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‘Drunken’ Weather Pattern Leads to Deadly Heat

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The heat wave that has built across the eastern U.S. — roasting cities from Memphis to Washington to Boston in a stifling blanket of heat and humidity — has had one strange characteristic that meteorologists cannot yet explain in a long-term climate context. Rather than moving west to east, as typical weather patterns do in the Northern Hemisphere, weather systems across the country have moved in the opposite direction, like a drunken driver on a dark stretch of highway, drifting from east to west during the past two weeks.

And like drunk driving, the weather pattern is having serious —  even deadly — consequences, with at least one death being blamed on the heat, according to the Associated Press

The "Bermuda high" that often pumps warm and humid air into the East Coast during July and August decamped around July 11 from Bermuda and came ashore, eventually migrating all the way to the Midwest by July 15. The summertime high pressure ridge, sometimes referred to as a “heat dome,” has set air pressure records as recorded by weather balloons in Pittsburgh and Virginia, and has been responsible for sending air temperatures rocketing into the mid- to upper-90s, and even the lower triple digits, in some parts of the East.



Animation of 500 mb pressure anomalies from July 12 to July 18, 2013, showing the migration of the heat dome from east to west (in orange and red) and the upper level low toward Texas (blue). Credit: Ryan Maue for Weatherbell.com.

New York’s John F. Kennedy Airport, for example, broke a daily high temperature record on Thursday, with a high of 100°F. The heat index, which is a measure how the temperature feels to the humid body, has reached the dangerous range of 105 to 115°F in some spots. Heat is the No. 1 weather-related cause of death in the U.S. in an average year.

Making the heat even more dangerous is that many areas affected have not been getting overnight relief. In New York’s Central Park, the overnight low on Wednesday night into Thursday morning was 79°F, tying a record for the highest such temperature for the date. Record-high low temperatures were also set in the Midwest and Mid-Atlantic. Washington, D.C. may challenge a record for the longest number of consecutive hours with air temperatures above 80°F. 

The National Weather Service issued heat warnings and advisories for nearly two-dozen states on Thursday, with a smaller number to be affected on Friday in the densely populated Mid-Atlantic and Northeast.

While heat waves during July are nothing new, the weather pattern that is creating this one is rare enough for meteorologists to take note. In addition to the Bermuda leaving its more tropical locale and camping out in Michigan, an area of low pressure at the upper levels of the atmosphere has also been roaming the U.S. since July 11, drifting from east to west, traveling from the Mid-Atlantic states to Texas, where it brought some welcome rainfall.

With the jet stream (in blue and green) located far to the north, over Canada, weather systems have drifted from east to west across the U.S.
Credit: Weatherbell.com.

The air flow heading in the opposite direction across the U.S. is abnormal, as is the strength of the dome of high pressure. In recent years there have been numerous instances of strong and long-duration high pressure areas that have led to extreme weather events, including the Russian heat wave of 2010. According to NOAA, scientists are scheduled to meet at Oak Ridge National Laboratory in September to explore whether such “monster ridges” of high pressure are becoming more frequent or more intense as the atmosphere warms in response to manmade greenhouse gas emissions.

Jon Gottschalck acting chief of the Operational Prediction Branch at NOAA’s Climate Prediction Center, told Climate Central in an email that it’s not yet clear exactly how unusual the recent weather pattern has been, or what has been driving it. “Yes, the evolution you describe of the upper-level low and high pressure ridge moving east to west is definitely unusual. But it is not easy to quantify really how unusual,” he said.

“It would take considerable time to crunch through the data and utilize a methodology to accurately pick events like this that have occurred in the historical record and quantify [them]. From a climate-forcing perspective, there is no clear climate pattern right now that we can point to as a contributing factor and so we can really only attribute this evolution to natural internal variability, at least at this stage.”

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Comments

By John Corcoran, Jr. (Calabasas CA 91302)
on July 18th, 2013

One of the doomsday scenarios mentioned is the stalling of reversal of the Gulf Sream and other such underwater engines driving weather systems and affecting climate. Any chance this behavior of the Bermuda High and the backward traveling low are canary-in-the-cave early warnings of upcoming shifts?

