Noon Sunday:
High pressure is now firmly in control, so a beautiful period of cold, dry mid-winter conditions are on tap through Monday night. Daytime highs will only reach the upper 20s today, then increase to near 32 degrees on Monday and Tuesday. Overnight lows will range from the single digits in the typical cold spots to mid-teens in town. Daily snow melt on the roads will cause many slick spots during the nightly refreeze; and while the snowpack won't melt much, it will settle/compact a bit in the coming days (since such light, fluffy snow is mostly air). With another storm on the way, however, we will likely be adding to the snowpack soon.

The next storm is very different from the previous storms of this winter. It's an Arctic clipper system that will track from the Northern Plains to the Midwest then into the northern Mid-Atlantic by Tuesday night. Gulf moisture will be limited this time, so initially the system will yield only a moderate snowfall (perhaps 5 to 10 inches) across parts of the Midwest. When the clipper reaches the coast, however, the pattern favors it "bombing" (that's meteorologist speak for "strengthen rapidly"). Atlantic moisture will be tapped and heavy, wind-drive snow may then fall from eastern PA into southern New England. This would place Lancaster on the western edge of the heavy snow. The range on possibilities here are: we get a few inches from the clipper but very little from the bombing low to....we get bombed by the deepening coastal with another 12-inch-plus snowfall! Regardless of the amount of snow received here, this upcoming storm promises to generate much higher winds than the storm we've just experienced. (Wind is a function of pressure gradient, and Saturday's storm only reached a minimum pressure of about 990mb whereas Wednesday's storm is forecast to drop to 970mb!) If this should verify (remember, it's just a forecast, not a given), then the modest drifting of Saturday's storm would pale in comparison to what would occur with this upcoming system. To make matters worse, the potential for 20 to 40 mph winds (with higher gusts) would not only blow the new snowfall, but also our current fluffy snowpack. Should all of these ideas come to fruition, then a REAL Blizzard would result from eastern PA into southern New England! Now that I've said that, please remember that it's all potential and conjecture at this point... Check back here tomorrow for an update, because the players will then be stepping onto the field (kickoff will be Monday night in the Midwest) and, thus, I'll be able to better analyze the match-up in order to release my "line" for the game. (Sorry for all the puns...I couldn't resist. Enjoy the game tonight!)

5:00pm Saturday:
A final wrap-up entry on this most remarkable storm. Snowfall reports across Lancaster county range from 16 to 26 inches, with 20 to 24 inches most common. (Many thanks to all of our great snowfall reporters!) Millersville's official snowfall was 24 inches (1.45" of liquid equivalent), which equals the other two great February storms on record...February 1983 and February 2003. The January 1996 Nor'easter continues as the top dog in terms of snowfall (30 inches), while the Blizzard of March 1993 remains the ultimate "storm of the century" with its crippling wind-blown snowfall (that stretched from GA to ME), record low barometric pressures, and massive drifts (to 10 feet in places!). Still, this winter goes into our record books as having the record December snowfall (16 inches) AND a record-tying February snowfall (24 inches). It's been a great run...can you even fathom a third "major" (12+ inch) event this winter???

The jet stream pattern remains in a favorable configuration for generating another storm. Of course, creating a major snow storm in the East requires that many ingrediants come together just right...which is exactly why they are so rare. Remember, Lancaster averages only four 12-inch-plus snow storms per decade...and we've just had two in a single season! Therefore, it is indeed hard to imagine that we'll get another major storm this season...however, the computer models are bullish on an Arctic Clipper bombing out along the coast of Delmarva on Wednesday. What the models are depicting would become a REAL blizzard for New England, and it could even drop a moderate to heavy wind-driven snowfall on eastern PA. Still, a lot can change in the coming days and it's premature to get too excited about the next storm when there's still snow on the roads from the last system. But I'll keep an eye on it, and provide daily updates. Until tomorrow, wishing you a warm and relaxing evening...and many rich memories of this great storm! --Eric

