Causes of the Russian heat wave and Pakistani floods

By: Dr. Jeff Masters , 2:56 PM GMT on August 13, 2010

The Great Russian Heat Wave of 2010 is one of the most intense, widespread, and long-lasting heat waves in world history. Only the European heat wave of 2003, which killed 35,000 - 50,000 people, and the incredible North American heat wave of July 1936, which set all-time extreme highest temperature records in fifteen U.S. states, can compare. All of these heat waves were caused by a highly unusual kink in the jet stream that remained locked in place for over a month. The jet stream is an upper-level river of air, between the altitudes of about 30,000 - 40,000 feet (10,000 - 12,000 meters). In July over Europe and Asia, the jet stream has two branches: a strong southern "subtropical" jet that blows across southern Europe, and a weaker "polar" jet that blows across northern Europe. The polar jet stream carries along the extratropical cyclones (lows) that bring the mid-latitudes most of their precipitation. The polar jet stream also acts as the boundary between cold, Arctic air, and warm tropical air. If the polar jet stream shifts to the north of its usual location, areas just to its south will be much hotter and drier than normal. In July 2010, a remarkably strong polar jet stream developed over northern Europe. This jet curved far to the north of Moscow, then plunged southwards towards Pakistan. This allowed hot air to surge northwards over most of European Russia, and prevented rain-bearing low pressure systems from traveling over the region. These rain-bearing low pressure systems passed far to the north of European Russia, then dove unusually far to the south, into northern Pakistan. The heavy rains from these lows combined with Pakistan's usual summer monsoon rains to trigger Pakistan's most devastating floods in history.

Figure 1. Winds of the jet stream at an altitude of 300 millibars (roughly 30,000 feet high). Left: Average July winds from the period 1968 - 1996 show that a two-branch jet stream typically occurs over Europe and Asia--a northern "polar" jet stream, and a more southerly "subtropical" jet stream. Right: the jet stream pattern in July 2010 was highly unusual, with a very strong polar jet looping far to the north of Russia, then diving southwards towards Pakistan. Image credit: NOAA/ESRL.

What caused this unusual jet stream pattern?
The unusual jet stream pattern that led to the 2010 Russian heat wave and Pakistani floods began during the last week of June, and remained locked in place all of July and for the first half of August. Long-lived "blocking" episodes like this are usually caused by unusual sea surface temperature patterns, according to recent research done using climate models. For example, Feudale and Shukla (2010) found that during the summer of 2003, exceptionally high sea surface temperatures of 4°C (7°F) above average over the Mediterranean Sea, combined with unusually warm SSTs in the northern portion of the North Atlantic Ocean near the Arctic, combined to shift the jet stream to the north over Western Europe and create the heat wave of 2003. I expect that the current SST pattern over the ocean regions surrounding Europe played a key role in shifting the jet stream to create the heat wave of 2010. Note that the SST anomaly pattern is quite different this year compared to 2003, which may be why this year's heat wave hit Eastern Europe, and the 2003 heat wave hit Western Europe. Human-caused climate change also may have played a role; using climate models, Stott et al. (2004) found it very likely (>90% chance) that human-caused climate change has at least doubled the risk of severe heat waves like the great 2003 European heat wave.

Figure 2. A comparison of the departure of sea surface temperature (SST) from average just prior the the start of the great European heat waves of 2003 and 2010. Temperatures in the Mediterranean Sea were up to 4°C above average in 2003, which has been implicated as a major cause of the Western European heat wave of 2003. Image credit: NOAA/NESDIS.

Feudale, L., and J. Shukla (2010), "Influence of sea surface temperature on the European heat wave of 2003 summer. Part I: an observational study", Climate Dynamics DOI: 10.1007/s00382-010-0788-0

Stott, P.A., Stone, D.A., and M.R. Allen (2004), "Human contribution to the European heatwave of 2003", Nature 432, 610-614 (2 December 2004) | doi:10.1038/nature03089. (Here is a free version of the paper, presented at a conference.)

