Cloud-maven – Page 50 – About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno

Trough bowl relocates to Arizona

Since the Big Bowl is just ahead, featuring our Seattle Seahawks, a team that played their games right near the University of Washington where I worked, it seemed like a good title, one that ordinary, football-loving peoples could identify with. But, of course, I am talking about “trough bowling” and the inclement weather that goes with them, right here in Arizona, not in New Jersey.

Models are foreseeing a spell of upper level troughs collecting in the SW US in the next week. In the map below from the NOAA “spaghetti factory“, you will see a great example of the best chance for a halfway decent rain in AZ as these several troughs march through, including one today (but too far north). All we get today is clouds, mostly middle and high ones, too high above us to rain on us, then later in the day, lower ones like Stratocumulus, but with tops too warm to form ice crystals, necessary for rain here in old Arizony even though it may look pretty gray at times.

Back to the maps….

In the map below, the red, yellow and gray lines all bulge southward toward the Equator in our area. The wind at this level (500 millybars, around 18,000 feet above sea level) travels along the lines going toward the SE off’n Cal, then bend back to the NE over Baja.

The air tends to sink and dry out in flow going to the SE, but tends to rise and moisten as it bends back to the NE. So, as troughs come and go, with the SW winds ahead of them pass by, there’s a chance for rain each time one goes by.

The third one that passes by, later on Thursday, February 6th, gives us the best chance for widespread rains, as foreseen for AZ by last night’s 5 PM AST model run.

How great would that be?

If you don’t believe me that widespread rains are forecast for AZ, you’ve given up on rain here after weeks of drought, I’ve added a map from last night’s model run. Its OK. I’m a weather forecaster and there’s a certain degree of incredulity, an aura really, that goes along with this occupation. We get used to it, kind of like economic forecasters do.

You can go here to poke around the NOAA model.

Valid February 6 at 5 PM AST. I've annotated it so you will know where Arizona is. Its shocking to me that I have to keep putting arrows on maps showing where Arizona is to my readers. — Valid February 6 at 5 PM AST. I’ve annotated it so you will know where Arizona is. Its shocking to me that I have to keep putting arrows on maps showing where Arizona is to my readers.

Valid at 2 PM, February 7th, 2014. — Valid at 2 PM AST, Friday, February 7th, 2014. The green areas denote where the computer model thinks rain has fallen in the previous THREE hours. There are several maps like this after this one for 2 PM, ones that extend the AZ rain into early on the 8th. Who knows at this point, but maybe half an inch could fall here in Catalinaland. Hoping so.

Mods are grim after this storm passes on the 7th, with the jet stream staying north of us, maybe for the rest of February, and that means chances of rain are nil. No jet, no rain.

Oops, I forgot to show you where Arizona is….here’s that same map again.

Same prog, valid for 2 PM AST, Friday, February 7th, 2014. Recall that this storm has been predicted, more or less, for about two weeks. — Same prog, valid for 2 PM AST, Friday, February 7th, 2014. Recall that this storm has been predicted, more or less, for about two weeks, as has the pattern change.

The first real chance of light rains here is just ahead, that on late on MONDAY! Looks like only a tenth of an incher, though, right now.

BTW, poppies in bloom (!) are being reported by hikers here in the Catalina area. Wonder if this has happened before in January?

Looking ahead to rain and other weather mischief in the days ahead.

The End.

Rainless January ends with a few drops

Sure, it was only a “trace”, less than 0.005 thousandths of an inch, but it counts as a rain day! Those drops fell just after 5 AM and the rain lasted for almost 6 minutes. Think I will call that patch of middle cloud that did this, “The Terminator”, to add a little drama to this event. “The Terminator” is passing over Oracle now at 5:55 AM. I also said I would check back with you when the drops started falling, too. So, here I am sitting here trying to think of things that would kind of get you excited about clouds and weather.

Recall it was posited here that rain was “likely” in January as January began. And now we have had that “rain”! Total and complete verification of a long range forecast! Looks like my forecasting accuracy will now go over 50% with this verification, too. So, I am pretty happy this morning, if you care, which I doubt.

BTW, this is part of the same system that was initially supposed to bring rain on the 27th, foretold about 10-12 days in advance. Often the day is not quite right that far in advance, but the event was captured. It wasn’t foretold to be much back then anyway.

