Drought is again expanding over the US West. Oregon, after a very rapid April and May snowmelt, is being advised to conserve water. And with high pressure building in over the Southwest, weather models are predicting the emergence of an extreme heatwave by late this weekend. One that current guidance is indicating will bring 100 to 120 degree (F) temperatures to a wide region stretching from California’s Central Valley, through Southern California, Northwestern Mexico, Arizona, Nevada and into Southern Utah.
(The US is expected to swelter under a heat dome that is predicted to form this weekend and expand on into next week. Record heat is predicted to first impact the US Southwest before building into the Central US by late next week. Image source: NCEP/NOAA.)
The trigger for what may become a record-shattering heatwave is the predicted development of a powerful atmospheric ridge. Model guidance now shows a strong high pressure system currently over the Northeastern Pacific extending its influence eastward over the coming days. By the middle of next week, most of the US is predicted to fall under the atmospheric sway of a big bully of a high pressure system centered over the Southwestern States. Spiking atmospheric pressures and clear skies are expected to then usher in record temperatures for much of the US Southwest.
For parts of California’s Central Valley near Fresno, temperatures could rise as high as 116 F by Wednesday of next week (June 21). That’s about 23 degrees (F) above average for this time of year and would beat the hottest reading ever recorded in any month for the city. The same day prediction for Sacramento is in the range of 110 F — a little shy of the all-time record, but a reading that would shatter the June 21 daily record by a good margin.
110 degree + readings are expected to blanket Southeastern California, Sections of Northwestern Mexico, Southwestern Arizona, and Southeastern Nevada. Near 100 degree readings are expected to extend as far north as Redding, California. In other words, a huge section of the Southwestern US is expected to experience Death Valley like weather conditions.
(Record heat is predicted to blanket most of the Southwest US by next week. This graphic shows predicted peak daily temperatures on Wednesday, June 21. Image source: Pivotal Weather.)
This kind of record heatwave is something one might have expected during an extreme year of the 20th Century in July. But what we’re seeing is its potential to emerge now in mid-to-late June. An indication that record global atmospheric temperatures are starting to have some rather serious regional impacts along the lines predicted by various Global Circulation Models. These models indicated a particular vulnerability of the US Southwest to extreme heat and drying under the atmospheric forces set off by human fossil fuel burning. And this predicted heatwave is building up in an atmospheric context in which global temperatures will likely be around 1.2 C hotter than 1880s averages during 2016.
In this context, the potentially building record heatwave threatens to greatly expand and reassert drought conditions in the US Southwest this Summer. Should it emerge as models are currently predicting, it will greatly increase soil moisture evaporation and remaining snowpack melt across the region — amplifying drought conditions in over a region where many had hoped a strong El Nino would stave off these kinds of climate change related impacts for at least another few years. And for these reasons along with the direct risks of heat injury to human beings, interests should closely monitor its development.
Links:
Quick Oregon Snowmelt Dampens Water Outlook
Hat tip to DT Lange
Hat tip to Colorado Bob
Sheri
/ June 14, 2016I livein Phoenix. Lived here most of my life and haveseen us get hotter and hotter slowly over 50 plus years. Wehavehad these high temps every few years for a stretch of days but these temps are going to run past the weekend and these are pushing the envelope of our highest temperatures. We also get our highest temps in June but who says we’re not going to have more of these heat waves this summer.
The areaof this heat wave is really scary. I have feared ezactly this kind of heat coming as climate change happened.
Thanks so much for your blog, Sheri
robertscribbler
/ June 14, 2016Warmest regards to you, Sheri. Stay safe. Let’s hope it’s not as bad as predictions now forecast.
robertscribbler
/ June 14, 2016For reference, the average June high for Phoenix is 102, for July it’s 104:
http://www.rssweather.com/climate/Arizona/Phoenix/
Miep
/ June 14, 2016120 predicted in Phoenix next Monday.
climatehawk1
/ June 14, 2016Tweet scheduled.
Jacob
/ June 14, 2016Off-topic, but still, I think, related to the southwest.
The trend being that it’s getting hotter (everywhere, but for the purpose of this comment particularly in the southwest) and that the water level of Lake Meade is descending. Barring the unforeseen the trend suggests less water in the future and not more. Now there is talk of an NFL franchise moving to Las Vegas and also an NHL expansion franchise being awarded to the city. As I understand it the city is stretched to the limit as it is. How are one or two professional sports franchises going to work if there is not enough water to support them, let alone enough water to support the rest of the “permanent” local and tourist populations?
