La Nina has returned

The National Weather Service earlier predicted that the chances of La Nina returning would be 50/50. As mentioned before, La Nina is the abnormal cooling of sea-surface temperatures along the West Coast of South America and the Equatorial regions of the south-central Pacific Ocean. During this event, weather patterns often favor a snowier and colder winter season for much of the northern U.S., including the Inland Empire.

During the heavy snowfall years of 2007-08, 2008-09 and 2010-11, we had a moderate to strong La Nina. Record-breaking snows were seen across the region as Coeur d'Alene had a whopping 172.9 inches snow during the 2007-08 season. A year later, during the 2008-09 season, Spokane had a record-breaking 96.5 inches of the white stuff as La Nina continued to dominate global weather patterns. During a normal winter, Coeur d'Alene sees 69.8 inches of snow while the Spokane International Airport measures 45.6 inches of the white stuff.

Although La Nina years do favor colder and snowier winters across the Inland Empire, not every event has brought the heavy snows to our region. For example, during the La Nina winters of 1967-68, 1970-71 and 1991-92, Coeur d'Alene's snowfall averaged below normal. In the 1967-68 season, only 38 inches of snow fell. Ironically, the next year, 1968-69, a La Nina year as well, 117.8 inches of snow was measured. In 1970-71, Coeur d'Alene picked up 53 inches and in 1991-92, only 36.8 inches of the white stuff fell in the Lake City.

Our winter seasons are certainly influenced by the abnormal warming and cooling of sea-surface temperatures. But, sunspot activity, long-term climate cycles and other oscillations play a role as well. During the heavy snowfall seasons of the last 3 out of 4 years, sunspot activity (storms on the sun) were extremely low. The slight decrease of solar energy may have contributed to the harsh winter conditions of 2007-08, 2008-09 and 2010-11 for our region and many areas across the northern U.S. and southern Canada.

For this upcoming winter, Cliff and I don't believe we'll see as much snow as last year, but totals may be near to slightly above the normal of nearly 70 inches. Solar activity has been increasing at a rather dramatic rate over the last several months. We've seen a number of solar flares from the sun as well. During the La Nina winters of 1967-68, 1970-71 and 1991-92, sunspot numbers were relatively high. The readings during those years are similar to the ones we have today.

From 2008 through much of 2010, the number of sunspots were either near or at zero. Within the last 3-4 months, solar activity has been increasing. We're now seeing average readings near 100 sunspots with a recent high of 173 sunspots on Sept. 16.

During the "peak" of the last maxima in the late 1990s, we were seeing 200-300 solar storms each day. Global temperatures were also at their highest level.

Many scientists suggest that the upcoming maxima will be very strong and may create many problems for power companies, satellites and other electronic devices like cell phones. Others are stating that the upcoming cycle will be so strong that it will effect or even change the Earth's magnetic field. We've already seen a few massive solar flares ejected from the sun that had the potential of causing satellite problems.

Cliff and I believe that the upcoming maxima will be strong, but short-lived. If La Nina intensifies, and solar activity continues to increase again over the next 12-18 months, don't be surprised to hear about more fluctuations of the Earth's temperature, probably to the upside if solar activity becomes stronger. But, on the back side of the solar maxima, global temperatures may start to decrease. Only time will tell.

In terms of temperatures for this upcoming winter, we wouldn't be surprised to see some record-breaking lows with readings well below zero in December or January. During this Cycle of Extremes, when we see above normal temperatures in September, our region often flips to the colder side in the late fall and early winter. Stay tuned for further updates.

NORTH IDAHO WEATHER REVIEW AND LONG-RANGE OUTLOOKS

By CLIFF HARRIS

It's been much cooler across the Inland Northwest in recent days. Afternoon highs, which were near 80 degrees earlier in the month, have slipped into the chilly 50s. Overnight lows, however, have been above the freezing mark due to the thick cloudcover and southwesterly winds aloft.

We've received about a half-inch of rain in the past several days. More showers will arrive locally in North Idaho early this week. It will be somewhat cooler and drier during the Oct. 12-19 "full moon" cycle with scattered frosts in the outlying areas. The last week to 10 days of October into the 'Halloween' period will feature scattered showers and seasonable temperatures.

As I said last week, longer term, if the reborn 'La Nina' cooler than normal sea-surface temperature event in the waters of the south-central Pacific Ocean does indeed gain strength in the next few months as expected, we could see as much as 80 to 100 inches of snow in the Coeur d'Alene area this fast-approaching winter of 2011-12.

But, if we also see increased sunspot activity this winter, our total snowfall would probably dip to around 65 to 70 inches, fairly close to the seasonal normal of 69.8 inches and far less than last winter's nearly double normal total of 121 inches.

CLIFF'S SPECIAL NOTE: My thanks to Randy Mann for filling in for me while I was celebrating my mother Muriel's 95th birthday this past weekend in Bend, Ore.

Cliff Harris is a climatologist who writes a weekly column for The Press. His opinions are his own. Email sfharris@roadrunner.com