Of course, today we remain in the same droughty, comfy-temperature pattern as we have been in the past few weeks; no surprises there. This standing pattern, the extreme cold in the East and toasty in the West, has been well foretold by our illustrious computer models.

But what’s ahead?

This, just in….. Big rains and even, big snows in Arizona here in Catalina, too! That’s my read. I am going with the very latest depiction of weather from our “gargantu-brain¹” model, the Weather Research and Forecasting-Global Forecast System model, “WRF-GOOFUS” for short.

Here are some great depictions from our equally great NWS NCEP WRF-GFS site which you might want to explore MORE than can be displayed here. Here we go, you drought bustin’, wildflower fluffin’ maps:

Stage 1) Actually setting the stage for something big here, valid at 11 AM, Thursday, February 8th:

Notable features, record cold in the Pacific NW and northern Rockies as a gigantic trough and pile of cold air marches down the West Coast. If this verified, temperatures would likely be in the single digits in Seattle, low teens at best. And this cold air and trough are headed this way, according to the predictions from last night’s global data taken at 11 PM AST.

Stage 2): Valid 24 h after prior map, 11 AM Friday, February 9th: Rain moves in to Catalina; reoord cold advances into southern Oregon and northern California.

Stage 3, day 3: Valid at 11 AM, Saturday, February 10th. In this depiction the cold air is arriving in Catalina, rain likely changing to snow. Record low temperatures likely in Cal and NV on this day. A day or so later in AZ.

Overall summary

Naturally, such extreme maps as these incorporating record low temperatures have to be considered somewhat suspect. But, from a risk standpoint, you have to be aware that they might well happen. This is the first series of maps to show such brutal cold in the West, and does correspond to a vast change in the circulation of the jet stream that will be under way as January comes to a close.

So, while the chances are low that this will play out exactly as shown, with all those record low temperatures, you have to be ready for something brutal even here in Catalina just in case. As I heard yesterday concerning planning for the virtually certain “megadroughts” in the future of the SW, with or without the aid of global warming since they are in the proxy data going back thousands of years, you have to plan for bad stuff anyway. But in this case, even while uncomfortable, it would be a good series of storms for us in just about every way except comfort.

Going out on a twig, not just a limb,

The End.

————————–

¹ A phrase stolen from Douglas Adam’s, “Hitchhiker’s Guide to the Galaxy” (theme; long version)

Rain foretold for Catalina on the 27th!

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).

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.

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.

DSCN7187 — 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.

———————————-

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.

The End.

Pattern to break down near the end of January

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.

The weather and circulation of January 1963

The weather and circulation of January 1977

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:

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:

Vadlid at 5 PM, Janaury 23, 2014. Temperature refugees racing from eastern US to Arizona! — 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….

See this; read these!

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 clouds. 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. — 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.

————————-on claims module——————————–

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.

3-13-12_Wallace on extreme events and in Science mag

Who the HECK is Mike?

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.

————————–

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.

January rain coming into view

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.

The End. (Trying to be more succinct…)

Rain likley in January

Mod rendering by IPS MeteoStar here. Rain, mountain snows in AZ only 400 h, plus or minus 100 h, away! (I’m kidding some here.)

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.

The End.

Sprinkles and gray; not a great day

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 as clouds beging to breakup. (Photo not zoomed or cropped?) — 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." — 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 going to be nice, scattered Cumulus, and the forecast I made one of the great ones of our time. Middle level clouds rolled over the top of these and put the kabash of that! — 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. A real shaft on the Catalinas! This was the last thing I expected to see. Such a shaft indicates that the top of this cloud got much higher (likely a few thousand feet) than any other tops yesterday, likely poking up through the higher layer of Stratocumulus clouds. — 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. — 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.

5:21 PM. "Cow and sunset"; $1200. — 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.

Generous storm dumps more than half an inch of rain on Catalina

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.

Yesterday’s cloud saga

Fast version here from the U of AZ. Too many pics and blurbage below.

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 in prior blogs. Egad! — 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!

2:04 PM. — 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. — 2:04 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. — 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 (launched about an hour and a half earlier, rises at about 1,000 feet a minute.) — 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!

The End.

Yesterday’s dust before the storm

5:17 PM. Cu fractus and humilis with edge of the approaching rain band clouds starting to obscure the sun through a dust haze. — 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 particles likely due to dust. Small aerosol particles, due to smoke, lead to a reddish sun. — 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 End.