Is This Model Correct? If So, Seattle Will Get Snow Tomorrow!

By now, you’ve no doubt heard all the latest about our chances of snow tomorrow. Overall, the general consensus seems to be that snow accumulations will be virtually non-existent in Seattle on Friday, with the greatest chance of accumulations well north of the city.

Latest model run of the UW NAM, showing 2 to 4″
of snow across the Seattle metro tomorrow evening

While it’s true that most computer models have depicted hardly any snow for the greater Puget Sound region tomorrow, the same cannot be said of the latest model run out of the University of Washington: the NAM.

Take a look at the snow forecast projected by the most recent run of the NAM. See that bullseye of light and dark blue directly over Seattle? That, my friends, is the estimated snowfall for the region within the 4:00 to 7:00 time frame tomorrow night: 2 to 4 inches of the white stuff! The next frame from the NAM, covering the time period from 7:00 to 10:00 p.m., paints an additional inch of snow across Seattle as the main precipitation shield moves north, hammering Everett. Maybe Friday will be snowy after all!

However, before you get too excited, bear in mind that this is only one model run, and that the resolution on this model–12 km–is not that great. The NAM is also run at a much higher resolution–4 km–but this version of the model has not been released quite yet. Sometimes, models run at lower resolutions (such as the one you’re looking at), miss key topographic features in Western Washington that have a major influence on whether Seattle sees a 36-degree rain or a 32-degree heavy snow–mountains, hills, and water, to name a few.

In addition, the University of Washington’s WRF model is forecasting nothing–zero, zilch, nada, nil–in regards to snow tomorrow night. Which model is correct? If only we could see into the future…

Regardless, it’s safe to say that the threat of lowland snow for tomorrow night has ratcheted up a few notches. Stay tuned as the bi-polar world of weather models attempts to sort things out for tomorrow night. It could be quite the ride!