For Colombia, The Rain Bombs of Climate Change Fell in the Dark of Night

As the lower atmosphere becomes warmer, evaporation rates will increase, resulting in an increase in the amount of moisture circulating throughout the troposphere (lower atmosphere). An observed consequence of higher water vapor concentrations is the increased frequency of intense precipitation events… — NASA’s Earth Observatory


Just off the coasts of Colombia, Ecuador and Peru, the Pacific Ocean has been abnormally warm of-late. For the past month, sea surface temperatures have ranged between 3 and 5 degrees Celsius above average. This excess heating of the ocean surface, facilitated by human-forced climate change, has pumped a prodigious volume of moisture into the atmosphere of this coastal region. Southerly winds running along the western edge of South America have drawn this moisture north and eastward — feeding into the prevailing storms that originate on the Atlantic side of South America and track eastwards.

(Sea surface temperature anomaly map from Earth Nullschool shows 4 degree Celsius above average ocean surfaces just off-shore of Ecuadore and Colombia. These extremely warm waters have helped to fuel very severe storms over Peru and Colombia during recent weeks. Such warm ocean waters are not normal and their highest peak temperatures are being increased by a human-forced warming of the Earth, primarily through fossil fuel burning. Image source: Earth Nullschool.)

Lately, these systems have blown up to enormous size as they’ve run across the Andes or collided with pop-up storms along the coast. And the amount of rainfall coming out of the resulting monster thunderstorms has been devastating. In Peru, hundreds of thousands of people have been rendered homeless by these deluges which have caused the tragic loss of 100 souls, destroyed thousands of buildings, 200 bridges, and 2,000 miles of highway. For the state, the estimated damage toll from this ongoing climate disaster is now 6 billion dollars.

Friday night, a member of this new breed of monster thunderstorms, pumped to greater intensity by the moisture bleed off the record warm ocean waters, unloaded a total of a half-month’s worth of rainfall in just a few hours upon the small Colombian city of Mocoa. More than five inches fell in 1-2 hours on a region where three rivers run out of the mountains toward this community of 40,000. The deluge arrived in the darkness. Its ferocious intensity unleashed a massive flood of boulders, mud, and water as the combined rivers leapt their banks and invaded the town. A nearby hillside, unable to retain integrity beneath this merciless assault of the elements, gave way — burying a large section of Macoa in rubble.

(Extremely high atmospheric moisture loading in the thunderstorm system approaching the Macoa region on Friday, March 31 is indicative of global warming’s impact on the Earth’s hydrological cycle. As oceans and lands warm, the rate of evaporation and precipitation increases. This change generates more extreme versions of storms and droughts by increasing the highest peak intensity for such events. Image source: Earth Nullschool.)

Residents caught unawares were forced to immediately flee homes with little more than the clothes on their backs — carrying infants or dragging children in tow as the flood waters swirled around them and as a wall of moving earth, uprooted trees and large rocks tore through town. Many escaped, but an estimated 254 residents were not so lucky and are now counted among those lost to the raging torrent and landslides.

President Juan Manuel Santos declared the city a disaster zone Saturday even as relief workers searched for survivors in the rubble and as make-shift shelters and hospitals were set up to aid the injured and displaced. According to CBC:

Santos blamed climate change for triggering the avalanche, saying that the accumulated rainfall in one night was almost half the amount Mocoa normally receives in the entire month of March. With the rainy season in much of Colombia just beginning, he said local and national authorities need to redouble their efforts to prevent a similar tragedy (emphasis added).



More Than 200 Killed in Colombia Flood — Swept Away as They Slept

Desperation Sets in as Flood Death Toll Tops 200

Damages Mount in Peru Floods

Earth Nullschool

NASA’s Earth Observatory

Hat tip to Colorado Bob

Hat tip to Zeebra Designs

Mangled Jet Stream, River of Moisture Set to Deliver Extreme Flooding to Mississippi Valley

The potential rainfall totals for a broad region centering just west of the Mississippi River Valley are absolutely extraordinary. For even a strong spring storm, this event may hit unprecedented levels. It’s the kind of abnormal event we’ve now come to expect in a world driven 1 C + warmer than 1880s levels by a merciless burning of fossil fuels that just won’t quit.


Mangled Jet Stream Aims River of Moisture at Central US and Gulf Coasts

Over the past few weeks, a record warm El Nino has been slowly cooling down in the Equatorial Pacific. One of the top three strongest events on record, this particular warming of sea surfaces in the Pacific coincided with never before seen global heat as atmospheric CO2 levels spiked to above 405 parts per million on some days during February and March. The record warm sea surface and atmosphere held a never before seen excess of water vapor and moisture in suspension — primarily over the Equatorial Ocean zones. And as the world hit peak temperatures during early March and began to back off a little, some of that massive excess of moisture was bound to wring out somewhere.

For such events, all you really need is a trigger. And over the past two days, forecast models have been predicting an insane dip in the Jet Stream. Today, we got it. A raging storm track over the Northeast Pacific roared its 200+ mph upper level winds down over the Western US and Mexico. It drew deep from a rich, record global warming intensified, low Latitude moisture flood as its tail end reached all the way to the Equator itself. This insanely deep trough then turned north, aiming an unprecedented atmospheric moisture flood fire-hose style at the storm-tossed airs above the Mississippi River Valley.

Huge Dip in the Jet Stream March 8

(An extreme dip in the Jet Stream stretching through the Western US and all the way to the Equator is aiming both Pacific and Gulf moisture at the Mississippi River Valley today. The severe storms that are now firing and that are predicted to continue over the next three days may result in an unprecedented flooding event. Image source: Earth Nullschool.)

