Over the past three months, a particular weather pattern has emerged: The earlier weeks of the month are drier and milder than normal; the later weeks are colder, wetter and even snowier than average.
It appears that March will end up cooler and wetter than normal as more showers are expected until the end of the month. As of early Monday, the average reading at the Spokane International Airport was about 2 degrees below normal. It’s quite possible that we may challenge the March all-time precipitation record of 3.81 inches set back in 1995 as more rain is expected through Saturday.
In terms of snowfall, the airport has received 35.7 inches since July 1, 2011. The normal for a season is approximately 45 inches.
Despite the recent chill, the good news is that it will soon warm up. By next week, we should see what I believe will be a fairly normal month of April, weatherwise. The sun and showers pattern will set the stage for a boatload of May flowers and trees that will leaf out a month earlier than last spring.
For much of the 2011-’12 winter, we were under the influence of the cooler La Niña sea-surface temperature pattern in the south-central Pacific Ocean. Readings near the South American coastline and to the west have recently warmed to near-normal levels, so La Niña is gone.
The recent warming along the South American coastline may be an indication of the formation of a new El Niño in ocean temperatures later this year.
But, we’ve been in a back and forth pattern of cooling and warming of ocean temperatures over the past three to four months, which could be happening again. There were indications that La Niña was going to completely fall apart last November, before it regained some strength in December.
It will take some time for the effects of La Niña to completely go away as there is a lag effect from the changes in sea-surface temperatures to the flow in the upper-level winds. Eventually, the warm weather east of our region will move over us.
Watch for more on this extreme weather pattern next week.