A disturbing (or exciting) convergence of mesoscale models suddenly occurred this evening; they all show the potential for a signficant windstorm on the coast and possibly a windstorm in the western Valleys late tomorrow night.
The WRF-GFS and our RPM both show almost exactly the same thing. A deep low tracking to about Astoria and then moving inland over SW Washington. Timing is the same too, with strongest wind here in the Northern Willamette Valley sometime between Midnight-3am. How strong could the wind be based on these models? The WRF-GFS shows 17 millibars from Olympia to Eugene! A common calculation for a possible peak gust at PDX is about 3.15×17 in this case. That would be between 50-60 mph, maybe similar to the Hannukah Eve storm in December 2006 (for Portland). Our RPM is slightly farther south with the low, showing 16 millibars from just Kelso to Eugene! That’s real impressive.
Now the MM5-NAM is a bit different, more of an open wave (not a closed area of low pressure), but it’s farther south. I’d put the strong winds somewhere down in the Valley, more like Salem and Eugene. It shows 11 millibars just from Portland to Eugene with a strong surge from the southwest behind the wave. It’s just slightly later too, closer to 3-4am.
So the possibility of a significant windstorm is definitely there; I’ll get more excited about it if the 12z runs all come in similar or stronger.
Other than that, today has been consumed by flood coverage. It has been the biggest flood since 1996 in the central valley. In some areas worse than 1996. Here are the 3 day rain totals:
Chief Meteorologist Mark Nelsen