A Smoky Day Ahead

Over the past few days Utah has fortuitously been located just to the south of some thick, smoky air, but that changed overnight as the winds shifted.  The Wasatch Mountains this morning look more like the Great Smokies.

That photo was taken about 7 am.  As things stand now (8:20 AM) I can barely see the base of the Oquirrh Mountains from my office at the University of Utah.

It's a bit too early to get a good look at the smoke in visible satellite imagery, but we can see it very clearly in ceilometer observations.  A ceilometer is an instrument that sends out a laser pulse and measures the amount and delay of the signal returned to ascertain cloud base height.  Smoke and other particles in the atmosphere, known as aerosols, also scatter some energy back, which is known as backscatter.

The plot below shows a profile of backscatter recorded from a ceilometer at the University of Utah Mountain Meteorology laboratory at Red Butte Canyon.  Time increases to the right and is in MDT.  Note the arrival of dense smoke denoted by the change in color from green to yellow at around 3 AM MDT.  You can also see that the smoke moved over this site first aloft and then near the surface.

Source: MesoWest

Today we will have an air quality double whammy of elevated PM2.5 and ozone.  PM2.5 at the Mountain Meteorology Lab has been running near or above 25 ug/m3 since about 4 MDT (consistent with the plot above).

Source: MesoWest

That rates as "moderate".  Keep in mind, however, that ozone levels the past few afternoons have been at or above the unhealthy threshold (red shading below).

Source: Utah Division of Air Quailty

I'm not sure where we'll end up today.  Sometimes the chemicals accompanying smoke enable a boost in daytime ozone production.   Keep an eye on things if you have concerns.  I'm planning on taking a day off from exercising.

Apocalypse Tomorrow

Smoke has been lingering around the Salt Lake Valley the past couple of days and, if forecast hold, is about to get much worse.

This afternoon's GOES-16 is quite remarkable and shows a thick blanket of smoke across much of the Pacific Northwest streaming off over the high plains.  The smoke here in the Salt Lake Valley is barely discernible, whereas its a thick blanket to our north.

Forecasts from the experimental HRRR-smoke model suggest we're going to see some of that thick smoke here tomorrow.  The forecast for 2 PM this afternoon (2100 UTC) shows vertically integrated smoke concentrations of around 15 mg/m2 over northern Utah, but much higher values to the north.

Concentrations roughly double by tomorrow.  The analysis below shows the situation at 6 PM (0000 UTC).

This should make tomorrow seem even more apocalyptic.

Keep in mind that ozone levels have been in the unhealthy for sensitive groups or unhealthy range the past few afternoon (lower graph below for Hawthorne Elementary in the Salt Lake Valley).  PM2.5 has been a bit elevated because of the smoke, but on the low side of moderate (top graph).

I suspect tomorrow we'll see PM2.5 concentrations rising some and another round of unhealthy for sensitive groups or unhealthy ozone.

I think I speak for everyone when I say I wish summer was OVER!

Hottest Summer Ever in Salt Lake Is OVER (or Not?)

As far as the traditional meteorological definition is concerned (June–August), the hottest summer in the history of Salt Lake City is now in the books.

The average temperature was 80.9ºF, beating 2013 by 0.1ºF.  Your pain and suffering has paid off!

Source: NOAA Regional Climate Centers

If you think that this place is becoming a hot house, you're right.  In Salt Lake City, the three hottest summers on record have all occurred in the past 5 years.  There wasn't a summer on record until 1988 with an average temperature above 77.5ºF.  Starting in 1988, we've had 9 summers eclipse that mark and three summers eclipse 80ºF.

And, while meteorological summer as defined based on the calendar has ended, we're looking at a continuing stretch dominated by high-amplitude ridging and well-above average temperatures.  At least the nights are longer now, enabling temperatures to drop a bit more overnight, and highs will only be in the low to mid 90s.  

And, if you must ask, yes, this is the hottest "year" on record for the year to date (January–August), although the race was quite tight with three recent years and 1934.  

Source: NOAA Regional Climate Centers

Will the entire calendar year go down as the hottest on record?  Only time will tell.

Innovations to Help Our Air Quality Are Right in Front of Us

The lack of progress on improve the air quality along the Wasatch Front is deeply disturbing.  Excuses and foot dragging seem to be the modis operandi of the day.

Yesterday, the Salt Lake Tribune reported that many Utah business leaders sent a signed letter to Governor Herbert asking him to propose "bold strategies for addressing air pollution in Utah" and urging the Division of Air Quality "to propose a wide array of strong and ambitious proposals as part the Serious SIP it submits for public comment this fall."  The "Serious SIP" refers to the Strategic Implementation Plan for reducing air pollution in the Salt Lake Valley, as required by the EPA.  The full letter is included with the Tribune article, available here.

The article notes that Bryce Bird, director of the Utah Division of Air Quality, said that "truly innovative air quality solutions that hold promise for Utah are difficult to come by."

While I agree that there is no quick fix, the view that truly innovative air quality solutions are hard to come by is complete BS.  We have never had more opportunities to make choices that dramatically reduce local emissions, and the opportunities are growing.

