Category Archives: Weather & Sky

More or Less Drought

Ranking the states by average percentage of land in drought, 2000-to-March-2021 (original map from Wikimedia Commons colored by Kate St. John)

27 November 2022

The western U.S. has always been drier than the east but as climate change heats up the planet, drought has become more prevalent. NOAA’s quarterly weather outlooks now include a 3-month drought prediction along with temperature and precipitation forecasts. Some places are more likely to experience drought than others. Which states are more likely? Which are least?

The graphic above is based on Stacker’s article, States With the Worst Droughts, that ranks states by average percentage of land in drought from 2000 to March 2021. Listing the states in order, I grouped them in 10s with darkest Orange indicating the top ten drought states and darkest Green for the 10 wettest. (White = the middle 10)

  • The top state for drought is Arizona. No surprise; it’s a desert.
  • The state with the least drought is Ohio!
  • Georgia and South Carolina stand alone with a lot more drought than their neighbors. Their drought ranking is like Kansas.
  • Hawaii (dark orange) and Alaska (dark green) are at opposite extremes.
Sign at Georgia Tech during the 2008 drought (photo by Mingaling via Flickr Creative Commons license)

As climate change continues to unfold human populations will migrate from less habitable to more habitable locations. In the U.S. we can expect people to move west to northeast in the coming century — from more drought to less.

Wondering about your state’s ranking? Click here for the Stacker article.

NOAA’s 2022-23 winter weather outlook is here.

(at top, base map from Wikimedia Commons, precipitation outlook from NOAA; click on the captions to see the originals)

Seen This Week

Burning bush leaf and fruit, 15 Nov 2022 (photo by Kate St. John)

19 November 2022

On Tuesday morning, 15 November, I found beautiful fruits on my walk in the neighborhood: Red berries on invasive burning bush (Euonymus alatus), purple berries on native American Beautyberry (Callicarpa americana), and dusty blue fruit on invasive English ivy (Hedera helix).

American beautyberry, 15 Nov 2022 (photo by Kate St. John)
English ivy berries, 15 Nov 2022 (photo by Kate St. John)

It began to snow so I hurried home and was glad I was indoors when it came down fast. It looks peaceful in slow motion at the end of this video.

The snow stuck to the grass, parked cars, and the Pitt peregrine nest …

Snow on the Pitt peregrine nest, 15 November 2022, 2:15pm

… then melted overnight as the temperature rose and low clouds moved in.

Low clouds at 8pm, 15 Nov 2022 (photo by Kate St. John)

By Friday most leaves were gone and the only green shrubs in Schenley Park were invasive plants: Bush honeysuckle in this view …

Scene in Schenley Park, 18 Nov 2022. The green shrubs are invasive honeysuckle (photo by Kate St. John)

… and bamboo near the railroad tracks.

Scene in Schenley Park, 18 Nov 2022. The green shrubs are invasive bamboo (photo by Kate St. John)

Tonight the temperature will drop to 19 degrees for a very cold start to the new week. Brrrrr!

(photos and video by Kate St. John)

Who’s There in the Fog?

Shadow in a Glory: a Brocken specter at Grisedale Pike (photo from Wikimedia Commons)

17 November 2022

Last weekend Chris Randall @ultrapeakschris tweeted a video of a shadowy figure walking in step with him in the fog. At first he thought it was another person. Instead it was a Brocken specter with a faint rainbow halo called a glory.


Wikipedia describes: A Brocken spectre is the magnified shadow of an observer cast in mid air upon any type of cloud opposite a strong light source (such as the sun). If the cloud consists of backscattered water droplets, a bright area and halo-like rainbow rings called a glory can be seen around the head or apperature silhouette. The phenomenon was named for Brocken Peak in Germany where it frequently occurs.

Sometimes the specter appears to hover in the sky like an angel as did this one with a triple glory that appeared to a mountain climbing team in Tajikistan.

Brocken spectre above the horizon, Peak Ozodi, Aug 2006 (photo from Wikimedia Commons)

Perhaps you’ve seen a Brocken specter from an airplane. I have, but I didn’t know what it was called.

