Category Archives: Weather & Sky

Seen Last Week: Snow and Elusive Crows

Crows & Ravens, Deer, Weather & Sky
Snow in Schenley Park, 20 Dec 2024 (photo by Kate St. John)

22 December 2024

In the run-up to the winter solstice the temperature dropped below freezing last week and the clouds moved in. Seen last week includes evidence of deer, snow and crows.

Evidence of deer: After the city parks bow hunt began in September the deer found other places to hang out including cemeteries and backyards. But we still see their evidence of their nighttime presence including this buck rub in Frick Park on 19 December.

Buck rub on a tree in Frick Park, 19 Dec 2024 (photo by Kate St. John)

Snow fell on Friday and Saturday. In this video its starts out a bit furious and then tapers.

Snowing in Pittsburgh on 21 Dec 2024 (video by Kate St. John)

Our search for the Pittsburgh crow roost continues. We need to find as much of it as we can before the Pittsburgh Christmas Bird Count on Saturday, 28 December. So far we haven’t broken 10,000 but we know there are more than that.

Though crows prefer to spend the night in trees we’ve discovered they also roost on rooftops in Oakland where we cannot see and count them. Dang!

Last night Carol Steytler found some near the Pitt Field House. Not a huge number, but encouraging. Her video is dark; it was the middle of the night.

Please help us find the crows. Leave a comment to let me know where you see lots of crows after 4:00pm in the city limits. Tell me about …

  • Huge flocks of crows
  • Seen after 4:00pm or Overnight
  • Where are they? Provide specific location, street or landmark.
  • If flying, what direction are they going? I’ll map your contribution and triangulate.

Next week oughta be interesting.

Celebrating the Winter Solstice

Weather & Sky
Sunrise in Pittsburgh, 18 Dec 2024 (photo by Kate St. John)

21 December 2024

Happy Winter Solstice! The days will be getting longer soon.

Most of us were asleep when the winter solstice occurred in Pittsburgh at 4:21 AM EST. We could not see it, even if we’d been awake, because today’s sunrise is at 7:39am EST. On this the shortest day we’ll have 9 hours, 16 minutes and 59 seconds of daylight.

In Britain, Stonehenge is aligned to mark the summer solstice at sunrise and the winter solstice at sunset. Nonetheless, Stonehenge holds their winter solstice celebration at sunrise every year. Here’s a video of last year’s celebrations.

Winter Solstice at Stonehenge in 2023

video embedded from The Independent on YouTube

BBC News describes this year’s event: Winter solstice celebrated at Stonehenge

Stonehenge is an even bigger feat of prehistoric engineering than we’d originally thought. In 2021 scientists learned that its igneous bluestones were imported from southwest Wales. This year a Welsh scientist discovered that its giant, partially buried, 6 ton altar stone came from Scotland! A truly cosmopolitan monument.

video embedded from BBC News on YouTube

No wonder people celebrate there.

Seen This Week: Color + a Major Lunar Standstill

Plants & Fungi, Weather & Sky
Orange! at Phipps Conservatory, 12 Dec 2024 (photo by Kate St. John)

14 December 2024

Color! Avoiding this week’s coldest weather, Charity Kheshgi and I visited Phipps Conservatory during their annual Holiday Magic flower show. This time I was captivated by summer colors. Orange! Yellow!

Yellow! at Phipps Conservatory, 12 Dec 2024 (photo by Kate St. John)

A Major Lunar Standstill is coming up tomorrow.

The Full Moon on December 15, 2024, will rise and set at its most extreme northerly points on the horizon—the result of a once-every-18.6 years “major lunar standstill.”

— Time And Date: Look Out for December’s Extreme Full Moon

How odd that just days before the winter solstice, when the sun stands still and rises and sets at its southernmost point, the moon is standing still at its northernmost point.

Watch for it tomorrow. Here’s the moon this morning with Jupiter to its left.

Jupiter and the Moon on their way to setting in the west, 14 Dec 2024 (photo by Kate St. John)

Wind Chill-y Today

Weather & Sky
“At extremely cold temperatures, your breath will quickly condense and freeze, giving a frosty look to eyelashes, clothing and beards” (NPS photo via Wikimedia Commons)

12 December 2024

We won’t have frost on our eyelashes but today it will feel like we ought to. Pittsburgh’s current temperature of 21°F is only half of the normal high (42°F), and the wind chill in 15-24 mph wind makes it feel much worse.