The World Meteorological Organization (WMO) has posted an analysis of the recent extreme weather events, concluding, "the sequence of current events matches IPCC projections of more frequent and more intense extreme weather events due to global warming."

See also my posts, The Great Russian Heat Wave of 2010: 102°F in Moscow and, Over 15,000 likely dead in Russian heat wave; Asian monsoon floods kill hundreds more.

Moscow sees real relief from the Great Russian Heat Wave of 2010
For the first time in more than a month, temperatures at Moscow's Domodedovo airport failed to exceed 30°C (86°F) today. Clouds and thunderstorms blew into the city this morning, keeping the high temperature down to just 29°C (84°F). This breaks a string of 35 straight days when the temperature reached 30°C. At Moscow's official observing site, the Moscow Observatory, this string was 30 days. Moscow's average high temperature for August 13 is 20°C (68°F), so today's temperatures were still well above normal. However, today's cool-down marks the beginning of the end for Russia's great heat wave. The latest forecast for Moscow calls for high temperatures below 30°C for the coming week, and Moscow may not exceed that threshold for the remainder of summer. Long range forecasts from the ECMWF and GFS models continue to suggest that a series of troughs of low pressure will attack the ridge of high pressure anchored over Russia, bringing cooler temperatures just 5°C (8°F) above average to Russia late next week. By ten days from now, the ECMWF model shows a strong trough of low pressure over Moscow, and a end to the Great Russian Heat Wave of 2010. Moscow still has to concern itself with smoke from the wildfires burning southeast of the city; winds are expected to shift early next week and bring the smoke towards the city again. However, the cooler weather should aid fire-fighting efforts, so the smoke problems should not be as bad as last week's nightmare.

Figure 2. Image from NASA's Aqua satellite of smoke from wildfires burning to the southeast of Moscow yesterday, August 12, 2010. Northerly winds were keeping the smoke from blowing over the city. Image credit: NASA.

The tropics are quiet
The remnants of Tropical Depression Five continue to bring heavy rain to portions of Southeast Louisiana today. Up to five inches of rain has fallen in regions near New Orleans. The GFS model predicts that the remains of TD 5 could move off the coast of Mississippi by the middle of next week and regenerate, but none of the other models is making this forecast. Both the GFS and ECMWF models are predicting that a tropical storm will develop off the coast of Africa by next Friday, August 20.

Donations urgently needed in Pakistan
The devastation wrought by the worst flooding in Pakistan's history requires a huge response by the international community. Wunderblogger Dr. Ricky Rood, author of our Climate Change Blog, has a friend working in Pakistan who underscored the desperate situation there:

This is the worst natural disaster in the history of Pakistan in terms of number of people and area affected. Although not as many people have been killed as in the 2005 earthquake, we have already nearly 900,000 displaced persons thus far just in Khyber Pakhtunkhwa. Crops are destroyed; shops, hotels, and other business have simply been swept away in Swat, which had just this year been cleared of Taliban and was on the way to recovery; and districts closer to Peshawar and parts of Peshawar district are still, or perhaps again after yesterday/today, under water. After the immediate emergency response, it will be years of rebuilding to replace what has been lost and to start to develop again. I know you have the power to control the weather, so if you cold give us a week or two without more rain at least we could keep the helicopters flying and give people a chance to go to their homes, recover what might still be there, set up tents if we can get enough to them, and start to clean up."

She gave the following recommendations for charities that do work in the flood-ravaged zone, and are effective at getting aid to those who need it the most:

Doctors Without Borders

The International Red Cross

MERLIN medical relief charity

The mobile giving service mGive allows one to text the word "SWAT" to 50555. The text will result in a $10 donation to the UN Refugee Agency (UNHCR) Pakistan Flood Relief Effort.

