In a surprising turn of events, the Portland National Weather Service (NWS) has decided to issue a Winter Weather Advisory for the Portland metro area, raising concerns and sparking rumors among local residents. While the forecast for the next few days remains unchanged, with rain and chilly east winds expected, the NWS has implemented a new probabilistic forecasting method to better convey the wide range of weather possibilities.

The Winter Weather Advisory comes into effect from this evening through Thursday, indicating the potential for snowfall in the area. However, it is important to note that the chance of sticking snow remains very slim in the lowest elevations west of Cascades. While some individuals may witness snow in the air at times, the NWS emphasizes that this is a rare occurrence.

Examining the graphical representation posted by the NWS on their Facebook page, it becomes apparent that the 6-10" snow mentioned stands at a mere 10% likelihood. This probability, previously not highlighted, raises questions about the necessity of issuing a Winter Weather Advisory for such a slim chance. With temperatures predicted to remain above freezing levels, it seems difficult for snowflakes to reach ground-level, except as potential freezing rain.

Additionally, all other weather models consistently show temperatures above freezing levels, with rain expected at times through tomorrow morning and midday. The NWS acknowledges that the slightly higher chance of snowfall is primarily driven by a single model, the GFS American model, which has a history of being inaccurate. The WRF-GFS and GRAF models, known for their reliability, also forecast rain for the region.

Despite concerns regarding the slim chance of significant snowfall, the issuance of the Winter Weather Advisory ensures that emergency managers have access to all possibilities. However, this also raises concerns about the "crying wolf" phenomenon, where worst-case scenarios gain disproportionate attention. The NWS assures the public that they are committed to accurate forecasting and acknowledges the frustrations and reservations surrounding the implementation of this new method.

As the weather situation unfolds, residents are advised to remain cautious and prepared for changing conditions. The current view at 6 pm today reveals a cold sideways-blowing rain in the metro area, underscoring the likelihood of rain rather than snow. While the chances of snow accumulation remain uncertain, it is important to heed the guidance and updates from the Portland NWS as the situation evolves.

The forecast for the coming days continues to indicate rain and chilly east winds, with temperatures expected to range between 40-45 degrees. Although there may be a slight chance of snowfall on hills around Gresham, it is more likely to result in a dusting rather than significant accumulation.

The Portland NWS, known for their diligent work and expertise in weather forecasting, will continue to monitor the situation closely and provide timely updates to ensure public safety.