National Phenology Network - Spring Arrived In American SE Earlier Than Any Point In 39 Year Record

[hatrack]

Across the south-eastern US, trees are unfurling their clouds of leaves after winter. Yet this picturesque and usually welcome development is this year cause for consternation. New data from the USA National Phenology Network (USA-NPN) shows that in parts of North Carolina, South Carolina and northern Florida, spring has arrived more than three weeks earlier than average, and earlier than at any point in the last 39 years it has been tracked.

The south-eastern US has historically experienced a large amount of variability in the onset of spring, so it is hard to say the climate crisis is directly responsible. Yet this year’s premature spring is part of a trend of rising temperatures and early leaf emergence that scientists have observed in recent years.

Phenologists – who study seasonal phenomena in the natural world – calculate the start of spring based on observations of “leaf-outs” (the appearance of tiny leaves on trees), blooms for species active in early spring (such as lilac and honeysuckle) and weather events and temperature conditions. The Extended Spring Indices have been used as an indicator of climate change by the US Environmental Protection Agency and the National Climate Assessment.

A 2016 study by the National Park Service found that of the 276 parks studied, three-quarters are experiencing the impacts of an early onset of spring, and half of the parks are experiencing an “extreme” early onset, as compared to historical averages. This 2020 early spring is currently affecting such beloved parks as Congaree in South Carolina and parts of Great Smoky Mountains on the border of Tennessee and North Carolina.

EDIT

https://www.theguardian.com/environment/2020/mar/06/spring-arrival-earliest-record-southern-us-climate-crisis

[lark]

1. Yes, we had no winter and spring came really early to NE FL.

However, once the shutdown started, things cooled down and the humidity went down as well. It stayed that way from mid-March until Tues. the day after reopening in FL. It's gotten hotter and more humid every day since reopening - or less particulates less heat, more particulates more heat and humidity? I know the humidity part is location driven since smog doesn't make LA humid but I bet it drives us the heat there too.

[quaint]

2. National Phenology Network, great information

May 20, 2020

Spring leaf out has arrived across much of the country, 3-4 weeks earlier than a long-term average (1981-2010) in parts of the West, Southeast, and Northeast and up to 3 weeks late in parts of the northern Great Plains, upper Midwest, and upper Northeast.

Comparison of 2020 spring bloom to average from 1981-2010

Spring bloom has also arrived across much of the country and follows a similar pattern of earlier spring bloom across the Southeast and later spring bloom in the northern Great Plains, Midwest, as well as parts of the Northeast.

How often do we see a spring this early or late?
In places where spring has sprung, how typical is this year’s spring? Darker colors represent springs that are unusually early or late in the long-term record. Gray indicates an average spring.

In parts of the Southeast and Northwest, this year's spring is the earliest in the 39-year record (dark green). In parts of Nevada, Wyoming, and Montana, this year's spring is the latest on record.

[link:|
(more graphs at link)