Good Afternoon,
Here are a few highlights of what’s going on in the west today.
Temperatures
Mid-C is showing mixed results after virtually every station was trending warm as of last week. The rest of the west is forecasting one or two degrees above normal on average over the next ten days, especially in Montana where Kalispell is four degrees warmer, and Billings set the ceiling at 5.4 degrees above normal.
In a substantial change from yesterday, Denver is no longer expecting a cool down heading into the weekend, but instead will rise further into the 80’s. By June 5th the area should hit a high of 86, ten degrees warmer than what was expected yesterday, and five degrees above normal. Also, showing potential rain each day through the 4th of June, albeit a tenth of an inch at max.
Hot is becoming even hotter in Phoenix as temps rose a couple degrees through the rest of the week compared to yesterday. The 4th is now expected to top out at 106, five degrees above normal and two above the previous forecast. Following a brief drop to the lower triple digits, it appears that Phoenix will then build to the next heat wave beginning on the 10th where temps are currently projected at 107.
Southern California is trending warm as well, now with a weekend forecast sitting 7 degrees north of normal, and upwards of five degrees above yesterday’s forecast (as of the 4th). The warm up looks to be short lived however as temps are expected to comfortably straddle normal for several days after with highs in the upper 70s to finish out the following week.
It’s going to remain mild in San Jose really for the foreseeable future as temps won’t even rise above normal until Monday, but even then, the daily high is expected to reach just 82. In a change from yesterday, the weekend is now looking four to five degrees cooler. That nice spring weather is forecasted through Mid-June as of now, but like always things can change quickly.
Portland’s foray on mild weather came to an end as it’s now expected to stay close to normal until next week. Compared to yesterday, the fourth is seven degrees cooler, though the daily high is still expected to swing 11 degrees above normal by the 6th, with a high of 81.
If you are curious just how hot it was last week in Portland, take a look at the Weather Actuals chart. Those green arrows are pointing to where the current year and the Max converge, in other words where Portland set new ten year highs. Each of those days came within four degrees of the all-time high as well.
It’s cooling off in Seattle and will stay that way through the weekend, especially on the fourth where the high will fall five degrees short of the normal. This cool down comes in as a change from yesterday’s forecast where temps were expected to rise above normal beginning on Friday, instead we see a difference in forecasts of up to seven degrees on the 3rd. We aren’t expecting Seattle to reach the 80’s again for a while, though late next week has a chance.
This actual high temp chart for Seattle shows how quickly the daily highs swung over the past few days. Seattle set a new 10-year high on the 28th at 86 degrees, and just two days later set a new 10-year low for daily highs at 58 degrees.
The Inland Northwest isn’t exempt from the cooldown we are seeing in Portland and Seattle, and it has an even more extreme swing in forecasts compared to yesterday. The 5th is now showing a high of just 67 which would place it five degrees below normal and seven below yesterday’s forecast. This low is sandwiched between two quick spikes in temps, both expected to just touch 80 degrees before falling back to normal.
Kalispell gets one more day of hot weather today with an expected high of 84 before dropping back to normal. The rest of the three-week forecast shows a snake-pattern of normal to 8 degrees above normal, but nothing into the 80’s.
Water Supply
How did the heat wave in the Northwest affect the snow supply? We have the raw data of course, but it can be nice to get some visual examples as well. Credit to Mt. Spokane and Whitefish Mountain for keeping their webcams going well past the end of the ski season, and allowing us to look at a seven-day difference in melt.
Mt Spokane on 5/25:
Mt Spokane on 5/31:
Whitefish on 5/25:
Whitefish on 5/31:
Here are my obvious observations. Mt. Spokane is toast after this week with only a few snow piles remaining. Whitefish (at about 1,000′ higher than Mt. Spokane) still has some decent snow remaining despite the high temps of the past week. Of course, today will likely mark the highest temp of the year so we should see another large dent made into the snowpack of Western Montana.
Grand Coulee spills have sat at 0 cfs since mid-day Sunday after a slowly tapering off beginning on the 18th. Gen peaked at 208,900 yesterday at 1 PM which matched the high from Monday at the same time. This high comes in at 24,000 cfs higher than the two-week average.
We’ll check in on how quickly the reservoir is filling up as it currently sits at 54% capacity. On the same date in 2016, GCL was at 73%, 52% in 2015, and 57% in 2014. In other words, it’s in line with most years, with last year as the outlier.
The largest week on week changes showed up on Dworshak (10.3′), Grand Coulee (10.5′), and Libby (12.7′).
Northwest 10 Day River Forecast
The River forecast will peak at 27,742 aMW, just a hair under STP’s high on the same day at 27,746 aMW. The low is expected on the 4th at 26,838 aMW. Today’s 10-day forecast is a significant decrease from yesterday beginning on the 2nd and moving through the remaining forecast.
Demand
NP-15 loads have plummeted compared to last week, to no one’s surprise. Demand peaked at 12,132 MW yesterday, down nearly 4,400 MW from the high of 16,525 we saw on the 22nd. The year-on year results are even more dramatic as yesterday came in about 6,000 MW below the same day last year.
Despite temps still in the triple digits, demand came off more than 2,000 MW week-on-week as of yesterday in PV. Yesterday also marked the first time we saw a year-on-year decrease in loads since May 19th, though the difference was just 450 MW.
Outages
We saw a bit more gas return online yesterday, 690 MW to be exact. This brings the total return in gas since the 23rd to 3,173 MW. 50 MW of solar returned online yesterday, while hydro added 130 MW of outages and wind a negligible 5 MW.
Transmission
After dropping flow to 1,470 MW mid-day of the 27th, we’ve seen steady increases for three consecutive days, bringing the daily average up from 2,325 MW to 3,104 MW yesterday. This is still well below the daily average of 3,669 MW from one week ago.
The huge swings in flow we saw over the weekend (from -2100 to 1534 in ten hours) have seemed to have subsided, though flows continue to change directions intraday. The current seven-day average sits at -369 compared to the daily average of yesterday at -269.
Have a wonderful week,
William