Category Archives: Weather & Sky

Footprints in the Snow

Mammals, Weather & Sky
Allegheny National Forest at Beaver Meadows Recreation Area, 12 Jan 2022 (photo by Barb Griffith)

15 January 2022

The sun was shining and the temperature was in the mid 30s when six of us arrived at Beaver Meadows Recreation Area in the Allegheny National Forest on 12 Jan 2022. We were there to find 40 red crossbills (Loxia curvirostra) reported on 29 December. Just one perched in profile would be enough for me. I had to see the beak.

There were few birds in the forest but with an inch of snow on the ground we saw plenty of tracks including the small footprints of meadow voles or white-footed mice, the species that leave most of the little tracks in winter(*).

This one dragged his tail as he bounded across the path, planting his back feet in the prints of his front feet as he hurried from one subnivean hole to the next.

Likely the footprints of a white-footed mouse, Beaver Meadows, 12 Jan 2022 (photo by Kate St. John)

Since meadow voles have relatively short tails my guess is that the print was made by a white-footed mouse, (Peromyscus leucopus) pictured below. Notice the long tail.

White-footed mouse (photo from Wikimedia Commons)

We saw many other tracks including:

  • Fox on the lake ice
  • Otters slid on lake ice near their den. A local man helped us with this ID and showed us a photo of the otters.
  • Red squirrels made small highways between trees.
  • Bobcat,
  • Snowshoe hare.

This was my first ever look at snowshoe hare (Lepus americanus) tracks but I recognized the distinctive large hind feet that spread like “snowshoes” to help them walk on snow. (An optical illusion may make the footprints appear to bulge. My boot is at bottom of the photo for scale.)

Snowshoe hare track + tip of my boot, Beaver Meadow Recreation Area, Allegheny National Forest, 12 Jan 2022 (photo by Kate St. John)

Here are two sets of snowshoe hare prints, plain and marked up with notes. In the smaller track the hind feet are just less than 4″ long. In the larger the hind feet are about 6″ long.

Tracks of two snowshoe hares, Beaver Meadow Recreation Area, Allegheny National Forest, 12 Jan 2022 (photos by Kate St. John)
Tracks of two snowshoe hares, Beaver Meadow Recreation Area, Allegheny National Forest, 12 Jan 2022 (photos and markup by Kate St. John)

And here’s the mammal that makes these prints. Snowshoe hares are active at night, dusk and dawn so of course we didn’t see any.

Snowshoe hare in winter at Denali (photo from Wikimedia Commons)

Ultimately we saw 10 species of birds, only 26 individuals, five of which were red crossbills. It was worth the trip for the snowshoe hares. Yes I did see a crossbill beak.

(*) Information on tracks is from Track Finder by Dorcas Miller.

(photos by Kate St. John and from Wikimedia Commons; click on the captions to see the originals)

Four Moods of the Sky

Weather & Sky
Summer-like clouds in winter, 5 Jan 2022 (photo by Kate St. John)

8 January 2022

The sky has been moody in the past three weeks, sometimes clear, often overcast. Here are four of its many moods.

Twenty-four hours of warm weather produced summer-like clouds (above) and strong winds on 5 January 2022.

A fiery red sunrise on Christmas Eve in Smithfield, Virginia looked like a forest fire through the trees. Fortunately it was not!

Fiery sunrise in Smithfield, VA, Christmas Eve 2021 (photo by Kate St. John)

The clear sky glowed before sunrise on the day before the winter solstice, 20 Dec 2021.

Clear sky sunrise, nearly solstice, 20 Dec 2021 (photo by Kate St. John)

Half an hour later, the full moon glowed in the west as sunrise touched the hilltops.

Full moon at sunrise, nearly solstice, 20 Dec 2021 (photo by Kate St. John)

(photos by Kate St. John)

Solar Noon is Never Noon in Pittsburgh

Weather & Sky
Sun, sky, clouds (photo from Wikimedia Commons)

3 January 2022

When I look up at the sun to estimate the time, I expect it to be noon when the sun is at its highest point. In Pittsburgh the sun’s highest point, called solar noon, is always later than clock noon and it varies. It’s 3 minutes after noon (12:03p) in early November, 34 minutes in early February (12:34p). The reason is explained by The Equation of Time and our location in the Eastern Time Zone.

