Wednesday, August 26, 2015

Short-Term Variability and Long Term Trends: Market and Meteorological

What would the media do without short-term market and meteorological variability?  On slow news days they could attempt to cover substantive issues in depth, but that would require investigation and analysis.  Ignore the media hype and separate the short-term variability from the long-term signal and life will be better.

From a meteorological perspective, both the short-term variability and long-term signal are looking pretty good right now.  Yesterday's high was 98ºF, but today will be much cooler.  A potent monsoon surge has pushed into northern Utah.  Check out the rise in precipitable water from ~1.5 cm yesterday morning to over 3 cm this morning.  Looks like they need to reset the scale on the plot below!

Source: ESRL
It's cool and comfortable out there this morning and today's high will probably be only in the high 70s, not much warmer than it is right now.  Showers and thunderstorms will abound.  Enjoy.  This short-term variability is just what the doctor ordered.

As is the long-term trend.  Signs of fall are beginning to appear.  Check out the yellow tint in the trees and the down leaves along the roadside in City Creek Canyon yesterday.  


I don't know what the next few months will be bringing investors, but for us, the long-term trend is a good one.  Fall and winter will be here soon.  

Monday, August 24, 2015

More Good Reasons to Kill Your Parking Pass

Today is the first day of classes at the U.  Insanity will prevail.  Mother Nature is already stirring the pot.  She produced a stray shower on campus just before 8 am that produced a direct hit on the new northwest parking garage.  You could barely see it on radar as it was only a few pixels wide and it was over as fast as it started.


Yup, Mother Nature is not too happy about these new parking garages.  There are two more opening up this semester, the central parking garage in the business loop and the aforementioned northwest parking garage next to my building (INSCC).  The latter, which is still under construction (although it appears they are allowing some people to park in it), is pictured below.


I have great disdain for these parking garages for a variety of reasons.  They are expensive.  They encourage driving to campus.  They block the sun, the sky, and the views of the mountains.  Did I say they are expensive?

In terms of annual parking fees, the central parking garage is a relative steal.  You can get a central A pass to park in it or A lots on campus for $552 or a central U pass also valid in U lots for $498.

However, for northwest campus commuters, commuter services has a special treat for you.  You need a T permit to park in the northwest parking garage, which costs $942, or an even pricier R permit (see http://commuterservices.utah.edu/).  Yikes.  @theU claims this morning that faculty and staff can park in the northwest parking garage today with any permit, but if you are driving in this morning, you will be greeted by a sign saying differently.  I guess "this morning" means before 8 am.


Moving to alternative commuting options isn't possible for everyone, but perhaps it is for you.  In April, I told commuter services to stick it.  I canceled my parking pass and since then I've driven to campus once and paid a few bucks to park in a visitor slot.  There are also options for paying for a day pass to park in an A or U lot, although it's a damn shame that those options aren't easier to access to encourage more mixed mode commuting (see my earlier post How I Told Commuter Services to Stick It).

U student Annie Putman has produced a great video discussing the many campus computing options, including some that I was not aware of, like Zimride for finding others to carpool with.


Perhaps this is the year for you to tell Commuter Services to stick it, at least with regards to your parking pass.  

Saturday, August 22, 2015

Temporary Reprieve

I woke up this morning, looked out the window and lo and behold there were the mountains.  It wasn't clear, but it was less hazy than I've seen it in the morning in a few days.

I decided to get out for a quick hike while the getting was good.  I opted to hike up Hidden Peak to take advantage of the tram on the descent as my knees have been feeling tender of late.  Up high it was actually fairly nice.  Smoky, but not terribly so.  If you look carefully at the photo below, you can see considerable layering of the flow with a nice clear layer near crest level.


Things are, however, deteriorating again, at least in the valley.  The trace below shows the PM2.5 concentrations at the University of Utah over the past five days.  There was a brief drop to just below 10 ug/m3 at about noon yesterday, followed by another bing increase, and then the drop overnight to the lowest values we've seen since the 18th.  Unfortunately, PM2.5 concentrations have jumped back up to 20, although at least for now, they are lower than they have generally been the past few days.


