All Systems Are Go!

Sunday, January 5, 6PM

Snow may move in a bit earlier than the midnight to 3AM that I said earlier, but no big changes otherwise. Once snow develops, it will quickly become moderate to heavy across the area and continue through the morning, then should taper to lighter snow showers through the afternoon. After sunset, the upper level low will cross the area and could bring another few hours of accumulating snow. I also think I should bump totals slightly, and now feel that we are looking at a 5 – 10″ event across central MD, and possibly more than 10″ in the areas that get under the heavier bands.

It’s going to be a fun storm, so I’ll send another update in the early morning as things get going.

Still on Track for Snow

Sunday, January 5, 11AM

I can’t recall the last time we had snow coming with a legitimate arctic air mass in place, but that’s what we have beginning tonight. The watches from yesterday have been upgraded to Winter Storm Warnings across the entire area, so decisions for school systems should be easy and quick. They will probably start announcing closings later this afternoon with an annoying scroll across Uncle Nam’s TV football games.

Models are still in some disagreement on how it all plays out for central MD, so my overall confidence in snow totals is not very high. For what it’s worth, my current thinking, and I am fairly confident on this point, is that snow will develop from southwest to northeast between midnight and 3AM. Snow will become moderate to heavy quickly and continue into the morning. Morning travel is not recommended as temperatures for the duration of the storm will be below freezing. By noon, I am expecting anywhere from 3 – 6″ to have accumulated. During the afternoon there will be a lull in precipitation with snizzle and maybe even freezing drizzle. During the evening, another steady area of snow should develop and add an additional 1 – 2″ to freshen up any crusty snowpack for a total of 4 – 8″.

Regarding the low confidence in snow totals, for central MD I think the chances of being under the 4″ threshold is less than being over the 8″ threshold. This storm will be packing a punch in the morning hours as warm air from the system collides with the arctic air. If we are going to get the higher amounts, it would most likely be during the morning hours. The afternoon lull and evening 1 – 2″ seems reasonable to me. It’s the morning that could, and hopefully will provide some surprises.

If I see anything different, I’ll send out shorter updates during the day.

The Biggest Snowfall In Years?

Saturday, January 4, 9:30AM

The National Weather Service has issued Winter Storm Watches across all of MD for the expected snowfall late Sunday night and Monday. The exact track has yet to be determined, but the major models suggest at least 4″ of snow for the entire area beginning around 1AM Monday morning. With temperatures expected to be below freezing across central MD for the duration of the storm (and probably for the entire workweek after), travel and schedules will likely be impacted. For the weather nerds (that is a term of endearment), more details follow.

A couple of days ago, I was concerned about a north trend in both the GFS and the Euro. Long- time followers of The Weather Mill know of this specter and how it can bring simultaneous tears of joy or heartache depending on the circumstances. January 30, 2010, is an example. That was the winter of the three blizzards; one, the week before Christmas, 2009, and the two that were days apart in February 2010. After the blizzard in December, we settled into a non-snow pattern through late January. Then, a storm that was expected to bring snow to the Carolinas, was suddenly nudged by the north trend specter and gave us a decent snowstorm bringing tears of joy to Mid-Atlantic snow-weenies, while Carolinians wept. You won’t find the term “north trend specter” in any meteorological textbook, but I assure you, it exists.

Anyway, back to our current storm. As I said, a couple of days ago I was becoming concerned that this north trend was happening to us, and as many of you know, it happens to us with frustrating regularity. But what was once our storm, was now becoming Philly’s, or even worse, New York or Boston’s. Every six hours, model run after model run kept ticking the storm north. Where we once were bulls-eyed by the storm, we quickly became underneath it as areas north of the Mason Dixon Line looked to get the goods. But, in a single run overnight Thursday, the Euro went from slipping north to suddenly way south. Richmond snow-weenies were high-fiving and northern MD’ers were kicking dust bunnies. The gfs also starting ticking south but not as drastically as the Euro. We were still going to get snow, but there is still a sickening feeling seeing (ridiculous and wrong) snow maps suggesting a foot of snow, and then six hours later seeing the same map with 3″ of snow. I know it’s unhealthy and I probably need medication, but once I get teased by a snow map, regardless of how much the 5% of me that is rational resists it, I get greedy.