Severe storms are now firing off along a line stretching from the Gulf Coast to Nebraska. Coastal flooding, gale force winds, severe thunderstorms, tornadoes and hail are all expected as part of what can best be described as an epic storm system. But perhaps the most dangerous feature of the whole event is the severe rainfall totals that are expected to accumulate over the next three days.

Foot of Rain or More over Mississippi River Valley in the Next Three Days

Rain that is expected to be extraordinarily intense and long lasting. Reports from the Weather Channel indicated the risk for rainfall rates in the range of 3 inches an hour in some of the heaviest storm cells. Meanwhile, model runs earlier today indicated a potential for as much as 20 Inches of rain for some regions over the next 72 hours. Official NOAA models are now indicating nearly a foot in peak rainfall regions in Eastern Texas and Western Louisiana with the potential for greater than five inches along a broad swath running from the Gulf Coast through to Illinois.

72 Hour rainfall totals NOAA NCEP

(NOAA predicts very extreme rainfall totals over a broad region of the Mississippi River Valley during the next three days. Image source: NOAA’s Weather Prediction Center.)

According to NBC news reports, more than 15 million Americans are falling under risk of flooding from this very severe weather system. One that has been compared with the South Carolina floods of 2015 due to its potential to produce severe rains. But one that is also much wider in coverage — capable of impacts over a far broader region.

In addition, those flooding rains will fall all over the Mississippi River Valley — resulting in an extreme threat of very severe flooding all along this great river and its tributaries. As such, we are likely to be dealing with a flood situation for many days after the initial rain event tapers off. With Spring on the way, with so much moisture still bleeding off the Pacific, with a record level of global warming greatly amping up the hydrological cycle, and with a trough development tendency setting up for this region — this particular extreme rainfall event may, sadly, be but the first of many this season.


Earth Nullschool

NOAA El Nino

NOAA’s Weather Prediction Center

The Roof is On Fire

Models Predict Big Jet Stream Dip

National Weather Service Radar Loop

National Weather Service Alerts Map

The Weather Network

The Weather Channel

Texas, Oklahoma and Louisiana Face Drenching, Possible Tornadoes

Hat Tip to DT Lange

Hat Tip to Anthony Sagliani

World Food Security in the Cross Hairs of Human-Caused Climate Change: Mangled Jet Stream, Ocean Heat and Melting Sea Ice To Deliver 500 Year Drought to California? Brazil, Turkey, Australia and More to Follow?

California snow pack January 18 2013California snow pack January 18 2014

(California Snow Pack for January 18 2013 vs the California Snow Pack for January 18 2014. Note the near-zero snow cover for this drought-impacted region. Image source: NASA/Lance-Modis)

“We are on track for having the worst drought in 500 years.” — B. Lynn Ingram, professor of earth and planetary sciences at the University of California, Berkeley.

Remember the historic drought that swept the US in 2011-2013? It was the worse drought in 50 years for some areas. Thankfully, the blocking pattern, excess heat and evaporation that set off this drought and that almost ran the Mississippi River dry abated and lessened, shifting westward and, instead delivered wave after wave of wet and stormy weather to the Eastern US.

Not so with the American West. There the high amplitude Jet Stream pattern remained, keeping regions locked in warm, dry conditions throughout the winter of 2012-2013, on through the end of 2013 and into the early months of 2014.

Looking further back, it was not just these years that had delivered dry weather to the US West Coast. California, ground zero for the current climate change related emergency, has endured dry, hot weather ever since the Pacific Decadal Oscillation (PDO) went negative ten years ago suffering drought years with almost bi-annual frequency.

Now, as Dr. Ingram notes above, California is currently ramping up to its worst drought in 500 years.

A long emergency for California

We only have to scratch the surface for the symptoms of systemic climate crisis in California to crop up. California water authorities failed to honor contracts for the first time in 54 years. Sacramento, as of December was experiencing its worst drought in 130 years even as conditions continued to worsen through January and February.

According to the New York Times, as of February 1rst, 40,000 people were at risk of losing access to water within the next 60 to 120 days. And State officials warned that this number was likely to rapidly rise as The State Water Project announced on January 31rst that it did not have enough water to supplement the fading supplies of local providers to a total of 25 million customers. Meanwhile, State emergency planners were laying out contingencies that included shipping water over land by truck to parched communities.

The drought is also having a devastating impact on local farmers with about 1/3 of California’s farmland expected to lay fallow, at least 25,000 farm laborers expected to be laid off work, and agricultural businesses expecting losses to mount into the tens of millions of dollars. Already, livestock owners in both New Mexico and California, unable to support their animals, have been forced to sell, as fields that used to support four foot high grass are brown and cracked.

Tim Quinn, executive director of the Association of California Water Agencies noted:

“I have experienced a really long career in this area, and my worry meter has never been this high. We are talking historical drought conditions, no supplies of water in many parts of the state. My industry’s job is to try to make sure that these kind of things never happen. And they are happening.”

Climate change, climate change, and climate change

Far flung and dynamic changes to the Earth System appear to have resulted in a variety of factors that have amplified the California drought. First, increasing global temperatures have amped up the rate at which water evaporates into the atmosphere by about 6%, this increased rate of evaporation results in more extreme conditions when heat and dryness do occur. So a drought that may last a year is likely to be even more intense, due to enhanced evaporation, than a comparable drought that occurred 50 or 100 years ago.

