. Middle level clouds rolled over the top of the lower Cumulus and put the kabosh on that! In a way, it was like that big meltdown in the last two minutes by the Washington State Cougars in their bowl game against the Colorado State Rams yesterday when the “Cougs” were leading by 15 points at that time and thought they had a bowl win with so little time left. But no. Like yesterday’s cloud forecast, the win went into the spin cycle at the drain and then down the tube. The writer worked in the Washington Huskies Weather Department, the Cougs in-state rival, but during bowl season the proper rooting etiquette for fhose teams in your league, the Pac 12.1:31 PM. Surprise of the day. A real shaft on the Catalinas! This was the last thing I expected to see yesterday, you, too. I’m sure. Such a shaft indicates that the top of this cloud got higher (likely just a few thousand feet) than any other tops yesterday, mounding above the tops of the higher layer of Stratocumulus clouds.
2:43 PM. A prototypical shot for pretty much the whole day, one in a Seattle motif; scattered to broken coverage in lower Cumulus and Stratocumulus, with another layer of Stratocumulus on top of the lower clouds.
Sun was able to sun behind the backedge of that Sc cloud deck and produced some spectacular lighting on Sam Ridge.
5:08 PM.5:21 PM. “Cow and sunset”; $1200.
The weather WAY ahead, that is, after the long dry spell now starting…
Still looking at storms passing through here as December winds down and during the first week of January, likely with cold, possibly exceptional cold, in the West. “Stay tuned”, of course.
Sutherland Heights, Catalina: 0.65 inches! Desert’s real happy now, greening up. Happy here, too. December will now end, with no precip seen before the end of the month, with a “not bad” 1.14 inches (normal is 1.86 inches).
A partial list of our generous rains, when they could have been so much less, from the Pima County ALERT gauges:
Gauge 15 1 3 6 24 Name Location ID# minutes hour hours hours hours —- —- —- —- —- —- —————– ——————— Catalina Area 1010 0.00 0.00 0.04 0.04 0.63 Golder Ranch Horseshoe Bend Road in Saddlebrooke 1020 0.00 0.00 0.04 0.08 0.43 Oracle Ranger Stati approximately 0.5 mile southwest of Oracle 1040 0.00 0.00 0.00 0.00 0.59 Dodge Tank Edwin Road 1.3 miles east of Lago Del Oro Parkway 1050 0.00 0.00 0.00 0.00 0.47 Cherry Spring approximately 1.5 miles west of Charouleau Gap 1060 0.00 0.00 0.08 0.12 0.79 Pig Spring approximately 1.1 miles northeast of Charouleau Gap 1070 0.00 0.00 0.00 0.00 0.75 Cargodera Canyon northeast corner of Catalina State Park 1080 0.00 0.00 0.04 0.04 0.59 CDO @ Rancho Solano Cañada Del Oro Wash northeast of Saddlebrooke 1100 0.00 0.00 0.04 0.04 0.63 CDO @ Golder Rd Cañada Del Oro Wash at Golder Ranch Road
Santa Catalina Mountains* 1030 0.00 0.00 0.00 0.00 0.31 Oracle Ridge Oracle Ridge, approximately 1.5 miles north of Rice Peak 1090 0.00 0.00 0.00 0.00 0.31 Mt. Lemmon Mount Lemmon 1110 0.00 0.00 0.04 0.08 0.71 CDO @ Coronado Camp Cañada Del Oro Wash 0.3 miles south of Coronado Camp 1130 0.00 0.00 0.00 0.00 0.20 Samaniego Peak Samaniego Peak on Samaniego Ridge 1140 0.00 0.00 0.00 0.00 0.20 Dan Saddle Dan Saddle on Oracle Ridge 2150 0.00 0.00 0.00 0.00 0.28 White Tail Catalina Highway 0.8 miles west of Palisade Ranger Station 2280 0.00 0.00 0.00 0.00 0.08 Green Mountain Green Mountain 2290 0.00 0.00 0.00 0.00 0.00 Marshall Gulch Sabino Creek 0.6 miles south southeast of Marshall Gulch
*Totals in the Catalina Mountains often compromised by piles of snow in the recording gauges that don’t register the correct amount until it melts.