11:30am Saturday:
Wow, what a storm! Snow lovers in Lancaster county really couldn't ask for more. The axis of heaviest snow set up about 40 miles farther north than expected, so the band of heaviest snow fell in areas between Lancaster and Baltimore rather than between the Mason- Dixon Line and Washington, DC. Many reports from across the county are now nearing (or exceeding) 24 inches, although northern areas are generally running a several inches less (I've had about 20 inches at my place in Manheim Township). Of course, measuring the snowfall accurately is very problematic--any measurement near a house or other large object will be affected by windflow around the object, and of course a lot of the snow from your roof is blowing down as well. So take a hike around your yard and take several measurements in more open areas to create an average (then submit your report using the link below!). The final band of accumulating snow is now descending across the county, so the moderate snow will taper to light snow and flurries in the next hour or so. An additional inch is possible in some places (especially across the south) but at this point it's tough to measure new snowfall versus blown snow. Regardless of the final numbers this storm ranks right up there with the grand storms of February 2003 and January 1996. And on the heels of the record-breaking December 19, 2009 storm, it is all that more remarkable. Of coure, many national media outlets continue to promote the "Blizzard of 2010" even though I have yet to see any official reports of actual blizzard conditions! Winds in our area really didn't come close to the three hours of sustained at 35mph needed for a blizzard. Of course, parts of NJ (perhaps Atlantic City) or northern Delmarva may still experience near- blizzard conditions today... Anyway, it's just one of those hypish (is that a word?) things that really bugs me--we have official definitions for various storms and impacts, yet they just don't seem to matter when someone wants to create a sensational narrative for the national news or an Internet site. I guess we should just start calling any wind-driven rain storm from the south a "hurricane" regardless of the whether the storm actually meets the official criteria! (Sorry for the rant...I'm feeling a bit punchy after three sleep-deprived nights.)

Looking ahead, Arctic air is now filtering in on that north wind you feel outside and tonight will drop into the teens, even single digits in the typical cold spots. Some sunshine will return Sunday and Monday, but with highs only in the upper 20s to near 30 there won't be much melting (although the fluffy snowpack will compact quite a bit, since it's actually mostly air). Another powerful jet stream system will then dig our way with another potential snow event for the mid-week. Check back this afternoon for a preliminary look at this storm. (If you still haven't yet had enough snow!)

7:20am Saturday:
Thanks for all the snowfall reports! It's great to see that some other people were up all night besides me (and PennDOT)... Anyway, your reports reveal the sharp gradient across the county, that we've come to expect this winter, ranging from 12 - 16 inches north of Route 30 to between 18 - 21 inches south of Route 30. I would expect another 3 to 8 inches of snow (although determining new snowfall versus blown snow will be difficult) before things taper off from late morning into the early afternoon. The long band of snow stretching across southern PA will gradually sag southeastward as the upper-level low, now over WV, pivots across VA and out to sea this afternoon. 10 to 20 mph winds will shift more out of the north this afternoon, so blowing/drifting will continue. Temperatures will hold nearly steady today, then drop into the upper singles to mid teens tonight as winds gradually decrease.

4:30am Saturday:
Okay, I've slept on it for an hour... I'm bumping my accumulation forecast to 18 to 24 inches across the southern portion of the Susquehanna Valley! See the revised Storm Outlook map below. Reports are coming in of 16+ inches in a few spots south of Route 30, so some of these locations may approach 2 feet of snow and perhaps a couple spots nearer the Mason-Dixon line get 26 or 28?! If so, this would make it the largest snowfall since February 2003 (24 inches fell) or perhaps even January 1996 (30 inches). Areas near and just north of the Turnpike are looking at 10 to 18 inches, with a sharp dropoff in snowfall amounts going northward towards I-80. Winds continue at 10 to 20 mph with some gusts to 30mph; this is not enough to officially make it a Blizzard here, but it's still a crippling storm and certainly many people will be using the "B word" to describe it here. Anyway, the coastal low is now deepening and beginning to track east into the Atlantic. So the large east-west band of snow, now across PA, MD, DE, and NorVA will begin to thin from the top (north) southward, while dry air tries to entrain in from the south. You can best view this trend with the regional radar. So I expect the snow to taper off across northern PA during the mid-morning and then taper off across the southern counties during the midday and early afternoon. BTW, given the magnitude of this storm....I want to return to something I pointed out a couple of days ago. Experiencing the December 19th snow storm (~ 16 inches) AND now this storm (20 - 24 inches in city?) in the same winter season is truly amazing and historic. Only three times before, in over 80 years of records, have there been two 12-inch-plus events measured in the Lancaster (city) area. Take lots of pictures and soak up the grand experience you have been gifted today!

