Hours later, at 3:30pm, a friend and I made our way from Indiana Township (between Fox Chapel and Cheswick) to Churchill. It took over an hour to get there. The traffic was horrendous and the roads that were open were littered with debris. Nadine, Sandy Creek, and Washington Boulevard were all closed.
But I got two photos of the river in flood.
High tide on the Allegheny!
p.s. This rain didn’t even set a record at the airport though there may have been localized records. My friend Julie had 4″ in her rain gauge in her Squirrel Hill backyard. Sue Vrabel commented below that she had 4.5″ in Churchill.
If you were out in the UK today, this will not be hard to work out. Infrared shows the temperature difference between areas with trees, and those without. Thanks to Meg Caffin and the City of Geelong, Australia, for the insight. This is what’s coming and we’re not ready for it! pic.twitter.com/N5PrCvIhYB
It’s been hot in Pittsburgh lately but nothing like the heat wave that’s sweeping Europe with highs above 100 degrees F. @JeremyDBarrell tweeted a long term solution with a compelling image by Meg Caffin.
Meg Caffin is an urban forest consultant from Australia who provides guidance for cities looking to beat the heat. Her image at top used an infrared camera to show the temperature difference between a paved churchyard and the trees behind it. I’ve made a Fahrenheit translation below. Yes, it’s 113oF on the pavement and only 77oF under the trees.
Trees cool the air by transpiring. They take up water from the ground and release it from the stomata in their leaves. The release doesn’t usually drip from the leaves as shown below. Instead it evaporates and that’s what cools the air.
Evaporation — changing a liquid to a gas — uses energy. According to the Transpiration blog, “Energy is absorbed into liquid water. This reduces the temperature of the surrounding plant tissue and nearby atmosphere. To evaporate 1 gram of water 590 calories of energy is required.”
Meanwhile if you’re feeling hot right now, visit a local park.
Beat the heat among the trees.
(embedded Tweet from Jeremy Barrell; infrared heat image by Meg Caffin for the City of Geelong, Australia (Fahrenheit added); transpiring leaf from Wikimedia Commons; photos of Schenley Park by Kate St. John)
Today we’re in Nome, Alaska on the summer solstice. If we were at the Arctic Circle the sun would never set today but Nome is 143 miles south. The sun does set here, but barely. It never gets completely dark. Instead, twilight lasts for 2.5 hours and then the sun is up again.
The photos above and below were taken at sunrise during the 2013 summer solstice from the Bering Land Bridge Preserve office in Nome. The photo caption says, “Up here in Bering Land Bridge, summer solstice means almost 24 hour days. Sunrise at our office here in Nome on the solstice is around 04:18 am, and the sun won’t set until 01:47 am the next day.”
The sun just skims below the horizon, then circles the town.
Indeed it is the longest day.
(photos from Bering Land Bridge National Preserve on Flickr, Creative Commons license; click on the captions to see the originals)
Spring is fire season in Pennsylvania. 85% of our wildfires occur in March, April and May.
There’s no drought in Pennsylvania right now, nor in most of the U.S. — as shown on the map below.
But you don’t need drought to have a fire. All you need are dry conditions, fuel, and a spark. In Pennsylvania we have all three in the spring: low humidity, gusty winds, and lots of old leaf litter drying out in the sun. The spark comes from people.
98% of Pennsylvania’s wildfires are caused by people and most of those are caused by people burning debris. On a sunny windy day those fires blow onto dry grass and escape to the wild. In April 2016 more than 10,000 acres burned in Pennsylvania.
Yesterday the fire danger was high in our state because the weather was so nice — warm and sunny with gusty winds. Across Pennsylvania people were out doing yard work. Some were probably burning piles of debris. I haven’t heard if there were any fires. (The fire danger is lower today, 4 April 2019, because the weather changed.)
If you live in a place that allows outdoor trash burning be careful out there! Spring is Pennsylvania fire season.
