jayyy

To put this question in common folk terminology, why is the 18z GFS so moist? Big punch from the WAA or is it the coastal?

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post those snow maps peeps, you know the drill Pics or it didn’t happen

Getting a bit chippy lads

Watching the radar weaken a bit as precip crosses over the mountains in E TN is as predictable as the end of an adult film. Shouldn’t worry folks around here much unless that trend continues as it goes further east.

Clouds overhead finally

Ahhh… the ‘ole east based niña, but acts like a niño pattern. Prepare for pummelization (Everyone except Ji)

Hugging DT’s call — famous last words

It’s a screw zone relative to the precip maxes in E MD / DE and WV…. But I agree, as far as this subforum is concerned, it depicts a pretty uniform 2-3” event.

All we need to do is will the initial shortwave into holding together and eventually merging with the coastal… instead of seeing it fade out as it approaches our area and transferring its energy to the coast Come on guys, we’ve got this.

For sure. I agree fully. As far as nws is concerned, their forecast makes sense. General 2-4” with lollies up to 6”.

Relatively clueless on whether or not the DC to BAL corridor will see 1” or 6” within 12 hours of a storms onset. You know… the usual.

One thing is for sure - some places will get 1-2”, while others relatively nearby see 3-4-5”. Nature of the beast when you’re banking on banding and WAA. Could very well see dc metro at 1-2” with Baltimore hitting 3-4” in this setup. Or both see 1-2” with 3-6” totals to the NW and NE of both metros. That line is very fine in these setups and often comes down to very minute differences in timing, track, thermals, etc. If you stick with 2-4” as the general forecast, it’ll likely verify for 90% of the CWA. Nowcasting is when we’ll be able to verify where the lollies / jackpot zones setup. Somebody expecting 6” will see 1-2” and somebody expecting 1-2” will see 6”. That's how these setups almost always pan out. We use previous setups to make our best educated guess on where that occurs leading up to the event, but we won’t know until it happens.

Indeed. How many times have we said “the initial slug of precip came in faster / heavier than modeled” or “we were a few degrees colder than modeled due to heavier precip than expected at the onset” after a marginal event was over? It certainly happens. Will it happen here? Maybe. Hard to know. We should get an idea pretty early on regarding how much of that precip is getting eaten up as it crosses the Apps. But it’s DC to Baltimore’s (central MD) best shot at seeing the higher end totals being depicted by the Canadian and GFS - as the likelihood the coastal gets going early enough to throw Atlantic moisture into the CWA is very low (models see that happening in southern New England - not anywhere near our latitude) The 4-5” being depicted near Baltimore could just be the obvious shortcomings of using global models this close to an event with this type of setup, but it’s still possible if the initial energy manages to hold together for a few extra hours. That’s why it’s best that we blend models at this juncture, which is why I think NWS’s 2-4” with 5-6” lollies area-wide is a very reasonable forecast for most.

Precisely! Each model has its relative strengths and weaknessess and some do better in a given setup, but there’s no model we can point to as gospel here or in any setup really. If the NAM GFS Euro HRRR RGEM show 1”, 2”, 3”, 4”, and 5” in your backyard respectively — I’d say 2-3” is pretty good bet. We of course all want to lean on the snowiest solution in any setup, but how often does that pan out? We typically see one model nail track, another model nail thermo profile, etc. Find a reliable model blend and know your climo. Good rules of thumb for sure.

Perhaps it is… so long as the MSLP stays in tact and tracks SW to NE to our south. Man, oh man, that’d be nice

It’s 1 model. The rest don’t. Think you’ll be alright up there friend. We’ve seen only 1 storm this year - can’t win em all. Last year, we were the ones cashing each storm as the 95 corridor saw zilch all season.

The gfs actually gives Baltimore and it’s nearby suburbs more snow than Winchester. Interesting.

The gfs actually did quite well handling that last storm… it was just a bit off on where that sharp cutoff would be. It had it further NW. otherwise, it handled the evolution of the system pretty well. Missed on the totals near I-70 and Richmond though With that being said, this setup is much different. Meso models are much more important for this type of setup when we’re talking about banding, transfer of energy to the coast, etc. GFS does well when it comes to handling one main area of low pressure tracking to our south. Not so much when we’re talking about two distinct areas of precip / lift and the interaction between them. The GFS tends to oversimplify things and see things much more uniformly, missing the nuances of miller b type storms.

That being said - the GFS just said F U and is sticking to its guns. DT is definitely hugging the GFS

If you live in the DMV, being in the northern portion of the CWA will benefit you 8/10 times, if not more, on average. Just been a wonky start to the season. Moving up to Union Bridge from south of I-70 has been night and day for me the past few seasons. HighStakes is right - it’ll even out - and then some. Just continue to be patient Tonight’s setup is much better for WV/ NVA & NE MD and points NE, than it is for the 95 corridor and central MD. As Bob Chill has warned us of a multitude of times, these types of storms do not typically end with the DC to BAL corridor / central MD jackpotting. The mountains eat up precip from the initial wave and the coastal gets going too late, leaving the middle of the CWA relatively dry in the middle, sandwiched between the two areas of best lift. We won’t know until the storms overhead, as models don’t always get the timing / placement right… but latest trends aren’t the greatest for 95. Models are bringing in the precip later And with less of a punch - neither of those scenarios help their outcome. If you’re expecting warning level snowfall, it’s more than likely you’ll be disappointed. However, if you’re cool with a solid few inches and a few hours of rippage, you’ll be satisfied. NWS’s call for 2-4” areawide with 5-6” lollies is a perfect call, IMO. No model will pinpoint exactly where these bands setup shop. It’s best to be realistic in these setups. Clskins area will see more snow than Baltimore or owings mills or dc 9/10 times in these setups. If you want warning snowfall in this setup, hug the GFS tight. It keeps the initial slug of moisture together, keeps the column cool, etc. 3-6” areawide.

These model runs tomorrow can’t come soon enough.

Let’s go!!! GFS looking prime for 95 This situation may be better suited for meso models, given the banding setup, but I’ll take it.

Great write up! Thanks for all of the info! Early trend forming perhaps that the deform band could form along or west of the bay?? Timing is everything here as you stated. Tomorrows 12z meso model suite will be absolutely crucial

Things getting a bit interesting for Baltimore and the I-95 corridor on the mesos as we get closer to the event. 3-5” looking likely for many. Suspect someone in WV will see 10” from this