Check here (U of AZ) and here, too, best after 7 AM AST. (Still dreaming about ONE site for all of these data…but this is a dream like the one Germans had in the 1960s, 1970s, and onward, about the Berlin Wall coming down and people being free. Its likely that one site for all AZ rain will take decades to accomplish at the current rate of progress which is none. Anybody listening out there? Of course not.
The day begins with overcast Nimbostratus and light to briefly moderate rain (the latter, which likely you would already know, my apologies for telling you again and making this blog longer than it already is for no good reason, which happens often anyway, 0.10 to 0.30 inches per hour).
9:35 AM. Nimbostratus layer begins to lift off the Catalina Mountains.10:13 AM. “Creepy cloud”, Stratus fractus. Keep an eye on it.10:30 AM. “Creepy” Stratus fractus has spurted north, while adding cloud material. Seems to glow from within.10:35 AM. Begins reaching upward toward Samaniego Peak! Then it was gone.12:02 PM. Nice example, one of the best, of Altostratus opacus mammatus (aka, testicularis). Downward hanging pouches released virga and snow flurries on the mountains a few minutes later.
1:09 PM. As skies clear, Cumulus begin to arise over the mountains. View toward Charouleau Gap, a name I have misspelled by leaving out the first “u” in prior blogs a time or two. Egad!
2:01 PM. Before long, with very cold air on top and a little warmth (52 F) at the ground, “soft-serve” (weak updraft) Cumulonimbus clouds arose over the Catalinas. (Top visible when clicked on.)2:04 PM. Sad sight. Dry air moving in seen here as the “wolves of entrainment” literally ripping apart a Cumulus congestus turret. Entrainment is the enemy of all clouds.2:17 PM. Fortunately, the dry air was held at bay for subsequent turrets, and this Cumulonimbus calvus arose as did others. 3:34 PM. Dog and me were both surprised by the overspreading Stratocumulus deck later in the afternoon, with tops in places cold enough for light showers. Was expecting sky to stay “partly cloudy” with scattered Cbs.
4:35 PM. Day pretty much ended as it began with Nimbostratus, this version really deep Stratocumulus that had reached the ice-forming level, not the much deeper version of Ns that caused the morning rain. Occasional light rain continued well into the night with the temperature declining to the low 40s. The lack of shafts indicates that the cloud tops are fairly uniform.
Today
Stratocu overcast gradually devolving to Cumulus and sunbreaks in the afternoon. Isolated sprinkles possible before noon, unlikely to be measurable; tops at marginal temp for natural ice formation now, required for precip here in AZ at -10 C, 14 F). Tops will subside to lower levels and warm up as day progresses. A few Altocumulus cloud remains from a dissipating storm that hit the Pac NW should also float over. Could provide interesting patterns. See this morning’s TUS sounding below, from the Cowboys:
The Tucson rawinsonde for 5 AM AST today. Launched about an hour and a half earlier, rises at about 1,000 feet a minute.)
The weather ahead and WAY ahead
Quiet times. Next rain/snow chance still end of Dec early Jan. Nuttin’ before then. Pity the Flatlanders east of the Rockies. Extreme cold, coming in surges, projected in models for eastern half of US over the next ten days. But then, my friend, its out turn!
5:17 PM. Cu fractus and humilis with edge of the approaching rain band clouds starting to obscure the sun through a dust haze on the horizon.5:18 PM. Close up of setting sun amid dust. Yellow sun means larger aerosol particles likely due to dust. Tiny aerosol particles, due to smoke, lead to a reddish sun. Here there are likely dust and some smoke particles intermingled. A purely dust haze, absent smoke particles, produces a sun whose color is little altered at low elevations (see below).May 2012. Example of a sunset only impacted by dust, little or no smoke. Dust generally has particles larger than one micron in diameter, much larger than the wavelengths of light from the sun, and so those particles don’t interfere with it much; don’t scatter out the incoming shorter wavelengths as smoke would, and this lack of scattering keeps the sun looking pretty whitish. Pretty hard these days not to have some very fine smoke particles up there.
