Watch out for big ice storm this winter
As I wrote this column Friday morning, it was cloudy with occasional rain showers and winds gusting to near 30 mph. More wet weather was expected over the weekend. By the time you read this, there is the possibility of snow showers in the lower elevations.
Many have come up to me to ask, “Where’s the snow?” Or, I have heard, “When is the snow coming?” Many of the forecast models were certainly pointing to measurable snowfall in the lower elevations last week. The storms would come in, we would get the moisture, but it would remain too warm for snow.
This may be a prelude to the weather pattern we’ll see for the rest of the fall and upcoming winter season. I expect to see a number of “disappointments” from storms that look like they’ll produce snow, but then we get only rain and a few snow showers at best. But there may be a storm or two that provide us with more snow than was originally forecasted as the storm will be warmer than expected. Our best snowfalls occur with temperatures in the upper 20s to low 30s.
For quite some time we continue to hear about the warmer than normal sea-surface temperature event, El Nino, in the waters of the south-central Pacific Ocean. Readings of over 5 degrees above average are seen along the Equator. We also have a lot of warm water across much of the eastern Pacific, the Atlantic Ocean and Indian Ocean. The only regions of cooler ocean temperatures are around Antarctica, Greenland, Japan and New Zealand. I’ve studied these sea-surface temperature patterns for over 20 years and haven’t seen an El Nino pattern like this one.
The tremendous warming of ocean waters will be pumping more warm air into the atmosphere. Many storms that move into our region will likely be moderated to the warmer side over at least the next 3-4 months. We’ll just have to wait and see. Based on the current weather cycles, the chances of a white Thanksgiving are less than 25 percent and the chances of a white Christmas are certainly less than 50/50. It doesn’t look promising, but I’ve seen stranger things in this pattern of wide weather extremes.
The biggest concern with this very strong El Nino, the biggest since 1996 and 1997, is the increased probability of ice in the lower elevations. Many can remember the big ice storm on Nov. 19, 1996, across the Inland Empire.
During that time, the region experienced a pattern of very cold air settling into the lower elevations. Temperatures at the surface were near or below freezing on that November day. However, readings were much warmer from above the surface to near 6,500 feet. Since the air temperature above the surface was above freezing, the rain drops did not change to snow. They became “supercooled” when they hit the ground as rain, and once they came in contact with buildings, power lines or other objects that were below freezing, the rain drops froze almost instantly. These are the conditions for freezing rain and ice storms.
In November 1996, about an inch and a half of rain fell on the frozen surface. There was also freezing fog, snow and mist. It was a mess as trees and branches were coming down due to the heavy weight of the ice. Ice covered power lines and transformers were exploding as more than 100,000 people lost power. It was the worst outage in more than 100 years. Other structures like homes, buildings and vehicles were caked with layers of ice of up to an inch thick. Total damage was about $22 million in Spokane and Kootenai counties.
For the rest of November, I still see precipitation totals near to below normal. Most of the moisture that falls this month should be in the form of rain in the lower elevations. But, on the back side of these storms, if there’s any moisture left, there may be some leftover snow showers. The higher mountains should be cold enough to see more measurable snowfall in the coming weeks. Remember, during El Nino years, we typically see drier and milder than normal weather for the late fall and winter season as most of the moisture goes south of us into California.
The massive ice storm in November 1996 occurred during the strongest El Nino in recorded history. The current El Nino is nearly as intense and may bypass the one back in 1996-97. Therefore, it’s quite possible that we could be dealing with periods of freezing rain over the next few months. Let’s hope that we don’t get a big ice storm like the one seen nearly 20 years ago.
Contact Randy Mann at randy@longrangeweather.com.