A SuperFront Will Cross the Northwest This Weekend

Most weather fronts that cross the region are unremarkable due to their passage over the relatively warm, uniform waters of the northeast Pacific.  

This weekend will be different:  a  SuperFront will make landfall late tomorrow (Saturday).  

Some of you will lose power.

Let me show you simulated radar images for three times:  10 AM, 4 PM, and 9 PM on Saturday from the UW high-resolution forecast system (from the 4-km grid-spacing domain).  Red indicates very strong winds, followed by yellow.  The arrows point to the frontal locations.

Wow. Very intense, sharp front.  Very heavy rainfall.

The high-resolution 1.3 km simulation run by my group at the UW produced an even more intense front (forecast around 8 PM shown).  Very impressive.

What about the predicted winds?

The City of Seattle supports the most high-tech wind prediction system in the country (called SeattleWindWatch, run at the UW), which includes an ensemble of many wind predictions for estimation of the uncertainties.  

The forecast below is for the winds over Seattle.  Several of the simulations predicted winds reaching 40 mph. Over the water, winds could be stronger,

 Winds will rev up after dinnertime and peak overnight.

Such strong winds, this early in the wind season when some leaves are still on the trees, mean power outages.  

As noted above, wind will be strongest over the water (see forecast below for 4 AM).   I suspect most of the power outages will be in such areas.

In addition to wind, the front should bring substantial ( and welcome) precipitation to the region, with the total through 4 AM Sunday shown below

So, if you live west of the Cascades,  get your meteorological popcorn out and be prepared for a dramatic meteorological show later tomorrow and early Sunday.