The storm: what about it?
Its here, such as it is. Stations upwind of Catalina and in the approaching rain band have been reporting about a quarter to one third of an inch this early morning in light to moderate rain. Seems that’s the most likely total here now, though our best model, from the U of AZ, has been indicating over half an inch in Catalina, and about a half an inch in Tucson. The rain may last only a few hours, but given our normal intensities, a quarter of an inch can pile up in a hurry (an hour) in these rain bands. Moderate rain is falling right now, 5:19 AM! Yay! Com’on rain!
Update: 0.15 inches in the first half hour here in Sutherland Heights Excellent.
BTW, this loop of rain areas every hour from the U of AZ shows that we here in Catalina will have the center of the upper level low pass directly over us! We’ll be in the spin. Pretty cool. You MIGHT even be able to see, in the distance, showers moving in different directions if you watch closely late in the day when it passes by.
The weather way ahead
The latest run of the wrf-gfs model, our best, and based on global data at 11 PM AST last night, has no precip here after today over the next 15 days, through January 4th.
Reason to be depressed?
Nope. This is where those crazy spaghetti (“Lorenz”) plots come in. They’re still indicating in their overall “messing around” that troughs here are a strong possibility near the end of December and early January. The ACTUAL model runs will vary from run to run tremendously in this regard, some showing nuttin’, then maybe the next one, having a big, cold trough near us. Stay tuned, “details at 11…”, aka, “later”.
The actual “answer” in the wind, of course, is not 42, as you might have thought, but that when you stand facing the wind, the low pressure is on your right (Buys Ballots Law), which means here in Catalina with today’s southwest wind, its over there toward Casa Grande, to the northwest. The two of you who read this blog, you’ll know that the low center is way beyond Casa Grande, and likely in Tonopah, NV, a low magnet.
It would be fun to live in Tonopah and be in a low so many times, the air all around you converging toward YOU. Here’s the latest map FYI, for those of you considering moving to Tonopah, NV1, a census designated place like Catalina:
3 AM surface weather map featuring the Tonopah Low. (From the University of Washington Huskies Weather Department. Nice. Play in the Fight Hunger Bowl on the 27th there in Frisco.
I know that many of you love the wind, such as we’ll have today, and a bit right now at 4 AM or so, and have wind-detecting lights that let you know when the wind is blowing at night when the plants and trees around your house start moving around so you can get up and see how hard its blowing…
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We interrupt this weather presentation for a Public Service Announcement:
Pima County reminds Catalinans who live east of Oracle Road to be sure to cap/shield outdoor lights off so’s the light doesn’t go up and out, wrecking our dark skies. This is mandated by Pima County code; those east of Oracle, save businesses on Oracle, live in lighting zone E3a, in case you didn’t know there was such a thing.
The astro guys up in the Lemmon Dome (aka, U of AZ Skycenter) need as much dark sky as possible, they’ve recently told me.
And, of course, you don’t YOUR wind-detecting and other flood lights illuminating the bedroom of the house next door, either, a phenomenon called “photon pollution.” Doesn’t mean YOUR property can’t be lit up like a little Las Vegas, but not those places next to you.
Pima County thanks you in advance for keeping your f…g light to yourself2!
————–end of PSA———————-
(I don’t actually cuss, but it was great to write that last sentence; kind of puts the hammer down on the whole piece I thought, to give you a little of the writer’s insights in framing it that way. Note, too, that the author has contrasted the vulgarity of the last sentence with the erudition that accompanies a footnote3.)
Heh, heh, night photon-phobe here snuck that PSA in on you in what is ostensibly only a blog only about weather. (Or is it “sneaked”? Oh, well. On to more questionable writing…)
The weather today
Tremendous changes have occurred in the weather maps since yesterday at this same time as the la-dee-dah map of yesterday for the western US has gotten energized by a sudden southward pouring of jet stream from the Gulf of Alaska. Low center to form today over southern Cal. Pretty dry at all levels in the southwesterly flow aloft now over us. Only a few Cirrus or isolated Altocumulus lenticularis today, as “main bang” of frontal rain band and associated wind shift, pressure rise, not due in until well after midnight. U of AZ mod has front passing through TUS between 7 and 8 AM tomorrow morning.