Weather conditions in Pittsburgh PA on 12 Dec 2024, 5:53am (image from NWS)

The wind chill temperature is how cold people and animals feel when outside. Wind chill is based on the rate of heat loss from exposed skin caused by wind and cold. As the wind increases, it draws heat from the body, driving down skin temperature and eventually the internal body temperature.

— National Weather Service (NWS): Understanding Wind Chill

This wind chill chart shows how temperature and wind create a “Feels Like” temperature. Blue-to-purple background colors indicate how quickly exposed skin gets frostbite. Under extreme conditions it can take only 5 minutes. (I have circled today’s approximate values in red.)

Wind chill chart from National Weather Service

Yes, it feels cold and to make matters worse our bodies are not used to it. Just two days ago it was partly sunny and 59°F on Monday afternoon, 10 December.

So bundle up. It is wind chill-y today.

p.s. How cold does it have to be to get frost on your eyelashes? Minus 50°F == -50°F.

Seen This Week: Sun and Unexpected Carbon

Musings & News, Phenology, Weather & Sky
Early morning sun and fog at Duck Hollow, 25 November 2024 (photo by Kate St. John)

7 December 2024

This week the city received a light dusting of snow but the ground was not as beautiful as the sky. Two examples: Fog and sun at Duck Hollow before Thanksgiving, and a very red sunrise on 4 December.

Sunrise in Pittsburgh, 4 December 2024 (photo by Kate St. John)

What is this? An arrangement of black carbon.

Faulty oven creates black carbon, November 2024 (photo by Kate St. John)

These were the unexpected result of a faulty oven thermostat that carbonized the Thanksgiving biscuits. Fortunately that carbon is only skin deep. My niece cut off the bottoms. The tops were yummy.

Weather Hazards Surround Us

Weather & Sky
What does 24 inches of snow look like? This is Lake Effect Snow in 2004 (photo from Wikimedia Commons)

5 December 2024

Today’s regional weather map is a bright splash of color, none of it good.

Pittsburgh weather map, 5 Dec 2024, 6am from NWS
  • Blizzard warnings (red) –> add snow 12-20 inches + wind gusts to 60 mph
  • Winter Storm Warnings (pink) –> add snow (but less than 20″) + wind gusts 45-55 mph
  • Lake Effect Snow (green) –> snow bands drop 10-20 inches + wind gusts to 50 mph
  • Gale Warning (pale pink) –> Lake Erie winds 40-60 mph, waves 10-15 feet

All of the forecasted snow is falling on top of existing snow. The photo at top shows 24 inches, though not from this snowstorm.

What do birds do when the weather’s this bad? We found out in November 2014 when a nasty snowstorm hit Buffalo, NY.

Avoiding The Storm

It’s a good day to stay home.

Remembering November Tornadoes

Climate Change, Weather & Sky
Tornado in Pennville, IN, 5 Nov 2017 (photo from NWS courtesy Matt Leach)

14 November 2024

Seven years ago this month, on 5 November 2017, a cold front spawned 24 tornadoes as it passed over Illinois, Indiana, Ohio and Pennsylvania.

The one that hit Williamsfield, Ohio was documented by the National Weather Service in Pittsburgh.

Damage in Williamsfield, Ohio from 5 Nov 2017 tornado (photo from National Weather Service, Cleveland)
Damage in Williamsfield, Ohio from 5 Nov 2017 tornado (photo from National Weather Service, Cleveland)

The November outbreak was unusual for its location and intensity, described in this vintage article.

Tornadoes in November

So far, this year’s November tornadoes are less numerous and are well south and west of here.

Seen Last Week: Frost, Fog and Fall Color

Phenology, Weather & Sky
Frost in the valley at Duck Hollow, 28 Oct 2024 (photo by Kate St. John)

3 November 2024

Last week began with light morning frost but rose to 80°F on Halloween.

The colors were gorgeous at Duck Hollow on Monday …

Fall color and blue sky at Duck Hollow, 28 Oct 2024 (photo by Kate St. John)

… while tendrils of fog chased each other across the river.

Fog tendrils blow slowly across the Monongahela River at Duck Hollow, 28 Oct 2024 (video by Kate St. John)

These wisps were formed at the rivers edge as clear cold air passed over warm water. Sunbeams make this a poor quality video, below, but you can see the wisps starting near shore. (You might also hear a song sparrow chipping in the background.)

