The long dry spell is breaking

After seven months in a row with below normal precipitation in Coeur d’Alene and much of the Inland Northwest, weather patterns have now turned toward the wetter side. As of the weekend, close to 3 inches of rain has fallen at Cliff’s station this month. Our normal moisture total for October in Coeur d’Alene is 2.22 inches.

As I’ve mentioned for the last several weeks, a new La Niña, the cooler-than-normal sea-surface temperature event, has been declared in the waters of the south-central Pacific Ocean. Although this new phenomenon is expected to be weak and only remain through the early part of 2026, early indications are continuing to point to wetter than normal conditions across the northwestern part of the country. Many are wondering about Halloween night as another series of storms is expected to move across the region. As of the weekend, there is an increasing chance of rainfall Oct. 31, with the heavier part of the storm more likely in the first few days of November. Depending on the speed of the storm, it’s going to be close for the trick-or-treaters.

If the rain falls on the evening of Oct. 31, it will certainly be a disappointment for many trick-or-treaters. Based on records going back to 1895, moisture has fallen on Halloween a little over 40% of the time in the Coeur d’Alene region. The average temperatures on Halloween range from a high of 52 degrees and a low of 34 degrees. The warmest Halloween in Coeur d’Alene occurred in 1938 with a pleasant 72 degrees. Three years earlier, in 1935, it was the coldest with a low of only 2 degrees. The wettest Oct. 31 in recorded history occurred nine years ago in 2016, as 1.20 inches of rain were measured. In terms of snowfall, Coeur d’Alene did receive 3 inches on Halloween in 1971.

There have been some notable weather events that have occurred near or on Halloween. According to the Weather Channel and WeatherForYou.com, in 1846, 87 pioneers were trapped by early and heavy snowfalls in the Sierra Nevada mountains. Known as the “Donner Pass Tragedy,” there were snow drifts up to 40 feet high and only 47 people survived.

Fort Lauderdale, Fla., had a very wet Halloween in 1965. On that date, nearly 14 inches of rain fell that resulting in a record-breaking October for precipitation as the city picked up over 42 inches of rain.

Another famous late October storm was the “Halloween Blizzard,” which dumped heavy amounts of snow and ice on the Upper Midwest in 1991. Over 2 feet of snow fell in northern Minnesota and many stations in Iowa reported up to two inches of ice on top of 8 to 15 inches of snow.

Amazingly, there was another major storm on that date called “The Perfect Storm” or “The No-Name Storm.” The big system was a nor’easter that combined with Hurricane Grace. Waves were as high as 30 feet along parts of the East Coast. Damage from that storm was over $200 million, with most of it occurring in Massachusetts and New Jersey.

Speaking of storms and snow, I did receive a question on how snow is measured. As many people know, climatologist Cliff Harris has been measuring snowfall in Coeur d’Alene since late 2003. He also measures the snow depths at three separate locations in his backyard, including the flat deck that’s away from both the house and trees or other various obstructions. Then, he averages out the three measurements for maximum accuracy. It’s almost hard to believe, but the guy has been measuring snow now for over 70 years! That’s amazing dedication to the weather.

Cliff systematically measures snow before it melts. If it falls as snow, it’s measured as snow. In this region of the country, we can experience a tremendous amount of melting, especially below 2,500 feet, even in the dead of winter. Therefore, there is a loss of accuracy if snowfall is measured only once or twice per day.

According to NOAA, the measurement of new snow at the National Weather Service is reported in “tenths” of an inch and readings are taken up to four times per day. For example, if 3 and a half inches of snow falls, it’s reported as 3.5 inches. However, when the snow is melted to get the liquid equivalent, then it’s reported in “hundredths” of an inch, which is what we will report on the Daily Weather Page and weather columns. To get the liquid equivalent from pure snow, Cliff Harris will take the collected snow in his rain gauge and melt it, usually in a microwave, to get the results.

 If one is looking to measure snowfall this season, then consider taking measurements at a location where the winds will not create snow drifts. If there are areas of snow drifts, then choose several locations to obtain an average. NOAA says that using a snowboard or an open flat surface is the best and easiest way to measure snow. A board of lighter color, about 2 by 2 feet, would be adequate. Other flat surfaces, such as a table or open deck, should also work well.

• • •

Contact Randy Mann at [email protected].