The equation of time is the difference between time measured using a sundial, also known as true or apparent solar time, and time measured using a clock, also known as mean solar time. [mean is 24 hours] …

The length of a solar day [from solar noon to solar noon] is not exactly 24 hours long. It varies throughout the year because of the elliptical shape of Earth’s orbit and its axial tilt. It is longer than 24 hours around the summer and winter solstices and shorter than 24 hours around the spring (vernal) and fall (autumnal) equinoxes.

— timeanddate.com: The Equation of Time

Earth’s eccentric orbit and axial tilt affect the location of the Sun as seen from Earth. If you take a photograph of the Sun at the same place and [Standard] time every day for a year its location varies in a lazy figure 8 called an analemma.

Analemma photo taken 1998-99 ourside Bell Labs in NJ by Jack Fishburn (GNU free licensing, Wikipedia)
Analemma photo taken 1998-99 outside Bell Labs in NJ by Jack Fishburn (GNU free licensing, Wikipedia)

Beyond the analemma, solar noon in Pittsburgh is always later than clock noon because we are longitudinally more than halfway west inside the Eastern Time Zone. For instance today, 3 Jan 2022, solar noon is at:

  • 11:37am in Bar Harbor, Maine
  • 12:00pm in New York City
  • 12:24pm in Pittsburgh and
  • 12:49pm in Indianapolis.

A graph of the number of minutes solar noon occurs before/after clock noon always follows the same curve below, echoing the analemma. In this graph I have altered the Y axis to match Pittsburgh’s solar offset from Standard Time. The curve is always above zero because solar noon is always later than clock noon in Pittsburgh.

Difference in time between solar noon and clock noon in Pittsburgh, PA (graph altered from Wikimedia Commons)

For clock-oriented humans it’s hard to know what time it is by looking at the sun. 😉

For further reading on the Equation of Time: Do you like math, astronomy, geometry? Check out the formulas in Wikipedia’s Equation of time article.

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

p.s. This table shows solar noontime in Pittsburgh at key points in 2022, derived from data at https://www.timeanddate.com/sun/usa/pittsburgh

Pittsburgh's Solar Noon in 2022

Frost Flowers and Needle Ice

Weather & Sky
Frost flower, Kentucky, Nov 2012 (photo on NWS website by Glen Conner, State Climatologist Emeritus for Kentucky)

30 December 2021

We’re having such a warm December that it may be mid January before we see ice again. When we do we are likely to see needle ice but it is too late for frost flowers.

Frost flowers, shown above, are beautiful, thin, curled ice confections that form in the presence of soggy unfrozen soil, freezing air, and dried plant stems that haven’t frozen yet. This week we have soggy soil and will eventually get freezing temperatures but all the plants have frozen at least once. The National Weather Service in Louisville, KY explains (paraphrased):

“Frost flowers are thin layers, perhaps credit card thickness, of ice that are extruded through slits from the stems of white or yellow wingstem plants, among others. … Practically speaking [this is] a once per year event, although not all individuals produce frost flowers on the first day of good conditions. The water in the plant’s stem is drawn upward by capillary action, expands as it freezes, splits the stem vertically, and freezes on contact with the air.”

Click here for more photos of frost flowers.

Needle ice is much more common in western Pennsylvania because it bursts up from saturated soil into freezing air. It too is caused by capillary action but it is more hardy than frost flowers.

Needle ice (photo by Kate St. John)

We’ll likely have needle ice some time in January. This vintage article tells you where to look.

Needle Ice

(photos by Glen Conner, State Climatologist Emeritus for Kentucky and Kate St. John; click on the caption to see the original)

Solstice Sunset is 3 Minutes Later

Books & Events, Weather & Sky
Sunset in Schenley Park, Candlemas 2021 (photo by Kate St. John)

21 December 2021

By the time the winter solstice arrives today at 10:59am we already will have gained three minutes at the end of the day.

Though the winter solstice has the shortest daylight — only 9 hours, 16 minutes and 57 seconds in Pittsburgh — it doesn’t have the earliest sunset nor the latest sunrise. That’s because the length of the solar day varies, solar noon to solar noon, while our clocks use the average day length of 24 hours. For a host of reasons, our clocks do not match solar time(*).

Thus the earliest sunset occurred 1 to 13 December in Pittsburgh and the latest sunrise won’t happen until 31 December and will linger for more than a week. See table below, built from information at timeanddate.com.