Brocken specter and glory seen from an airplane over San Francisco area (photo from Wikimedia Commons)

And finally, you can create a Brocken specter in nighttime fog if you work at it. The caption on this photo says: “On an exceptionally foggy night, I parked my car at one end of the parking lot, facing into the lot, and covered one headlight with a floor mat. Standing before the uncovered light, I photographed the shadow that I was thus casting into the fog : a Brocken spectre.”

Brocken specter in California fog at night (photo from Wikimedia Commons)

Who’s there in the fog? It’s you!

(photos from Wikimedia Commons; click on the captions to see the originals)

The Oort Cloud

Illustration of Oort cloud by Pablo Carlos Budassi via Wikimedia Commons

16 November 2022

Far, far away at the edge of our solar system there’s a spherical cloud of icy objects with an inner cloud like a bicycle spoke reaching toward the Sun. No one’s ever seen it. It’s the home of comets.

The Oort cloud is the theoretical concept of a cloud of predominantly icy planetesimals proposed to surround the Sun at distances ranging from 2,000 to 200,000 AU (0.03 to 3.2 light-years). It is divided into two regions: a disc-shaped inner Oort cloud (or Hills cloud) and a spherical outer Oort cloud.

Wikipedia: Oort cloud

The Hills cloud, or inner Oort cloud, contains roughly 5 times as many comets as the outer ring.

Diagram of Oort cloud (image from NASA via Wikimedia Commons)

Long-period comets (which take more than 200 years to orbit the Sun) probably come from the Oort Cloud, which is sometimes described as a “cometary reservoir.””

NASA: Oort Cloud overview

It’s the home of Comet Hale-Bopp which appeared in 1997 and will return to the inner Solar System around the year 4385.

Comet Hale-Bopp, 1997, over Pazin in Istria/Croatia (photo from Wikimedia Commons)

Hale-Bopp is out there with the planetesimals, minute planets believed to be composed of cosmic dust grains that accumulated with many others under gravitation to form a planet.

(photos and illustrations from Wikimedia Commons; click on the captions to see the originals)

p.s. an AU is an Astronomical Unit = the distance from Earth to Sun in one Julian year (365.25 days).

Atmospheric Effects

Total lunar eclipse, digiscoped through Pittsburgh city lights and haze, 8 Nov 2022 (photo by Kate St. John)

8 November 2022

This week southwestern Pennsylvania witnessed many atmospheric effects from clear skies to troubled clouds, rainbows and a total lunar eclipse. Here are the stories behind six pictures.

  • Total lunar eclipse, 8 Nov 2022, 5:29am, photo through my birding scope. The sky was hazy and I am terrible at digi-scoping so by the time I got a decent shot of the moon it was leaving my view. But you get the idea.
  • Atmospheric optics around the sun, 5 Nov 2022, 9:20am, Yellow Creek State Park, PA. Ice crystals in the clouds produced two sun dogs, a 22 degree halo, and a circumzenithal arc (upside down rainbow at top). Click on the links to read about each phenomenon.
Ice crystals in the clouds produce two sun dogs, a 22 degree halo, and a circumzenithal arc, Yellow Creek State Park, 5 November 2022 (photo by Kate St. John)
  • Layers of troubled clouds, 5 Nov 2022, 5:45pm: Later that same day two layers of clouds raced overhead in gusty wind. The lower layer threatened rain at the horizon while the upper layer glowed in sunlight.
Lower clouds threaten rain at the horizon while upper clouds catch sunlight, 5 Nov 2022 (photo by Kate St. John)
  • Light mist over the Monongahela River at Duck Hollow, 3 Nov 2022, 10am.
Haze over the Monongahela River at Duck Hollow, 3 Nov 2022 (photo by Kate St. John)
  • Rainbow over Pittsburgh, 6 Nov 2022, 1pm: On Sunday I hiked at Hays Woods with Linda Roth (in foreground) and the 40 Acres AKA Hays Woods Enthusiasts. We got caught in a brief downpour but there was a Big Sky reward: a beautiful rainbow.
Rainbow as seen from Hays Woods, Pittsburgh, 6 Nov 2022 (photo by Kate St. John)
  • The sky glows before sunrise on a clear day, 7 Nov 2022, 6:27am.
Sunrise, 7 Nov 2022 (photo by Kate St. John)

Keep looking up for more atmospheric effects.

