More should fall before the end of this episode today, perhaps another 0.25 inches, rain that will push the total to almost an inch as another band approaches us (at 5 AM)! What a great, needed rain, though some forecast details were off the mark. The front and its rainband went by between 2-3 AM, dropping 0.32 inches here. Was thinking it would be more; half inch. The U of A Beowulf Cluster model output had the timing of that perfect, however. The larger surprise was the 0.42 inches in the prior “pre-frontal” rainband that developed over us and to the south last evening and rained until about midnight, much more than was anticipated by the model or me.
In any event, it was fabulous to hear the rain falling on the roof.
Yesterday’s clouds
What was interesting were all the little things that went on, for example, the puff of dust when the wind picked up in mid-day (shown below). We haven’t had much wind over several weeks, and I suspect that there were a lot of very fine particles ready to blow around at the first significant wind over the deserts to the south and southwest of us, and that wind not having to be exceptional to get them in the air. That dust puff came in about the time the first lower clouds did, then quickly moved off even as the wind increased.
First, dessert:
5:10 PM. Sunset before the storm. Wasn’t really looking that good around this time as the Cumulus and Stratocumulus clouds flattened late in the afternoon, and the virga coming out of them diminished. It looked for a moment like I was in a crepsucular ray; felt kind of special, maybe just me being highlighted by the sun.4:46 PM. Rainbow. What is interesting here is that by this time the ice and virga around had decreased from mid-afternoon as the clouds flattened, but while the tops warmed to around -10 to -12 C (this from the TUS sounding) they were still able to produce a little ice/snow which melted into rain on the way down and produced this rainbow. These cloud top temperatures are marginal for ice formation in AZ, if you care.
4:58 PM. Explanatory razzle-dazzle in photo.12:15 PM. Dust invades Oro Valley along with the development of small Cumulus (fractus and humilis).
3:30 PM. Heavy ice cloud emits from a modest Cumulus (mediocris). Since the top ejected in dryer air aloft, and with no cloud base below this ice plume, no rain can reach the ground. It just evaporates while settling out. Tops here almost certainly colder than -15 C.
More rains just ahead
Yep, models coming around pretty well on the rain issue. From Canada, two more rain spells are ahead, Saturday, and then on the following Wednesday the 19th. The first one is marginal, range of rain from a trace to maybe 0.25 inches, tops. The second rain is looking much more substantial, though not as much as last night, probably of the order of a third of an inch or so. You can loop this venerable model here; haven’t looked at anything else yet. Those two periods of rain in this model have increased in amount over time, which is a good trend.
In the longer term….
Its becoming more clear with every day that we have indeed entered a new weather regime, ending the droughty weeks of yore. This is supported in the model runs based on last night’s data beyond the next week (beyond the time frame of the Canadian model output linked above) as strong storms are indicated to crash into California and then march through Arizona with substantial rains. Supported, too, in our model output “tester”, the “ensembles of spaghetti” which point to troughs and jet streams affecting us over the next 15 days. And, if it is a regime change, they usually last longer than just the 15 days of model runs.
But how much affect will a wet spell NOW have on our spring wildflower bloom? Will find out; forgot to do that yesterday…
For those in a hurry: no rain before 5 PM AST, rain beginning between 5 PM and 8:42 PM; most of rain after midnight into mid-day. Since people forget, I’ve added a musical reminder there: “After midnight, we’re gonna let it all hang down.” Could be that incoming front talkin’ to us.
It will also be a fantastic day for clouds, probably some nice lenticulars today downwind of the Catalinas and elsewhere as the wind strengthens above us. Keep your camera handy.
For retirees, or others who have a LOT of time….
The long story line about how to forecast when
Its ALWAYS fun and a challenge to try to foretell when the rain will start to fall by the clock. Did some radio work like that in Seattle, i.e., “rain beginning between 11 AM and 2 PM”, “no rain before noon”, and also for the Washington Husky baseball and softball teams, when to take the tarp off, resume play, when put the tarp on, etc.
