Monday, July 27, 2020

NYC Weather Forecast: Excessive Heat New Normal in Climate Change - Bloomberg

NYC Weather Forecast: Excessive Heat New Normal in Climate Change - Bloomberg



The
water off Long Island is 76.3 degrees Fahrenheit and nearly 73 degrees in
Massachusetts Bay




New York’s Sweltering Heat Is the New Normal for Climate
Change
Odds are high 2020 will wind up among top five warmest years
ever.

By Brian K Sullivan
July 23, 2020, 6:52 PM GMT+1

New Yorkers sweating through this month’s heat wave can
blame the oceans—a cool patch of water off the Pacific coast of Peru, more than
3,500 miles away (5,632 kilometers), and near-record warmth offshore in the
Atlantic. The cause and effect is a reminder that climate change’s toll is
coming due.

The cold water across the equatorial Pacific is locking in place
two high pressure systems — reservoirs of heat — at either end of the
continent.   These weather patterns, also
called ridges, promote heat and dry out the land beneath them. At the same
time, the Atlantic Ocean is feeding its warmth onto the land, adding to heat
that is already fixed across the U.S.

“Once you get a dome of heat like that it is very tough to
get rid of it,” said Jim Rouiller, lead meteorologist at the Energy Weather
Group LLC. “The weather models may chop it up, but it’s resilient, you might
get two days of normal but we rebound again.

The first half of 2020 was already quite hot—just 0.05
degree Celsius lower than the record set in 2016, according to the National
Centers for Environmental Information in Asheville, North Carolina. The odds
are high 2020 will end up in the top five warmest years ever.

In the last 30 days, 97 all-time warm records were set
around the U.S. with no low temperature marks being posted. In the previous 12
months, 179 warmest records were set to just 12 lows.

The heat in the year’s first half has already had
consequences. It pushed waters in the Gulf of Mexico to record highs in spring,
leading Florida to experience summer-like temperatures in April. It has also
fueled the Atlantic along the U.S. East Coast to warmer-than-normal levels, a
condition made worse in recent weeks as temperatures have soared across North
America. Many daily heat records that fell in the last week were near the
coastline, surprising some meteorologists.

Right now the Atlantic is quite hot. The water off Long Island is 76.3 degrees
Fahrenheit and nearly 73 degrees in Massachusetts Bay
, according to
the U.S. National Data Buoy Center.

“Once a heatwave gets established, it tends to perpetuate
itself because the soil gets drier and drier, which allows it to get hotter and
hotter,” said Jennifer Francis, a researcher at the Woods Hole Research Center.

This is where climate
change is making things worse,
she said. As the planet warms, the
contrast between the heat at the equator and the cold at the pole decreases.
That
saps the strength of the jet
stream,
which otherwise would serve to defuse the heat. The result is a
circular river of winds too weak to move these big ridges of hot air across
continents. Hence, the dome of heat stays stuck for weeks or months.

“Heatwaves are getting hotter, pure and simple,” Francis
said. “It’s one of the most direct symptoms of global warming.”

The intense heat raises the possibility for drought, which
adds to the potential for temperatures to rise even more. Without moisture in
the soil, the sun’s energy is focused on heating the air and not evaporating
water, which just drives up temperatures even more. The cool Pacific water
that’s helping produce the heat is close to becoming what’s known as a La Nina,
which can cause droughts and floods worldwide.

There are silver linings. In the Midwestern crop belt,
blasts of rain during the past few weeks should help alleviate the drought
conditions that have crept up in states including Nebraska, Iowa, Indiana and
Ohio. The rainfall, combined with sweltering heat, should be a boon for crops
like corn, which typically go through the yield-setting pollination phase in
July.

Matt Bennett, a farmer in central Illinois and commodity
analyst at AgMarket.Net, planted his crops in April, earlier than usual,
because of the warm temperatures. “Hot and wet is what you want,” he said.



































































— With assistance by Michael Hirtzer



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