Friday, August 21, 2015

Guest Post by Washoe County Air Quality - Monitoring Wildfire Smoke

Well the smoke has returned... it seems like an appropriate time to have Washoe County Air Quality guest blog about the smoke again.

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     Wildfire smoke contains many different pollutants with fine particulates (PM2.5) being the most concerning (see blog post "Wildfire Smoke in Northern Nevada). The Washoe County Air Quality Managament Division's PM2.5 monitoring network has been monitoring since 1999. In addition to the two permanent PM2.5 monitors at our Reno3 and Sparks monitoring sites, we recently deployed portable beta attenuation monitor (E-BAM) for PM2.5 monitoring at Pleasant Valley Elementary to expand our network during wildfire season (see map). An E-BAM's purpose is to get accurate PM2.5 data so that the public can make health based decisions as soon as possible. Decisions like keeping windows closed at night, having recess or practice indoors, and cancelling events like a triathlon are just some of the decisions that can and have been made because of this type of air monitor. 

How do BAMs work?

Beta attenuation monitors sample each hour by emitting high-energy beta rays through a spot on a filter tape that has outside air flowing through it. These beta rays are counted by a scintillation detector to determine an hourly PM2.5 concentration. This concentration is then translated into an air quality index to make it easy to understand what an hourly sample value like 38 µ/m3 means for your health (Unhealthy for Sensitive Groups).

What can I do to protect myself?

#BeSmokeSmart ! We are asking the public to Keep it Clean. Be Smoke Smart. Pay attention to your local air quality by going to The new portable PM2.5 monitor will also be sending data to AirNow in addition to our other monitoring sites. Due to the limitations of monitoring every hour, transferring the data, and having AirNow update at 30 minutes past the hour, data on AirNow can be delayed up to 90 minutes. Here are some other things you can do to Be Smoke Smart:

  • Stay indoors with the windows closed; if too warm go to evacuation center or away from the area
  • run an air conditioner if you have one, but keep the fresh-air intake closed and the filter clean
  • reduce activity and stay hydrated
  • keep indoor air as clean as possible
    • eliminate tobacco smoke 
    • don't use candles
    • don't vacuum (yes, I am giving you an excuse not to clean.)
  • follow the advice of your doctor
  • do not rely on dust masks
  • evacuate or temporarily relocate if needed 
Thanks to the NWS in Reno for being a partner in getting wildfire smoke information out to the public. For more information on local air quality for Washoe County, go to 

What Exactly is El Niño and La Niña? Bonus: What does this mean for us?

El Niño and La Niña are weather catch phrases that are thrown around pretty frequently, but how many of us truly know what these features are? They are complex atmospheric-oceanic circulations, and to be honest, it's more than we could even explain in a short blog post, but we will cover some of the basics here.

Let's start with El Niño since we currently have these conditions in place. El Niño is the warm phase of the El Niño Southern Oscillation (ENSO) and refers to warming in the equatorial Pacific sea surface temperatures (SSTs) compared to normal. Here is a quick video explaining this phenomenon:

La Niña is the cool phase of ENSO and refers to cooling in the equatorial Pacific SSTs compared to normal. One more quick video to explain:

The strength of El Niño and La Niña episodes is determined by the difference in SSTs compared to normal and are measured in a region of the east-central Pacific Ocean known as the Niño 3.4 Region:

The Oceanic Niño Index (ONI) is a measure of the departure from the normal sea surface temperature in this region. This is the standard by which the strength of El Niño and La Niña episodes are measured. The average sea surface temperature in the Niño 3.4 Region is calculated each month and then averaged with values from the previous month and following month. This running three-month average is then compared with the average sea surface temperature for the same three months during the 1981-2010 30-year climate normal period giving a value for the ONI. Positive values of 0.5°C or greater reference the warm phase, or El Niño, while negative values of 0.5°C or less reference the cold phase, or La Niña. Curious how these have measured up through the years? All the values can be found here, or you can also check out this graph which shows January 1950 through late spring 2015:

The data for this graph was provided by the Climate Prediction Center (CPC), with the graph produced by Golden Gate Weather Services

Now that we know what these phenomena are, let's talk about what is really important - how does each impact us locally. El Niño or La Niña more likely to bring the Sierra and northwest Nevada a wet winter? Do you have your answer? Chances are it isn't what you think. There seems to be the notion that El Niño equates to a wetter than average winter and La Niña the opposite. How many of you remember the incredible winter of 2010-2011? Here's a couple pictures to refresh your memory:

Believe it or not, this was a moderate to strong La Niña year! 