Those radio forecasts were made early in the morning on weekdays (KZAM-FM, 1982) and weekends (the latter during Weekend Edition on KUOW-FM, an NPR affiliate, 1987-1992). It was thought that such a forecast, given early in the day, would be the most useful one for a listener planning his/her day if it could be done well enough. This would be ESPECIALLY true on weekends when the listener could do whatever with his/her time rather than be in a building all day at work. But, could you do it well enough using the surface obs, weather maps, satellite imagery, and model forecasts generated the evening before, such as they were in those days. It was deemed a forecasting experiment in those days. It wasn’t being done elsewhere in SEA.
BTW, there was no weather radar in Seattle during those days if you can imagine such a thing.
However, I will also add that radar is really not that useful in SEA anyway since forecasts for the next 8-12 h is a window of time in which radar can’t be used, for example if the incoming rain is still off the coast of Washington! Reading the sky was much more important in determining how close the rain was, integrating that interpretation with the satellite imagery.
Or those days when showers would form that aren’t present in the early morning when you’re giving your forecast. The passage of a front in Seattle, BTW, is usually followed by a brief clearing followed by passing showers, unlike say, back East where once a band of rain goes by, that’s it for the rest of the day.
So, here we are in Catalina facing a great storm, our best of the winter. How close can you come to getting the start time here in Catalina? That’s the game. Today, the models are SO MUCH better, you have to look at them carefully, and know whether they run a bit fast in bringing in rain, and if there are any significant errors built in.
OK, here goes the first look, based on the passage of the core of the jet stream at the 500 millibar level, around 18,000 feet. The criteria that rain starts when its overhead and after it passes was developed during the early 1970s whilst the author, a forecaster, was working for a HUGE randomized cloud seeding experiment in Durango, Colorado. It was found that almost no precip fell in Durango before the 500 mb jet passed (95% of the wintertime precip there fell only after this happened). That study was later expanded to the ENTIRE US and it was found that wintertime (November through April) precip in the interior of the Southwest also followed that Durango criteria very closely; it was almost a black and white predictor.
So, let’s look at when the jet passes over us here (using IPS MeteoStar’s great forecast renderings again) and see what time it goes by (of course, in this era, the models also “know this” relationship; not so well in the early 1970s).
Valid for 5 PM AST today! Note the coloring. It shows where the velocity of the wind is higher and lower. Yellow, browns and reds are highest.
Valid for 11 PM AST tonight. Should be raining real good by now; jet has passed overhead and is to the south and east of us.
Like Seattle in some ways, this early onset of rain is from clouds for the most part, are ones that haven’t formed yet! They’ll be forming and filling in to the southwest of us and here, deepening as this big trough works inland toward us.
Next, if you were to measure the movement of the frontal rain band now in southern California over the past 12 h or so with a ruler, or piece of paper, you would find that at its present rate of movement that frontal band would be here around 10 AM tomorrow. So, you would have rain starting in the evening, peak rain in the morning. Done.
Now after this simple exercise, let’s see what the BEST model has in mind for the rain start, that from the U of A, processed by their intimidating “Beowulf cluster” (you can call it up here) based on data from 11 PM AST last night. This should be a very accurate forecast, and we hope resembles what was said above; no rain before 5 PM, but raining soon after that. (BTW, I have not looked yet; part of the “game” today; can you do as well as the model with a simple approach?
OK, here is the coverage of rain expected by 5 PM AST in the U of A model: not much, but its upwind.
Coverage of rain by 5 PM AST. Not much.Rain coverage by 9 PM tonight. Should have rained some to be redundant.
In sum, that simple technique was not so bad.
The main frontal band is still to the west at this point, 9 PM AST, and it doesn’t pass over until after midnight. Then the rain lingers into the mid-morning to early afternoon. Amounts still look VERY substantial. This model projects around a half an inch or more here in Catalina by tomorrow night. The range of values, given the various uncertainties in models and clouds and weather, bottom amount 0.25 inches (only 10% chance of less), top amount, an inch (only 10% chance of more), these percentages generated from this keyboard, BTW.