In addition, loss of sea ice, snow, and permafrost plays a key roll in re-shaping the Jet Stream. According to Dr. Jennifer Francis and other polar researchers, receding sea ice cover is likely to result in more powerful and long-lasting Rossby Wave type blocking patterns. This happens as more heat becomes concentrated in the polar regions, causing the Jet Stream to meander in great swoops and whirls. These large waves can become fixed into blocking patterns for extended periods. In the up-slope of these waves, warmth and heat predominate. In the trough or down-slope, stormy, wet and cool conditions prevail.

And just such a blocking pattern has dominated the US West Coast for 11 months running. The result is extraordinarily intense dryness, even during the rainy season of November through March.

PNAS drought model US southwest

(Image source: PNAS)

Sadly, according to climate models, we can expect this kind of dryness to intensify over the US Southwest as human caused global warming grows more extreme. A report conducted by PNAS in 2010 and authored by Seager and Vecchi confirmed other model findings that the US Southwest would continue to dry as the climate warmed — the upshot being that the wet season for the West would eventually evaporate.

Above, the PNAS drought model shows evaporation beginning to increase during the first two decades of the 21rst Century. Then, by about decade 2, precipitation rates rapidly fall and evaporation rates gradually rise through to 2100. The red line shows the compounding effects of evaporation increase and precipitation decrease over 24 separate climate model essays.

Rossby wave over West Coast Weakens

(Rossby Wave over West Coast Weakens. Image source: University of Washington)

It is worth noting that on a positive, and slightly hopeful, note, the current blocking pattern over the US West Coast and related Pacific Ocean waters has weakened somewhat. This should allow some moisture to flow into the parched west over the coming days and weeks. And, in the forecast, we do see a proper storm or two emerging from this new pattern. Unfortunately, we’d typically expect about 20-30 storms of this kind during a typical winter season and with March bringing in the end to this year’s rainy season, along with the northward retreat of the moisture flow, it appears likely that California will have to endure at least another 6 months of dry conditions before seeing any hope of major storms returning next fall/winter. A remote potential to say the least given both long-term trends and current conditions.

‘Like a microwave on full blast drying the Earth:’ drought, drought, and more drought

Dr. Kevin Trenberth, one of the world’s premier climatologists, in an email to Joe Romm recently noted:

“The extra heat from the increase in heat trapping gases in the atmosphere over six months is equivalent to running a small microwave oven at full power for about half an hour over every square foot of the land under the drought. No wonder wild fires have increased! So climate change undoubtedly affects the intensity and duration of drought, and it has consequences.”

Under such conditions, we would expect both drought and wildfires to proliferate. And, in fact, this is exactly what we are seeing. As major wildfires impacted both California and Arctic Norway during winter time, Brazil, Turkey, China, Argentina and Australia were also all experiencing some of their worst or most intense droughts on record.

In Brazil, the least rain in two decades is spurring a cattle sell-off that would be very familiar to livestock farmers in California and New Mexico. The expected summer rains did not come and Brazil, a heavily meat-dependent nation was left with soaring food prices after the sell-off as stocks first surged, then plummeted. The epic drought for this region is also causing a number of other impact such as coffee shortages and a related reduction in hydro power as rivers run dry.

Nearby Argentina also saw severe drought-related shocks in recent months as a December drought inflicted serious harm upon Argentina’s corn crop. In a typical year, Argentina produces about 32 million tons of corn. But this year’s drought is estimated to have wiped out about between 7 and 14 million tons of the crop. Argentina is the third largest producer of corn and with the US revising estimates down for its 2013-2014 crop, supplies of the grain are being drawn ever-lower. Though very intense, the December drought had abated by mid-January, providing a respite for other crops such as soybeans.

In Turkey, Lake Sapanca, which provides water for hundreds of adjacent farms, was within a half meter of ‘dying’ as a combination of drought and water drilling had pushed the lake to its limits. Local farmers have, for decades, drilled the land to provide irrigation water for farms and livestock. Now, the drilling is sapping the lake bed. A period of drought had, as of late January, left the lake in such a state that local officials were claiming the lake would be dead after another half-meter fall. The lake which is nourished both by springs and ground water has been deprived of flows both by human climate change induced drought and by human drilling into the lake’s spring-bed.

In Australia, drought conditions are now worse for some locations than at any time since 2003, a tall order since the 2003 to 2009 drought was Australia’s worst in 1,000 years. For Sydney, that means the lowest rainfall totals in more than 70 years. This particular drought hit both hard and fast with Australia seeing normal conditions before Christmas, but after, very intense heat and dryness resulted in a rapid scorching of farmlands, crops, and grazing fields. The dire drought situation has resulted in government relief funds being released to affected farmers. NSW Minister for Primary Industries, Katrina Hodgkinson noted to the Sydney Morning Herald:

“Seasonal conditions are now deteriorating at a rapid rate across a large portion of NSW and both the severity and speed at which this drought is moving is astonishing. Primary producers in some parts of NSW have simply not had the opportunity to prepare for another severe downturn in seasonal conditions so quickly after the Millennium drought broke.”

Lake Poyang May 2014Lake Poyang Jan 2014

(A mostly full Lake Poyang as seen from Satellite on the left during May of 2012. A parched and almost completely dry lake Poyang as seen from Satellite during January of 2014. Image source: NASA/Lance-Modis.)

And, in China, the largest lake for that populous nation has now dried up. Poyang, a massive lake usually spanning 3,500 square miles has been turned into a sprawling field of earth parched and cracked by a combination of drought and water diversions resulting from the construction of the Three Gorges Dam. According to reports from The Guardian and Chinese News Sources, a drought stretching from 2012-2014 in the region of Poyang is now the worst in at least 60 years leaving lake refill almost non existent as upstream river flows to the lake were periodically cut off by water storage operations at the Three Gorges Dam. The result was an extreme lowering of lake levels and dry bed conditions that have driven farmers and fishermen in the region out of business.