Pittsburgh PA Sunrise & Sunset near the Winter Solstice

If you cue on sunrise the days will seem to get shorter into early January.

If you cue on sunset your day has already gained three minutes this month and is getting longer.

(*) For the ultimate in “Our clocks don’t match solar time” consider that Solar Noon happens around 1pm during Daylight Saving Time. Solar Noon is in the 12 o’clock hour, as it should be, during Standard Time.

(photo by Kate St. John)

Seen This Week: Phipps Christmas Lights

Birds of Prey, Books & Events, Weather & Sky
Phipps’ Holiday Light Garden at dusk, 16 Dec 2021 (photo by Kate St. John)

18 December 2021

This week’s shorter days and unusually warm weather found me outdoors appreciating sunsets, merlins and Phipps Winter Light Garden.

On Thursday 16 December I visited Phipps Conservatory at 4pm for the Holiday Magic Winter Flower Show and Light Garden. At dusk it was 62oF, so of course no snow, but perfect for strolling in the garden. The show runs through Sunday 9 January 2022 so there’s plenty of time to visit. Click here for tickets.

Phipps’ Holiday Light Garden at dusk, 16 Dec 2021 (photo by Kate St. John)

As night fell songbirds came into the garden to roost. Robins and mourning doves zoomed overhead. White-throated sparrows chirped in the bushes near these blue lights as they settled for the night.

Phipps’ Holiday Light Garden at dusk, 16 Dec 2021 (photo by Kate St. John)

The Cathedral of Learning, framed by decorated trees.

Cathedral of Learning as see from Phipps’ Holiday Light Garden at dusk, 16 Dec 2021 (photo by Kate St. John)

Indoors the flowers were spectacular. These beautiful angel’s trumpets (Brugmansia versicolor) are native to Ecuador but extinct in the wild. You can see them in the Tropical Forest room.

Angel’s trumpet flower (Brugmansia versicolor) in the Tropical Forest room, 16 Dec 2021 (photo by Kate St. John)

Orchids and poinsettias.

Orchids at Phipps’ Holiday Flower Show, 16 Dec 2021 (photo by Kate St. John)

Earlier in the week, on Monday 13 December, I walked Schenley Park’s golf course to watch the merlins come to roost. During my last two visits — 23 Nov and 13 Dec — there have been three merlins that begin arriving at 4:30pm. Each one chooses the top of a bare tree to watch night fall. Eventually they roost in the pines.

The distant photos below show two of the three merlins as dots at the tops of trees. If you can’t see them, click on this photo for a markup with circles.

Tiptop of trees: 2 of 3 merlins at Schenley Park golf course, 13 Dec 2021 (photos by Kate St. John)

After I left the merlins that evening, I saw this spectacular sunset on my way home.

Sunset, Pittsburgh, 13 Dec 2021 (photo by Kate St. John)

So beautiful … it made me glad to be alive.

(photos by Kate St. John)

The Normal Temperature Has Changed

Climate Change, Weather & Sky
Annual U.S. temperature compared to the 20th-century average, using Climate Normals 1901-1930 to 1991-2020. (NOAA NCEI)

17 December 2021

We often hear the word normal on the weather report as in: “Today’s high was 64 degrees F with a low of 49F and was 23 degrees above normal.” (That was yesterday’s temperature in Pittsburgh and, yes, it was 23 degrees above normal.)

Climate normals are always a 30-year average of temperature and precipitation as recorded at each U.S. weather station. Recalculated at the end of each decade, the new normals announced in May 2021 are based on the most recent 30 years of data: 1991-2020.

Normal is a rolling average and it keeps getting hotter. The 10 maps above compare each decade’s normal temperature to the 20th century’s average. We have moved from cool blue (top left) to angry red (bottom right).

Normal might not feel hot for people in their early 30s because it’s what they remember throughout their lives, but for retired people like me the current normal is the climate of less than half my life.

I remember the snowy Decembers of my youth. Even without the graphs I can tell the normal temperature has changed.

For more information on the current climate normals and the trend in precipitation (which is not trending in one direction), see NOAA, 1 May 2021: The new US Climate Normals are here.

(map from NOAA NCEI)

Peregrine Goings On in Early December

Peregrines, Phenology, Weather & Sky

12 December 2021

The Cathedral of Learning peregrines remain on campus all winter, keeping tabs on their territory making it safe for future nesting.

