By Gordon McCraw, Meteorologist for the Tillamook County Pioneer
An interesting and difficult forecast for the next couple of days as several areas are on the border of snow, no-snow! The big picture is, we had colder air push into the area yesterday and thus the Tillamook area sees freezing, or below freezing temperatures in the overnight hours. Fortunately, the marine effect heats up the area during the day, pushing the temperatures into the low 50s. The valley area is not as lucky as the colder temperatures are stuck under an inversion and trapped by the mountains. This is element one!
The next thing to add to the mix is a low pressure area moving to the northeast from west of northern California. This is spinning some moisture or light rain up into the area today that will affect our area around noon today. Because of the valley’s low temperatures, the Coast Range summit precipitation type will be dependent on the temperatures up across the top, which are still below freezing this morning as I write this. This explains why the National Weather Service issued a Winter Storm Advisory for the Coast Range from 10am today until 4pm tomorrow. They say there is a chance of 2-5” of snow there, with a chance of 5-10” above 2000’.
Now, if you are headed over to the Portland area, the rain will be hitting them also around noon today, where the high temperature is forecast to only reach 42. This means you will be okay during the day but then when the sun goes down, the temperatures there will also fall, and with the forecasted low of 35, and with some strong, cold, east winds pouring in from the Gorge, areas just east of Portland could see some low level snow. The Advisory is for up to 3” of snow from 8pm tonight through 4pm tomorrow. If you need to go east of that, they start talking feet of snow.
So, bringing it back over to our side of the Coast Range, obviously tonight will be rainy with the winds becoming southeasterly 10-15 gusting to 20, the low down near 40, then tomorrow more rain with southwesterly winds 8-12, the high makes it to near 49. More rain is likely tomorrow night with easterly winds 5-10, the low near 41. The Coast Range Summit is looking at more snow or a rain/snow mix tomorrow.
Friday, the rain eases some during the day, still breezy with east winds 14-18 gusting to 30 thanks to the low pressure area moving eastward through Washington and weak high pressure moving though here, the high near 48. By Friday night, we see more rain with another front pushing in from the southwest that also brings increasing easterly winds now 20-25 gusting to 35-40, the low near 40. As far as the Coast Range goes, with the warm system coming, but with the cold temperatures still hanging at the surface, there precipitation type will be changing during the day, snow in the morning, a rain/snow mix in the afternoon, then rain, or snow, or freezing rain that night.
As for the weekend, things should start to warm up enough that the Coast Range is looking at all rain finally. Here, yep, more rain, and breezy, Saturday into Sunday, highs near 53, lows near 41. And next week??? Well, you guessed it, a chance of rain still Monday and Tuesday, highs near 55, lows near 42.
My final thought is about the rivers, yes, the flow rates will increase from the rain, but no river flooding is expected, you could still see the usual Urban and Small Stream flooding that happens during the heavier rain periods, but, that is it!