Midday models confirm the trends for a more amplified system, and other than northeastern MD, we are all under a winter storm warning for 5-10” of snow (north to south).

I’ll update with more specifics later this evening.

Let me preface this by saying that the short-range 12km NAM model has a reputation of being on steroids and has a tendency to over-forecast precipitation totals.  However, this morning’s midday NAM is hard to discount, especially when its brother, the 3km, also ups the ante.  Both show the coastal low that develops tomorrow in a more favorable position that would give the region more precipitation into Sunday morning.  If I was a forecaster, as of now, I would still go with a 3 – 5″ event generally from north to south across central MD, but I would add the caveat that it’s subject to change.  That accumulation range is based pretty much solely on an approaching warm front from the southwest that will override cold air entrenched at the surface (it’s called warm air advection) ultimately causing lift and in this case, precipitation.  In the meantime, a weakening storm center in KY/TN will eventually transfer energy to the coast tomorrow.  Where that new storm forms could have impacts on our area and the nam says we should keep an eye on forecasts throughout the day today.

I have plans during the day today but will stay current on model runs.  I may send out a couple of short updates as those runs complete, so hopefully I won’t be cluttering anyone’s mailbox (as I write this, some of the other intramural league midday models are also showing an increase, but I want to wait until the midday Euro run to start celebrating).

All the mid-day runs are in and the trend of small positive changes continue.  Every model is now depicting at least a 3 – 5″ cold snow event beginning tomorrow evening into Sunday morning.  The Canadian RGEM and the US FV3 have the most snow, which is always concerning when the Euro doesn’t agree, but the most recent Euro does now show a solid snow event across the area.  Not as much as the other two, but a significant increase from its earlier runs, and a solid 3 – 5″.

As of now, the NWS has not issued any watches or advisories, but I expect that will change in the next few hours.  The best news is that we are still over 24 hours from the start, so there is still time for more improvement.  For this to become a really good event, we need the coastal low to throw back some Atlantic moisture, and I still think that is unlikely for us in central MD, but the recent model runs suggest it’s something to keep watching.

By the way, there’s been some recent chatter that the US weather models have been compromised by the federal government shutdown, but I have read from meteorologists that work for the NWS, that that is not the case.  For whatever reason, the verification scores of the GFS temporarily dropped around the time of the shutdown, but there was no correlation.  The American models are being fed the same data as always.

More later.

The early Euro run hasn’t come out yet, but some of the other morning medium and short-range model runs look somewhat better for tomorrow night’s snow event, specifically the new GFS (fv3) and the Canadian short range RGEM.  Even on those two “best case” scenarios, it’s still modeled as an advisory event for central MD of 2 – 4″, but I’ll be watching the model runs closely today to see if we can eek out a high end advisory or even a low end warning over the weekend (warnings are for 5″ or more, which I still think is unlikely for central MD with this system).  I’ll write a more detailed update later today or this evening after all the mid-day runs.

By the way, by the look of the long-term models, tomorrow night may be just the beginning of what could be a very memorable stretch of winter weather.

The development of the storm has changed but the result for central MD still looks the same.  For now, I’m still thinking light snow should develop Saturday evening and continue into Sunday morning with accumulations from an inch in northern areas and 3″ in the areas closer to DC.  Temperatures will be below freezing so Sunday morning may have some slick spots on untreated surfaces.

A coastal storm will form during the day on Sunday but right now it looks to be too far to the south to have an impact on central MD.  I’ll update tomorrow afternoon on any changes.

The mid-day model runs are done for the day, and there is fairly good consensus that central MD should see some snow this weekend.  The GFS has been the most erratic with one recent run giving the region as much as a foot and then six hours later it turns around and gives us flurries, while the Euro has been fairly consistent with a modest 1″ to as much as 4″ event.  Interestingly, the Euro has shown a slight increase over the past 2 model runs, so with 4 days to go, if this is a trend, then there there may be some room for improvement.  Hopefully the incremental increases continue, but for now, just know that snow is possible beginning Saturday evening and lingering into Sunday morning with modest accumulations.

I’ll update again tomorrow.

You know it’s been a bad winter when it’s January 7th and BWI has recorded only 1.7″ of snow, but as bad as it has been here, it could be worse.  Normally snowy Boston, for example, has only recorded .2″ of snow, and other than the early December storm that hit southern VA and western NC, just about everyone along the east coast has been void of snow this year.  However, that looks like it’s about to change. A well-advertised pattern change is coming and all signs are pointing to an extended period of quality winter weather for the entire eastern seaboard.  Whether or not the mid-Atlantic scores in the next 6 weeks is a completely different question because a good pattern doesn’t always translate to good snow, but I have to admit that I like our chances.

Though the pattern doesn’t look like it takes a firm hold on the area for another week or so, our first chance of snow is this weekend.  The gfs and euro have differing solutions right now so no point going into great detail other than to say that Saturday evening and early Sunday bears watching.

There hasn’t been much to talk about since missing out on the big snowstorm that hit the Carolinas a couple of weeks ago as things haven’t been very good for snow lovers across the mid Atlantic.  On the bright side, as much as I would love to see a big snowstorm for Christmas, if we can’t have wall to wall winter conditions from Thanksgiving to March, then December is probably the best month to forfeit.  After all, our biggest snow storms generally come in the second half of winter, so if we have to have a cruddy snow pattern, we might as well get it over with in December.  Of course, a bad December does not mean that things will improve in January or February, but in the case of this year, there’s is a lot of chatter that things may change for the better around the New Year, and maybe for the much better.

Mid to long range models are suggesting that the abundance of precipitation that we’ve had over the past 7 months will continue, and most important, that our current cross-country zonal flow of Pacific air will eventually buckle resulting in a ridge in the western US and a trough in the east.  That should translate to warmer conditions out west and colder in the eastern half of the US. Though the change is still a couple of weeks away, just about every model is now showing that not only will the trough happen, but that it may be persistent.  Combine that with the high latitude blocking that is also showing up on some models, and the necessary ingredients could be lining up for some good snow opportunities after the first of the year.

Hopefully there will be more to talk about in the next week or so.

All models presently keep the Sunday/Monday storm well to the south but I am still holding out hope that things will begin to change in our favor in the next 24 hours.  Also, the cold pattern that recently looked like it would breakdown and become warmer, now looks to instead reload and give us more opportunities for winter weather as we head into the holidays.  So even if this weekend isn’t our storm, there look to be other opportunities in the near future.

Hopefully, I’m not cluttering anyone’s email, but the old GFS and the Euro still have not come around to the idea of a snowstorm for central MD this weekend.  However, this morning’s experimental FV3 is a great hit for all of northern VA and MD and even southern PA (again, the FV3 will be replacing the current GFS early next year). Snow begins Sunday morning, is heavy during the afternoon and evening, ending early Monday.  Snow maps at this range are silly, but it would definitely be a major event for the area.

Though one event should not be used to crown a particular model suite, it will be interesting to watch and see how all of this plays out.  In the meantime, an arctic front crosses the area tomorrow bringing fresh cold air, brisk winds, and the possibility of snow showers.  Beyond tomorrow, clear skies and cold temperatures in to the weekend.