How much, you ask?
Hmmmmm. Was thinking 0.10 inches to 0.75 inches yesterday, but U of AZ mod today, from 11 PM AST last night, now has an amount similar to the high end SOP guess made here yesterday. Here’s the good news from the U of AZ mod. This precip addition is gonna be so great for our spring bloom!
Total water equivalent precip for this storm ending at 6 PM AST tomorrow. “Water equivalent” was used since it’ll be snow on the Lemmon where something over 1.5 inches is indicated. Keep in mind that these model calculations of precip often run a bit on the high side.
I’ve been learning you up on these things, and when I saw this one from last night’s global data, I gasped, as you might.
Valid at 5 PM AST, January 2, 2014. If you’re going to the Rose Parade on the first, take a jacket. Big pattern change suggested, another cold spell as the West experienced in early December, and in the coming week.
We’re trending toward another cold spell in the West as the year ends and the new one begins. And, a pattern like this impugns a wet spell here, too. Sorry snowbirders.
Note those yellow “control” contours piling up to the North Pole practically in the mid-Pacific and the slogan, “what goes up must come down.” So, mods here are seeing a pretty good signal amid the noise of a big ridge in the central and eastern Pacific; jet stream not running much west to east, but rather north and south, and that kind of deflection leads to temperature extremes, high ones poleward, and low ones equatorward, in this case, in the western US. So, watch out.
Remember, too, that the atmosphere remembers, and when we see a pattern showing up that we’ve already had, we place that bit more credibility in a model forecast, as here. In popular culture, there’s an old saying about relationships that resembles this: “If he/she did it to her/him, he’ll do it to you.” I bet you didn’t think you’d read that here. Applies to weather “persistence” or repetition of patterns, too.
As a final longer range note, the CPC, via their ensemble of models, has predicted five months of drought in the SW and Cal as 2014 begins because that’s what most of their climo models agreed on. These predictions were issued a couple of weeks ago, however.
IMO, don’t place too much faith in that prediction. We have no La Nina/El Nino hat to hang our forecasts on, and those factors that are there, Pacific Decadal Oscillation, North Atlantic Oscillation, Artic Oscillation, Antartic Oscillation, my oscillation (doesn’t everyone have one? Seems that way sometimes) don’t have the forcing power of a strong El Nino/La Nina.
Finally, its already been exceedingly dry in Cal, the writer’s home state, and these drought periods always have interruptions, and so, IMO, I would bet quite a bit that there will NOT be FIVE months of drought in Cal and the SW. It could be a lower than normal water year in these places overall (Oct-Sept) but five more uninterrupted months of drought? I don’t think so.
Clouds? Oh, yeah….
Hell, I’ve talked about everything else but clouds ’til now…
4:08 PM. Classic Altostratus translucidus, an all ice cloud.
5:31 PM. Solid As above the Catalinas as the sun creeps out from the backedge of the As deck.5:52 PM. Moderately good sunset, Cirrus spissatus, uncinus, coupla Altocu.
1In descriptions of recreational activities, they mention hiking and stuff like that, but not “being in a low center.”
2BTW, if you like dark skies so’s you can see as many stars as possible, or our dark mountains at night, here’s a place that talks about trying to preserve dark skies, something that is rapidly disappearing on this planet, the International Dark Sky Association. Apparently, its not just us here in AZ by the observatories that likes those dark skies, part of the reason we live right here.
3 In literature, sometimes termed “the Jeckyl-Hyde device”, one that complexes the writer’s personality through vivid, contrasting language or subsidiary devices in a single sentence.
7:16 AM. Altocumulus castellanus virgae. Has light snow falling out of it in tiny filaments, Aircraft measurements show that those filaments, snow fibers, that are falling out right below the base are only 10 to about 30 yards (meters) wide. “Floccus” would be OK, too. Notice that there are two turrets, one is older, has holes in it on the left, while the younger one on the right side looks more solid, firmer. The younger one has not yet formed a strong virga trail, but will as it ages. These are Cumulus to Cumulonimbus transitions in miniature and in slow motion.