Here is the Beowulf total storm rain ending at midnight tomorrow night:
What’s after this?
Mods still showing spate of storms over the next couple of weeks, this one not a one-hit wonder. And there’s support for these storms in our venerable ensembles of spaghetti. Main brunt of storms: California. Expect to read about them.
But are our rains too late for our spring flowers? Dunno.
Title properly sung to “Rawhide1“, a western theme song for a TEEVEE show known by heart by all us TEEVEE viewers of old, and how it might be sung today by a weather-centric cowboy, one that lived in “a area” of drought, like us.
On with the story…
There was a couple “stray” model runs (hahaha) yesterday, ones that dried up all the storms but the BIG ONE tomorrow night and Friday. Those runs were quite bad ones; looked like the CDO wash today.
It had been penned from this keyboard recently, if you can say, “penned” in the context of a keyboard, that a SERIES of storms were on their way to Catalina after the drencher Thursday night into Friday, so I had a vested interest in not showing those runs.
I know, too, when you read that C-M person had said that there were a lot of storms coming that you were probably ecstatic. Maybe thought the drought might be vanquished by “a few good storms” over the next two weeks to a month. Maybe you did something fun that day after you read what I posted about a lot of storms ahead; maybe called in sick and went to Ms. Mt. Lemmon to see if you could see some precursor clouds off to the west.
Therefore, having written about all those storms in my last post, I had the responsibility to ignore the later model runs with no rain in them (after Friday) and wait for those other rains to re-appear. (Its funny, but it happens.)
I am pleased to report, after not telling you about those dry model runs, that the series of rain days the model had before have magically re-appeared, though no as “juicy” as before, and I can resume telling you about them! This is so great!
Here are a couple of examples from last night’s WRF-GFS run from data taken around the world at 5 PM AST, the first for Sunday morning, 5 AM AST. The two panels below are posted in smaller sizes because they have less credibility being as far in advance as they are; click on them for a larger view.
What about the drencher coming in tomorrow night and Friday? Let’s let the highly paid TEEVEE weather practitioners take that today. They’ll be all over it, and they’ll do fine. I’m sure… They’re all pretty good.
Sunday afternoon, the 19th, new rains approach.Morning of the 27th. Good fantasy rain here; too far out to count on, but. “hey” its something to write about!
Yesterday’s sunset
What would a C-M be without a sunset picture, this of Cirrus clouds.
5:27 PM.
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1Frankie Laine remindner here; a great song with a lot about weather and flooding in it; cuss word, too, bold for those days. Had Clint Eastwood in it; whodda guessed he’d be still making movies 100 years later?
It doesn’t get any better for a desert in southeast Arizona than this; a model run with NINE panels of rain, including rain on Christmas morning, and here they are from last night’s 5 PM AST global data, our best computers in action. Remember the bad old days just a few weeks ago when no rain was foretold in the models for 15 days ahead, and that dry forecast was seen day after day for another 15 days?
Those days are gone. The “mean”, as in average position of, mean (as in bad, angry weather) trough is here now. You are in it. You can’t escape. “Trough bowl” in progress!” We’re going “weather bowling”! OK, enough exclamatory statements. This doesn’t mean every day is bad, but storm days will keep recurring beginning next Friday.
Here are a couple of those forecast panels from last evening, the first for Friday’s major rain about which a news release was released. This is so great. What’s even greater is that the Canadians, with their more accurate model, are on board for a big Friday rain, too! Two models with rain, as we know, guarantee a rain!
Friday morning the 14th at 5 AM AST.Also valid for Friday morning, the 14th at 5 AM AST. See lower right panel for rain areas over the prior 12 h.
Here’s another one on Christmas Day (left out some other rain days):
Storms will be dropping like bowling balls, one after another, like down a water slide, moving southeastward every few days out of the Pacific over the next two weeks, likely longer since once patterns get established they persist. In fact, “persistence” is one of our greatest forecast techniques, just saying what’s already been (say, cold and wet), will be what’s ahead. Its great!
