Causes of the Russian heat wave and Pakistani floods

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

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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.

References
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

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2375. KEEPEROFTHEGATE (Mod)
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2370. Patrap


5-years later, 108-year-old Katrina survivor sees progress in city

Lavinia Lundy was 103 when Katrina hit and flooded her home.
Member Since: July 3, 2005 Posts: 420 Comments: 127549
2369. KEEPEROFTHEGATE (Mod)
Quoting ho77yw00d:



yes you are right a lot of blogs do have trolls but ignore them dont quote them just act like they dont exsist because I am just saying that this site is very well used by many!


yes we are many
we are legions
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Quoting MississippiWx:


Lol...Umm...


wth? :/
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Quoting MississippiWx:


Lol...Umm...


I second that...
Member Since: July 6, 2010 Posts: 113 Comments: 31456
2365. xcool
KerryInNOLA:haha
Member Since: September 26, 2009 Posts: 2 Comments: 15620
this is not good

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Tornado Warning

TORNADO WARNING
KYC069-205-150030-
/O.NEW.KJKL.TO.W.0015.100814T2352Z-100815T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE JACKSON KY
752 PM EDT SAT AUG 14 2010

THE NATIONAL WEATHER SERVICE IN JACKSON KY HAS ISSUED A

* TORNADO WARNING FOR...
NORTHEASTERN FLEMING COUNTY IN EAST CENTRAL KENTUCKY...
NORTHERN ROWAN COUNTY IN EAST CENTRAL KENTUCKY...

* UNTIL 830 PM EDT

* AT 750 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
STORM WAS LOCATED NEAR WALLINGFORD...OR 9 MILES EAST OF
FLEMINGSBURG...AND MOVING EAST AT 40 MPH.

* LOCATIONS IMPACTED INCLUDE...
MUSES MILLS...WALTZ AND TRIPLETT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

TO REPORT TORNADOS...LARGE HAIL OR FLOODING TO THE NATIONAL WEATHER
SERVICE...CALL TOLL FREE AT...1...8 7 7...6 3 3...6 7 7 2...WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 3850 8359 3844 8357 3842 8349 3840 8346
3840 8341 3836 8337 3834 8336 3833 8333
3826 8331 3833 8367 3850 8363
TIME...MOT...LOC 2352Z 281DEG 33KT 3840 8354

$$

PELTON




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2359. xcool
scott39 .yeah lol
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Hey Patrap, what's going on with our Low?
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2355. scott39
Quoting xcool:



moveing south ...
That Sat there looks like its trying to develope over land! LOL
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2354. xcool



moveing south ...
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Quoting xcool:


What is that track? A possible disturbance?
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2350. scott39
Quoting xcool:
scott39 .start at 1;30am
thanks
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ho77yw00d..

Very true..
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2347. xcool
scott39 .start at 1;30am
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2346. Patrap
Some needed relief in Moscow tonight.


Current Conditions

Moscow Sheremetyevo, RS (Airport)
Updated: 25 min 15 sec ago
Smoke
64 F
Smoke
Humidity: 77%
Dew Point: 57
Wind: 4 mph from the ENE
Pressure: 30.24 in (Falling)
Member Since: July 3, 2005 Posts: 420 Comments: 127549
2344. scott39
Xcool, When does the next run of ECMWF come out?
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Quoting FLPandhandleJG:


I agree with u mostly but its like this on a lot of blogs now days.. Ur always going to get trolls hate to say it.. But it is still informative like u said.. Thats y we got a ignore button or hide there posts b/c of potential trolls..



yes you are right a lot of blogs do have trolls but ignore them dont quote them just act like they dont exsist because I am just saying that this site is very well used by many!
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2341. xcool
cmc 18z Appear to Act Crazy xxtd5 i meaning very strong storms
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2337. scott39
If this Low gets at a lattitude of about 27n-28n in the GOM and conditions stay favorable. Its going be a little more than a rain event. IMO
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2335. Patrap
Member Since: July 3, 2005 Posts: 420 Comments: 127549
2334. xcool
Member Since: September 26, 2009 Posts: 2 Comments: 15620
Quoting Patrap:
2309. KanKunKid,

Thanx,thats really kind.




NEXRAD Radar
Atlanta, Storm Total Surface Rainfall Accumulation Range 124 NMI



Patrap, can you show a more zoomed out map of the area? Wondering how far east this is moving before dropping southwest if it does. Just got over a rain shower here in South Cent. MS. Also wondering how it will effect track later on.
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2332. Patrap
Quoting IKE:


I finished up this morning.


Good move.
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2331. scott39
Quoting HurricaneDanielle:
Scott, there's an ULL in the GOMEX
You mean that one in the SW GOM on the water vapor Sat Loop? Xcool was saying theres no ULL to blow apart the Low thats going back in the GOM!
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2330. IKE
Quoting Patrap:
Dewpoint-5 has a bead on yas Ike.

Best get the Mowing done this evening.



I finished up this morning.
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2329. Patrap
Dewpoint-5 has a bead on yas Ike.

Best get the Mowing done this evening.

Member Since: July 3, 2005 Posts: 420 Comments: 127549
2327. IKE
Two more days of peacefulness....


TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT SAT AUG 14 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS.

$$
FORECASTER BRENNAN
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2326. Patrap


I can see the Big H from my porch easily to the South

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2325. xcool
scott39 .very strong
Member Since: September 26, 2009 Posts: 2 Comments: 15620

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.