She mentioned that it is better to send money to the organizations doing the relief work than to try to organize shipments of goods.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

Sign In or Register Sign In or Register

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 2075 - 2025

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

2071. xcool

Member Since: September 26, 2009 Posts: 2 Comments: 15707
Sorry St. Simon....nice lighthouse.
Member Since: Posts: Comments:
http://www.nrlmry.navy.mil/tcdat/tc10/WPAC/91W.INVEST/shear/20100814.1800.gms-6.shear.wind.cimss.x.jp g

Pretty high shear in the Western Pacific. This could be the reason for the strange lack of activity.

(The buttons for adding URLs, Images don't appear in Chrome!)
Member Since: Posts: Comments:
2067. xcool


cv storms
Member Since: September 26, 2009 Posts: 2 Comments: 15707
2066. xcool

18z NAM
bit strong
Member Since: September 26, 2009 Posts: 2 Comments: 15707
Quoting StSimonsIslandGAGuy:

We got a shower around 1:30 with 0.31" at our house. But the heavy rains are organizing and staying to my north as well. They may head back down this way tonight as the front oozes closer.

Member Since: Posts: Comments:
Quoting gulfcoastdweller:
can you guys give me your thoughts on XTD5 coming back into the Gulf?

What was left of it this morning was near Auburn drifting toward Atlanta, and has since dissipated into an area of broad, balmy, humid, sultry and downright unpleasent area of tropical low pressure. As to regeneration in the Gulf......I've written it off, regardless of what the models suggest.
Member Since: Posts: Comments:
Quoting CybrTeddy:

I'm not even that lucky. :-(
ECMWF 12z 240 hours.

Member Since: Posts: Comments:
2057. Patrap
fxus64 kmob 141904 aaa

Area forecast discussion
National Weather Service Mobile Alabama
200 PM CDT Sat Aug 14 2010

Aviation [14/18z]...overall VFR conditions will dominate through the
forecast period. Vicinity showers and thunderstorms and tempo groups
through early evening. Brief IFR/MVFR visibility conditions and
variable winds up to 15 knots are possible in and near the
thunderstorms. The convection will dissipate by late evening...with
VFR conditions prevailing the remainder of the night. /22

*** previous discussions ***

Short term [today and tonight]...low level circulation associated
with former td#5 northeast of Montgomery this morning where radar
imagery shows convection flaring up in that area. New rain showers activity
has recently developed further west over Monroe County Alabama and east
of Jackson MS suggesting a weak low-level convergence axis exists
across central Alabama. As low-level circulation drifts east-northeast and away from the
mob County Warning Area this afternoon...anticipate afternoon convection to become
rather disorganized and short-lived. This should result in less
coverage than yesterday especially given that best moisture has
shifted north of the area into central Alabama. Expect convection over land
to wane quickly after sunset with nocturnal showers expected over
the coastal waters.

For Sunday through Monday night...a consensus of the
GFS/ECMWF/Gem/NAM/UKMET moves the remnant surface low of td5
southwestward across the northwest Florida Panhandle and into the
northwest Florida coastal waters through Sunday night then westward
across the Alabama coastal waters through Monday. A system well to
the north brings a trailing front into the southeast states
meanwhile which will stall north and west of the region. The GFS is
the slightly stronger member of the group but with good agreement
otherwise the consensus looks reasonable and have increased
confidence in how this will play out...the net result of which is
higher probability of precipitation for the forecast area. Will follow along the trend from
the dayshift and increase probability of precipitation a bit more on Sunday with likely probability of precipitation
for much of the area save the northwest portion...then likely probability of precipitation
for the coastal counties Sunday night and Monday with chance probability of precipitation
inland. Copious amounts of tropical moisture remain over the area
during the period...with the highest values of precipitable values
near 2.9 inches shifting from southeastern Alabama southwestward
across the southern portion of the forecast area through Monday
night. This extreme deep layer moisture portends continued
potentially high rain rates through the period...especially over the
southern half of the forecast area during the daytime where the best
deep layer lift will be present. The risk of flash flooding
continues to depend on the strength of the surface low set to track
across the near shore waters...which is still sufficiently in
question to hold off on a Flash Flood Watch at this point...but this
will need to be closely monitored on subsequent shifts. HPC quantitative precipitation forecast
looked reasonable and was used through the period. Muggy conditions
and warmer temperatures over the western portion of the area on
Sunday will result in heat indices of 104 to possibly 108 which will
need to be monitored as well. /29