An example of how you could have become quite the neighborhood weather guru last October and November. As a cloud maven junior, you would have already gained some prestige in your neighborhood. Now imagine adding to that status if your neighbors had come up to you in October at some point and asked about the winter. You would ONLY have had to have known about the weather you had already had for the past week or so to state, with furrowed brow, “I foresee much the same weather OVERALL as we’re having for the next two weeks, maybe a month” to your neighbors! And the majority of the time, you would be right! Think of all the right forecasts you would have made day after day in October, November, into early December!
This is because, as all weathermen and weatherwomen know, the jet stream and the storms it carries gets stuck in groves like the water in rivers for weeks at a time; but then suddenly jumps the banks into a new pattern. So, using retrospective forecasting techniques, your going to be right a majority of the time. To paraphrase so many internet ads, “this is a little known secret that weather forecasters don’t want you to know.”
But today you’d be so WRONG with that retrospective forecast technique! Change happens.
The “stream” is “jumping the banks” right now–some kind of tipping point has been reached somewhere and the new, cold and wet pattern is about to begin in the West, its just ahead beginning with that big rain here on Friday into Saturday.
But how do you know that one storm is the beginning of many, not just a breakthrough fluke in a continuing dry pattern? Confidence is added by having some spaghetti, not just examining the many panels of rain. Here, 10 days out, we are in the trough bowl! Little doubt about it; count on it.
And because our rains are associated with cold air invasions, there’ll be snow birds heading back to Illinois and Wisconsin pretty soon, wondering why they came to Arizona. Of course, the ski birds will be quite happy with the pile up on top of Ms. Mt. Lemmon.
What’s the real unknown here?
How much precip will our cold wet regime really bring? While we’ll have a number of opportunities for drought denting storms, they could also be a stream of minimal, relatively inconsequential ones. That’s the real bugaboo here in this monumental pattern change. The exact trajectories the storms take is going to be pretty unknown today. We could end up with frequent storms and cold days, but only average rainfall or even a little below after two weeks. Or, as in the first slug on Friday and Saturday, a total in one 24 h period that gives the December amount into respectable levels just by itself.
C-M has a gut feeling that we will see above average rains here over the next 30 days (two inches or more). “Gut feelings” are pretty worthless, but, there you have it.
Remember our logo, “Right or wrong, you heard it here FIRST!” :}
A local meteorologist and Catalina resident held a news conference earlier today and announced that rain will fall in Catalina on Friday, December 14th. Few exact details were announced, but it was stated that the rain will begin before dawn on Friday, December 14th and last most of the day. The exact amount was not stated, but it was said that there would be at least 0.25 inches, but not more than 1.00000 inches, noting that the storm has the potential to be a “real drencher” if it approaches the top end of the forecast.
Such a rain, it was pointed out, would only be the second such rain since the water year began on October 1st. That prior rain of 0.48 inches, fell on November 9th, more than one month ago.
A few images of raindrops were presented to remind Catalina residents of what to look for on December 14th.
Prior to this news conference and due to the long dry spell, it was believed by many Catalina residents that winter rain might not fall again. No rain is expected prior to the December 14th event.
Being the time of football bowl games, and with 35 just ahead, it seemed an appropriate thing to say. And, let’s face it, there are never enough bowl games1.
You can see this “trough bowl” phenomenon in a 5-day average of the contour heights at 500 millibars (around 18,000 feet), courtesy of the Washington Huskies Weather Department, whose company team is actually in one.
Below is where we started at the beginning of December. Remember how floody it was in northern Cal and Oregon? That’s what can happen if a trough bowl stagnates just to your west (but not too far), since most of the rising air is to the east of the “bottom” of the bowl (where the arrows point roughly).
And, being away from the core of the jet stream at this level, us Catalina-ites experienced day after day of zephyrs moving 75-80 F air around in the afternoons. Not bad really. But change is good.
Arrows denote bowl troughs, where the “average” position is. There might be one there in central Asia, too.