On Friday I saw an adult red-tailed hawk circling up over the museum and thought for his sake, “You’re asking for it!” Sure enough, both peregrines popped off the Cathedral of Learning and zoomed down to relentlessly dive on the hawk until he flew low between buildings at Carnegie Mellon.

Scaffolding has been rising at Heinz Chapel but I paid no attention until a peregrine found it interesting. On Wednesday 8 December I noticed a dot on the top rung. Through binoculars I identified Morela checking out the new view (circled).

What’s that dot on top of Heinz Chapel scaffolding? A peregrine! 8 Dec 2021 (photos by Kate St. John)

Meanwhile Morela and Ecco are thinking of spring even though the winter solstice is more than a week away. Their abbreviated bonding rituals are becoming more elaborate as they bow they turn their heads, nearly touch beaks. Both have been digging the scrape(*) and Morela sometimes pauses to stand in it.

Here’s a selection of their goings on in early December.

  • Ecco waits for Morela to arrive
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10

p.s. The scrape (*) is the depression in the gravel where Morela will lay her eggs.

(photos by Kate St. John and from the National Aviary falconcam at Univ of Pittsburgh)

Seen This Week: Fall Color

Schenley Park, Trees, Weather & Sky
Ginkgo turning yellow at Schenley Park, 13 Nov 2021 (photo by Kate St. John)

20 November 2021

This week we had a last blast of fall color, a partial lunar eclipse and a surprising confirmation of pigeon fertility. Here are a few scenes from 12-19 November.

The ginkgo trees (Ginkgo biloba) turned yellow and will probably drop their leaves in a single day. Red oaks and hickories made a bright splash of color at Phipps’ outdoor garden on Monday.

Red oak at Phipps garden, 15 Nov 2021 (photo by Kate St. John)

Some beech leaves were already brown though the leaf veins were still yellow. Beech leaves cling to the smaller trees all winter, becoming paper thin and rattling in the wind.

Beech leaves turn brown though the veins are still yellow, Schenley Park, 15 November 2021 (photo by Kate St. John)

On Wednesday 17 November four of us drove north hoping for water birds but were disappointed by the lack of bird activity, particularly after the clouds moved in. Colorful leaves were scarce in Crawford County, especially at Conneaut Outlet swamp where high water killed the trees. This scene says “November in western Pennsylvania.”

Conneaut Outlet, Crawford County, 17 Nov 2021 (photo by Kate St. John)

On 18 November I saw a pigeon feeding two babies at its nest on Filmore Street near the Cathedral of Learning. Yes, nesting in November! Feral rock pigeons (Columba livia) breed year round if there’s enough food — and there is at this pile of birdseed on the corner.

Birdseed for pigeons at S. Dithridge & Filmore, 18 Nov 2021 (photo by Kate St. John)

As expected the partial lunar eclipse was obscured by clouds in Pittsburgh at 4am on 19 November. Only a tiny bright uneclipsed sliver is visible. The clouds are lit from below by the city lights.

Partial lunar eclipse obscured by clouds. Only the bright sliver shows in Pittsburgh, 19 Nov 2021 (photo by Kate St. John)

More leaves fell this week but most of the trees are not yet bare. Here’s a week’s worth of change at Schenley Park, 12 and 19 November.

Maples are bare, oaks are red, Schenley Park, 12 Nov 2021 (photo by Kate St. John)
Not yet. Most of the trees are Not bare. Schenley Park, 19 Nov 2021 (photo by Kate St. John)

The leaves are hanging on about two weeks longer than they used to. When will most of the trees be bare in Pittsburgh? Soon.

(photos by Kate St. John)

Remembering a Wintry November

Weather & Sky
Snow and ice after a winter storm (photo from Wikimedia Commons)

19 November 2021

This week’s weather was mild with highs up to 65oF and most lows above freezing until this morning. Not so seven years ago.

For three days in mid November 2014 a winter storm hammered the Great Lakes and brought unusually cold weather to western Pennsylvania. Pittsburgh was very cold without much snow but there was an amazing storm in Buffalo, New York. Here are two vintage articles that tell the story.

A reason to be grateful for very cold weather: Winter is a Great Pest Control System

How birds avoided the Buffalo blizzard of 18 November 2014. Avoiding The Storm

(photo from Wikimedia Commons; click on the caption to see the original)