Fog forms at Duck Hollow, 28 Oct 2024 (video by Kate St. John)

Slanting light illuminated the trees at Schenley Park.

Fall color and slanting light in Schenley Park, 29 Oct 2024 (photo by Kate St. John)

A leaf-hidden cocoon reminded me why clearing out leaves is bad for insects. This insect will overwinter on a leaf in Frick Park and emerge as — perhaps — a butterfly or month next spring. Or it may become food for a bird this winter. The insect chain is broken where don’t leave the leaves.

Insect cocoon on a leaf at Frick Park, 30 Oct 2024 (photo by Kate St. John)

Making the Sun Set Earlier

Books & Events, Weather & Sky
Sunset times in Pittsburgh, late 2024 (photo by Kate St. John)

2 November 2024

Spring Forward, Fall Back. Daylight Saving Time ends tonight as our clocks turn back an hour. Tomorrow the sun will set an hour earlier. A lot of us will be grumpy. Some will be depressed.

Most Americans agree that changing the clocks is bad.

Numerous polls have found that most Americans believe that a standard time should be fixed and permanent—as many as 75% favor no longer changing clocks twice per year. One of the most common observations among researchers of varying backgrounds is that the change itself causes most of the negative effects, more so than either standard time or daylight saving time. Researchers have observed numerous ill effects of the annual transitions, including reduced worker productivity, increased heart attacks and strokes, increased medical errors, and increased traffic incidents.

— Wikipedia: SP Act Debate

There are places that don’t participate in this dreaded exercise: Arizona, Hawaii, Puerto Rico and other U.S. island territories.

Map of Daylight Saving Time in U.S. from Wikimedia

But there is an area in northeastern Arizona of self-governed indigenous tribal land where part of it uses Daylight Saving Time (DST) and the center does not. The DST area is the Navajo Nation which spans three states and has chosen to use DST. The donut hole is the Hopi Reservation that uses Standard Time. Here’s a closer look.

If you drive from Tusayan, AZ to Tuba City to Ganado to Window Rock in March through October, you will change time zones seven times between Standard Time and DST. (Did I count correctly?) People who have to make that trip will be relieved that everyone is on Standard Time tomorrow.

Changing your clocks: Everything connected to the Internet — mobile phones, etc. — will change automatically at 2:00am Sunday. The rest of the clocks are up to us.

animation from Wikimedia

p.s. I wonder what happens to a cellphone on the trip from Tusayan to Window Rock during DST.

Emerging From The Deep

Climate Change, Water and Shore, Weather & Sky
Youghiogheny River dam with lake at normal level (photo from 1993 via Wikimedia Commons)

1 November 2024

In 1944 the US Army Corp of Engineers completed a flood control dam across the Youghiogheny River that created a lake into Maryland. The project included a new bridge for US Route 40 because the Great Crossings Bridge at Somerfield would be submerged and so would the town’s low lying streets and buildings.

map of Youghiogheny River Lake and Recreational Area from USACE via Wikimedia

Normally the lake is full and beautiful. You would never know there was a bridge underneath it.

Beautiful Youghiogheny River Lake (photo from recreation.gov)

But this year a drought in the Youghiogheny watershed has lowered the lake so far that you can walk out on the old Great Crossings Bridge.

video embedded from CBS Pittsburgh on YouTube

This Google Map shows both bridges.

embedded Google Map showing submerged Great Crossings Bridge north of US Route 40

Pittsburgh is not in severe drought so it’s hard to understand how this lake could drop unless you know where the river comes from. The Youghiogheny is a north-flowing river with headwaters in the mountains of West Virginia and Maryland. Notice that the rest of the Monongahela river basin starts in West Virginia as well.

Monongahela River Basin, Youghiogheny highlighted (map from Wikimedia Commons)

The headwaters of both the Youghiogheny and Monongahela have been in drought since early July. At this point the drought is Extreme to Exceptional in western Maryland and West Virginia.

Northeastern US Drought Map, 29 Oct 2024 (map from US Drought Monitor at UNL)

Water levels have dropped in both rivers but the Monongahela cannot afford to get too low because it carries a lot of barge and boat traffic.

Barge moving downstream on the Monongahela River at Duck Hollow, 18 Sep 2023 (photo by John English)

However, there is water upstream to feed the Monongahela. Releases from Youghiogheny River Lake have, in part, kept the Mon navigable.

And so the old bridge emerges from the deep.

p.s. This isn’t the first time the old bridge has been exposed.