Well, them days of stagnation, a “Snow Bird” paradise, and really wasn’t that bad if we coulda only had some rain, is gone. Here’s what ahead:
Arrows denote roughly the bottom of trough bowls where storms collect.
Weather will change, as you already know from our TEEVEE people who make a LOT of money, from stagnant to vibrant, winds and storms from time to time as the trough bowl develops in the West.
Trough bowls are like repositories for storms, and around the globe there are typically 4-5 of them, waves in the westerly jet stream whose apexes mark the “bowl”. Storms dip down into them from the northwest and then shoot out to the northeast, usually with lots of precip, after reaching the “bottom”, the most southerly extension of the bowl.
As you can see, we are a bit toward the west side of this bowl and that means the storms will be cold ones coming from the Pacific Northwest, at least to begin with. Also, coming from that direction, they’ll be a bit rain challenged for us.
Mods still have a trace of rain on the 13th associated with the first storm to “fall” into the Bowl from the northwest, preceded by a dry cold front passage tomorrow. Bundle up, it’ll be a very noticeable dry front passage with good northerly winds here in Catalina.
In the longer term, the “bowl” shifts farther to the West and there are actually some rain days showing up in the 10-15 day period. But, as we know, unless they are supported by some spaghetti, those predictions are dicey, and they’re not well supported =s not too reliable. Still, hope springs eternal, or at least until the next model run.
The End.
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1Maybe more teams should get to go to bowl games,not just the elite teams….as was posited long ago for the NCAA basketball tournament by Jesse Jackson in a presidential candidate debate of 1988 on NPR’s, “At Loggerheads.” Here, Jesse and George Herbert Walker Bush, debate how many teams should be invited to the NCAA basketball tournament. Harry Shearer moderates: At Loggerheads
Our deep blue sky, loaded with interesting Cirrus clouds yesterday, and generally low in contrail impact, makes southeast Arizona a haven for Cirrus cloud watchers. Though no one site is completely immune from them, a sky like this, so free of contrails, is impossible on most of the Atlantic Seaboard due to air traffic. It was just so pretty here yesterday with so few contrails! Here are a few shots:
10:01 AM. Mostly Cirrus fibratus advance toward Catalina.11:30 AM. Tenuous strands of CIrrus fibratus, ones underneath higher, scattered Cirrus clouds. Long strands like these require hours to form, and moist air for a great depth below the much higher, spawning flecks, now long gone.2:05 PM. The upstream tail where the much of the Cirrus clouds form approaches. The lack of long strands, and little specs of cloud tell you that these Cirrus clouds are quite young.5:19 PM. Patchy young Cirrus clouds with an older contrail at right. This photo shows how contrails eventually evolve to resemble natural Cirrus clouds.
The weather ahead: cold front’s a coming
Its been well predicted for 1-2 weeks that a cold front would pass through our area on Dec 9th-10th. At times the models had substantial rain here, but it’ll be a dry blast from the north Sunday night. What makes us here in Catalina a little different in experiencing this frontal passage is that the high pressure behind the front pushes air along the Catalina mountains from the north here, and we often get quite a windy episode, 15-30 mph likely Sunday night. But, because we have no official weather reporting stations, and the Catalina Mountains block that north wind from Tucson so that they don’t get it, so us here in Catalina are about the only folks that know its quite windy, with a chill in the air.
This cold front is part of a large scale pattern change in the jet stream that is taking place, one that will vastly increase our chances of rain in the weeks ahead as storms barge into the Pacfic Coast farther south than they have and head this way. No longer will we be in a stagnant condition where day after day the weather is almost exactly the same; not much wind, temperatures above normal. Instead there will be occasional windy episodes as storms get close, temperatures closer to normal, and we hope, one that gets far enough south for a good rain.
Some rain is showing up now overnight on the 13th-14th. In our rain frequency chart, the peak rain days in December were the 11th-13th, deemed a statistical fluke from this keyboard in the 35 year record.
