Thursday – February 7, 2019 – 12:15pm
Gordon McCraw, Tillamook County Weather
As the weekend get closer, the information gets more interesting. It appears the current pattern does not look to change significantly over the next week to 10 days, so, it looks like the cold is here to stay a while, and so is the occasional snow chance. Today we have a low pressure area moving southward to our west. The system is far enough to the west that about all we see is the cloudiness today.
Of greater interest, there is a trough of cold, cold low pressure in northwestern Canada that will push down, then a low forms in the area of the British Columbia coast as it moves offshore a bit, pulling Arctic Air with it, later tomorrow as it drops down towards Vancouver Island and the Washington Coast, and strengthens. As this happens, we also see precipitation developing and wrap around the low. As this happens tomorrow, we end up having a warmer southerly component which pushes the snow level up during the day. The area will see mainly light rain during the day tomorrow.
As the low continues to move further south, pushing in the colder temperatures from the north and east, the snow levels will rapidly drop, and the rain transitions to snow over in the valley Friday evening then works its way over to the coast Friday night into Saturday. It looks like we would only see a rain/snow mix or maybe a trace here with areas to the south and east of the Coast Range seeing less and ½”. Friday night lows here only down to the mid 30s.
Here is where the fun begins! The precipitation increases Saturday as the low nears the area, and we transition to snow sometime Saturday afternoon as the temperatures drop into the low 30s by Saturday night. Overall into Sunday morning the coast could see around 1-2” of snow with a few isolated areas getting heaver precipitation and seeing up to 4”. If you think you want to go over the Coast Range, they likely pick up 4-8” above around 1000’ into Sunday with the potential that a few isolated areas could see up to 12”.
Now the precipitation diminishes Sunday and the high temperature depends on how much sun we see. I suspect we may get into the upper 30s to near 40 so…some of the snow could melt. With Sunday night’s lows expected to be down around 30, we can add ice concerns to the snowy road concerns.
The latest models runs now add another low to the mix for Sunday night into Monday which would again bring in more moisture and precipitation. Since all areas would likely be below freezing, this means we could see another 1-2” of snow at the coast and another 5-10” in the Coast Range Passes.
Beyond that, with little pattern chance, it looks like we will see continued below average temperatures with periods of rain, or rain/snow, or snow through at least midweek.
Lots of disclaimers though as the track and speeds of these systems can change without warning. There is high confidence in the forecast for tonight through tomorrow, moderate confidence on the forecast for Friday night into Saturday, and low to moderate confidence in the snow event for Sunday night into Monday. There is always a chance the lows trajectory could speed up, slow down, or land further north or south than forecasted. Any of these changes significantly alter the outcome.
I would expect the worst-case scenario and hope we were over prepared. Once it starts, it’s to late. We get one more update tomorrow to narrow down the information, we hope!