Category Archives: Weather & Sky

Seen This Week

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

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)

Watch The Moon Turn Pink Nov 19

Partial lunar eclipse, Las Vegas NV, 10 Dec 2011 (photo from Wikimedia Commons)

15 November 2021, Pittsburgh, PA

If you live in the U.S. Eastern time zone, set your alarm for 3:30am Friday morning to step outside and watch the moon turn pink.

In what will be the longest partial lunar eclipse in 600 years, the moon will reach maximum darkness — and pinkness — at 4:02am EST, best seen from North America, the Pacific and eastern Russia.

Why pink? The Guardian explains, “During a total lunar eclipse, when the moon is in the Earth’s shadow, the only light reaching the moon passes through the Earth’s atmosphere. That produces a red tinge, or a deeper red colour after big dirty volcanic eruptions.”

Visibility of partial lunar eclipse on 18-19 Nov 2021 (image from NASA)

The eclipse will happen at the same time everywhere (UTC) but local time will differ. In Pittsburgh the eclipse will end just before sunrise and then the moon will set.

What phase?When in Universal Time (Zulu time)?When in Pittsburgh?When on the West Coast?
Penumbral eclipse begins0602 UTC on 19 Nov1:02am EST on 19 Nov10:02pm PST on 18 Nov
Partial eclipse begins0718 UTC2:18am EST11:18pm PST on 18 Nov
Maximum eclipse0902 UTC4:02am EST1:02am PST on 19 Nov
Partial eclipse ends1047 UTC5:47am EST2:47am PST
Penumbral ends1203 UTC7:03am EST4:03am PST
Sunrise7:11am EST
Moonset7:22am EST

Will we see the moon turn pink in Pittsburgh? Not well, if at all. In this century the 19th of November has been cloudy 75% of the time. Friday’s forecast says sky cover will be 50% at 4am. Check Pittsburgh’s Clear Sky Chart on Thursday 18 Nov before you set your alarm.

Our best chance for seeing this eclipse is to watch it Live at I’ll be up at 4am anyway to write this blog. I’ll let you know what I see.

p.p.s. Here’s an interesting factlet from “An eclipse never comes alone! A solar eclipse always occurs two weeks before or after a lunar eclipse.” Indeed, there will be a solar eclipse on 4 December 2021 but we’ll have to be in Antarctica to see it.

(photo from Wikimedia Commons, map from

Fall Back an Hour Closer to Zulu Time

Shepherd gate 24-hour GMT clock at the Royal Observatory, Greenwich, UK (photo from Wikimedia Commons)

6 November 2021

When Daylight Saving Time ends tonight our time zone will move one hour closer to Zulu Time.

Zulu (Z) Time is the aviation and military name for Greenwich Mean Time (GMT) or Coordinated Universal Time (UTC). Wikipedia explains that back in 1950, when time zones were identified by successive letters of the alphabet, the Greenwich time zone was marked by a Z as the point of origin.  Z in the military alphabet is called “Zulu.” Z time = GMT = UTC.

Pilots use Zulu Time for navigation described in the video below. The internet and your cellphone use Z time behind the scenes.

Time Zones around the world are a patchwork based on local laws. Most of the world does not participate in DST though more than half of the world used to. This morning’s screenshot from (6 November 2021, 4:45 EDT) will look different in North America tomorrow morning. Click here to see how the colors changed in North America on 11 Nov 2021.

Time zone map screenshot from at 6 Nov 2021, 4:45am EDT

I’m not a fan of changing the clocks and wouldn’t mind if we changed them tonight and never changed again. 🙂

Further reading:

  • Click here for the NATO phonetic alphabet where A,B,C… is Alpha, Bravo, Charlie…
  • Example of internet Z time: When I download my cellphone photos from Google to my computer they are labeled in Z time, not in the local time they were taken by my cellphone.
  • Most of the world does not participate in DST. Light gray areas on the map stopped participating, dark gray never used DST.
World map of Daylight Saving Time regions (image from Wikimedia Commons)

(photo of clock and map of DST from Wikimedia Commons. Time zone map is a point-in-time screenshot from Click here to see the current Time And Date map.)

Arcs And Dogs

Moonrise at sunrise, 3 Nov 2021 (photo by Kate St. John)

5 November 2021

This week clear skies and thin cirrus clouds produced optical phenomena in the sky.

On 3 November the waning crescent moon rose just before sunrise, reminding me of the upside down rainbow I saw two days before.

On Monday afternoon the sky had a thin skim of icy cirrus clouds and contrails that did not obscure the sun but allowed its light to create arcs and sundogs. This was the first time I’ve ever seen an upside down rainbow, the rare circumzenithal arc.

When the sun is low, arcs curve away [from it]. The circumzenithal arc, one of the most colorful of the ice-crystal phenomena, is always seen high in the sky. Its curve is centered on the zenith, and it is seen only when the sun is within 18-26 of the horizon.

National Audubon Society: Field Guide to North American Weather

Here are two photos of the arc at 4:22pm, 1 Nov 2021.

Circumzenithal arc, Pittsburgh, 1 Nov 2021 (photo by Kate St. John)
Circumzenithal arc, Pittsburgh, 1 Nov 2021 (photo by Kate St. John)

Twenty minutes later the arc was gone but sundogs appeared as bright spots to the left and right of the sun. In this photo from Schenley Park Golf Course, one sundog is accentuated by a contrail. Downtown Pittsburgh is in the distance.

