What will winter bring for the Mid-Atlantic this season
October 20th, 2009 at 11:19pm
Is a snowy winter in store? Or just cold and dry, wet and mild?
After I put out the blog with the NOAA Winter Forecast for this 2009/2010 season, I thought I would try to discuss this a little more in regards to the mid-Atlantic and what it means for me. First let’s take a peak at the average annual snow fall for Maryland:
So we can see that for most seasons we see between 17 and 26 inches in the immediate region, especially the more north and west you go from downtown DC. Of course the average is likely made up of widely varying amounts of snowfall each season. And while I believe this map to have been done in 2001, I wonder if there has been much change since that year considering the last year of good amount of snow has been 2003. The past six years have been rather boring with below average snowfall, some years barely seeing any.
Now based on the forecast, this season we are expected to see equal chances of average amount of precipitation. That doesn’t necessary translate to snow for your area since we often see rain in winter because of the average winter temperature being above freezing both at the surface and at the 850mb level and higher. But, and this is a big but, if the NOAA forecast holds true, we are likely to see a 40%+/- chance of below average temperatures. This hopefully will mean more days that when the precipitation falls, it will be cold enough for snow. It might mean more smaller storms of a few accumulation…say between 2 and 6 inches of snow, rather than are large storms (that typically come out of the southern states…along with gulf moisture) that can add up to 15+ inches of snow in one storm (sometimes over more than 24 hours of snowfall).
For me personally, it means I need to look into the forecast further, check out other forecasts (like accuweather) and see how they compare. I also will try to learn what other factors I need to look at. For one example, I need to learn more about the NAO (Norther Atlantic Oscillation) and what impacts (if any) El Nino will have on our area. Other important facts are how do these forecasts address upper air support forecasts. Sure, the surface may be colder, but will the 850mb level be sufficiently colder to support more snow events, or will we see more ice events from mid-levels being too warm. How about thicknesses (don’t ask me to explain…still learning that one too)?
One thing for sure is, I am more than willing to travel, but would love to stay local to cover winter storms…DC is a great region for it. And with the NOAA forecast extending the “drier” bubble over the Great Lakes region…I may not be able to venture up to see Lake Effect snows this season…time will tell of course.