Implications for world food security

Major droughts during 2011-2012 impacted many of the world’s primary agricultural basins, resulting in forward food supply dropping to as low as 72 days. Since that time, food supplies have slightly recovered but are well below previous levels last seen in the 1990s at 104 days. Food insecurity and failure to distribute food to the malnourished remains a priority at international agencies like the UN which has identified numerous countries including Cameroon, the Central African Republic, Somalia, Syria, Mali, Sudan and Nigeria, among others, as extreme risks for hunger and famine. Relief agencies have allocated billions of dollars to address this problem but the UN continues to identify climate change as a major threat to global food security with the potential to wipe out all previous progress moving forward.

The droughts in California, Turkey, Australia, China, Argentina and Brazil so far for 2014 put the world at risk for another bout of food insecurity later this year should major weather and climate related crop disruptions emerge in other primary food producers such as the bread baskets of the US, Russia, and Europe (The US, Brazil, China, Russia, and Europe are top food producers). It is worth noting that, in large part due to the ongoing southwestern drought, the US has revised a number of its crop projections downward for end 2014.

With polar amplification playing havoc with the Northern Hemisphere’s weather systems, with Australia sitting in a pool of expanding warm Pacific Ocean water that makes drought more likely there, and with the Eastern Pacific edging closer to La Nina, conditions warrant a continued monitoring of both weather and the state of world food supplies. The added global heat engine also impacts soils and crop growth in ways to which we are currently unaccustomed, resulting in more extreme instances of flash drought as well as flash flood. In this respect, the examples of Australia and Argentina are of particular concern.

Though global crisis has not yet returned, it lurks at the edges as drought, extreme weather and over-use of ground water supplies continues to threaten a wide swath of productive zones. So, at this point, the situation is one best described as tenuous with ongoing regional impacts over the Sahel region of Africa and in other sporadically vulnerable locales.


Historic Drought of 2011-2013

August 2013: Hottest Ocean Surface Temperatures on Record Defy ENSO, Spur Continental Deluges

Blended Land and Sea Surface Temperatures2

(Image source: NOAA)

ENSO, the global regulator for, generally, how much heat the world ocean system dumps into the atmosphere, remained on the cool side of neutral for much of August 2013. Ocean surface temperatures in the Eastern Equatorial Pacific remained 1 to 2 degrees Celsius below the 1981-2010 average for most of the month. In a normal year, such departures would tend to depress both global ocean and land surface temperature averages. But, for the world’s global oceans and related land atmospheric system, all was well outside the range of normal.

For beyond the Eastern Equatorial Pacific, most of the world’s oceans ranged from .5 C to up to 4 C hotter than average. A particularly hot region dominated an area east of Shanghai in the Pacific bordering China, Japan and the Korean Peninsula. The hot surface water extended under the powerful influence of an anomalous heat dome that brought dangerous 100-110+ degree (F) temperatures to these countries throughout much of August. This hot zone stretched eastward across the Pacific and on toward the US west Coast — a vast swath of water measuring 2-4 C hotter than the 1981 to 2010 average for much of the month.

These anomalously hot conditions outside of the region normally responsible for governing ocean temperature trends resulted in global ocean temperatures tying 2009 for the record high of .57 degrees Celsius above the global average. But 2009 was an El Nino year. With the Eastern Pacific remaining rather cool, one has to wonder what the hell is going on? Everywhere but in the Eastern Pacific, the ocean surface appears to have heated up. The more rapidly spinning gyres and the greater rate of up welling aren’t doing their usual job of cooling down both the ocean surface and the Earth’s atmosphere. For August, record hot ocean surface temperatures pushed global averages higher. Should ENSO switch to hot under such conditions — prepare for world temperature records to start dropping like dominoes.

Land-Ocean 4th Hottest on Record

All that said, It appears the huge volume of water vapor dredged up from the record hot oceans had done its work in marginally cooling off the continents. Heat pumped huge volumes of ocean water into the atmosphere where it formed powerful storm systems that, during event after event, dumped record amounts of rain. In deluge after deluge, regions saw 100, 200, 500 and even 1000 year floods. The most recent, in Colorado, resulted in thousands of homes lost, tens of thousands displaced, and yet one more major disaster response effort from the US federal government. The US inundation was mirrored this summer by events in the Amur region of Russia and China, massive rainstorms spurring a deadly glacial outburst flood event in India, record floods in Canada, immense floods in Europe, major floods in Pakistan, and a consistent set of record floods striking the central and Eastern US. If we hadn’t also seen major floods in 2009 and 2010, we could call 2013 the year of the flood. Others are calling such events ‘the new normal.’ But normal it is not.

All this rainfall over the world’s continents appears to have resulted in land surface temperatures ‘only’ in the range of 11th hottest on record with land surface temperatures at .62 C hotter than the 20th Century average (NOAA/NCDC). These record hot temperatures combined with all time hot ocean temperatures to make August 2013 the 4th hottest in the 134 year climate record.

