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New La Nina picking up steam

by RANDY MANN
| October 19, 2020 2:44 PM

We now have a La Nina, the cooler-than-normal sea-surface temperature event in the waters of the south-central Pacific Ocean.

The cooler waters have extended all the way down the West Coast of South America. Most regions of cooler waters are averaging about 1-3 degrees below normal near the South American coastline and there are some expanding regions along the equator that have sea-surface temperatures about 3-5 degrees below average.

Over the last month, cooler waters have expanded in the south-central Pacific Ocean, which may indicate that we could see at least a “moderate” La Nina event in the coming months.

U.S. forecasters say the new La Nina should peak at the end of the year and start to diminish in the spring. In Australian Bureau of Meteorology, the government weather service that tracks sea-surface temperatures has also declared that the new La Nina event should improve moisture totals in the Southern Hemisphere, which would lower the chances of another disastrous fire season. In late 2019 and early 2020, Australia experienced its worst bushfire season in history.

With the current sea-surface temperature pattern, we’re also expecting to see the active normal tropical storm and hurricane season continue through November, perhaps into December. Ocean waters off the coast of Africa are also still warmer than normal, where many of the systems originate.

Many forecasters, including Cliff and I, are saying that we could see a record-breaking 30 named storms before the official season expires at the end of November, which would break the record of the monster season in 2005 with 28 named storms. We’ve already gone through the list of names and now into Greek letters.

COLDER, SNOWIER HERE

Assuming this new La Nina stays with us into early next year, the chances are higher for a snowier and colder winter season across the North Country. Numerous outlooks are already predicting a rough winter for parts the Northern Hemisphere.

However, this is not good news for the southern U.S., especially the southwestern portion, including much of California, as La Nina patterns often produce drier-than-normal weather in those regions. Therefore, it may be a very long wildfire season for residents of the Golden State and parts of the southwestern U.S.

To increase the probability of a snowier-than-normal season in the North Country, we usually need a La Nina event. However, despite the recent cooling, sea-surface temperature patterns are a little different when comparing the ocean waters of today versus the pattern in late 2007 and 2008, when we had all-time record snowfalls.

From late 2007 into 2008, scientists stated that we experienced a strong, cooler La Nina event. Ocean waters were much cooler along the equator and the eastern Pacific Ocean as well as the arctic regions. Today, we have a weak La Nina, but it could expand into a moderate event before 2020 comes to an end.

Current sea-surface temperature data now shows an expansion of a large area of warmer-than-normal ocean waters in the eastern Pacific Ocean northward into the arctic regions. Sea-surface temperatures have been consistently warmer in the arctic regions since 1990, as much as 5-10 degrees Fahrenheit above normal levels in recent years.

Another factor that may need to be considered for a big snowy season is the low sunspot activity. I compared the solar activity from late 2007 when we started that big snowy year versus late 2019. In terms of the lack of sunspot activity, solar conditions are very similar to the 2007-08 season, when a whopping, record-breaking 172.9 inches of snow fell in Coeur d’Alene. Since this Aug. 15, there have been 47 days with no sunspots on the sun, so activity remains extremely low.

Whether the warmer waters in the Gulf of Alaska have a major impact on our precipitation remains to be seen. Depending on how these weather patterns line up, it’s possible that much of our moisture could come as rain in the lower elevations, but the mountains may see another big year for snow. But, as I mentioned earlier, the chances are looking good for a snowy winter in Coeur d’Alene and the rest of the Inland Northwest.

In the meantime, a series of storms brought nearly 1.60 inches of moisture to Coeur d’Alene last week. There were reports of snow over the higher mountains and we should see more snow shower activity in the higher elevations early this week.

Toward the end of this week, we’ll get a taste of winter as temperatures will be getting colder, along with a chance of snow. We’re also starting to see changes in the upper-level wind patterns as it looks like more Pacific storms will start to move through the Pacific Northwest in November.

There’s a chance we could see dry weather for Halloween, but it does look chilly. I’ll keep updating the 14-day weather outlook for Coeur d’Alene that’s available on The Press Facebook page and The Press website.