Reluctant El Nino; Climate changes affecting power plants ability to generate?

68F high temp at MSP at 2:59pm Tuesday

68F average high temp at MSP for September 25th

60s again Wednesday

70s return later this week into the weekend

80F possible in southern Minnesota (and the metro) by next week

0" rainfall forecast for most of Minnesota through at least October 3rd

El Nino defies forecasts so far this fall - details below

ClimateCast: Heat wave & drought of 2012 affecting power plants generating capacity -story below

MSP quick look forecast:

Source: Twin Cities NWS

Dead on average:

So this is "average" weather!

Tuesday's high of 68 was dead bang on average for September 25th. If you're wondering what September 25th is supposed to feel like, now you know.

There was actually a pretty strong north to south temp gradient across Minnesota Tuesday. I saw 48 in Grand Marais, and 73 in Fairmont...a difference of 25 degrees.

Source: University of Utah

Warming trend resumes Thursday:

We'll (enjoy?) one more "coolish" day Wednesday with highs again in the 50s north & 60s south.

The next warming trend kicks in Thursday and builds into the weekend. Temps should crack 70 by Thursday & Friday, and mid-to upper 70s will return this weekend. This looks like one of the best weekends of fall shaping up...so plan to enjoy accordingly.

Source: Twin Cities NWS

Warm southwest breezes and late early October (did I just type "October?") sunshine will boost temps toward 80 degrees again as October kicks off on a warm note early next week.

Source: Iowa State University

Wanted: Rain

The milder return to summer like weather for the first full weekend of fall is nice, but comes against a backdrop of deepening drought in Minnesota.

Looking at the medium range models reveals little hope for a good soaking rain anytime soon. The GFS is cranking out a big goose egg for model output rainfall through at least October 3rd.

Source: NOAA

There are some signs a low pressure system could sweep into Minnesota with decent rains next Thursday or Friday.

Source: College of DuPage Weather Lab

Stay tuned on that one.

Reluctant El Nino?

I've talked about the potential (and CPC forecast) for a developing El Nino this winter. Indeed an "El Nino Watch" continues.

But so far tropical Pacific Sea Surface Temperatures (SST's) have been slow to warm.

Source: NOAA/CPC

In fact, some areas have actually cooled slightly in the past 30 days.

Source: NOAA/CPC

Most CPC "dynamic & statistical" models had forecast warming in September. That forecast warming is behind schedule at this point.

El Nino winters show about a 70% statistical bias toward milder than average winter temps in the Upper Midwest. It's not a slam dunk in an El Nino year...and this El Nino has yet to fully develop.

The safe and easy play so far is to suggest that this winter will be milder than average in Minnesota, but probably not as mild as last year. There are still several "plates" spinning that drive seasonal climate... to so speak. We need a little more data on AO, PDO, ENSO evolution etc etc. before we can make a reasonable (but far from certain) outlook that may have some actual value.

Look for the Weather Lab "Winter Outlook" in mid-late October.

Source: Climate Central

ClimateCast: Climate Change affecting power plants access to "cooling water?"

Climate changes seem to be exposing many previously "unthinkable" scenarios.

The record heat wave and drought of 2012 appears to have exposed a significant flaw in the amount of "cooling water" is delivered to many power plants in the USA & Europe. Lower water levels, and warmer water temps make it more difficult to rely on adequate cooling after for both nuclear and coal fired plants.

Image: U.S. Department of Energy

Low water levels and "overheated water" actually limited generating capacity or completely shut down power plants at times this summer.

The story from Andrew Freedman at Climate Central.

During the scorchingly hot and dry summer of 2012, low water levels and hot temperatures forced several power plants in the Midwest and the East to curtail their output or cease operating altogether for a time. The drought that reached its peak during late summer has been the worst to strike the U.S. since the 1950s, and comparable in some ways to the Dust Bowl-era droughts of the 1930s. Climate projections show that drought conditions as well as heat waves are expected to become more intense and frequent in coming decades as the climate continues to warm.

This past summer there were several instances when power plants had to shut down after running into water temperature thresholds. For example, the Millstone nuclear plant in Waterford, Conn. had to partially shut down in mid-August because the waters of Long Island Sound had become too warm to cool the plant, a development that plant operators had never encountered before.

In July, the New York Times reported that the Braidwood Generating Station, a nuclear plant about 60 miles southwest of Chicago, had to be granted a special waiver to continue operating after the water it was taking in for cooling purposes hit 102°F, two degrees above the legal operating limit for the plant.

And according to an article in the Washington Post, the Illinois Environmental Protection Agency also granted special exceptions to four coal-fired power plants, along with three other nuclear plants this summer, in order to allow them to discharge water that exceeded water temperature limits.

When power utilities have to shut down plants or reduce generating capacity unexpectedly for any reason, it can create power disruptions during peak need and raise electricity costs as provider may have to unexoctedly buy more expensive power on the spot market.

I used to work in Chicago for a weather firm issuing specialized weather forecasts for Braidwood and other ComEd power facilities. Back in those days, low water levels or water that was "too warm" never presented a problem.

Climate changes are increasingly testing many of the "climate assumptions" that were the foundation for engineering much of our society.

PH