Ocean Heat/Moisture Dump Showing Up in Sea Level Record

Whenever the oceans heat up, we begin to see evaporation and rainfall rates rising. Record flood events over the Continents is just one visible effect of this heightened rate of evaporation. It is now also starting to show up as large cyclical dips in the rate of sea level rise. Note the start of this volatile shark tooth pattern in the graph, provided by AVISO, below:

Pace of Sea Level Rise Since 1992

Pace of Sea Level Rise Since 1992

(Image source: AVISO)

In the above graph we can clearly see the large counter-trend drop in sea level during the major flood events of 2010 (See “It Rained So Hard The Oceans Fell“). Subsequent very rapid sea level rise from 2011 to end 2012 easily made up the difference, keeping ocean rise on the 3.19 mm per year track its been following over the past couple of decades. By 2013, a similar ocean to atmosphere to land-mass water dump became again visible in the sea level charts. Observed major flood events throughout 2013 provide a final corroboration of this massive and volatile amplification of the water cycle.

Looking Ahead

The Ocean-Atmosphere-Cyrosphere system appears to be moving into a period of wider and more powerful fluctuations. The hydrological cycle, primarily governed by the pace of ocean water evaporation and rate of rainfall, is receiving larger moisture dumps from heating seas. As such, it is beginning to encounter periods of extreme rainfall during major evaporation years. Record ocean heat, a primary driver to this amplified and erratic hydrological cycle, is increasingly occurring outside of the typical pattern of hot El Nino and cool La Nina cycles. The fact that we have record ocean warmth during an ENSO neutral pattern that is leaning toward cool is yet one more out of boundary condition and should be cause for serious concern.

Any return to El Nino conditions will likely result in larger volumes of heat transferred from Ocean to atmosphere. With global temperatures testing new limits even as the Equatorial Pacific remains cool, we can only surmise that any new return to ENSO will result in another leap to record hot conditions.


National Climate Data Center Global Analysis: August 2013

AVISO Global Sea Level Analysis

It Rained So Hard The Oceans Fell

Drought, Burning Rings of Fire out West, Severe Flooding in the East: How Climate Change and a Mangled Jet Stream Wrecked US Weather

Earlier this summer, I had a weather conversation with my mother. She was excited about a new business venture my sister had undertaken (Adventure Kayaks) and for an upcoming trip to Yosemite in August to celebrate her and my father’s 45th wedding anniversary. She wondered about the weather, hoping it would be a good summer for both the new business and the trip. Without thinking too much, I said:

‘Rain, cooler weather, and storms in the east, drought, heat and fires in the west.’

Immediately after saying this, I felt reticent. Perhaps I shouldn’t have spoken? Maybe I would scare my mom. What good would it do to ruin her enjoyment or her looking forward to both the trip and to my sister’s potential success?

It’s worth noting that, thankfully, the storms and cooler weather that did emerge with fury and flood in the east did not ruin my sister’s kayaking venture (although it did result in numerous interruptions both during spring and throughout summer). Should a tropical storm or hurricane make landfall on the US east coast this August, September or October, however, the devastation could be vast, perhaps exceeding a 1 billion dollar disaster event (more on this below).

But as my mother boarded her plane to California and a potential date with Yosemite yesterday morning, these were the satellite images I was looking at:

Yosemite Fire NASA Earth Observatory

Yosemite Fire NASA Earth Observatory

Image source: Earth Observatory

The vast Rim fire that had grown to consume over 192,000 acres as of today was steadily devouring the western border of Yosemite. You can see it on the above infrared satellite picture provided by NASA as a ring of bright white steadily inching into the indicated yellow border of Yosemite.

Jennifer Francis, Stu Ostro and How I Knew

Earlier this summer, my mother chided me on my ‘attempts to predict the weather.’ In a phone conversation last night, she asked ‘how did you know?’

It’s fair to say that in the overall prediction of more storms and rains in the US east, with more risk of flooding, and more heat and dryness out west, with more risks of fire, that I wasn’t entirely certain. However, I’d recently read the work of climatologist Jennifer Francis and had been listening to and following the statements of Stu Ostro. During early spring and summer, I observed a Jet Stream pattern setting up over the US that appeared to be settling into a ‘stuck position’ that would result in the high likelihood of the conditions I communicated with my mother. It’s worth noting that in looking at these Jet Stream patterns it’s not difficult to make such predictions because the patterns change slowly, they lumber and tend to remain stuck for long periods. Once a pattern settles into place, it’s a good bet that it will stick around for at least a few months these days, a fact that the models nail but which meteorologists, in general, have failed to communicate. In short, this is a climate change driven change in the weather.

In fact, some meteorologists and climatologists seem entirely reticent to accept this new weather pattern, despite the fact that it is a powerful tool for weather prediction and will tend to result in less surprises. The big troughs equal record floods sticking around for a long time and the big ridges equal record heat, drought, and probably fires sticking around for long periods of time.

In an example of this reticence, a recent paper by a University of Colorado researcher concluded that Jennifer Francis did not have enough evidence to support her claims of an observed slowing in the Jet Stream. Unfortunately, the paper included, as a part of its findings, a cross section of the atmosphere in which the Jet Stream does not typically reside even while the paper included a sample during which changes were already occurring, which would have likely biased its results. Despite these biases and errors, where the paper actually did measure Jet Stream flows, it corroborated Francis, showing Jet Stream slowing during the periods measured. This is odd considering the fact that the concluding statement contradicts the papers own findings, a point which Dr. Francis, herself, provides.

It’s easy to understand why reticence still lives in the science. As I noted above, it’s understandable to feel reticent when being the bearer of bad news. No one wants to be the messenger that gets metaphorically ‘killed.’ But without making use of the clear understanding provided by Francis and Ostro, we will continue to be surprised by extreme floods, storms, fires, heatwaves and droughts that can be easily predicted by simply looking at how the Jet Stream sets up and where it gets stuck. Instead, ‘surprise’ after ‘surprise’ just keeps coming our way.