Sundog, contrail and sun, Pittsburgh, PA, 1 Nov 2021 (photo by Kate St. John)

Check out this amazing photo of a halo, two sundogs and a circumzenithal arc in Riedbergpass, Germany. I’d love to see this one day. Keep looking up!

(photos by Kate St. John)

First Killing Frost?

Frost (photo by It’s No Game via Flickr Creative Commons License)

4 November 2021

This morning Pittsburgh’s official temperature dipped to 28 degrees F at 5:51am at Pittsburgh International Airport(*) and 27 degrees an hour later. This is long enough and low enough(**) to be the first killing frost of the winter.

Weather Conditions for Pittsburgh International Airport, 4 Nov 2021 through 6:51am (image from NWS)

However, we still haven’t had a killing frost in some parts of Pittsburgh. Where I live in Oakland the low was only 31 and at the Allegheny County Airport in West Mifflin, 6.5 miles south of me, the temperature dropped briefly to 30, then rose to a steady 31.

Weather Conditions for Allegheny County Airport, 4 Nov 2021 through 6:53am (image from NWS)

Did we have a killing frost?

If you live in suburbs your garden died this morning. If you live in the city it may be fine except for very tender plants.

The City of Pittsburgh is usually 5 degrees warmer than the suburbs. That’s a big reason why crows come to town for the winter.

(photo of frost by It’s No Game via Flickr Creative Commons License, Pittsburgh weather data from

(*) Until the official data is published later today I assume that Pittsburgh International was the same temperature as Pittsburgh’s official weather station in Coraopolis, 2.88 miles away.

(**) 28 degrees F is generally considered the temperature of a killing frost and is certainly true for corn and soy farmers. Tender garden plants, such as impatiens, die just below freezing.

It Looked Like Hail, But Was It Graupel?

Did we have graupel? Here is graupel on the ground in Germany (photo from Wikimedia Commons)

18 October 2021

Yesterday evening around 6pm rain obscured the northeastern horizon — Larimer, East Liberty and Shadyside. Eventually the cloud moved over us and dropped white pellets that clicked on the windows and bounced off the windowsills. There was no storm, just a dark cloud that ought to have been raining — except it wasn’t wet.

Was it hail? Was it sleet? Was it graupel?

I wasn’t outdoors to examine the pellets — they melted almost instantly — but I thought of graupel, also called snow pellets, because it was seven years ago this month (4 Oct 2014) that I first saw and wrote about it: Graupeling.

Did any of you see yesterday’s icy precipitation in the East End? What was it?

The National Weather Service has a helpful chart.

Chart from National Weather Service in Pittsburgh on 4 October 2014

(photo from Wikimedia Commons, chart from the National Weather Service in Pittsburgh)

Seen This Week

Sunrise on Thursday 14 October 2021 (photo by Kate St. John)

16 October 2021

It’s been three and a half weeks since the September equinox and every day is shorter than the last. Sunrise draws attention because it’s later every day. On Thursday the sky turned red before the sun appeared.

In the half light after sunset Morela prepared to roost.

Morela is ready to leave for her roost, 13 October 2021, 6:59pm (photo from the National Aviary snapshot cam at Univ of Pittsburgh)

The days are the same length as in late February during peregrine courtship. Morela and Ecco visited the nest as if they are thinking of spring.

Morela and Ecco bowing, 13 October 2021, 6:14pm (photo from the National Aviary snapshot cam at Univ of Pittsburgh)

Meanwhile most plants and trees have set fruit, including this streetside Callery pear.

Callery pear fruit, 14 October 2021 (photo by Kate St. John)

And in Downtown Pittsburgh I found a directional message on our tallest building.

“There is the sky, so that must be Up.”

There is the sky so that must be Up, Downtown Pittsburgh, 13 October 2021 (photo by Kate St. John)

(photos by Kate St. John)

Foggy Morning

Fog on spider webs (photo by Kate St. John)

5 October 2021, 8:45am

It’s foggy this morning in Pittsburgh as it has been for several days. On Saturday, heavy dew gleamed at Frick Park and laced the spider webs with beads of moisture.

Foggy morning with dew at Frick Park, 2 October 2021 (photo by Kate St. John)

Today the temperature is warm enough under the trees that there is no fog beneath them though there is plenty above.

Foggy morning in Pittsburgh; no fog beneath the trees, 5 October 2021 (photo by Kate St. John)

On Friday at Schenley Park we could see at ground level but fog above the trees made the sun look like a moon under the arch of the Panther Hollow Bridge.

Sun rising in fog just below the Panther Hollow Bridge, Schnley Park, 1 October 2021 (photo by Kate St. John)

When the fog cleared, the Cathedral of Learning emerged as from a magical kingdom.

Fog clearing in front of the Cathedral of Learning, 1 October 2021 (photo by Kate St. John

Today the fog has intensified in the last hour, no birds are stirring in the trees and Ecco is waiting at the Cathedral of Learning to start his day.

Ecco waits at the green perch, 5 October 2021 (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

(photos by Kate St. John & from the National Aviary snapshot camera at Univ of Pittsburgh)