Since then, the Euro stopped sagging south, stabilized, and in recent runs has ticked a bit north, but still too far south for central MD to get into the really greedy stuff. Don’t get me wrong. There’s a lot to like about the Euro. With the heaviest axis of snow to the south, so is the warm air, and as a result, we are in the low to mid 20’s all day Monday with a steady, fluffy snow that isn’t going anywhere. Per the latest run of the Euro, about 4″ of snow falls at the Mason Dixon Line and then increases to about 6″ in Baltimore and to 8″ just north of DC. So, a general 4 – 8″ of snow, and probably exceeding my biggest snowfall at home in years. I should be satisfied.

Meanwhile, the GFS is similar to the Euro but brings the goods a little further north. Like the Euro, snow starts around 1AM on Monday morning, but is heavier into the morning commute, maybe a dry-slot of light snizzle during the day, and then another round in the evening as the upper level low passes and transfers to the coast. Total snowfall on the GFS is about 6″ along the Mason Dixon Line, 8″ around Baltimore, and nearly a foot closer to DC.

Then there’s the NAM. The NAM is like your drunk uncle that passes out watching football during the holidays and wakes up occasionally to yell at the terrible call of a play on TV that’s actually a commercial for Levi’s. The thing is, that every once in a while he gets lucky, wakes up at the right time and makes a very good observation. Uncle NAM is showing a general 8 -10″ snowfall across all of central MD that frankly, isn’t too hard to believe. Just know that with snow, I’m irrational.

My personal opinion is that the dust hasn’t settled yet and we don’t know where the biggest axis of snow will be, and most importantly, how we get there. I do think it’s going to snow, and it’s going to be impactful. I just don’t know what path we end up taking. It would be great to wake up on Monday morning to moderate snow that continues all day and then stops just after sunset, but I don’t think it plays out like that. We are going to have to watch for all the regular caveats around here including the dry slot, a warm layer in the mid-levels that changes snow to sleet, and the dreaded “rob Peter to pay Paul” transfer of energy to the coast. I’ll save the meaning of that weather term for another day.

I’ll update later today.

This Afternoon and Evening Commute

Friday, January 3, 6AM

There’s a lot of potential winter weather to talk about over the next 72 hours with Sunday night and Monday beginning to come into focus, but for now, I am going to focus on this afternoon’s system. I’ll update on the Sunday night/Monday storm later this morning. Also, apologies for the ramble, but I don’t have time to do any real proofing right now.

A clipper system will cross the area this afternoon and bring the potential for a strong line of snow showers. Depending on location, surface temperatures may initially be too warm to support snow, but any rain will change to snow quickly. This is not expected to be a long duration snow event, but it is worrisome because of the potential brief intensity and also the timing. Right now it looks like a line of showers will cross central MD from about 2-4PM. Surface temperatures at the time are expected to be above freezing in all locations, but in the areas of heaviest precipitation, high snow rates could overcome warm temperatures and briefly accumulate on even roads. This could happen anywhere across central and northern MD, but models have focused on the northern tier (along and north of I 70) as the most likely areas to have issues. As a result, the NWS has issued Winter Weather Advisories for the counties bordering PA (Frederick, Carroll, Baltimore, Harford, Cecil) as well as Howard county.

Again, this will not be a long duration snow event and for many areas the snow will not be an issue. There is some concern however, that once the front passes and temperatures drop relatively quickly, that there will not be time for pavement to dry before temperatures fall below freezing this evening. Again, most likely areas for concern are the normally colder areas to the north.

So, in brief, this afternoon will probably be no big deal for most areas, but be prepared for a brief period of heavy rain to snow showers, and possible icy conditions once the sun begins to set.

More on Sunday night and Monday later this morning.

Snow Squalls Tomorrow Afternoon. A Significant Storm Possible Early Monday

Thursday, January 2, Noon

A reinforcing cold front with an associated Clipper system will cross the area Friday afternoon and may bring some snow squalls. Models have been focusing on right around sunset for any shower activity, but with temperatures expected to be above freezing, any impacts should be relatively minor.