Being in the Sierra and northwest Nevada puts us right in between the greatest El Niño impacts, which brings better chances for rain to southern California and better chances for drier conditions to the Pacific Northwest. We have had both wet and dry El Niño years and La Niña years as well as ENSO neutral years. Unfortunately there is just not much correlation with ENSO for our part of the world. Since the 1930s we have had 6 strong El Niños and even these have ranged from dry to very wet in the Sierra and western Nevada. There have been two winters with particularly strong El Niños (1982-83 and 1997-98) and both of these winters were very wet in the Sierra with instances of significant flooding in both California and Nevada. However, this is only 2 data points in the admittedly short 65-year data set and does not guarantee that we will have a wet winter this year! Anyone who has lived in the region since the mid-1990s will likely remember the destructive January 1997 floods, but this occurred in the previous winter (1996-97) during an ENSO neutral year.

Now, I know what you're thinking...wasn't last year forecast to be an El Niño? Well, that is true, but the difference is last year we were in an ENSO neutral phase and only a weak El Niño was forecast, which took longer to develop than expected. This year we are already observing moderate El Niño conditions in the tropical Pacific Ocean (image below) with the forecast for it to only intensify. There is now high confidence in strong El Niño conditions persisting through the winter of 2015-2016 (strong being ONI values of +2 degrees C or warmer). I'm sure many of you have been hearing the hype about this being a "Godzilla-like" El Niño, and while a strong one is forecast, whether this becomes a record-breaker remains uncertain.

This graphic from the Climate Prediction Center is showing sea surface temperature (SST) anomalies in the Niño 3.4 region

There is one other big question mark...the Blob! The warming in the eastern Pacific Ocean along the west coast is unprecedented and climate experts have no idea how this feature will interact with a strong El Niño. This "blob" has been linked to the ridge of high pressure which has been plaguing the west the past 4 years and could affect how El Niño drives weather patterns into California.

Seasonal Sea Surface Temperature (SST) anomalies showing the "blob" and El Niño. 
A composite showing the overall pattern during the past 4 winters which has driven the west into a major drought.
So, with all these details in mind, what does this mean for us here in the Sierra and northwest Nevada? The latest Climate Prediction Center outlook for January through March 2016 favors better than average chances for above normal precipitation from about Lake Tahoe south, with below normal chances favored in the Pacific Northwest. With this being said, however, it is only an outlook, not a guarantee, and confidence remains low to medium for our region. The other factor is medium to high confidence in above normal temperatures this winter, which could indicate an increased frequency of warm storms with high snow levels.

The official CPC outlook for January through March 2016 precipitation as of August 20, 2015.

We know the drought is on everyone's mind and it would be incredible if we had a wet winter! Just remember, it took 4 years to create the precipitation deficits we now have, so it will take more than one wet winter to end the drought! If we combine the last 4 years, much of northeast California, the Sierra, and northwest Nevada are more than one year behind on precipitation. Even if we had the incredible winter of 2010-2011 again, we still wouldn't be caught up to normal.

For a great reference on the latest state of the ENSO and predictions for the upcoming season check with the Climate Prediction Center. You can also view our short YouTube video on El Niño which is our office's take on keeping it real with what you can expect for the upcoming winter.

Tuesday, August 18, 2015

Smoke and Radar: American Fire Smoke engulfs Reno 2 years ago today.

Everyone is familiar with weather radar and how it can detect areas of precipitation, but radar is also an indispensable tool when it comes to helping identify storms which have the potential to become severe. Normally when we refer to severe storms in the West, we are referring to storms that are capable of producing damaging winds/hail and also flash flooding. Here in the Sierra and western Nevada, tornadoes are fairly uncommon but still can happen as was the case this past June in Hawthorne, NV where an EF-1 tornado formed. 