When Rossby Waves Get Stuck: Changing to a More Radical Jet Stream

Dr. Jennifer Francis has observed that loss of sea ice and snow cover in the Northern Hemisphere has resulted in a slowing of the Jet Stream in recent years. Sea ice volume, the measure of total ice in the Arctic Ocean, since 1979 had declined by as much as 80% when measured at its low during 2012 (this measure may rally back to around 75 to 78 percent lower than 1979 this year, but the overall trend remains a death spiral). Greenland melt is unprecedented at 500 gigatons per year and with Arctic heatwaves blasting the tundra both permafrost and snow cover are at record and near record lows. 80 to 90 degree temperatures now often advance to the shores of the Arctic Ocean, with the coldest air pushed back above the 80 degree north latitude line, confining it to a shrinking region that, increasingly, huddles closer to the remaining large ice sheets in Greenland. Overall rates of warming for much of the Arctic are about .5 degrees C temperature increase each decade, more than twice the global average.

A more quickly warming Arctic results in changes to the atmosphere’s heat balance. According to Francis, the height of the atmosphere over the Arctic is rising relative to atmospheric heights in the lower lattitudes, this loss of slope results in lower gradients from north to south and since temperature, atmospheric height and pressure gradient drive Jet Stream speed, the Jet Stream slows down. And as the Jet Stream slows, it tends to seek out the highest gradients it can find. The result is more northward invasions of the polar region of the Jet Stream ridges and more southward invasion of the Jet Stream troughs. This amplification creates a rather large and elongated sine wave called a Rossby wave pattern.

Jet Stream Pattern Change. Image source: NOAA.

Jet Stream Pattern Change. Image source: NOAA.

In the sequence above, we see the progression of a flat Jet Stream to a Rossby wave ridge/trough configuration to, eventually, cut off lows and highs. In the past, such waves tended to set up for briefer periods, extending for days or weeks before returning to the usual, more flattened motion of the Jet. In more recent years, large Rossby type waves have been the typical pattern, one that transitions to cut off lows before it returns to a configuration more similar to (b) in the diagram, before setting up as a Rossby-type wave again.

Perhaps more importantly, this b, c, d progression has tended to occur again and again and again over the same geographical region for months and months on end. And, looking back at Jet Stream maps over the past months, this is exactly what we find.

Below is a progression of images I’m providing from this blog’s archive. It includes either direct temperature measures that indicate Jet Stream patterns or a mapping of air flow speed indicating the Jet Stream’s path.

Clover leaf Jet Stream Pattern April, 2013.

Clover leaf Jet Stream Pattern April, 2013.

(Image source: ECMWF)

In ‘For Central US, Climate Change and a Mangled Jet Stream Means Drought Follows Flood Follows Drought’ I described how the Jet Stream pattern had consistently switched from large trough to large ridge configurations over the past few years bringing either heatwaves and droughts or storms and floods. But the left hand portion of the image provides a good record of the Jet Stream configuration as of mid April this year. Following the temperatures, on the west coast we see a large, hot ridge and in the central and eastern US we see a deep, cool and stormy trough.

Wednesday July 3, Rossby wave still in effect over US.

Wednesday July 3, Rossby wave still in effect over US.

(Image source: ECMWF)

Throughout May and into June, this ridge over west, trough over east, pattern continued. By late June, a massive, record-shattering heatwave had set up over the US southwest. I described this highly anomalous event in ‘Mangled Jet Stream and Global Warming to Shatter Earth’s Highest Recorded Temperature This Week?’

Looking at the ECMWF image above we again see the highly exaggerated ridge/trough dichotomy setting up over the US with very hot, dry conditions out west and cooler, wet and stormy conditions in the east.

At this point, I want to tap Stu Ostro’s own observations to add to the Jennifer Francis mix. What Stu has found is that large, powerful high pressure systems have tended to develop more and more often. These extraordinarily dense systems seem to be exploding to new heights in a thickening atmosphere. Primarily, these monsters are driven by heat and so they tend to live in the massive ridges provided by our new, exaggerated and slowed, Jet Stream pattern. That said, these beasts can spring up almost anywhere there is a massive abundance of heat to tap, as one did over a super-heated region of ocean near Shanghai this summer sparking its own monstrous heat wave.

These large heat domes have major and far reaching effects. To understand them, we must first step back to think about the broader effects of human caused warming before looking at how heat domes manifest in the atmosphere. Based on models of the Earth’s atmosphere, we know that for each 1 degree Celsius of Earth temperature increase we get a corresponding 8% amplification of the hydrological cycle. What this means is that evaporation happens 8% faster and condensation happens 8% faster — OVERALL.

Since 1998, we have observed temperatures that are, on average, .8 degrees Celsius above those seen during the 1880s. What this means is that the hydrological cycle has amplified by 6% over this same time period. Because of this dynamic, droughts are more intense, but rainfall events are also more intense. Yet since the atmosphere is uneven we can expect this 6% amplification to manifest in somewhat more extreme fashion at the locations where more extreme Jet Stream patterns set up.

Mangled Jet Stream Dumps Deluge on US Midwest

Mangled Jet Stream Dumps Deluge on US Midwest

(Image source: California Regional Weather Server)

What goes up must come down. And that massive heat dome over the western US and Canada had been baking moisture out of the soil at unprecedented rates over an extended period from April to August. The moisture injected into the heat dome rose and rose, The high pressure system suppressed cloud formation so the moisture had no where to go but up and out. Eventually, this moisture found the edge of the massive high and spilled over into the storms riding along the Jet Stream trough rushing down from the Arctic Ocean and into eastern Canada and the US (hat tip to Colorado Bob).