Amongst the many fundamental differences between this pollution event and our winter inversion events is that most of the PM2.5 is being transported in rather than being produced from local emissions. As a result, changes in flow direction can cause some large variations in PM2.5.  I guess for now the best approach if you want to get outside is to take advantage of the less hazy periods when you can.

Friday, August 21, 2015

CPC Gives Northern Utah Skiers No Love

The NOAA/NWS Climate Prediction Center (CPC) issued their latest three-month outlooks yesterday and they give northern Utah skiers no love.

For December through February, they give northern Utah slightly elevated chances of above average temperature and slightly elevated chances of below average precipitation.

Source: CPC
Source: CPC
Does this mean we're in for another warm winter with bad snow?  No.  In the images above, equal chance (EC) areas in white are not projected to have an average winter.  Instead, EC means that the likelihood of below average, average, or above average temperature or precipitation does not differ from their climatological odds of 33.3% each.  In other words, the tools available for seasonal forecasting do not allow us to anticipate a strong loading of the seasonal climate dice one way or the other.  Areas in red (temperature) or brown (precipitation) are areas where the likelihood of above average temperature or below average precipitation, respectively, are higher than climatology.  So, for northern Utah, they are giving us just slightly higher than climatological odds of above average temperature and below average precipitation since the odds are between 33% and 40%.  In other words, the seasonal climate dice are loaded just slightly on the side of above average temperature and below average precipitation.

These outlooks are based on a variety of tools including seasonal climate forecasts, composites (averages) of past years stratified by El Nino, La Nina, and neutral conditions (this year they are banking on El Nino), and a few other statistical tools relating past weather to various factors.  El Nino composites typically feature a precipitation dipole with below average precipitation over the interior northwest and above average precipitation over the southwest, roughly consistent with the outlook above.  Below is the average precipitation anomalies from three ensemble suites produced by the NCEP Climate Forecast System (CFS) for December to February.  I've drawn a black line at the approximate position of the central Wasatch.  Each of these ensemble means has a dry northwest and a wet southwest relative to climatology, with the central Wasatch in the transition zone.

Source NCEP
Keep in mind that the composites generated by CPC use very coarse precipitation data that does not specifically look at the central Wasatch, while the CFS does not resolve the Wasatch in any way, shape, or form.  Thus, one needs to be cautious in interpreting these outlooks and projections.  We can, however, use past data from Alta Guard to stratify central Wasatch snowfall by El Nino, La Nina, and Neutral and even strong El Nino and La Nina events, as we have done several times in the past (e.g., El Nino Likely for the 2015-16 Winter).  You probably know the story here.  Not much signal in the noise.  We've boldly put a linear trend line on the data, which does show a very small trend to lower values as one transitions to strong El Nino, but the scatter is so large that I think that's neither physically or statistically significant (we haven't bothered looking at the latter).  Note that this is for various 3-month periods during the cool season, not specifically December to February as in the plots above.  This scatter exists because: (1) Utah sits in the transition zone between the El Nino/La Nina precipitation dipoles, (2) other factors affect the seasonal climate besides El Nino, and (3) there is always some randomness in the weather that occurs during any given season.  

So, we may be looking at a Godzilla El Nino, but for the central Wasatch, that means nothing.  Don't fall for the hype.  For the central Wasatch, we really have no idea what kind of winter we are going to have.  It could be big, it could be bad, or it could be average.  Further, the amount of snow we get isn't always as important as when it comes and how it comes and those details are even more uncertain.  

Thursday, August 20, 2015

Earth's Fever Reaches Record Levels

No surprises here.  The National Centers for Environmental Information issued their monthly summary for July and the globally averaged temperature was the highest for any month since the start of records in 1880.  Their full report is available here.

