Wasatch Weather Weenies

For the second day in a row, we have hit a maximum temperature of 105ºF at Salt Lake City airport.  Never before observed in June, we've now done it twice. Source: NWS It is becoming increasingly apparent that this has the potential to be a historic heat wave.  Arguably, with two 105s in June, we are already there, but the GFS continues to keep a very high amplitude ridge over us through the next week.  Below is the forecast for next Saturday afternoon. The 700-mb temperature in that forecast is 20.5ºC, which would be an all-time record.  It's too soon to say that will verify, but I mention it to indicate that the triple digits could be around for a while.  We have to hope that a short-wave trough somehow clips us or that we get some airmass thunderstorms going to avoid 100. Thus, head to the hills or, if that is not possible, stare at the photo below and think cool thoughts.

It appears that today's maximum temperature at the Salt Lake City airport was 105ºF, which is a record for the day and I believe the all-time record for June. Source: NWS Let me see if I can cool you off with some Alaskan weather.  There's probably no place in the world that offers the combination of mountain and marine meteorology like Southeast Alaska.  With the Mendenhall Glacier as a backdrop, we gawked this morning at a stable marine boundary layer with fog.  Those with careful eyes will notice evidence of shear-induced turbulence at the top of the fog layer, which was likely related to thermally driven gap flow into Gastineau Channel. Yup, it's a world away from Utah.

A quick-and-dirty way to forecast summertime maximum temperatures in Salt Lake City during situations where there are gradual changes in the airmass is to simply adjust the forecast based on the model-predicted temperature change at 700-mb. Here's how it works.  Let's start with yesterday's observed 700-mb and maximum temperatures at the Salt Lake City airport. 5 PM 700-mb temperature: 13.8ºC/56.8ºF Maximum temperature: 34.4ºC/94ºF Differential: 20.6ºC/37.2ºF Next, take the model late afternoon 700-mb temperature forecasts for the next few days and estimate the maximum temperature based on the differential above. Thursday (today) : NAM 700-mb temperature: 16.6ºC Estimated Max temperature: 37.2ºC/99.0ºF GFS 700-mb temperature: 17.4ºC Estimated Max temperature 38ºC/100.4ºF Friday : NAM 700-mb temperature: 17.9ºC Estimated Max temperature: 38.5ºC/101.3ºF GFS 700-mb temperature: 18.3ºC Estimated Max temperature: 38.9ºC/102.0ºF Saturday : NAM 700...

I'm back in town after a quick trip to Boulder and the National Center for Atmospheric Research.  Apparently I missed out on the "big" precipitation event, which gave us a trace of rain Monday at the Salt Lake City International Airport.  That may have ended our stream of days without precipitation, but the streak of days without measurable precipitation continues. Source: NWS There is a very real chance that we will make it through June without measurable precipitation.  Only a rogue convective storm could ruin that streak. We are now about to enter what should be a hot stretch.  We mentioned a few days ago that the GFS was going for extremely warm temperatures for later this week , with forecast 700-mb temperatures near 20ºC, which is on the outer edge of our current climatology (I emphasize current because higher temperatures are coming in future decades).  The good news is that the latest forecast are slightly cooler, putting the 700-mb temperature ...

Minor edits have been made to this post to make some important clarifications as suggested by commenter Tommy T below .   Moonset this morning over the Boulder Flatirons.  Sponsored by Bud Light. I've been enjoying the hype and hyperbole over the Big Moon the past few days.  It's a wonder that we all haven't gone werewolf (well, perhaps some of you have).  There is both fact and fiction at play here. The moon's orbit is elliptical and thus not quite circular.  Although the average distance to the moon is about 385,000 km, at perigee , when it is closest, it is about 365,000 km away, whereas at apogee , when it is farthest, it is about 405,000 km away.     There is no doubt that this causes a change in the apparent size of the moon.  The solid angle subtended by the moon varies from about .56º at perigee to about .49º at apogee.  This does make the size of the moon seem to vary.  The moon subtends a larger solid angle and ap...

I have this simple "rule" for recognizing when the atmosphere is going into big-time outlier mode over Salt Lake City and I call it the 20/20 rule.  Situations in which the 700-mb (roughly crest level) are less than –20ºC or more than +20ºC are rare and on the outer edge of the distribution of temperatures we observe over Salt Lake City. The latest GFS forecast suggest that we will flirt with the +20 later this week, putting the +20 contour somewhere between Provo and Salt Lake on Friday afternoon. The record high for that day is 102ºF and if this forecast holds up we may make a run at that, possibly exceeding it if the southerly flow can get going.  This is still a 5 1/2 day forecast, so no point in getting to excited (or depressed) yet, but it appears we may be in for a scorcher.

