1-2" of total rainfall possible Friday-Sunday; another 1-2" possible next week (Tue-Thur); Windy?
January 24, 2024
By now you've probably seen some news media hyping things up that another massive weather event is in store for us next week with catastrophic rainfall/flooding, devastating winds, downed trees, and power outages. Breathe! Look, it rains here in Oregon. Sometimes A LOT. Sometimes A LOT within a SHORT PERIOD. Sometimes we get windy storms too! Just about everyyear we get a few storms that drop a lot of rain within a short period of time which causes some mudslides and we see some storms with gusty winds which could topple a tree if the soil is saturated enough. This is nothing new! Relax and take a few deep breathes!
So here's what's going on:
RAINFALL Here in Cottage Grove: After today (Wednesday), two storm systems with a good moisture fetch that extends out to near Hawaii will bring a total of up to around 4" of combined rainfall to the area Friday through Thursday of next week. At this time, the projected range of total rainfall is 2-4" here in Cottage Grove (may change).
MOUNTAIN AREAS: Could get 3-6" of total rainfall Friday through Thursday of next week. The upper end of this predicted total could cause a few mudslides that typically occur with this amount of rain. Low level snow melt will add additional water runoff.
RIVERS / FLOODING: The aforementioned rain totals will come from two different storms, but a break in the rainfall is expected later Sunday through Monday. THIS IS A GOOD THING - it allows rivers to do the job of letting storm water drain out. Yes, rivers will be running high and swift. Also, these storms are expected to be more on the "warm" side, so snow levels will be higher than usual (6500-8000'). This means that some snow melt will occur below the 6500-8000' snow line, which will add more water into the creeks, streams, and rivers. This all means that some flooding may occur at those areas that normally get flooded when it rains a lot.
WIND / DOWNED TREES: Nothing new to Oregon (except the Ice Storm)! We do get several storms per year where winds get gusty and about one or two storms per year where the potential for strong winds exist in Cottage Grove. With these storms, there is potential for wind gusts of somewhere between 30 and 40 mph. These, by itself, are not very strong and normally wouldn't do much damage. However, when the soil is saturated from a lot of rain, it becomes easier for winds to topple a few weak trees. So yes, it's possible that there could be a report of a few downed trees SOMEWHERE, but NOT EVERYWHERE. The mountains have the best chances to get winds over 35 mph (40-50 mph?) and Cottage Grove has a better chance for winds staying under 30 mph (20-30 mph).
HOW MUCH WIND AND RAIN WE GET will depend on the exact track of the low pressure systems and how much moisture actually gets entrained into each one. Therefore, there's some uncertainties. Some data suggests that the main parts of one or both of these storms may stay north of our area with north of Albany/Salem Oregon and Washington getting the brunt. That said, a slight 50 mile difference in the track of these storms could mean more or less rain and wind for our area.