EVERETT, SEPT. 23: The summer season is officially over. Today, Sept. 23 is the first full day of fall. Days are getting shorter and nights longer with more fall-like weather in the past few weeks, a reminder that the winter season is not far off.
We can see why September is National Preparedness Month, the best time to prepare in advance for what is likely coming soon. North Sound fall and winter weather often involves heavy rainfall, flooding and landslides; strong damaging windstorms, and lowland snow and ice. These kinds of adverse weather are the key reason for you to prepare in advance.
The latest seasonal weather outlook was released last week, and it shows that La Niña is set to return for this winter. La Niña is the opposite sibling of El Niño – when the ocean waters in the eastern Pacific Ocean tropical waters – the waters west of Peru – are cooler than average. El Niño is when those same tropical waters are warmer than average and that was the case this past winter.
La Niña and El Niño have big consequences for how the North Pacific storm track behaves. For La Niña, Pacific storms spend more time moving onshore into the Pacific Northwest as opposed to El Niño when the storm track takes a more consistent path into California and beyond.
El Niño winter seasons for Western Washington tend to be warmer than average and lean toward before-average precipitation and a poorer mountain snowpack. That was the case this past winter.
La Niña winters are sharply different. They tend to be cooler and wetter than average and produce a healthy mountain snowpack. Earlier this decade, there was a rare three straight La Niña winters – the winters of 2020-21, 2021-22, and 2022-23. In each of these winters, the mountains received an above-average mountain snowpack, and the North Sound had snowfall events impacting normal life activities.
Latest Seasonal Weather Outlook
The fresh seasonal weather outlook shows continued development of La Niña returning. The outlook for this fall and winter reflects the usual La Niña tendencies of cooler-than-average temperatures and above-normal precipitation for December through February. This trend also points to a healthy mountain snowpack by next spring, good news for snow enthusiasts, and water managers and power generation authorities.
The outlook for October and November indicates odds tipped toward a wetter-than-average fall with no trend in temperatures.
Impacts of La Niña
Ranking El Niño, ‘Neutral’ (around average tropical Eastern Pacific Sea surface temperatures), and La Niña winters, La Niña is number one for producing lowland snow. Each of the previous three La Niña winters earlier in this decade resulted in lowland snow across much of Western Washington.
The lowland snow season typically starts in mid-November and extends into March. Snow not only disrupts transportation but often results in power outages as well. Many of the top ten snowiest winters in Western Washington have occurred during La Niña winters.
Now is also the time to get ready for the potentially damaging windstorms, along with flooding and landslides.
The windstorm season usually begins in October. The nation’s strongest non-tropical windstorm for the lower 48 in American history occurred on Oct. 12, 1962 – the Columbus Day Storm. Winds in the interior of Western Washington including the North Sound exceeded 100 mph, blowing down thousands of trees, damaging homes and utilities with power outages for over two weeks, and resulting in 46 fatalities.
This region usually gets a strong damaging windstorm about every 10 years. All other strong windstorms are compared to the granddaddy of them all – the Columbus Day Storm. The last significant windstorm in this area was the Hanukah Eve Windstorm of December 2006.
Our region is way overdue. Perhaps ask this question – what if another Columbus Day type windstorm struck again? Would you be ready for an extended period of time without power?
The flood season usually gets rolling in late October and runs through March. Flooding is number one for Presidentially Declared Natural Disasters in Washington. Given how warmer global temperatures hold more moisture, any storms that carry a higher volume of moisture can produce heavier rain amounts in the same time period. It is quite possible these wet storms could dump more rain and result in more significant flooding than in the past. This issue has been the case not only across the country in recent years but also around the world.
Are you ready for these hazards or perhaps an earthquake too? Now is the time to prepare. For helpful tips and checklists for your home, car, pets and more, go to ready.gov or the CDC Winter Preparedness website.
One key item for your home, business, school, health care facility or place of worship is a NOAA Weather Radio all-hazards – a lifesaver for the price of a pair of shoes. Remember, when you are weather aware, you are weather prepared.
To help protect you, your family and your business, get prepared this month during National Preparedness Month and you will be better prepared for whatever nature creates this fall and winter.