But, here’s a rain threat materializing in the very window. Hmmmm. Further, if you look at the spaghetti plot for this time period, a trough is guaranteed in this region on the 13th-14th, though getting circumscribed by the jet stream that is, its south of us as the trough goes by is what’s marginal with this trough situation, a requirement for almost all winter rain here.
Since we don’t have any clouds and storms to think about, I thought I would think about the moon for you. Here is a fragmentary view from yesterday morning through some Cirrus:
Have any thoughts yet?
Well, here is a surprise that’s been around for a few years but I just found out about it:
The moon is a piece of the earth!
Yep, “Theia”, another planet whose exact size is unknown, COLLIDED with the earth about 3.5 billion years ago! That, my fiend, is the leading theory for the moon’s origin; this from the November 23rd issue of Science: Science-2012–1006-1
I can’t post more beyond these newsy pages from Science because Science is not yet apart of the Open Access Movement where you can learn things from journal content for free! Imagine! Besides, on the second page there is an advertisement for a vacation in June in Iceland, in case you get too hot here.
But, after that diversion, and thinking of Theia (nice name for a girl, BTW), think of the damage! The shaking!
How are we still in orbit? Where’s the crater? (Must be pretty damn big!)
Why would you think such a crazy thing in the first place? After all, as advised in this Disney-produced proper musical ambience and skit (Extraordinary Claims); EXTRAORDINARY CLAIMS require EXTRAORDINARY PROOF!
Amen.
So where’s the proof?
Its in the isotopes. Amazingly, beyond even Ripley’s Strangely Believe It, much of the isotope composition of the moon is identical with the earth, not like those from meteorites and stuff like that. So, there you have it, though there are some unanswered questions yet. Apparently, it got so hot at the collision interface that everything melted back together, no crater
If it was to happen again, I hope it doesn’t happen during a bowl game (teevee viewing guidance here), since I wouldn’t want to miss the story in case it was played down due to an important upset, as here from an old Seattle Times mention of an asteroid that looked like it might collide with earth. At least this news was on the front page. Gee, if it had happened, maybe we’da got us a new moon to look at!
Pretty upset this early AM to find that the US’s Weather Forecasting and Research-Global Forecast System (WRF-GFS) model run, a model costing millions of dollars BTW, ingested last night’s 5 PM AST global data, BUT then threw up an identical twin that matched the Canadian Enviro Can model output that came out 24 h earlier! It was unbelievable to see this, humiliating really, something akin to a reverse nose job.
Recall that the USA! model had rain here and a big cold trough right over Catalina on the evening of December 9th into Monday morning the 10th. The Canadian model had that SAME trough over Cornhusky Stadium, Lincoln, Nebraska!
The Canadian model was right.
Here’s are the two forecast maps made within 24 h and each for for the SAME DAY AND TIME by our own WRF-GOOFUS model: on the left, the rainful run from the previous day that made me so happy (until I had some “spaghetti” and saw it was likely a bogus output). The panel on the right is the sickening output from last night, both rendered by IPS.
Valid for Monday, December 10th at 5 AM AST. Sweet! From last night, also valid at 5 AM AST, Monday, December 10th. Horrible, unbelievable amount of change between the two. Makes you feel sad for weathermen and weatherwomen that have to deal with these things.
I really wanted Enviro Can to eat some crow with their forecast of MY trough over Nebraska. But no! “Bow down to Canada”, as heard here if you substitute in your mind the word, “Canada” for “Washington.” Hey, its got the lyrics at this site and so it should be pretty easy for you to sing along with it.
BTW, the Canadians (Enviro Can) don’t feel they have to show “spaghetti” plots to reveal how bad their numerical forecasts might be because they are always so right (in the 144 h time frame available from Enviro Can). “Don’t need no spaghetti.”
Can we say the same?
Doesn’t seem like it. We need “spaghetti” so we can see how bad our model forecasts might be. Calling Obama now…. not “happy with crappy”, to quote some overseas manufacturer’s creed, here. OK, our models aren’t exactly “crappy” but they aren’t as good as they should be.
