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Posted at 03:31 PM ET, 03/22/2012

Epic March heat wave in Midwest, Great Lakes and Northeast: link to global warming?


Top: Massive heat dome over eastern North America at 8 a.m. March 22. Bottom: Satellite image showing low pressure over Midwest to eventually kick heat dome out. (Wright Weather-top, University of Washington-bottom, via Stu Ostro )
For more than a week, dozens of towns and cities in the Midwest, Great Lakes and Northeast have smashed, obliterated and demolished warm weather records - sometimes on multiple consecutive days.

Meteorologists and other weather commentators have frequently commented they’ve never seen anything like this, exhausting superlatives*.

Well-known global warming advocate Bill McKibben put it this way on Twitter: “I know I’m a little obsessed with this heat wave--but: it’s not just off the charts, it’s off the wall the charts are tacked to.”

In some cases, records highs have been destroyed by more than 30 degrees, and even morning low temperatures have bested previous record highs.

In Marquette, MI, Wednesday’s record-crushing high was 81 compared to the old record of 49, which even the morning low of 52 topped. The same day Grand Rapids, MI scored its all-time record temperature departure (for highs) soaring to 87, 40 degrees above normal.

The typically conservative National Weather Service isn’t mincing words in describing this heat. From the blog ClimateSignals:

When low temperatures are the same as previous record highs, “that’s incredible — to me, that’s just mind-boggling,” said Mike Halpert, deputy director of the National Oceanic and Atmospheric Administration’s Climate Prediction Center.

Today, Chicago, hit 80 for the 8th time in 9 days and set its 9th record high in as many days. The 8 80+ days this month matches the record for most 80+ days in April! The waters of Lake Michigan are warmest on record (since 1980) in March according to NOAA’s Great Lakes Environmental Research Laboratory.

The National Weather Service forecast office in Chicago posted this reaction:

It is remarkable enough to watch longstanding all-time record temps be threatened . . . but the total scope (duration and intensity) of this warm spell is something that has [been] historic and [is] unlikely to be matched in our liftetime

Some of the heat into New England is equally shocking. University of Utah meteorology professor Jim Steenburgh offered the following commentary on records set in Vermont and Maine Wednesday:

Burlington, Vermont hit 81. Their old record for the date was 68. Bangor, Maine reached 83! 83 in Maine in March, are you kidding me? Their old record was 64.

The heat has been equally if not more impressive in eastern Canada. Wunderground’s Jeff Masters blogged (bold indicates added emphasis):

Not only was yesterday the warmest March day in recorded history for many of Canada’s major cities, it was also warmer than any April day at many locations. St. John, New Brunswick hit 25.4°C (78°F.) Not only did this crush the record high for March (previous record: 17.5°C), it is well above any temperature ever measured in April (extreme April temperature on record: 22.8°C.) Halifax, Nova Scotia hit 25.8°C yesterday, beating their all-time March record of 25.6°, and their all-time April record of 26.3°C, set on April 30, 2004.

Weather Channel senior meteorologist Stu Ostro, who has documented many examples of extreme weather in recent years, told me he is “freaked out by some aspects of this.”

Wunderground weather historian Christopher Burton told his colleague Masters “it’s almost like science fiction”

Connections to global warming?

We know this overall extreme weather pattern is a result of abnormally huge ridge in the jet stream over Eastern North America which has remained stationary for days.

But with so many records being broken by such large margins and for so long - what can we say about any connection to global warming?

There are a range of perspectives.

University of Utah’s Jim Steenburgh is convinced global warming has a role in this.

Welcome to the new climate in which heat waves are pushing farther outside the envelope of what has been observed previously during the historical record. .... I’m usually very cautious about linking weather events to global warming as there is considerable natural variability in the system, but these are jaw-dropping records and such events are more likely today than 60 years ago.

Related link: NASA scientist Hansen warns “climate dice” already loaded for more extreme weather

The Weather Channel’s Ostro shares a similar perspective:

While natural factors are contributing to this warm spell, given the nature of it and its context with other extreme weather events and patterns in recent years there is a high probability that global warming is having an influence upon its extremity.

Related link: Global Warming May Have Fueled March Heat Wave Odds (Andrew Freedman, Climate Central)

AccuWeather’s meteorologists are somewhat more reluctant to connect the dots. Consider these two opinions:

“You need more data to prove global warming,” AccuWeather senior Meteorologist Brett Anderson said. “In only one season, you really can’t link it.”

and...

“It may well be that the state of the ocean water temperature surrounding North America is just in an ideal arrangement to maximize warmth over North America.” [AccuWeather Meteorologist Jim Andrews]

While the configuration of weather systems made this heat wave possible, I favor the viewpoints of Ostro and Steenburgh that global warming contributed to its intensity. The background increases in greenhouse gases - at levels unprecedented in at least 800,000 years - are stacking the deck for more extreme heat events such as this and we have observed increases in average and extremely high temperatures.

Skeptics may point to relatively cool weather elsewhere across the globe at the moment or even unprecedented snow recently at low elevations in Oregon . But the cool weather on the flip side of this massive heat dome in the Western U.S. hasn’t even come close to rivaling the heat’s intensity. Compared to 3,550 warm weather records set in the U.S March 12-18, there were a piddling 18 cold weather records according to the National Climatic Data Center.

The truth is, in recent decades, we seldom experience cold events that come close to matching the intensity of warm weather events. The increase in atmospheric heat-trapping gases is the most compelling explanation for this discrepancy.

(*Oft-used descriptions for this stretch of uber warm weather have included: Mind-boggling, eye-popping, unthinkable, unreal, unbelievable, astonishing, unfathomable, historic, unprecedented, crazy, insane, mutant, incredible, amazing, stunning, unheard of, surreal, remarkable, jaw-dropping, etc)

Related blog posts:

Exceptional March heat wave re-writing history in Midwest, Great Lakes and Northeast (from Wednesday)

Mind-boggling warm weather records swell in Midwest, Great Lakes, Northeast (from Tuesday)

Midwest, Great Lakes basking in unprecedented warm weather for March (from Monday)

Back door cold fronts kick heat out of mid-Atlantic, Great Lakes (from Friday)

Historic record warm weather brings summer to central and eastern U.S. (from Thursday)

Greenhouse gases and global warming activate the steroid era of our atmosphere

By  |  03:31 PM ET, 03/22/2012

 
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