Nws Portland Weather Briefing - Snow, sleet or freezing rain

Welcome to today’s weather briefing from the National Weather Service office in Portland to talk about the potential for a brief period of snow, sleet or freezing rain early Friday morning. A storm system will move into the region later tonight that has the potential to bring a mix of snow, sleet, and/or freezing rain across the lowlands early Friday morning.  The prime threat time will be from around 2am to 10am expect in the Columbia River Gorge where the threat will persist into the early afternoon. Of course, this time period means that any frozen precipitation that falls will affect the Friday morning commute. Potential impacts are hazardous travel from icy roads and the potential impact to airfield operations. The forecast for a wintry mix of precipitation early Friday morning is not clear cut due to uncertainty in how cold temperatures get tonight. Here’s some items we know and uncertainties that remain. This will be a short duration event with potential impacts during the Friday morning commute. At this point in time, we expect a very brief period of light snow flurries, quickly transitioning to sleet or possibly freezing rain early Friday morning that may affect the morning commute from the Kelso-Longview area southward into the Portland metro area. There is some potential for a short period of frozen precipitation in the central and southern Willamette valley as well. The precipitation will turn to all rain by 10 am. The biggest uncertainty with this scenario is whether the surface temperatures will be below freezing or not when the precipitation moves in. Extensive low cloud cover tonight may result in temperatures remaining above freezing. In this situation, the precipitation may briefly begin as snow or snow flurries, but quickly transition to just rain. These are the areas prone to snow, sleet or possibly freezing rain. There is a moderate risk of a wintry mix of precipitation from the Kelso/Longview area southward into the Portland-Vancouver metro area as well as Columbia River Gorge. Prime threat times are from around 2am to 10am expect in the Columbia River Gorge where the threat of frozen precipitation may last until early Friday afternoon. There is also a slight risk of a wintry mix of precipitation for a short period of time in the central and southern Willamette Valley and adjacent foothills. We expect the temperatures to warm quite rapidly in this area with the threat ending by 9am. Here is a summary of impacts and forecaster confidence levels. Forecaster confidence is low to moderate for the possibility snow, sleet or freezing rain in the northern part of the forecast area from around 2 am to 10am Friday morning and the Columbia River Gorge through early Friday afternoon. Confidence is low for the chance snow, sleet or freezing rain central and southern Willamette Valley. Any snow, sleet or freezing rain that falls will create hazardous driving conditions. You can monitor the forecast in your area by going to our webpage at weather.gov/portland.