By any measure today is simply heavenly.  What a treat to have such weather in late June. The University of Utah from the "Living Room" Unfortunately, the forecast suggest that Hell will be paying us a visit with a massive upper-level ridge progged to develop over the western US late next week.  It's still a ways out, but it has that heat wave look. Between now and then, the $64,000 question is can we get some precip out of the short-wave trough that glances by Monday night and Tuesday.  It appears to be our only hope for rain at the airport this month.  My money is on a rainless June.

Most of California is characterized by a Mediterranean climate with extremely dry summers.  Even northern California is typically dry.  Here is the average precipitation (inches) for June, July, and August at selected cities in the northern part of the state (courtesy Western Region Climate Center ). Eureka: .68, .15, .32 Redding: .79, .10, .15 San Francisco: .13, .02, .04 Sacramento: .18, .03, .06 So, summer rain is rare, especially as one approaches July. The latest forecasts, however, suggest that northern California might be getting some over the next few days with a storm coming in for Sunday through at least Tuesday.  The GFS in particular calls for >1.5 inches along much of the California coast north of San Francisco and mountain accumulations of several inches. Bigfoot will be surprised!

My friends of Meteorological Solutions Inc. sent me some remarkable observations taken near Milford, Utah yesterday.  It is hard to imagine a lower atmosphere completely devoid of water vapor, but yesterday in Milford is probably as close as you can get.  The observations taken ~1700 MDT (2300 UTC) show an hourly average temperature of 82.6ºF/28.1ºC and a Relative Humidity of 0.427%, yielding a dewpoint of -42.3ºF/-41.3ºC and a dewpoint depression of 125ºF/69.4ºC. That's the big 125 in Fahrenheit!  I don't have an encyclopedic memory, but good luck finding something bigger than that.  Maybe in the central Sahara, the Empty Quarter, or Death Valley?  Incredible.

In the far Pacific Northwest they call it the June Gloom , the seemingly never ending extension of the rainy season into June.  Places like Portland and Seattle are typically heavenly (dry and mild) in July and August, but that gorgeous weather always seems to take forever to arrive.  Over the next week, I suspect that northwesterners will be pulling their hair out.  The GFS pretty much keeps them in an active storm track, resulting in frequent periods of rain and forecast accumulations approaching four inches in places. Source: NCEP Those are healthy accumulations when you consider that the GFS doesn't fully resolve the mountains and their influence on precipitation.  Unfortunately, Utah remains on the edge of the storm track, with no precipitation forecast.  We only flirt with the June gloom, which is too bad as a good soaker would be appreciated here.  Let's hope the storm track dips a bit further south than progged.

There's some wild weather to be found in western North America thanks to a jet stream that is in outlier mode. The dynamic tropopause (jet level) analysis for 6 PM MDT yesterday afternoon shows a high amplitude upper-level ridge over Alaska, a short-wave trough over the Yukon, and a closed upper-level low off of the Pacific Northwest coast. The impact of the Alaska–Yukon ridge-trough system on the weather of parts of Alaska is astounding.  How about a maximum temperature of 90ºF in Valdez yesterday.  How crazy is that?  Their previous record high for the day was 75ºF.  It also broke their all-time record high of 87ºF.  Have a read of the rather enthusiastic record event summary from the National Weather Service.   Meanwhile, ahead of the closed low off the Pacific Northwest coast, Utah is mired in fire-weather hell. How about these observations from Milford yesterday where at 3:52 PM MDT they reported a temperature of 90ºF and a dewpoint ...

If you have never taken a trip to the northern Great Salt Lake (a.k.a. Gunnison Bay), do it.  It is a spectacular place, far removed from the hustle and bustle of Salt Lake City.  We made a trip to the Spiral Jetty today and had a great day enjoying the swimming and the sites. The Spiral Jetty was built by Robert Smithson in 1970 Yeah, that's right, the swimming.  Or, better put, floating as we forgot goggles and the last thing you want to do is get that water in your eyes.  Many people have floated around at Saltair and Antelope Island, which is all fine and dandy, but the salinity in that half of the lake (a.k.a. Gilbert Bay) is "only" about 10–12%, whereas in the north half is usually near 28%.  Ocean water is about 3.5%. Source: USGS So, if you really want to bob like a cork, the north arm is the place to do it.  In fact, a float in the north arm is a great lesson in buoyancy, as I discovered today. I can't hold a pose like that in f...