Smoke on Satellite

  The satellite image below (fig 1) shows a true color view from the afternoon of the 8/18/13. What is notable is the smoke plume from the American Fire hovering over the Sierra west of Lake Tahoe. The next image later that afternoon (fig 2) show thunderstorms had formed across the Sierra south of Tahoe while smoke had begun to travel up slope of the Sierra. 

Figure 1: MODIS-Terra satellite image from the afternoon of 8/18/13.
Wildfire smoke can be seen along the west slopes of the Sierra.

Figure 2: MODIS-Aqua satellite image later that afternoon.
Thunderstorms can be seen developing along the Sierra south of Lake Tahoe.
Smoke from the fire can be seen travelling up the Sierra
near the developing clouds and storms. 

Smoke on Radar

Thunderstorms continued to develop across the Tahoe Basin and clouds began to hide the view of the smoke from satellite imagery. How do you then track the movement of smoke when clouds are hiding them from view on satellite???  That's where radar came into play that day.  Although it is not always possible, the smoke plume was able to be detected by radar that day as it was located at an elevation and distance within sight of the radar. 

The image below shows (fig 3) shows an outflow wind boundary from a thunderstorm that was traveling east over the Carson Range and towards Reno. The big question was: Is this outflow going to bring smoke with it?  Without webcams or spotter reports to provide the answer, we turned to our radar.  

Figure 3: Thunderstorm outflow boundary pushing eastward towards Reno.

The radar loop below shows this north-south oriented outflow boundary pushing cross the Carson Range.  The WSR-88D radar sitting on top of Virginia Peak received an upgrade to include Dual-Polarization technology (or Dual Pol for short) back in 2012.  One of dual-pol’s benefits is that it’s able to distinguish not just where precipitation is but what type it likely is (hail, snow rain) and even if it's not precipitation at all (insects, birds, dust, smoke).

The loop below shows one of those complex dual-pol products called Differential Reflectivity. Basically with dual-pol, the radar can now send out a vertical and horizontal radar pulse, in the process it can get a rough idea on the orientation and what the shape of the detected object might be. In this case, the radar was detecting something that wasn’t rainfall but most likely was detecting the smoke being caught up in the outflow boundary. 

A few minutes later suspicions were confirmed as the wall of smoke became visible over the top of the Carson Range. (fig 4)

Figure 4: Once this boundary pushed over the Carson Range, the wall of smoke 
became visible from the NWS office.

This wall of smoke rapidly descended down into Reno in about 30 minutes and resulted in a rapid deterioration of air quality and visibility. Dual-pol radar proved extremely useful in getting an early alert of the possible smoke threat and we were able to get the word out with short-term products and social media about the oncoming smoke! We managed to capture a timelapse of the smoke descending the mountains and completely engulfing Reno. The 9 second time lapse that afternoon runs from 5:20pm-6:00pm.

Below are a few links to our social media outlets and also some air quality sites that we find quite useful year-round. Thanks for reading!

Bureau of Air Quality Planning: UNR PM2.5 Sensor: Map of Particulate Sensors: NWS Reno Social Media: NWS Facebook: NWS Twitter: NWS YouTube:

Sunday, August 16, 2015

Guest Post by Washoe County Air Quality - Summer is the Season of Ozone

Enjoy this guest post from our friends at Washoe County Air Quality

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Forecast calls for sunny skies and hot temperatures for Northern Nevada. The air quality should be good as long as there isn't any wildfire smoke, right? Well, not necessarily. Let me explain. 

Summer is the season of ozone (O3). There is both stratospheric and ground level O3. The stratospheric ozone protects us from the Sun's harmful ultraviolet radiation. Ground level ozone is an air pollutant that harms humans and the environment especially during hot and sunny summer afternoons. 

Ground level Ois created by the chemical reactions between volatile organic compounds (VOCs) and oxides of Nitrogen (NOx) in the presence of sunlight. NOx and VOCs, also ozone precursors, come from motor vehicles, industrial processes, power generation, and consumer products among many other things including wildfire smoke. Urban and suburban areas will have higher levels of ozone than rural areas, but it can travel hundreds of miles. 

