Main Event: GFS v EC

Good morning,

Lots of chatter about snow this weekend… but I’ haven’t been able to do any real looks until this morning, with work and issues outside of work needing my full attention.

As for the weekend, we appear stuck in a pattern where we have record-setting warmth while we are at work/school, and then cold, windy, unsettled weather arrives for the weekend. This weekend will be no different.

Short version: A good bet of cold rain or perhaps wet snow — the latter most likely in the Piedmont and western mountains — Sunday into Sunday night. We could see a coating or so on grassy surfaces, but this is still 3 days away and a low-confidence forecast. There is the potential snow could be heavier (The European), or that we could get just light cold rain (the GFS). It’s too early to pin it down, so if that’s all you need for now, I’d stop there.

Long version: We’ve got all the ingredients for a snow storm, except it’s entering the 3rd week of March. The NAO (North Atlantic Oscillation (a measure of whether or not we have the requisite blocking high over the northern Atlantic (if we have a blocking high, it’s “negative”))) is as negative as it has been since our blizzard… supporting the idea that we’ll have a high to our north and a coastal low this weekend. But the blocking high is not going to stick around… it’s more a transient feature… so the models are handling this weekend’s weather vastly different. If the blocking north Atlantic high were to sit tight for a week, then I’d issue at the very least a Fat Free Milk Advisory, or perhaps even upgrade this to a Toilet Paper Watch. But it’s not… and again, the models are all over the place with how this plays out.

First bowl of porridge, the U.S. GFS model: According to the GFS, it’s a non-event. The blocking high breaks down (not like a nervous break down), and the coastal low scoots out to sea. It’s faster too, with the pcp – cold rain — arriving late Saturday and lingering into Sunday morning. The GFS’ gut-check models, the tweaks and reruns known as Ensembles”, all agree, to the point where it’s hard to just toss the GFS forecast out the window.

Second bowl of porridge, the European: This model, called the “EC” (for “European Community” Model (or the “Burning Bush”, tongue-in-cheek by yours truly)) and the GFS are the two big hitters in medium range (3-5 day) forecasting. And the EC is all about a negative NAO/blocking high and a subsequent strengthening coastal low… and yes, a rare late-March snowstorm… like 4-8″, Sunday afternoon into Sunday night.

Second Bowl, side of cinnamon… the UKMET model: Hard for me to separate this from the EC, as these often say sort of the same things being essentially from the same folks… even though this one is run solely by the UK Met Office. The UKMET model says if you put your snow blower away, get it back out. It’s got the Toilet Paper Watch and a SOB Advisory in effect (Stock up On Booze). Snow, potentially heavy, Sunday evening.

Third bowl, the Canadian model: The CMC usually doesn’t see a potential snowstorm it doesn’t like. That’s why it’s handling of this event is a bit surprising. It’s literally like the 3rd bowl of porridge… not a lot of snow, but not none either (how’s THAT for a double negative!)… it has wet snow in the Piedmont Sunday afternoon and evening, but not a snowstorm. Probably enough to whiten the ground and non-paved surfaces.

Desperate times call for…

The Navy NAVGEM (formerly NOGAPS): We joke that if you are really desperate for input, look at the NAVGEM/NOGAPS. This model is famous for having ominous looking storms that miraculously produce no pcp. But the NAVGEM/NOGAPS is all-in on a snow storm Sunday evening. Esp the latest run (the 06z). Huh.

OK. I’ll keep you posted…. but I’m gonna be touch and go with work and things outside of work.

Take care.

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