So how bad was it? I measured the snow accumulation outside my house.
|Fig 1 -- 24 hour meteogram from the top of the UW Atmospheric Sciences building as of 2047Z, Nov 23 2010.|
Snowfall amounts are difficult to measure from an automated station, and the one on the roof of the atmospheric sciences building isn't really equipped for that. However, some snow apparently did melt and fall into the rain gauge (they may have a heated rain gauge, actually...I'll have to check on that...). However, I suspect this is just random snow melting into the rain gauge. I'm guessing this because the precipitation amounts (the second panel from the bottom) have continued to increase slowly during the day today even though there definitely has been no new snowfall. So, I wouldn't trust the precipitation measurements from this plot.
As this cyclone has been departing, you can see in the pressure plot (the third from the bottom) that our pressures have been steadily rising. This points to high pressure and widespread subsidence building in, which suppresses vertical motion in the atmosphere. This is why the skies are so clear--it's more difficult to form clouds without some kind of lifting mechanism. You can see for yourself how clear it is in the last panel of the meteogram, which is showing incoming solar radiation. On a completely clear day you'd expect to see a nice sinusoidal curve of the shaded region which shows increasing solar radiation as the sun climbs higher in the sky in the morning and decreasing solar radiation as the sun goes down in the evening. You can see that so far today we have a nearly perfect sinusoidal curve, meaning very clear skies. Compare that to yesterday on the left hand side of the plot where all the thick clouds kept us from getting much solar radiation at all. Remember--clouds don't block out ALL the solar radiation--otherwise it would be completely dark on a cloudy day. Some still gets through--though not much.
Another view of the clear weather over Washington:
|Fig 2 -- Visible satellite image of Washington state from GOES-W for 2045Z, Nov 23, 2010. From the College of DuPage website.|
Well, now the next question is--where is this storm moving next?
|Fig 3 -- Objective surface analysis from 20Z, Nov 23, 2010. From the HOOT website.|
However, I think this system is only going to deepen as it moves out over the Rockies and into the plains and midwest. Models also agree with this conclusion, but how can we see that now?
|Fig 4 -- 500mb wind analysis for 18Z, Nov 23, 2010. From the HOOT website.|
|Fig 5 -- ECMWF 24 hour forecast of 500 mb geopotential heights and winds for tomorrow morning at 12Z. From the HOOT website.|
This all adds up to what could be a powerful storm for the upper midwest. We'll be watching in the days to come to see just how bad it gets.