Breathing levels of ozone can cause a variety of health problems including throat irritation, coughing, chest pain, and congestion. Ozone can also worsen bronchitis, emphysema, and asthma. It can reduce lung function and inflame the lungs. Repeated exposure may permanently scar lung tissue. Even healthy people can experience difficulty breathing. Because Ozone typically forms during hot, sunny days, anyone who spends time enjoying the outdoors especially children, the elderly and active adults are at risk. 

You can protect yourself and those around you from Ozone by paying attention to your local air quality forecasts and real-time AQI. Go to for Washoe County air quality information or for your local area (some areas may not have monitoring data on AirNow.) Exercise, play, or work outside when ozone levels are not high, typically during the morning and evening hours. 

You can also reduce your emissions by: 
  • driving less, 
  • not idling your engine, 
  • commuting by bike or public transportation, 
  • filling your gas tank up at dusk, 
  • using environmentally friendly paints and cleaners, 
  • and bring energy efficient at home and work. 

 The Washoe County Health District Air Quality Management Division (AQMD) is also doing its part to reduce Ozone precursors and educating the public. The annual smog check program is one of the measure in Washoe County to reduce emissions from motor vehicles. AQMD also permits sources of VOCs and NOx from business and industrial facilities. Under our award winning public education "Keep it Clean" campaign, we implement clean air strategies like having idle-free areas around schools and encouraging and advocating for biking, walking, public transit, alternative fuel vehicles, and other sustainable practices. 

Everyone can do something to take care of our air so we can all enjoy summertime in the Sierra and western Nevada. For more information go to and follow us on Facebook, Twitter, and YouTube

-Washoe County Air Quality 

Saturday, August 15, 2015

Hot Temperatures This Week

Hot temperatures are returning to the Sierra and western Nevada this week (forecast details). Although some new record maximum temperatures may be hit this week, we are largely past the climatologically "hottest" part of the year. We typically see our hottest temperatures during July where the city of Reno can easily surpass 100 degrees for multiple days in a row. Although this past July was an exception to that rule since we had a significant monsoon push with thunderstorms for much of the month.

Here are a few snapshots at the forecast maximum temperatures we are expecting for early this next week. 

So what? It is going to be in the 90s and near 100 degrees out in central Nevada, no big deal right? Well it can be a big deal for those who spend their days working outside, especially for fire suppression personnel out on many of the large ongoing fires in the region. Since we are looking at multiple days of these hot temperatures, it would be a good idea to have some plans for mitigating the heat and to have some cooling options, especially if you plan on being outdoors! 

Here are some additional steps you can take to stay safe during a heat wave:
  • Drink plenty of water or other non-caffeinated and non-alcoholic beverages. 
  • Wear loose, lightweight clothing.
  • Find a place to cool off. If you don’t have air conditioning at home then spend some time in a public location that does, like a shopping mall or a library.
Avoid spending time outside during the peak heat of the day (typically 10am – 3pm). If you exercise outdoors, avoid the worst of the heat by going early in the morning. If you work outdoors, check out the heat safety tips for workers from the Occupational Safety and Health Administration.

One of the most important things to remember is to NEVER leave pets or children in cars, even for just a few minutes. There have already been 14 heatstroke deaths of children THIS YEAR

Courtesy of through San Jose State University

There is also a very telling video going around the internet asking "How Long Can This NFL Player Tough It Out in a Hot Car?" Basically never EVER leave children or pets in a car unattended, even when it isn't that hot. There have been hyperthermia deaths during the fall, winter, and spring!
  • Honolulu, HI, March: A 3-year-old girl died when the father left her in a child seat for 1.5 hours while he visited friends in a Waikiki apartment building. The outside temperature was only 81 degrees. 
  • North Augusta, SC, April: A mother left her a 15-month-old son in a car. He was in a car for 9 hours while his mom went to work. She is now serving a 20-year prison sentence. 
  • Greenville, TX, December: A 6-month-old boy died after being left in a car for more than 2 hours by his mother. She was charged with murder. The temperature rose to an unseasonably warm 81 degrees on that day.
For more information on Heat Safety please check out this website and be sure to follow #BeatTheHeat on Twitter.