The result was multiple flood events starting with the Midwest floods of April, then the massive Canadian floods (Calgary) of June, then the Toronto floods, then the Midwest floods of early August, and lastly the east coast floods of mid to late August. The Calgary floods were the worst ever recorded in Canada, the Toronto floods were the worst recorded for that region, and in the Midwest floods of early August, four months worth of rain fell in just one week.

Monthly rainfall estimates August 2013.

Monthly rainfall estimates August 2013.

(Image source: The Weather Channel)

On 8 August, the time of the second barrage of major Midwest floods this year, we find the Jet Stream in the same elongated configuration with a large northward ridge extending all the way from the southwestern US to the Arctic Ocean and with a deep trough diving back down into the central and eastern United States. As noted above, the mangled Jet Stream delivered its overburden of moisture directly to the US Midwest, dumping four months worth of rain in just one week.

A second pulse of moisture rode far south along this Jet Stream flow to dump massive amounts of rain over the southeastern US about a week after pummeling Missouri. This flow combined with a compromised tropical system to saturate the southeast, with some regions receiving as much as 300 percent their annual rainfall totals by late August.

One of the hardest hit areas is Lake Okeechobee. Water levels there as of mid August hit 16 feet at the Hoover Dike, a level that requires weekly monitoring for cracks or ruptures. The dike stretches over 140 miles along the perimeter of lake Okeechobee and was intended to keep the lake in check during major storms and hurricanes after large outburst events in the early 20th Century resulted in thousands of lives lost. The dike is 25 to 30 feet high and is as wide as a football field. The US Army Corps of Engineers has been working feverishly to shore up the dike in a project that will take years to complete.

At 16.5 feet water level, the dike will require daily monitoring. For each inch of increase above that level, the pressure put on the dike would greatly increase risks of catastrophic failure. The causes of such high water, this year, were neither tropical storms nor hurricanes. Florida has been, thus far, spared the wrath of these strong storms. Deep Jet Stream troughs and a constant Atlantic moisture flow have, instead, resulted in day after day rain events for much of southern Florida, pushing August totals near Lake Okeechobee above 16 inches, filling the massive lake and putting the dikes at risk. Should a hurricane or tropical storm strike Florida during late August, September, or October, the dike could overtop or rupture, unleashing the massive lake on communities sitting beneath it. (Hat tip to Colorado Bob).

As the threat of massive floods continued to increase in the east, the west was erupting with wildfires. Fire containment efforts went into high gear both exhausting the Forest Service Fire budget and briefly pushing the national fire alert level to 5. The Rim Fire, so close to my parents’ vacation site, expanded to 192,723 acres today making it the 6th worst in California history.

Rim Fire on August 28th, 2013

s Rim Fire on August 28th, 2013

(Image source: Lance-Modis)

You can see this massive fire, now 23% contained, burning to the west of Yosemite in the Modis shot below. A more detailed report of this major wildfire is provided by WeatherUnderground here and here.

Mangled Jet Stream Temporarily Edges Eastward

My parents wanted to see Yosemite’s amazing waterfalls. A major source of my reticence in telling them the likely pattern for this summer was that the heat and drought out west would probably dry out many of those magnificent falls. And, sadly, this has happened. So even if they brave the smoke and fires to reach Yosemite, the one attraction my mom had been most excited to see will likely be somewhat less magnificent.

But a cloud has suddenly appeared in this wrinkle. For the Jet Stream had edged slightly east.

As of the middle of last week, reports of heatwave conditions had emerged throughout the US Midwest with North Dakota, South Dakota, Nebraska, Illinois, Wisconsin, Iowa, Minnesota and Missouri experiencing temperatures in the range of 20 degrees (Fahrenheit) above average. With heat index values hitting as high as 110 degrees, communities sweltered and school systems declared closings. In California, where temperatures had remained in the upper 90s to lower 100s for much of summer, the trough advanced, pushing temperatures back down to the 70s. An upper level low flirting with the west coast may even toss a few fog clouds and rain showers toward California. Such an event would be a welcome change for both my parents and for beleaguered fire fighters in the region.

In any case, the shift is expected to be short lived with ECMWF models showing the Jet Stream again backing up and reforming a hot and dry ridge pattern over the US west. So the Midwest can expect cooling and a return to more stormy, rainy conditions while the US west, after only a brief respite, continues to bake:

Mangled Jet Stream Early September

(Image source: ECMWF)

The September 7 ECMWF forecast again shows a large and powerful Rossby-type wave pattern with a very large and hot ridge setting up over the US and Canadian West with a deep trough digging down toward the US East Coast. It is the same pattern we’ve seen since at least April, a pattern that has delivered numerous rounds of heat and drought to the US west and an equally vicious and persistent pattern of storms and flooding from the central US to the east coast. The Jet Stream has, essentially, been stuck these past 5 months and there is no end in sight. For even if this configuration of the Jet were to move, it would likely simply re-distribute the locations of heatwaves and droughts and storms and floods.

If anything, this past summer has been yet one more validation in evidence of the work of Dr. Francis. And it is because of her work that I, a relatively untrained observer, can make the accurate prediction that a large region from the Mississippi west to California will continue to stay hot and dry and will continue to see risk for large fires, while the region to the east will remain cooler and stormier so long as the current Jet Stream configuration continues to persist. The western region will risk periods of record heat, continued drying of lands, rivers and aquifers, and fires of record size. The eastern region will continue to risk record floods and storm events. As summer proceeds to fall, shifts in these weather patterns have the potential to grow violent with the possibility of powerful nor-easters or hybrid storms developing near the US East Coast. Both the southeast and Florida remain very vulnerable to continued large rain events or tropical storms and hurricanes as time moves forward and in the event of pattern persistence. Meanwhile, long range model forecasts show this general pattern continuing to persist until at least early to mid September.