We now have extremely efficient and effective battery powered lawn equipment including trimmers, leaf blowers, and battery powered lawnmowers.

I replaced my 22-year old gas-powered Craftsman lawnmower with a battery powered one this summer and what an improvement.  The battery powered lawnmower cuts better, is quieter, and doesn't belch out noxious fumes.

How about a batter powered snowblower?  I have one of these too.  It kicks ass.  No fumes and you don't have to tune it up each fall.

Over half of our emissions are mobile.  Yup, there's a solution for that too.  I don't have one of these yet (hanging on to my 14 year old minivan), but one's likely in the future.  

Plus, there are some old fashioned tools available.  These have been around for decades.

Migration from the internal combustion engine is entirely possible today, and it offers the most potential to improve air quality along the Wasatch Front.  Granted, 1.5 million people are not going to run out and buy an electric car tomorrow, and economic factors are a challenge for many in our community, but the argument that there are no truly innovative solutions is complete hogwash.  They are right in front of us.  We should be pursuing every possible avenue to stimulate and encourage migration toward electric vehicles (hybrids and plug-in hybrids also encouraged as a transitional technology).

Of course, electric devices and vehicles do produce emissions if the electricity source is a fossil-fuel power plant.  They also can produce emissions during the extraction of materials and manufacturing process.  However, those emissions are not local and concentrated in an urban area.  Transformation to low-carbon energy production is also essential, but a story for another day.

Beware of Sound Bite Harvey Attribution

Imagine the western U.S. equivalent of Hurricane/Tropical Storm Harvey.

Rain nearly nonstop in California for 6 weeks.  Runoff turning the Central Valley into an inland sea.  Sacramento buried under 10 feet of water.  Damages of more than a half-trillion dollars.

Now that would be a climate catastrophe right?

Except, it already happened.

During December.

In 1861.

Granted, the damages were not more than a half-trillion dollars.  That's merely the lower estimate of storm damage if it happened today.  But in December 1861, a megaflood in California killed thousands of people and 800,000 cattle.  A catastrophe by any standards, and it happened before significant global warming.

Source: USGS, Ingram (2013)

I write this to emphasize caution in interpreting the causes and contributors to the severity of floods produced by Harvey during and following the immediate aftermath of the storm.  The meteorology and hydrology of extreme events is mutlifaceted and highly complex and deserving of a more careful and cautious analysis.

Let's think back to the California Megaflood of 1861.  It it happened today, how would the press and public view it?  It would be unprecedented in "modern" (20th century or later) times and viewed as a disaster at least on par with Harvey. Paleoclimatic evidence suggests that such events have a "return interval" of 300 years, so we know such an exceptional event is possible when natural variability brings all the key ingredients together.  On the other hand, we expect global warming to serve as an amplifier of events of this type (see The Coming Megafloods).  In addition, we've changed the landscape of both the mountains and the Central Valley in ways that greatly affect hydrologic response.  So, will the next California megaflood be natural, caused by global warming, or caused by our land-surface modifications?  One can imagine all sorts of great clickbait headlines, but clearly, the causes are mutifaceted.

And, it is especially difficult to quantify the effects of global warming on a single event.  Global warming is having an effect on our weather and there are good reasons why we expect heavy precipitation events to increase in frequency and become more severe.  We should be concerned about this.

However, careful analysis is needed to truly understand the ingredients leading to the flooding produced by Harvey and the degree to which global warming has contributed to an increase in the likelihood of an event of such magnitude.  

Further, I am concerned about giving people a false impression that climate change is the only issue at play when it comes to our vulnerability of natural disasters.  Most scientists recognize this is the case, but the headlines command the attention of the public.

Andrew, Katrina, Harvey, and other tropical cyclones serve as reminders of our incredible vulnerability to natural disasters.  Paraphrasing Will Durant, "Civilization exists by meteorological consent, subject to change without notice."

In addition, we aren't prepared for the climate of the 20th century, let alone the one coming in the 21st century.  As a society, we are not only exposed to extreme weather events associated with heavy precipitation, but we're essentially doubling down on that exposure through ongoing, concentrated development and poor land-use practices and planning in vulnerable areas.

If we are to build a more weather and climate resilient nation, we need to recognize the multifaceted nature of the challenge.  Harvey serves as a wakeup call (unfortunately, we've had them before) and is not the last jaw dropping weather disaster we will face.

Misery Continues

Houston and the surrounding area are absolutely snake bit.  Tropical Storm Harvey now sits over the Gulf of Mexico just south of Galveston.  Although the precipitation area has broken up some, Houston and environs remain in one of the main shields.

It's been absolutely unbelievable how that area has been a magnet to precipitation for this event.  Such a shame.

It ain't over yet.  We all want this thing to be over, but Harvey will continue to float around SE Texas and western Louisiana through tomorrow.  The National Weather Service is calling for 2-3 inches today and another 2-3 inches tomorrow for the Houston area.  These numbers are lower than seen earlier this week, but are going to slow the recovery.  Let's hope that the stronger bands and precipitation regions spare the area.

Perhaps I'll write more later, but right now I've reached a point of numbness.