(photos by Kate St. John)

Fall Color This Week

Sunrise in Pittsburgh, 28 October 2022 (photo by Kate St. John)

29 October 2022

Fall color was brilliant this week, especially at sunrise.

Bright red was gone from our hillsides as the maples faded but other leaves took up the slack in yellow and orange. Below:

  • Bottlebrush buckeyes are yellow in Schenley Park.
  • Japanese knotweed is yellow-orange at Duck Hollow.
  • Blue-green porcelain berries were eagerly eaten by migrating robins.
  • Red honeysuckle berries attracted cardinals and house finches.
  • Confused flowers! Forsythia bloomed along the Nine Mile Run Trail even though its leaves were a deep purple-red.
  • Red oaks are red-orange in Schenley Park.
Bottlebrush buckeye leaves turn yellow in Schenley Park, 25 October 2022 (photo by Kate St. John)
Fall color, Japanese knotweed, Duck Hollow, 27 October 2022 (photo by Kate St. John)
Porcelain berry fruit, Nine Mile Run Trail, 27 October 2022 (photo by Kate St. John)
Honeysuckle fruit, Nine Mile Run Trail, 27 October 2022 (photo by Kate St. John)
Forsythia blooming in late October, NMR Trail, 27 October 2022 (photo by Kate St. John)
Fall color, Schenley Park from Panther Hollow Bridge, 25 October 2022 (photo by Kate St. John)

A week from now the trees will be half bare.

(photos by Kate St. John)

What’s in the Sky?

Wispy contrails over Pittsburgh, 15 Oct 2022, 1:40pm (photo by Kate St. John)

22 October 2022

Pittsburgh skies put on a show in mid October.

On the 15th feathery contrails were pushed by high winds at 30,000 feet. We could not see them at dawn because of the lumpy clouds.

Sunrise with clouds, 15 Oct 2022, 7:20am (photo by Kate St. John)

The next day the wind dropped, a temperature inversion set in, and rotten-egg smog gathered in the Monongahela Valley, below.

Inversion shows pollution from US Steel trapped in the Mon Valley, US Steel’s Edgar Thompson Works and Kennywood in the distance, 16 October 2022, 9am (photo by Kate St. John)

Temperature inversions are typical in October and November when warm air above traps cold air at the ground, filling the valleys with haze or fog. In Pittsburgh the pollution from US Steel Clairton Coke Works is also trapped, intensifying the rotten egg smell of hydrogen sulfide (H2S) in the Monongahela Valley.

Weather or not, US Steel Clairton always emits these pollutants. The 16th’s stinky haze capped more than ten days of unusually terrible air pollution from USS Clairton(*). Here’s how bad it was: How Bad has Air Quality Been? H2S Was Below PA Standard For Only 3 Hours This Week. (Note: H2S level is supposed to be below the standard to keep our air clean.)

The air smelled better October 17-20 including on this beautiful morning of October 20.

Sunrise, almost clear, 20 October 2022 (photo by Kate St. John)

Yesterday’s pollution was pretty bad. Hoping for better air.

(*) US Steel’s Clairton Coke Works is the largest coking facility in the U.S., baking coal to make coke for steel production. Coking removes coal’s impurities by turning them into gases including stinky hydrogen sulfide (H2S). In March 2022 Allegheny County Health Department reported that “Based on all available data and resources, H2S exceedances that occurred at the Liberty site during the period of Jan. 1, 2020, through March 1, 2022, can be attributed entirely to emissions originating at US Steel’s Clairton coking facility.”

(photos by Kate St. John)

Seen This Week

Fall leaves, Schenley Park, 12 Oct 2022 (photo by Kate St. John)

15 October 2022

Fall colors were looking good in the City of Pittsburgh this week. A maple in Schenley Park turned shades of orange and red while the sunrise worked to match it.

Sunrise on 12 Oct 2022 (photo by Kate St. John)

This acorn in Schenley Park is a squirrel’s dream come true, the largest acorn native to North America. Bur oaks (Quercus macrocarpa also spelled burr oak) were planted in several places in the park more than 100 years ago, most notably at the main trail entrance near Bartlett Playground. This species withstands harsh conditions and is one of the most drought resistant oaks.