We have reached that time of year when you have to take a few moments to appreciate any cool airmass that pushes into the state.  With a forecast high of only 77ºF at the Salt Lake City Airport, sip and enjoy every breath.  If you can get out for a hike or ride, do it.  The models hint that we might get another cool down later next week, but July is coming and the dog days of summer will be here soon enough. The hot weather the past several weeks has helped us catch up on where we stand thusfar this year relative to the average climate for the 20th century.  Recall that the statewide annually averaged temperature for Utah has not been below the 20th century average since 1993, and that last year was the hottest in the instrumented record. Utah's statewide average temperature departure from the 20th century average.  Source: NCDC I frequently comment that it is unlikely that we will ever again see a year with a statewide average temperature below the 20th...

A cold frontal passage has ushered in some cooler air, but has been accompanied by some very strong winds.  Here are a few of the peak gusts thusfar from around the area: Flight Park (near point of the mountain): 72 mph Saratoga Springs: 68 mph Lehi: 59 mph Point of the Mountain: 57 mph Highland: 54 mph Antelope Island: 53 mph Pleasant Grove: 51 mph Orem: 50 mph

Schematic of the Traveling Microburst ( Fujita 1981 ) Yesterday evening I was working on my computer at home when the Emergency Broadcast System alarm went off on the TV in the adjoining room.  It really got my attention since I wasn't expecting much in the way of severe weather, so I thought it was either an Amber alert or perhaps something more serious.  I walked over to where I could see the TV and noticed it was a severe thunderstorm warning issued for Salt Lake and Davis County. The culprit was a microburst , a localized downburst that produces strong straight line winds at the ground as depicted above.  The one we had last night was an example of a dry microburst as most of the precipitation that generated it evaporated before reaching the ground.  Some meteorologists differentiate between microbursts and macrobursts depending on the size of the area affected.  Indeed, this event may have had macroburst scale, but we will stick with microburst f...

Black Forest Fire.  Source: Colorado Springs Gazette Wildland fire is raging once again near Colorado Springs.   El Paso County Sheriff Terry Maketa reported at 9 am this morning that at least 80 homes have burned in the Black Forest Fire, with over 7,000 homes evacuated.    The wildfire ran more than 8 miles yesterday.  Atmospheric conditions were simply atrocious.  At the Colorado Springs Airport, temperatures yesterday afternoon reached the high 90s.   That's bad, but the air was unbelievably dry.  At 3 PM MDT, it was 96ºF with a dewpoint of -4ºF.   That yields a dewpoint depression (the difference between the temperature and the dewpoint) of 100ºF and a relative humidity of 2% .  It doesn't get any drier than that (well, it could, but not by much).   Winds during that period were also gusting to more than 30 miles per hour, although they reached as high as 44 miles per hour just a couple of hours earlier. ...

Source: www.tumblr.com In the wake of the busting of my forecast for yesterday (see previous post) and the attainment of 100ºF at the Salt Lake City airport, the Wasatch Weather Weenies will be celebrating an early Festivus and airing our grievances today.   Mainly I just want to belly ache about my blown forecast.  In forecast contests, I have certainly taken advantage of the tendency for the Salt Lake City International Airport (KSLC) observing site to go crazy warm in strong southerly flow, but yesterday's 100ºF was ridiculous.  I still don't believe it!  The afternoon sounding shows a convective boundary layer that extends all the way to 500 mb and a super adiabatic layer near the surface where the temperature was 96ºF.   Source: NOAA/NWS/SPC Such a layer is absolutely unstable and difficult to maintain.  Thus, getting a few more degrees out of such as sounding is difficult, especially when the winds are strong.  Yet it happened yest...

Forecasts that I've seen on the news and in the media the past couple of days have been hinting that we would hit the big 100 on Monday.  It's going to be hot today and tomorrow, but it looks to me like the timing might be wrong to get to the triple digits. The problem is this.  There is a tongue of very warm air forecast to move across Utah late today and tonight in advance of a closed low that is approaching Utah from the southwest.  The warm tongue is forecast to extend across southern and central Utah by 6 PM MST this afternoon. As a result, Salt Lake is not in the heart of the warm air this afternoon and our 700-mb temperatures only make it to about +15 or +16ºC.  That's unseasonably warm and good enough for temperatures in the low to mid 90s, but not enough for the big 100. The warm tongue then moves over us late this evening and tonight.  By mid-day tomorrow, cooler air (cooler being relative here!) associated with the closed low is already s...