Too, I have to deal with Canadian relatives that will be gloating today, I am sure. Maybe this spectacular example of “model divergence”, as we would call it, Canadian vs. US, is the talk of Canada today, and that’s what makes today’s wrf-goofus output sting so much.
I really want to call President Obama on this and tell him about it; I know he would add it to his list of things that need to be fixed in our country. Even if you have only a tinge of jingoism, you HAVE to be upset that the Canadians in their big little country, have a better weather forecasting model than we do! I think I am going to have to lie down for awhile…calm down.
So, what is ahead in our weather?
Of course, we have to look at the Canadian model first to get the most reliable one to see if they have anything for us… (hahahahah, sort of). I always do look at that one first, but I don’t brag about it. The summary of last night’s Enviro Can run, out to 144 h: they got nothin’ for us, just some cooler air over time. Cirrus clouds will be floating by from time to time as they do on most days. Did you know that Cirrus is a precipitating cloud? Yep, little ice crystals are always settling out leaving those pretty trails. Mt. Everest would know this…
Hope you had some good log entries describing the varieties and species of Cirrus… If you did, you’ll be getting closer to getting that Cloud Maven Junior Tee.
7:01 AM. Sunrise Cirrus.5:32 PM. Sunset Cirrus, maybe with a contrail in there, dammitall.
A day of pretty Cirrus and a nice sunset yesterday:
5:35 PM.
Now for some more of that Catalina climo, featuring December
(Most of these data below are due to the folks at Our Garden right here in Catalinaland just off Columbus._
First, the rainfall frequency chart for December. Not much going on. Chances of rain on any day about the same as any other, no trend up or down during the month, except for that one peak. Below this chart, in the monthly averages for the October through September “water year”, you’ll see that the average rainfall has jumped up considerably in December from November. Yay!
But will it rain at all in December 2012?
Let’s check…and also look, just for the HECK of it, whether any trough/storm is headed here in the 11th-13th rain frequency peak shown in the first plot…to see whether the atmosphere “likes” to have a little rain in Catalina in that time frame this year.
Below, the USA WRF-GFS model output, again rendered by IPS MeteoStar, from the global data taken at 5 PM AST valid for Monday, December 10th at 5 AM (close enough):
Astounding! A strong trough with rain IS predicted in about that time frame where the chance of rain in our 35 year record peaks, though a bit early. If this map verified, rain would be ending at about the time of this map, 5 AM AST on the 10th, it would be very, very cold, probably in the upper 30s in that rain. Amazing.
But let’s check with the superior Enviro Can model from the Canadians, our friends to the north, because-its-built-on-the-Euro-model-where-they-have-more money-for-big-computers-and-better-models-than-we-do.
Not even close to the prediction by the USA model!
Unbelievable difference, in fact. In the USA model, the apex of the trough is over us in Catalina and in the superior (or will it be?) Canadian model, its over the “‘Braska” Cornhuskers, Lincoln, NE, maybe ONE THOUSAND miles farther east!
Unbelievable2. This is a phenomenon, BTW, which does happen from time to time, that is called, “model divergence”, to put it mildly.
The NOAA spaghetti factory, which I have annotated for you below:
Outstanding forecast reliability is indicated in the Pacific, off Asia, but who cares?
Sadly, only mediocre reliability indicated here in the Great SW USA, as shown in the wanderings of the blue lines.
But will a trough be close to us?
Pretty much count on that because so many blue lines feint to the south in interior of the western US. I think we’ll surpass the Canadians this time…
There’s still a chance of rain on the 9-10th, but its pretty slim. Having cold air invade us, to varying degrees is pretty much guaranteed even if sans rain because that nearby trough will drag cooler air this way as it goes by.
Its the AMPLITUDE that matters here, and in our USA model, that is not so well known. In fact, the blue lines, with so many of them north of us are telling us that the actual forecast map from last night’s global data is an outlier model run; can’t count on it. It will likely come and go on the future model runs.