Bur oak acorn, Schenley Park, 9 Oct 2022 (photo by Kate St. John)

Goldenrods are blooming in the small meadow near Bartlett Playground.

Goldenrod in meadow, Schenley Park, 12 Oct 2022 (photo by Kate St. John)

During my walk to Schenley Plaza on 11 October I saw a peregrine fly toward Heinz Chapel’s scaffolding and disappear among the dense rods.

Heinz Chapel scaffolding, 11 Oct 2022 (photo by Kate St. John)

If he hadn’t moved I would not have found him. Ta dah! (See inside red circle.)

Peregrine falcon perched (circled) on Heinz Chapel scaffolding, 11 Oct 2022 (photo by Kate St. John)

Amazingly he was easier to see through binoculars from Schenley Plaza tent. Too far for a photo.

(photos by Kate St. John)

By Jove It’s Thors Day

Jupiter & moon Europa from Hubble Space Telescope, 25 Aug 2020 (photo from Wikimedia Commons)

13 October 2022

Today is Thursday, Thor’s Day, or Jove’s Day. We’ll celebrate with some quick facts about Jupiter.

The Romans named the fifth day of the week dies Jovis (“Jove‘s Day”) after the planet Jupiter. In Germanic mythology, Jupiter is equated to Thor, whence the English name Thursday for the Roman dies Jovis.

— From Wikipedia: Jupiter

Jupiter was big in the news last month when on 27 September 2022 the planet was at its closest, brightest and best in 70 years. On that date the Earth flew between Jupiter and the Sun, putting Jupiter in opposition and in bright sunlight as it rose at sunset.

Three days later it rose after sunset so the sky was dark showing off Jupiter’s four largest moons, the ones first seen by Galileo in 1610.

Jupiter & Galilean moons, 30 September 2022 (photo by George E. Koronaios via Wikimedia Commons)

Modern day space probes and telescopes can see the Galilean moons in full color. The image caption on the photo below explains: From left to right in order of increasing distance from Jupiter, Io is closest, followed by EuropaGanymede, and Callisto.

Jupiter’s Galilean moons as seen from NASA’s Galilean spacecraft (image from Wikimedia Commons)

Timelapse photography allows us to see the Galilean moons orbiting Jupiter as NASA’s Juno spacecraft approaches. These are only four of the 80 known satellites of Jupiter, most of which are less than 10km (6.2 miles) in diameter. 80 moons!

Jupiter and the motion of the four Galilean moons taken by JunoCam aboard the Juno spacecraft, June 2016 (animation from Wikimedia Commons)

Moons Io and Europa have sparked a lot of interest.

Jupiter doesn’t have rings like Saturn, but it ought to. Why not?

Because it’s bigger, Jupiter ought to have larger, more spectacular rings than Saturn has. But new UC Riverside research (21 July 2022) shows Jupiter’s massive moons prevent that vision from lighting up the night sky.

Science Daily: Why Jupiter doesn’t have rings like Saturn

And finally, Thursday is a good day to feel jovial. According to Wikipedia, the older adjectival form jovial, employed by astrologers in the Middle Ages, has come to mean “happy” or “merry”, moods ascribed to Jupiter’s astrological influence.

Happy Thursday!

(images from Wikimedia Commons; click on the captions to see the originals)

Fiery Skies

Sunrise in Pittsburgh, 6 October 2022 (photo by Kate St. John)

8 October 2022

Sunrise and sunset have been very colorful in Pittsburgh lately.

On 6 October the sky was clear with some thin clouds and airplane contrails. The rising sun lit the contrails a hot pink-red. Detail photo above, wide-angle below.

Sunrise in Pittsburgh, 6 October 2022 (photo by Kate St. John)

On 30 September the sunset was fiery.

Sunset in Pittsburgh, 30 September 2022 (photo by Kate St. John)

Every day is shorter as sunrise and sunset get closer to each other. By 18 October we will have an hour less of daylight than at the Equinox.

p.s. Unfortunately the sunrise on 6 October many have been colorful because the air was so bad. Everyone in the Mon Valley could smell it. Hydrogen sulfide exceeded the 1-hour limit at the Liberty-Clairton monitor, an exceedance which “can be attributed entirely to emissions from US Steel’s Clairton coking facility.” Read more at

(photos by Kate St. John)