|Fig 1 -- NEXRAD base refelctivity mosaic for 1738Z, Dec. 20, 2010. From www.weather.gov.|
|Fig 2 -- Contoured pressure and shaded moisture at the surface at 17Z, Dec. 20, 2010. From the HOOT website.|
Of course, because we do a pressure correction to mean sea level in our surface pressure maps, sometimes that messes up our pressure field in the mountains. So just to be sure the low we're seeing above is an actual surface low and not just some natural error due to there being lower pressure at higher terrain, let's look at a surface pressure change map for the past three hours.
|Fig 3 -- Surface pressure changes (contoured) over the previous three hours at 17Z, Dec. 20, 2010. From the College of DuPage website.|
|Fig 4 -- 300 mb wind and geopotential height analysis at 12Z, Dec. 20, 2010. From the HOOT website.|
But maybe conditions will improve? Let's look at the 24 hour NAM forecast for 300mb winds.
|Fig 5 -- 24 hour forecast from the NAM model of 300mb winds and geopotential height at 12Z, Dec. 21, 2010. From the HOOT website.|
|Fig 6 -- 24 hour forecast from the NAM of mean sea level pressure (contoured) , temperature (shaded) and winds for 12Z, Dec. 21, 2010. From the HOOT website.|
So yes---there will be some snow with this low as it slowly moves out over the plains. But winter storm warnings for heavy snow are the worst you'll see. No blizzard warnings or high wind warnings or anything like that. This low simply has no support for it to grow...