Long term [tuesday through friday]...a blend of the GFS/ECMWF/Gem
moves the system northward into Louisiana Tuesday into Wednesday.
Will keep probability of precipitation in the chance range during this period but with
higher probability of precipitation over the western half of the area where more deep
layer moisture and convection associated with the departing system
will be present. For Thursday into Friday see a return to more
typical convection although abundant deep layer moisture will still
be present over the area. Will have chance daytime probability of precipitation with slight
chance probability of precipitation at night. Temperatures will be near seasonable levels
through the period. /29

Member Since: Posts: Comments:
2056. will45
Quoting gulfcoastdweller:
can you guys give me your thoughts on XTD5 coming back into the Gulf?

only thing i can say is it has a lot of model support
Member Since: July 18, 2009 Posts: 1 Comments: 1093
Member Since: Posts: Comments:
Quoting will45:
Good job guys on flagging and reporting the troll. Thats the only way to handle it.

Most of us know who it is. Doesn't matter if you flag him though, he'll just be back with a new handle tomorrow.
Member Since: Posts: Comments:
2048. will45
Quoting aquak9:
hi will! yes I am doing my job as a responsible paying member of the WU community. :)

Good for you puppy :-)
Member Since: July 18, 2009 Posts: 1 Comments: 1093
2047. aquak9
hi will! yes I am doing my job as a responsible paying member of the WU community. :)
Member Since: Posts: Comments:
Quoting StormSurgeon:

It's healthy to push one's self away from the computer now and then. I'm watching the PGA Championship myself.

True....I need to work on my blog anyways.
Member Since: July 2, 2009 Posts: 0 Comments: 2811
2045. will45
Good job guys on flagging and reporting the troll. Thats the only way to handle it.
Member Since: July 18, 2009 Posts: 1 Comments: 1093
Afternoon...I see the 12Z run of GFS takes those 2 systems out to sea, un like the 06 run that had one near eastern florida...I guess itll flip flop from run to run especially since nothing has formed yet.
Member Since: Posts: Comments:
2042. aquak9
it's just like fishing!

SSI- you are probably gonna get some good rain. We on the other hand...oh never mind. You know how that story ends.
Member Since: Posts: Comments:
Gettin pounded here by XTD5 in Macon lol.. 3 trees hit by lightning so far

Member Since: Posts: Comments:
2039. xcool
Member Since: September 26, 2009 Posts: 2 Comments: 15707
Quoting TexasHurricane:
I guess everyone is taking a tropic break. Blog seems to have slowed down...

It's healthy to push one's self away from the computer now and then. I'm watching the PGA Championship myself.
Member Since: Posts: Comments:
Quoting TexasHurricane:
Still odd to see this at this time of year.....

That will change soon
Member Since: June 1, 2010 Posts: 0 Comments: 82
Another system drifting south over the Gulf Stream?

Member Since: Posts: Comments:
I guess everyone is taking a tropic break. Blog seems to have slowed down...
Member Since: July 2, 2009 Posts: 0 Comments: 2811
Still odd to see this at this time of year.....

Member Since: July 2, 2009 Posts: 0 Comments: 2811
Quoting StSimonsIslandGAGuy:
Hey Teddy, how are ya? One good thundershower here at 1:30 and looks like more on the way.

I'm not even that lucky. :-(
ECMWF 12z 240 hours.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Member Since: July 2, 2009 Posts: 0 Comments: 2811
2025. scott39
Quoting TexasHurricane:
XTD5 wants a name this time. Will see
Member Since: Posts: Comments:

Viewing: 2075 - 2025

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

Top of Page

Dr. Jeff Masters' WunderBlog


Dr. Masters (r) co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

JeffMasters's Recent Photos

Afternoon clouds over Southwest Puerto Rico
Storm clouds gathering over Half Dome
Sierra snow
snowman at Yosemite Falls