Today’s sunrise of the day
7:20 AM. Altostratus.
About up and down…
That giant low pressure center, so needed by us droughty folks here in the SW, has materialized in the western Pacific, shoving gigantic amounts of heat and clouds poleward (up) toward Alaskans. We like to call them Eddy or Eddys; they keep the poles from getting too cold and the Equator too hot by shoving air around. This low in the western Pacific has forced a big northward bulge in the jet stream up that way where it had previously been pretty much a west to east flow. A region of higher pressure is created aloft when there are injections of warm air into the northern latitudes by storms1.
When air surges northward and builds a region of higher pressures in the jet stream like that, it buckles and turns southward on the downwind side of the high pressure (or ridge) almost immediately. In this case, and lucky for us, the buckle is toward the south over the western US and ultimately down into Mexico, but not too far, we hope.
What goes “up” in latitude must go “down”, more or less.
Surface weather map with satellite imagery for 11 PM AST last night.500 millibar map for 11 PM AST. Ridge pilling up in AK-Bering Sea, about to turn jet southward into the western US.
So, that inconsequential looking area of clouds and low pressure which appears to be jetting across British Columbia and Alberta in the first map, will suddenly begin enhancing and expanding southward, new low pressure centers will form in the Great Basin area. It will get windy here for a time. Very exciting.
I guess what I am trying to say, too, is that old timey weather folk like this writer would look at a map like these above, even without the satellite imagery, and think, “Oh, my”, “Change gonna come“, as Sam Cook so sweetly sang so long ago, a drastic change for the area downstream of the giant low and its heat plume.
Things are out of balance at this “map moment”; weather “Koyannisqatsy“, too much swirling low in the west part of the Pacific and strangely quiet downstream over the US at the SAME latitude as that giant low is reaching down toward out there far to the west of us. “This will not stand”, as someone once said about an invasion of a Middle East country. And the “quiet” in the West won’t stand, either. Balance in latitudes affected by storms is a key proviso of weather, a kind of conservation law2 we used to talk about a lot, and still do in undergraduate courses.
We could go back all the way to the Middle East to see the roots of the storm that blew up in the western Pacific. It was already a strong upper level wave that showed up in the Middle East as the snow situation there was beginning to take place. As a strong upper level feature, it was the trigger for the stupendous low that formed when it exited the Asian continent, found heat and temperature contrast that are the building blocks for strong storms.
The clouds and storm ahead
Models have been wetting it up more and more here, sometimes the US model have no rain at all as the trough and its clouds passed too far to the SOUTH of us. But lately, that US model has been increasing the amount rain here, not taking the low so far south. The Canadian model has had rain here in every run for days, so its been more consistent on this pattern, not taking the low too far south.
Valid at 11 AM Friday from IPS MeteoStar, December 20th. The colored regions are those in which the model has calculated precip over the prior 6 h. Note heavy band over Catalina! (Dried up a lot on the next run at 11 PM AST, though.)
Due to the variable nature of the precip amounts seen by the mods, you have to figure there’s an awfully wide range of amounts that can occur here in Catalina from a tenth of an inch on the bottom, to as much as .75 inches if everything goes really well. U of AZ mod will have more to say about this in the next 48 h.
Of course, as cloud mavens, we’re interested in the sky as well as the storms. Lots of precursor high clouds today again like yesterday, and if the usual trend continues, those clouds will lower some as the day goes on from just Cirrus, Altostratus, sometimes augmented by Altocumulus. These kinds of clouds can lead to some fantastic sunrises and sunsets, so have camera ready. You only have a couple of minutes to capture the peak of the “blooms.”
The End.
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1Remember, low density air (air filled with warmth and humidity), if deep, leads to a small change in pressure as you go up in the atmosphere, and so by the time you’re at 50,000 feet, you’re in a HIGHer pressure region than those regions where the air is not so warm. How odd. So surges of warm air and clouds from the Tropics build regions of high pressure aloft, and that’s what we’re seeing now.