(photo of fire from Wikimedia Commons (actually a prescribed burn). Maps from US Drought Monitor and U.S. Forest Service Wildfire Danger Forecast; Click on the captions to see the originals)
Note: Allegheny County does not allow outdoor trash burning.
Monday’s animated Spring Leaf Index (18 March 2019) shows that leaf out was ahead of schedule through late February but fell behind in northern Virginia, the southern Great Plains, and the Pacific Northwest when cold weather hit in early March.
According to the model, spring hasn’t reached Pittsburgh yet but I’m conducting my own Leaf Out Survey in my neighborhood. I took the honeysuckle photos below on 11 March and 16 March 2019. Both were cold days after a spurt of exceptionally warm weather. The tiny leaves on the right show the effect of 77 degrees F on March 14!
Do you have leaves in your neighborhood yet? Is spring on time?
Science predicted this more than a generation ago, but most of us couldn’t imagine how it would feel. Now that we’ve seen 30 years of change and more is in store, we’re anxious to know what our climate will be like in the future.
It shows that Pittsburgh’s 2080 climate will feel like Jonesboro, Arkansas does today. Jonesboro is 665 miles away from here, near Memphis, Tennessee. (Click on the image to see the website. Use website controls to see more complex answers.)
The map bubbles explain: Our winters will be 10.8F warmer and 46.8% wetter. Our summers will be 10F warmer and 17.6% drier.
Let’s compare current to future using graphs. Pittsburgh’s current climate averages are shown below from U.S. Climate Data.
Sixty years from now our average winter lows will barely reach freezing. July and August average highs will be 93+ degrees F but watch out for the highest highs. August record temperatures in Jonesboro are all above 103oF!
Our precipitation will be really different. We’ll go from a fairly steady 3 inches of rainfall per month to a rainy season in November-to-May and a dry season June-to-October. This might resemble California’s wet (flood) and dry (fire) seasons.
In this NASA video a robotic spacecraft called Juno makes its sixteenth fly-by (Perijove) since arriving in mid-2016. Its closest approach is almost dizzying. I feel better when the spacecraft zooms away and we see the swirling clouds.
Did you notice that Jupiter is on the sound track, too? The fourth movement of Gustav Holst’s The Planets is called Jupiter, The Bringer of Jollity. Listen to the entire majestic movement here.
An article about ice on a very icy day, 8oF and falling.
Considering how often the temperature has fluctuated in Pittsburgh this winter I’m surprised we haven’t seen more glaze ice.
Glaze ice is the name for the icy coating caused by freezing rain or freezing drizzle. If the accumulation is small, the effect is beautiful and the electricity stays on. The photo above from Wikimedia Commons is more beautiful than my own below.
When glaze ice is 1/4 inch thick or more the Weather Service calls it an ice storm. A quarter of an inch doesn’t sound like much but it’s so heavy that it weighs down the trees and they fall on power lines, streets, parked cars and houses. Power lines and power towers can fall, too. According to Wikipedia, “just one quarter of an inch of ice accumulation can add about 500 pounds (230 kg) of weight per [power] line span.” No wonder things come crashing down.
In January 1998 I wasn’t in Maine for the Great Ice Storm but I remember its results quite vividly. We visited central Maine in September and there were still broken trees everywhere. Folks who lived through it said they were without power for weeks. Everyone was stuck near home — couldn’t drive anywhere — so the radio stations connected people by announcing supplies and requests for help. Everyone pulled together.
After a beautiful red sunrise the sky cleared enough to reveal thin, wavy clouds flowing overhead. The National Weather Service said these clouds were at 11,000 feet — “alto” height, not cirrus height — but they really looked like this cirrocumulus undulatus photo at the International Cloud Atlas. Notice the feathery details in the photos above. (The four slides show two in normal color and two enhanced for contrast).
Cirrus clouds indicate a change in the weather. So did the red sunrise, photographed by Dan Dasynich. “Red sky at morn, sailors forewarn.”
Almost clear on Tuesday we had rainy, foggy weather the next day. The clouds told us it was coming.
(slideshow photos by Kate St. John, sunrise by Dan Dasynich)