During this past winter, we discussed how desperately we need more comprehensive air quality monitoring in the Salt Lake Valley .  Well, there is an article this week in the New York Times about efforts to sample and map air quality in New York that provides a glimpse of what could be done in Salt Lake City.  Be sure to check out the video. The basic idea is to couple an air quality monitor with a smart phone and them map the data on a web site.  Imagine the quantity and density of observations that could be collected in the Salt Lake Valley (outdoor and indoor) in this fashion.  It is a little unclear from the video and the article precisely what can currently be measured, but the  Aircasting web site  suggests carbon monoxide and nitrogen dioxide.  The video suggests they can measure particulate matter too (perhaps this is inferred based on the correlation between carbon monoxide and particulate matter).  In any event, any of these measuremen...

There's a lot to love in the latest satellite loop for North America: Ridging over the western US with some afternoon convection mainly over the high terrain A Mesoscale Convective System (MCS) forming from convection over the high terrain of New Mexico and the flatlands of central Texas that drifts eastward to the Texarkana area (I've always wanted to say Texarkana!). Tropical Storm Andrea making landfall in what I'll call the Bight of Florida.   And, way up in the upper right hand corner, one can find an extratropical cyclone that is bringing some snow to NewFoundland and Labrador.   Yup, there's something here for just about everyone except perhaps severe convection aficionados, although there is a tornado watch in place for much of Florida due to the effects of Andrea.

There has been considerable coverage the past few days of the unfortunate deaths of Tim Samaras, Paul Samaras, and Carl Young in the El Reno, Oklahoma tornado on Friday .  This post is not to comment on that incident, which to my knowledge has yet to be fully investigated.  Instead, I wish to draw some parallels between storm chasing and backcountry skiing as I wonder if the two groups might be able to learn from each other. Like the backcountry ski community of Utah, a wide range of individuals participate in storm chasing.  These individuals include (but are not limited to) research meteorologists using mobile radars and other instruments to try and better understand tornado dynamics and processes, volunteers attempting to provide ground truth for weather warnings and their verification, professional storm chasers taking photos and videos for resale, people on guided tours (yes, they do that!), and folks just out for fun.  You can draw a parallel to the Utah...

Lush grass and gardens in the Avenues at the start of June. There is no official start of the dry season, but June 1st serves as a reasonable demarkation as June, July, and August are the only months that average less than an inch of rain at the Salt Lake City International Airport. We head into the dry season with the valley looking lush (by Utah standards).   It's actually quite remarkable how green everything is given that May brought only 1.26 inches of rain to the Salt Lake City Airport, compared to an average of 1.95 inches.  That rain, however, was fairly well distributed with .54 inches falling from May 17–20 and then .63 inches falling from May 28–29.   That's the good news.  The bad news is that our spring runoff is already almost over.  Most SNOTEL stations have no snow (white squares) or less than 25% of average snowpack snow-water equivalent (SWE, dark red squares) for early June.  The only site at more than 50% of average is Lakef...

I'm looking for photos for a mountain weather book that I am working on.  It's embarrassing to admit that I don't have anything of these in my own library, but I don't. Iconic photo of deep snowpack at Mt. Baker during world record 1998/99 season Close-up photo of a graupel particle Photo or series of photos showing a cloud undergoing glaciation Photo of extreme rime on lift towers, buildings, trees, etc.  Photo of interlodge sign at Alta Photo of Alta buried immediately following the end of interlodge Photo of the untracked or lightly tracked sidecountry north of Snowbasin from the resort - something that shows the "lure" of powder.   If you have anything that might work, send it to me in an e-mail: jim.steenburgh-at-gmail.com and we'll see if it will do the job.  This is a low budget project, so I can promise fame but not fortune!

There are just a few patches of snow in the upper basin, which are nearly impossible to discern in this photo.  Yeah, this is June 2nd!  I'm guessing we won't be getting much water from this canyon this year.

The cover of Bruce Springsteen's compilation album The Promise was taken by photographer Eric Meola in Utah in 1977. Columbia Records  Bruce Springsteen hasn't written much about Utah, but it is featured prominently in The Promised Land on his album Darkness on the Edge of Town (even if there is no Waynesboro county in Utah). On a rattlesnake speedway in the Utah desert I pick up my money and head back into town Driving cross the Waynesboro county line I got the radio on and I'm just killing time Working all day in my daddy's garage Driving all night, chasing some mirage Pretty soon little girl I'm gonna take charge. The dogs on main street howl, 'cause they understand, If I could take one moment into my hands Mister, I ain't a boy, no, I'm a man, And I believe in a promised land. I've done my best to live the right way I get up every morning and go to work each day But your eyes go blind and your blood runs c...