11:30pm Friday:
I just measured 6.5 inches at my house (Manheim Twp.) and, as I'm sure you've noticed, the snow is becoming noticeably drier and the winds are picking up. Northeasterly winds of 10 to 20mph, with higher gusts, add blowing and drifting to the mix overngiht through Saturday afternoon. The heaviest snow is on tap the next 6 to 8 hours, before a gradual taper-off develops (from north to south) late morning into early afternoon. With snow totals now in the 5 to 8 inch range across the county (and over a foot in the mountains of southcentral PA) it's beginning to look like this storm will exceed the big snowfall we experienced on December 19, 2009! Of course, measuring this snowfall will be more difficult since the wind will be blowing the snow around (whereas there was minimal wind with the December storm). Anyway, it's sure looking like there will be spots across southern PA that may receive 20 or even 24 inches. Perhaps that 18 - 24 inch band on my Storm Outlook map needs expanded a bit farther northward? Let me sleep on that for a bit... Enjoy the storm!

9:00pm Friday:
Just returned from a family hike in the snow--what a gorgeous evening! Fresh, sprakling, peaceful snow falling and the smell of wood-burning fireplaces in the air...absolutely wonderful. Here's a snapshot of my happy gang enjoying the evening. :-) Anyway, all systems are go with this storm and the snow is already piling up across the region. There are several reports of 4 inches across the southern half of the county, and the next heavy band is now developing over northern MD and heading our way. Model guidance has become more steady the last 12 hours with all models finally on board with the idea of a 10+ inch snowfall across our region, and twice that in the areas of maximum snowfall (which I continue to feel will be an west- east band roughly parallel to the Mason-Dixon, but centered about 20 miles south of the state line). If you want to see/experience the heaviest snow, then set your alarm for around 2:00am and head out for a hike. I think I will!

Here are the links to view a full listing of reports submitted to the MUWIC and NWS co-op reporters from around the Commonwealth.

7:30pm Friday update:
Temps have dropped below freezing and the first band of heavy snow is now moving across Lancaster county from the south. I received a report from a recent MU MET grad in southern York county--he received 3 inches in one hour as this band passed over last hour! While I can't guarentee this amount of snow in your location, the band will bring our first good "pop" of accumulating snow this evening. This type of storm is "all about the bands"...places that received several of these heavy bands are where snow totals will approach 20 inches. While you can view these bands developing over the region on the NWS radar composite (look for the dark green and yellow bands), they are best viewed locally on the WGAL radar (although there are some false "holes" in the precip over parts of York and Lancaster due to ground clutter algorithms). These bands typically form, progress, and then begin to fizzle over the course of an hour or two (think of summertime thunderstorm evolution on radar); they are dynamic and somewhat random features, so while they are easy to observe, they are hard to forecast. Check back for another update around 10:00pm or so.

3:30pm Friday update:
Whew! Is it Spring yet? I'm just glad this storm is going to miss our area....

(Just kidding!)

Okay, the storm is developing pretty much as expected. Surface temps got a bit warmer (upper 30s) today than expected--further proof that this is not a classic front-end loaded system, but instead a complex hybrid "jump" storm. Expect a few surprises, in terms of how this storm pans out and the snowfall it produces. Lots of crazy numbers are being thrown around. I heard the NWS is calling for 22 - 30 inches in Washington, DC--that could bust by a fair amount! First, it's been snow there for a few hours with no accumulation due to warm low-level temps. Furthermore, the first half of this storm, which is being feed by a subtropical plume, will be rather warm aloft and not so ideal for snow crystal growth aloft. As a result, I expect the first half of the storm to yield rather wet snow at a 10:1 ratio; this holds for everyone in the region, both here in PA and down in MD, VA, NJ. As the secondary low develops overnight, the atmosphere will cool both at the surface and aloft. Surface temps will drop into the 20s overnight while temps aloft (where the snow flakes are being generated) will cool to around -15C, which is ideal for crystal growth. As a result, this evening's wet snow will turn into a moderately dry snow by daybreak Saturday...and so the latter part of the event may yield snow at a ratio closer to 15:1. Anyway, I think VA may underperform (relative to the NWS snowfall forecasts), and I continue to believe that the axis of maximum accumulation is from Garrett county MD east along I-68 and across northern MD and northern Delmarva (per my Storm Outlook map below). The southern counties of PA will be oh so close to the max snow.... I'm sticking with the 10 - 18 inch forecast here, but I won't be surprised to receive a few reports of 20" across the southern counties of PA. Convective banding is always the wild card with these Nor'easters--get a band over your head and you get a couple hours of 3-inch snow per hour, whereas if a band sets up just upwind of you, then you get robbed of moisture and get much less snow than you otherwise would have. These are things we can watch for on radar later tonight and early Saturday.

I'm going to shift into more of a blogging mode this evening, so I'll be making numerous entries here throughout the storm. I invite you submit your snowfall reports (below). Enjoy, and be safe out there!