At this point, the current US Jet Stream pattern will have been in place for at least 6 months.




Arctic Heat Wave Re-Intensifies Over Central Siberia Setting off Rash of Tundra Fires

Siberian Fires July 23

Large fires break out over Siberia during renewed Arctic heat wave.

(Image source: NASA)




Over the past week, temperatures have been building throughout Central Siberia. A broad swath of heat pushed thermometers into the upper 70s to upper 80s (with isolated spots showing 90+ degree readings, Fahrenheit) in a broad region stretching from Siberia’s forests all the way to the Arctic Coast. These heatwave conditions set off more than a score of large fires that raged through both Arctic forest and across broad areas of tundra. The largest of these fires covered areas up to 1000 square miles and numerous smoke plumes were visible from satellite, some of which stretched more than 800 miles in length. A larger pall of smoke from this region covered areas of North-Central Russia, the Arctic Coast and sections of Europe more than 2,000 miles away.

You can view these fires and related smoke plumes in the NASA Aqua Satellite image provided by Lance-Modis above.

The scorching Arctic heat wave and massive burning has been set off, once again, by a high amplitude northward bulge in the polar Jet Stream and related ‘heat dome’ high pressure system resting just beneath the bulge. As you can see in the below image, provided by the California Regional Weather Service, this particular heat bulge extends past the 80 degree North Latitude line, nearly reaching the North Pole. This extraordinary upward sweep in the Jet has completely compromised the polar vortex, allowing hot air to build far north and pass deep into the Arctic Ocean environs.

jetstream_northern July 23

(Image source: California Regional Weather Service)

Arctic coastal temperatures usually average less than 50 degrees Fahrenheit at this time of year, but the region beneath this Arctic heat dome has averaged about 15-20 degrees hotter over the past week. Further south, where the tundra fields and arboreal forests of Siberia lay, temperatures have been even warmer with highs stretching into the middle and upper 80s and even lower 90s in some isolated locations. The added heat and the occasional thunderstorm that will typically form under such highly unusual Arctic conditions enhances the chance of wildfires. Now, after a week of such conditions, more than a score of large fires rage.

Siberian Heatwave July 23

Tuesday daytime temperatures for Siberia. Red indicates temperatures ranging from 77-86 degrees Fahrenheit. Note the broad swath of these temperatures riding up from Russia all the way to the Arctic coastline. These measures represent daytime temperatures at the point recorded and do not necessarily record daily maximum temperatures for a given location.

(Image source: Arctic Weather Maps)

Unfortunately, forecasts call for hot conditions to persist over this region of the Arctic at least until Saturday. Then, the heat dome and related Jet Stream bulge is predicted to slowly shift toward Europe, bringing heat, dryness and related risk of wildfires along with it.

This particular heat wave is the most recent of many to plague the Arctic during 2013. Large Arctic regions from Siberia, to Europe, to Canada to Alaska experienced periods of extreme heat where temperatures rose 10, 15, 20 degrees or more (Fahrenheit) above average. The added heat and evaporation in one region appeared to aid in the formation of record floods in another with both Europe and Canada experiencing some of their worst floods on record.

Strange changes to the Jet Stream and the water cycle driving these extreme events are directly related to human-caused global warming. In the first instance, human-caused warming has set off a series of events that have caused a major erosion of Northern Hemisphere sea ice. Since 1979, more about 50% of sea ice extent and 80% of sea ice volume has been lost. Since the 1900s, more than 60% of sea ice extent has melted away. The sea ice, which tends to lock cold air in the Arctic, is thus dramatically weakened. The result is that more warm air tends to pool in the Arctic. As this happens, the temperature difference between the North Pole and temperate regions lessens. This loss of differential causes the Jet Stream to slow down. As the Jet Stream slows, it tends to move more like a lazy river, creating big loops, large high amplitude waves and numerous cut off flows. The net result is that weather systems move more slowly, causing weather patterns to persist over longer periods.

The high amplitude waves that have tended to form in the Jet Stream also result in warmer air being transported toward the North Polar region. In the case of the current Siberian heatwave and wildfires, this is exactly what is happening. What we have seen, this summer, is a ring of very hot conditions developing in the higher Latitude regions from about 60 degrees North to about 80 degrees North. This is the zone where much of the extreme Arctic heating has emerged.

This second factor, added atmospheric heat, causes greater evaporation to occur, especially in regions where the heat is most intense. On average, the global hydrological cycle, which is the net rate at which water evaporates and then comes back to the Earth in some form of precipitation, increases its intensity by 8% for each degree Celsius of warming. Currently, average global temperatures are about .8 degrees Celsius hotter than the 1880s average. So the rate at which water evaporates and the rate at which it falls from the skies as rain and snow has increased by more than 6%. In the hot regions under the Jet Stream bulges and related heat dome high pressure systems this means far more intense soil drying and risk of wildfires. In the wet regions of cut off lows and down-slopes in the polar Jet Stream this means more intense rainfall events.

In essence, this is how human caused global warming is helping to drive extreme weather events now. And the current Siberian heatwave and related wildfires is just one case in point.



California Regional Weather Service

Arctic Weather Maps

The Arctic Heat Wave, Heat Domes, and a Mangled Jet Stream

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