Let the Games Begin

Looks like my Drought Monitor shift is going to do it’s thing…

Models have come in, and they’ve gone from no agreement to uncanny agreement, and the end result is a late-season winter storm.  The good news is you’ll have three days to fret about it… and I’ll have three days to keep changing the forecast on you.  It’s what we do.  I mean, seriously… if we gave you a forecast 3 days out that was a sure thing, well, then we’d become pretty irrelevant.  But it is a meteorologists’ job – nay their very duty – to keep changing the forecast, thereby increasing the need to keep listening!  Shhhh… it’s a trade secret.  😉

So the short version, as being portrayed in the latest guidance… Clouds increase Sunday as cold air funnels into the region during the day.  By Sunday evening, snow will develop in the north, while rain or snow develops closer to DC.  Mixed pcp will change to all snow Sunday night, lasting into Monday morning.  Too early to give amounts, but we are talking about accumulating snow… enough to disrupt travel Monday morning.

A Few Details:  Models are in very good agreement that after a nice Friday and Saturday, a late-season winter storm will impact the area Sunday into Monday, with a potential for a second round Monday night into Tuesday (not gonna worry about that right now).  This resembles our dealio from a couple Mondays ago where a dry, cold northwest wind caused rain to change to snow, but the high will be in a better position for snow this time… located more to our northeast over New England, vs to our northwest with the last one.  At the same time, a low will develop across the Delta and track to the Mid-Atlantic Coast.  How far north this low tracks will – as always – determine how much of what we get.  Pcp is slated to arrive during the late afternoon Sunday from the southwest, starting as snow in the north and rain fro D.C. south. Sunday night, pcp will intensify and change to all snow… before tapering off to flurries or drizzle/freezing drizzle Monday.

BTW, the GFS, which was insisting this storm would not happen, has gone all-in, and now has a notable snowstorm (4-8″) from D.C. north, with locally higher totals.
GFS liquid equivalent (in mm) as snow (initialized 12z 3/13); 25mm = 1

GFS liquid equivalent (in mm) as snow (initialized 12z 3/13); 25mm = 1″, which would be ~ 10″ assuming 10::1

The Canadian is calling the GFS’ bluff with it’s own version of all-in, with snow topping 10″.
CMC liquid equivalent (in mm) as snow (initialized 12z 3/13); 25mm = 1

CMC liquid equivalent (in mm) as snow (initialized 12z 3/13); 25mm = 1″, which would be ~ 10″ assuming 10::1

The European is a much tamer, lighter snowfall… ~ 2-4″.  If I had to offer up a prelim guess, this looks like a 3-6″ snowfall +/- 2″, with most of the accumulations on grass/elevated surfaces.  This time of year, any snow that falls during the day will have trouble sticking, and roads are now much warmer due to the higher sun angle.
Talk to you all tomorrow.


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