Reply to this comment

By Lanny Sinkin (San Antonio, Texas 78209)
on July 18th, 2013

“From a climate-forcing perspective, there is no clear climate pattern right now that we can point to as a contributing factor and so we can really only attribute this evolution to natural internal variability, at least at this stage.”  If there is no clear climate pattern, then there is no clear evidence of natural internal variability.  An equally reasonable hypothesis is that climate change has moved from climate instability to climate chaos.

Reply to this comment

By Eric Peterson (Front Royal, VA 22630)
on July 19th, 2013

“...there is no clear climate pattern right now that we can point to as a contributing factor and so we can really only attribute this evolution to natural internal variability, at least at this stage.”

I agree.  Summer circulation patterns are notoriously difficult to predict.  Summer ENSO predictions are practically impossible and downstream responses are all over the map.  Summer responses to CO2 doubling are more difficult than winter as well.  The only prediction that could come into play is Hadley cell strengthening, but the ridge this past week is too far north for that to apply.

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By Hans Berg (San Clemente CA 92672)
on July 19th, 2013

This is all consistent with a weakening jet stream due to considerable warming in the upper atmosphere over the arctic.  Google Jessica Francis at Rutgers jet stream to learn more.

In a nutshell, the jet stream is driven by the difference in upper-air pressure between mid-latitudes and the arctic.  Pressure differences are established by temperature differences.  With the temperature delta shrinking dramatically (MUCH warmer relative to normal in the arctic right now) the jet stream slows and changes from a rushing mountain creek to a meandering river (or “drunken” as described in the article).

This is not complicated; things are out of whack and they are going to get much worse.  The canary is dead.

What are you going to do about it? 

I suggest tuning out the BS and putting positive mental energy into solar and wind power.  Your instinct is correct.  These technologies are now CHEAP, particularly relative to the alternative that is taking us to a scary place.  I sell solar and can assure you it is absolutely ready to go on a massive scale economically. 

Of course, doing so would disrupt the most powerful and wealthy businesses on the planet.  Understand this point clearly; it makes everything make sense.

Godspeed to you and God Bless America

Reply to this comment

By Eric Peterson (Front Royal, VA 22630)
on July 19th, 2013

“With the temperature delta shrinking dramatically (MUCH warmer relative to normal in the arctic right now)”

It is actually much colder than normal in the Arctic, see http://ocean.dmi.dk/arctic/meant80n.uk.php

It is Jennifer Francis and her theory is quite speculative and contrary to mainstream climate science which says that the jet stream will speed up and move poleward.

Reply to this comment

By Camburn (ND)
on July 19th, 2013

There is a growing body of scientific evidence that the sun changes are driving the jet stream.  An example is this:

http://www.sciencedirect.com/science/article/pii/S1364032113003651

Reply to this comment

By MorinMoss (NY, NY 10037)
on July 20th, 2013

@Eric Peterson The graph for the current state in 2013 is tracking the long-term average very closely and looking at day 120 onwards is very similar to the last decade.

Reply to this comment

By Eric Peterson (Front Royal, VA 22630)
on July 24th, 2013

MorinMoss, the average in that graph is from 1958-2002 and represents a variety of climate regimes from cooling in the 60’s and 70’s to warming in the 80’s and 90’s.  Therefore it really is much cooler than normal up in the Arctic.  Click on some other recent years and you will see how much warmer they are compared to the present year.

The broader point is that Arctic warming is nonexistent this year and cannot be blamed for weird weather, but rather the reverse (the cooling is just another facet of weird weather)

Reply to this comment

By Gay Pearson (Falmouth/ME/04105)
on July 24th, 2013

so alot more zonal flow is expected ?

Reply to this comment

By universalspirituality (Terrace Bay,ont p0t2w0)
on July 27th, 2013

I recently read a book Great Waves of Change by Marshall Vian Summers, a real eye opener,, an Amazing read, I encourage others to get this free book and enjoy the read.

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