Winter 2009-2010 in Annapolis: Round 2

After a wholloping snow storm ("Round 1") back on 19 December, during which I recorded 22" of snow in my yard, Annapolis was hit with another fairly significant snow event yesterday. I'll remember this most recent snow event ("Round 2") not for it's ferocity of wind or for its mammoth snow totals, but instead for its surprise. I discussed early in the week with my students the possibility of 8-10" of snow by the weekend, only to have the QPF bullseye shift south in each successive model run. The 06Z NAM-WRF run of Fri 29 Jan went so far as to predict only 0.01" of liquid-equivalent for our area (granted with a fairly tight gradient of precip, with over 1" of QPF just to our south in south-central VA). I put up that image in both my classes and basically told my students to enjoy a dry Saturday. Subsequent model runs began moving the QPF maximum farther north, but even as late as 12Z yesterday, none of the reliable models indicated that Annapolis would receive significant QPF (all were then indicating between 0.25-0.5" liquid-equivalent). So needless to say when the precip began in earnest a little after 9 a.m., and lasted through 7 p.m., giving a total of 8", I was quite surprised. I think the object lesson from this event is to not be so black-and-white with a forecast, but present the summary of the model output with the nuance that it deserves. (Still not sure how you can "nuance" yourself from 0.01" to > 0.50" of QPF in 26 hrs, though!)

Here are a few pics from the event. I walked over to Jose and Juan Carlos's house in the morning to retrieve my camera and talked them into coming back to my place to spend the afternoon downloading music videos from YouTube and eating soup. We went out to play in the snow (and measure it... what would a good meteorologist be without at least taking some visual observations?!) To that end, I measured 5.8" at 345 PM (1945 UTC), and 7.5" at 545 PM (2145 UTC). Other nearby observers measured 8" in Annapolis at 8 p.m., and my observation agrees well with that, so I'm saying that 8" fell in the Annapolis area yesterday.

Finally, as a heads-up, models are showing cyclogenesis off the Carolina coast *twice* this week: once on/about Tue/Wed, and again next weekend Fri/Sat. ECMWF and CMC, two pretty reliable models, are showing strong cyclogenesis for the 2nd event, and the GFS shows low pressure formation as well, just not as strong. We'll see what falls. Already this winter has seen approx 33" of snow in Annapolis, 22" from the 19 Dec storm, 8" from the 30 Jan storm, and ~3" from various other small events.