We just had a flurry pass through the west side of the metro area, one of those “green” spots on the radar I mentioned on the previous post.
I’ve looked through several more model runs, stared at the radar screen a few times, and have a few thoughts:
1. Many of us will stay dry tonight through Thursday morning, thus in those areas no commuting issues Tuesday morning
Take a look at the WRF-GFS rainfall accumulation map through 4am tomorrow. Little or nothing for most of the metro area and anywhere south into the valley:
And a wider view showing anything that might fall after 4am. A few hundredths of an inch. If it was rain, we’d say a few sprinkles or a light shower later tonight or Tuesday morning:
and our RPM…totally dry!
2. The coast is pretty much done with frozen precipitation. Temps have warmed above freezing everywhere except where a light easterly flow is coming down the Columbia River. Even that will gradually warm tomorrow morning. Yes, still some icy streets around Astoria possible overnight.
3. Very spotty snow flurries, with a dusting or so, are possible at some point this evening through the Tuesday morning commute inland, mainly from Portland north. I think a lot of us will just wake up to flurries or a dusting on the ground. Others could see up to 1/2″ or so in the eastern part of Clark County (Battle Ground, Hockinson, Camas) and eastern Multnomah County (Troutdale, Gresham, Corbett). Plus Vernonia, Banks, St. Helens, and Scappoose. The best spot could be up at Kelso and Longview where there will be a little more moisture.
4. A bigger issue is that areas of freezing drizzle or freezing rain showers could develop instead of or with flurries. That’s because slightly warmer air is moving in around 2,000-3,000′ up. It only takes a few minutes of liquid drizzle or rain to coat a road and make it an ice rink; far more dangerous & destructive than a half-inch of snow.
5. Best areas for frozen precipitation of any sort away from the Cascade foothills? Higher terrain north and west of downtown Portland (West Hills, Columbia County, Cowlitz County, Kelso/Longview)
IF we get more precipitation than expected, especially if it’s freezing rain, roads will be a huge mess for the Tuesday morning commute. NO ROADS WEST OF THE CASCADES WILL THAW UNTIL SOMETIME TUESDAY. If a road looks wet, it’s icy. Stay tuned here, on FOX12 (starts at 4:30am!) or on our Facebook/Twitter pages. We are FOX12WEATHER on both of those.
I’ll do another update later this evening if conditions warrant…but for now I’ve run out of text colors to use, so I’ll sign off.
Chief Meteorologist Mark Nelsen