Behind the front will be gusty winds and even colder temperatures for the weekend, setting up what may be our first accumulating snowfall of the season Sunday night and Monday. We are still over three days out so details still have to be ironed out. My biggest concern is that over the past 24 hours, models have been consistently ticking north with the system, which could introduce the dreaded mixed precip, or even all sleet. Presently, both the early Euro and midday GFS runs have central MD in the “all-snow zone,” but there isn’t much wiggle room left as some sleet is being depicted just south and east of DC. I am admittedly concerned the north trend isn’t over, but hopefully models have made their biggest adjustments and won’t have any serious shifts over the next few days. It’s still a early to talk about potential snowfall, but regardless of whether we are all snow or not, there is growing consensus that Monday morning’s commute will be impacted.

More later.

It’s About Time…

2024 may be going out with a bang regardless of your New Year’s Eve plans as a strong cold front crosses the area this evening. Expect a line of showers and possible thunderstorms from about 5 to 8PM from west to east. After the frontal passage, gusty winds and seasonably cooler temperatures for tomorrow, New Year’s Day. Then, a cold air mass settles in and, as far as temperatures are concerned, we may be in for the best stretch of winter weather in several years. Models have been advertising a prolonged stretch of cold lasting at least into the second half of January. Even better, normal to even above normal precipitation is expected. Whether that translates to snow is still to be determined, but models are already starting to focus on a few threats.

First, a weak clipper system may bring some snow showers to central MD Friday evening and night, but it does not look to be anything more than cosmetic, and even that may be too strong a description. The next system for Sunday night into Monday has greater potential, but I would not expect details being ironed out until the weekend. After that, we will have to wait to see how deep and broad the trough is that sets up over the eastern half of the country to see if we can reel in a sizeable event.

Regardless, the buzz from the pros is that the next few weeks has more potential than any winter period over the past five years. Frankly, that isn’t saying much, so I’ll be trying to keep my enthusiasm in check until I’m confident of snow. But it does feel pretty good to start tracking potential storms again, and I hope to be updating more frequently these next few weeks. Fortunately, and thanks to my secret Star Buddy’s mug gift, I am ready to go!

The computer image below (courtesy of Pivotal Weather) is from today’s 12z European model run depicting 1AM Monday morning. But be warned. Long-time followers of the WM know that snow in these parts can be fickle, so don’t get your hopes up just yet. Winter here is almost always a bumpy ride.

Saturday AM Travel

If you’re traveling early tomorrow morning, there may be icy conditions because of falling temperatures overnight and residual moisture. Beyond that, the holiday week looks rather uneventful other than some possible rain showers early in the week.

Looking further ahead, the models are teasing a much better pattern for snow beginning the first week of January. We’ve seen this before over the past few years, so we’ll have to see how it plays out.

Happy holidays!

Update for Thursday Morning

4PM, December 4

The nam still likes a strong line of snow squalls between just before or during the morning commute across all of central MD, while the hrrr has the same line but it’s rain. The NWS has issued a special weather statement for the normally colder areas to the northwest including Carroll and Frederick counties for the possibility of a quick burst of moderate to heavy snow that could cause icy conditions for a short time. If you’re traveling to or from those areas in the morning, you may want to leave a little extra time.

For the rest of us, although it is not likely, it’s possible that the immediate metro areas could also experience a moderate to heavy burst of snow with the passage of the front. Temperatures should be above freezing but be prepared for the possibility of reduced visibility and even slippery conditions during any heavy snow.

If things look more promising for snow, I’ll update again.

Probably Not a Big Deal For Us

Tomorrow morning doesn’t look to be real problem for the commute, but one of the higher resolution models (NAM) has been consistent from run to run that a line of moderate snow showers will cross the area around 6-7AM. Combine that with the always accurate HRRR that comes into range this afternoon, and I’ll keep watching and needlessly update later today.

Meanwhile, the mountains are under a blizzard warning for the same system, so snow lovers can at least look at webcams of Canaan and Wisp later tonight and early tomorrow in the hopes of an early season snow fix.