Some people or organizations don’t seem to be living or operating in the real world to be entertaining such thoughts as a long term viability.
I live in the central valley of California near Sacramento and I am concerned about our water availability as well. In one of the strongest El Nino years on record we’ve received barely normal precipitation. One cannot help but be wary of what the future is going to bring.
With that in mind, short of mass migration away from these regions, or the occasional short-lived deluge, and as ridiculous as it sounds: I can only envision an as yet theoretical massive desalination and fresh water transportation infrastructure could ever possibly sustain any populations of the size that currently exist out here. One powered by an equally massive solar power infrastructure. Even someone with limited vision as I can see that something of the like will be necessary, even if only to support a population that is vastly reduced from what exists in these regions today.
wili
/ June 14, 2016“Some people or organizations don’t seem to be living or operating in the real world” I would expand that to most of the population.
robertscribbler
/ June 14, 2016Solar condensers, desalination, and mass migration are probably all in the very near future. If you look at the problem from the perspective of climate change resiliency, you’ve got to greatly increase water conservation efforts while making choices not to add water hogs to your infrastructure. If you replace a big portion of power generation with renewables like wind and solar, then you also have a dramatically reduced water demand coming from the power sector.
I think the Southwest will probably, and unfortunately, need desalination and possibly solar condenser stations. But all the states involved should also be looking very seriously at various conservation measures as well. Closed loop systems with underground storage are probably going to start cropping up in these drying regions.
Sheri
/ June 14, 2016NHL and NfL in Vegas???? THAT is insane with what is happening there. We have amateur hockey leagues here in metro Phoenix and they’re ice time for games and practice runs 24 hrs during their season and i think that is insane. Of ourse, if you want unreality Vegas is a great place for it! It is like a giant, giant amusement park these days. And they really only have one source of water that is Lake Mead.
Sheri
Genomik
/ June 15, 2016My guess is they will dam the California delta and build solar desalination plants and pump freshwater backwards up into river systems which can also be diverted to Central Valley and Southern California. Also a similar thing can happen in Baja where Colorado river once dumped in ocean. Lastly they will eventually need to build a dam under Golden Gate Bridge to prevent flooding.
Many don’t know this but Around 1848 before California was settled and the delta was diverted for Ag and consumption the delta was a giant swamp. Hot and humid mosquito infested and hot. That’s why rice can grow there. Things have changed dramatically there since then. Most of the swamps have been diverted, levees, farms and cities built. I don’t recall area but pretty large.
https://en.m.wikipedia.org/wiki/Sacramento%E2%80%93San_Joaquin_River_Delta
robertscribbler
/ June 15, 2016With sea level rise, Central Valley is a flood risk. California is at risk of becoming a diked-in desert.
dtlange
/ June 14, 2016USA West Coast: The offshore flow signals the ridge setting up.
Exposing the Big Game
/ June 15, 2016Reblogged this on Exposing the Big Game.
Spike
/ June 15, 2016SE Europe faces heatwave conditions in few days
robertscribbler
/ June 15, 2016Great catch here Spike. Big dust storm on the way as well.
Spike
/ June 15, 2016Last night in my bit of central UK we were woken by the noise of rain – quite the most intense and torrential sudden downpour I’ve ever seen which lasted perhaps half an hour. The road outside was running like a river. There was pretty widespread flooding in Birmingham area yesterday as large amounts of rain fell in an urban environment with little soak up capacity.
Nothing compared to what has happened in Europe of course, and I see more warnings from Estofex for the next few days.
robertscribbler
/ June 15, 2016Sounds like a mini rain bomb.
Europe seems to be smashed between so many weather influences with climate change. Melting Greenland, warming Arctic, and the Sahara attempting to move north. It’s a real hot spot for very extreme conditions.
Thom Foote
/ June 16, 2016We own a 10 farm, with 1 acre fenced, in a pine forest north of Spokane (20″ of precip/yr). We grow culinary and medicinal herbs and sell locally and to our co op. This year I am putting all of my growing beds in drip and finally have a small (8k gallon) pond full and non-leaking. I have covered the pond to prevent evaporation losses. Water storage is going to be the key element in my farming efforts coupled with low pressure drip irrigation. I am trying to prepare for a future of earlier runoff and melt.
dtlange
/ June 16, 2016That’s good planning. Make every drop count.
Good luck to you.