All summer we noticed curly dock (Rumex crispus) leaves and not the flowers. Now our attention is reversed because the seeds have turned a rich brown. The stalk is ugly, however the seeds are fascinating up close, each one surrounded by the calyx that produced them. The papery wings allow them to float on water and fly a bit in the wind.
The most obvious sign of fall is the temperature. 43 degrees F at dawn today. Speaking of gloves, you’ll need them when you go birding in the morning.
This week’s spooky sunsets and hazy skies in eastern North America are due to smoke from the massive wildfires in Washington, Oregon and California. The smoke is so intense that it’s dispersing across the continent and across the Atlantic, causing haze in Europe.
Near sunset on Monday 14 September the sun was a strange shade of pink in Pittsburgh, captured above in true color by Jonathan Nadle.
We can’t see the smoke coming but the satellites do, blowing eastward in two paths on Tuesday 15 September: one over the Northern Plains and Great Lakes, the other over Nebraska to Kentucky and Virginia.
The haze is inconvenient for us but truly hazardous on the West Coast. The dark brown colors on the map below are the worst air quality in the world. The air is so bad that people are leaving the area. I know of at least one person who’s fleeing from San Francisco to Pittsburgh.
Last night two hours after sunset bird migration was intense over the southeastern United States. The birds showed up as blue blobs on Doppler weather radar but there was a noticeable gap over Louisiana, southern Mississippi and southeastern Alabama. The birds were avoiding Hurricane Laura.
This National Weather Service radar map from 26 Aug 2020, 9:48pm EDT shows where the birds won’t go. (I’ve added a pink line to illustrate their self-imposed boundary.) I believe the small blue blob south of the pink line –at Jackson, Mississippi — is a sign of birds leaving for safer locations.
Humans were urged to leave too because of the coming storm surge, 20 feet high, as illustrated in the Weather Channel video below.
The National Hurricane Center has forecasted “unsurvivable storm surge” from Hurricane #Laura in parts of Louisiana and Texas. Do NOT underestimate this storm.
In this 8 August 2020 photo, the Monongahela River is full near the Homestead Grays Bridge, yet rainfall since June 1 is down 2-4 inches in the Monongahela watershed and the ground was bone dry at that time. This got me thinking … How could the river be full when we’re nearly in a drought? The abundance of water is deceiving.
Ever since Europeans arrived in western Pennsylvania they’ve worked to make our rivers more navigable. In the early 1800s these efforts barely made a dent, especially in late summer when the dry season turned the rivers into shallow pools and rivulets. The Lewis & Clark Expedition coped with this after they left Pittsburgh a month later than planned. Embarking on 31 August 1803 the Ohio was so low that the expedition had to push and drag their laden keelboat over many shoals. It took them a week to reach Wheeling. (read more here).
Because of the “lakes” we have lots of river traffic, making the Port of Pittsburgh the 15th largest port in the U.S. when measured in domestic trade. On the Mon River the trade seems to be mostly coal.
The river is full when rainfall is low because the water is controlled for navigation.
p.s. Some people say the dams are for flood control but the locks and dams don’t perform that service. As Rob Protz points out, the flood control dams are very different. (See the Conemaugh River Dam.) Even with those dams in place we still get floods, though perhaps less frequently.
This week brought a profusion of August flowers and very localized rain.
Above, tansy’s rayless flower heads look like daisies without petals. Tansy (Tanacetum vulgare) has only one kind of flower — the small yellow ones in the central disk. Daisies have two kinds — the central disk plus white flower rays.
Below, cup plant (Silphium perfoliatum) is blooming in Schenley Park showing off the cupped leaves that give it its name.
Asiatic dayflower (Commelina communis) can be invasive, too, though the flower lasts only a day.
This week brought rain to our new home north of Schenley Park and continuing drought just south of here. At home on 11 August it rained so hard that a bug took shelter on our window. Its location 70 feet off the ground explains why chimney swifts fly so high.
While the bug was avoiding rain north of Schenley, no rain fell in the park just a mile away.
It’s been so dry in western Pennsylvania this summer that we find ourselves wishing for rain. Yesterday some areas were lucky. It rained 0.61 inches at Pittsburgh’s airport but not throughout the region. Precipitation is still down -2.24 inches since June 1. Are we in a drought?
The US. Drought Monitor map (28 July 2020 above) shows drought conditions and severity across the country. Pale orange in southwestern Pennsylvania indicates areas of Moderate Drought with short-term impacts (“S“). Yellow is Abnormally Dry.
The map above changes quickly if it rains heavily one day. The Drought Severity Index (Long Term Palmer) map, below, charts prolonged abnormal dryness or wetness and matches what gardeners and farmers are dealing with. Southwestern PA has felt like it’s in a drought and, yes, according to the Palmer Index the situation is Severe. (Black on the map is missing data.)
Our situation in Pennsylvania is mild, though. The real concern is out West where the Drought Monitor is bright red (Extreme Drought) with long term impacts (“L“) and the Palmer Index is dark orange.
West Texas is suffering the double whammy of rampant COVID-19 + extreme drought. Today’s a good day to count our blessings in southwestern Pennsylvania.
According to the USA National Phenology Network, Spring is three weeks ahead of schedule in the southeastern US:
Spring leaf out has arrived in the Southeast, over three weeks earlier than a long-term average (1981-2010) in some locations. Charlottesville, VA is 24 days early, Knoxville, TN is 20 days early, and Nashville, TN is 18 days early.