Meteorologists typically present temperature trends in terms of anomalies (i.e., a departure from some long-term average).  For July, the globally averaged temperature anomaly was 0.81ºC (1.46ºF), the highest on record.  In 2nd place is 1998, also a strong El Nino year.

Source: NCEI
Since July is also the warmest month of the year globally (this reflects the greater fraction of land in the Northern Hemisphere), this July was also the warmest in the entire 1627 month record going back to 1880.  Yup, Earth has a fever and the only prescription is more cowbell.


Or, more accurately, the only prescription is less carbon. It is the combination of long-term global warming with the strong El Nino that is leading to these unprecedented numbers.  

Like politics, all weather is local and the good news for Utah is despite remarkable high globally average temperatures, Mother Nature was good to us and we actually came out below the 20th century average and enjoyed the coolest July since 1997.

Source: NCEI
Our good fortune is clearly evident in the analysis below which shows departures from average temperature for the month.  We're in the blue, indicating below average, but red, indicating above average predominates.  Note that these anomalies are with respect to 1981–2010.  Comparison with the 20th century average would produce a plot shifted even more into the red since the 20th century average temperatures are lower than those of the last 30 years.  
Source: NCEI 
The likelihood that 2015 will be the hottest year on record continues to increase.  

Wednesday, August 19, 2015

There's No Escape from the Worsening Pollution

Smoky sunrise over the Salt Lake Valley this morning.  Note the faint outline of the Wasatch Mountains on the left side.
Over the past three days, air quality over the Salt Lake Valley has deteriorated as smoke from fires to our west and northwest is transported into the area.

This morning, hourly averaged PM2.5 concentrations sit at 32 ug/m3 and are approaching the transition from moderate to unhealthy for sensitive groups.  
Source: DAQ
There was a spike to even higher values the day before yesterday, but I'm not sure if I believe it.  We didn't see it in our data from the University of Utah, which shows we're currently sitting at the highest PM2.5 concentrations of the entire event.  

Source: MesoWest
Making the situation even more miserable is the ozone.  Ozone is photochemically produced (i.e., produced by sunlight) and thus tends to reach a peak in the afternoon.  We've been topping out each afternoon at about 70 parts per billion, which is also in the moderate category.

So basically, we have a noxious mix of both PM2.5 and ozone in the afternoon and evening and I suspect we'll see the highest levels of the former this afternoon.  I may elect to skip my bike ride later today.  

Unlike wintertime inversion events, you can't climb above this stuff.  Mixing in the summer extends through a deeper layer.  The photo below was taken yesterday by the KSL Helicopter and you can see the top of the gunk sitting above the crest of the Wasatch.  


This summer, a major field program is taking place to examine the aerial extent and underlying processes of high surface ozone concentrations in the Great Salt Lake Basin called the Great Salt Lake Summer 2015 Ozone Study.  It involves collaborations between the University of Utah, Utah State University, Weber State University, and the Utah Division of Air Quality (more info here).

As part of the project KSL has graciously allowed sensors to be placed on their news chopper and the data is extremely illuminating.  The data below was collected yesterday.  The blue line is the chopper altitude (above mean sea level) and the green line is the ozone concentration.  Ozone concentrations were between 60 and 65 ppb when the chopper was below about 3000 m, but as the chopper ascended above 3000 m, they climbed to nearly 70 ppb right at the top of the gunk layer (about 17:05 local time).  Then, the chopper briefly penetrated into cleaner air aloft and the concentrations dropped to less than 50 ppb.  The chopper then descended back into the gunk layer, finding the 60 ppb air once again below about 3000 m.

So, you have no hope of climbing above this in Utah unless you have a plane or helicopter.  Further, and this has been found in other areas, ozone concentrations may actually be somewhat higher at higher elevations near the top of the gunk layer.  We're stuck in it and there's no escape.  Our best hope is a shift in the flow direction.  Next week looks cleaner with southwesterly or southerly flow, but it's hard to say if the weak systems coming through later this week and this weekend will crack the smoke or just give us temporary or partial relief.