La Nina is still hanging in there

Editor's note: Randy Mann, a meteorologist who compiles the daily weather page for the Press, and teaches physical geography at North Idaho College, is pinch hitting for Cliff Harris on this week's Gems column.

Sea-surface temperatures along much of the equatorial regions are still much cooler than normal. Since early March, ocean temperatures moderated a bit near the equator, which was giving indications that La Nina, the cooler than normal sea-surface temperature event, was weakening. But, within the last several weeks, ocean temperatures along the South American coastline near Ecuador and Peru have cooled to below normal levels once again.

During our big snow years, including the current 2010-11 season, we had a La Nina that was influencing global weather patterns. During each of those years, 2007-08, 2008-09 and 2010-11, Coeur d'Alene averaged well over 100 inches of snow. Last season, by contrast, we had an El Nino. Ocean temperatures along the equatorial regions were much warmer than normal that resulted in much below normal snowfall totals for the 2009-10 season.

Last month, there were indications that we were perhaps heading toward the beginning of a new El Nino, the warmer than normal sea-surface temperature event. However, with the recent cooling along the South American coastline, it's possible that La Nina may be restrengthening. The Southern Hemisphere is now in its fall season and heading toward their winter in late June, which could continue the cooling process.

Between November of 2010 and mid-January of 2011, La Nina was gaining strength. We still have a weak-to-moderate "La Nina" sea-surface temperature pattern, and, despite some regions of ocean warming, it appears that this phenomenon will be with us through at least the middle of this year. Beyond that point, it's difficult to say.

I still believe that La Nina will slowly weaken over the next several months. If sea-surface temperatures do warm up along the equatorial regions by this summer or fall, then the winter of 2011-12 should not be as snowy as the one we just experienced.

To the northwest of the Hawaiian Islands, ocean waters are still warmer than normal. Whether this trend continues still remains to be seen. One thing is for sure, we're seeing dramatic shifts in sea-surface temperatures in months rather than years.

SOLAR STORMS HAVE RISEN DRAMATICALLY

Solar activity has been increasing on an impressive level over the last several months. From March 25 through March 29, there have been an average of over 100 solar storms, with a high of 132 sunspots on March 27. Since that date, the number of sunspots (solar storms) has averaged between 50 and 80.

Prior to the increased solar activity, we were seeing virtually no sunspots on the sun. It appears that we are certainly heading toward a period of higher numbers of solar storms and toward a new "maxima" as solar flares are increasing as well.

On Feb. 14, 2011, the sun had its most powerful eruption in more than four years. Radio communications in China were disrupted for a short time.

During the "peak" of solar activity in late 1990s, we were seeing 200-300 solar storms each day. The next solar "maxima" cycle is due in late 2012 or early 2013.

Many scientists suggest that the upcoming maxima will be very strong and create many problems for communication systems and electronic devices. If the solar flares were strong enough, damage from the storms could top one trillion dollars.

During periods of high solar activity, we can experience interruptions with satellite communications, which may interfere with GPS and television signals. In Montreal, Quebec, on March 13, 1989, a huge solar flare induced a magnetic storm and completely shut down the Hydro-Quebec power grid that led to widespread blackouts.

Although we are heading toward a period of high solar activity, no one is certain how strong this next 'maxima' cycle will be. Only time will tell.

In terms of our local weather, it still looks like a cooler and wetter than normal April and early May across North Idaho and the Inland Empire. There will, however, be some occasionally sunny days with mild temperatures. But, there could still be some rather 'rare' spring snowflakes in the air, especially early in the period.

Longer-term, we're still hopeful for a warm and dry summer season in 2011 as 'La Nina' weakens in the tepid waters of the Pacific.

A very strong stationary ridge of high pressure could begin in June lasting through July, August and at least early September. This should mean lots of 'Sholeh Days' this summer with afternoon highs near or above 90 degrees. At least three or four days may see afternoon maximum readings near or above the century mark in the Inland Empire.

But, if we do see unusually hot, dry and windy weather this summer, it could spell BIG TROUBLE for this region's parched grasslands and forests. Fires could rage over wide areas of the Far West later in the season. Stay tuned.

Randy Mann can be reached at randy@longrangeweather.com.