WxUSAF

The issue is the TPV is not dropping down toward Hudson Bay anymore on the GEFS. Instead it stays strong and moves up over the pole. If it’s going that way, I’d rather it go park itself in Mongolia than hang over the pole.

Huh?? 6z? Looks pretty rough to me.

Healthy looking snow squall near the m/d line. Heads up @mappy @psuhoffman @losetoa6 @HighStakes

Agreed. That’s pretty tasty as is and a tick or two away from top tier longwave pattern for mid Atlantic snowstorms.

Wife reports flurries in Columbia a little while ago

As I recall, Boxing Day storm had some warnings of a fail ahead of time. Was kind of on/off the model progs, we were always kind of on the edge, Miller B risk, etc. March 2013 was just a complete out of nowhere gut punch. I’ll never forget going to bed with this wall of snow approaching on radar, people on here in central VA seeing heavy snow and already exceeding forecast amounts. I told my wife I thought we’d get more than expected. Then I woke up the next morning and it looked like Monday morning with like 1” of slush and I just was dumbfounded.

HMs take on this discussion

@tombo82685, yeah will be interesting to see how things look in 48-72 hours. GEFS starts moving the TPV south on the 28th, and not coincidently, that's when the EPO ridge goes up. That's the mark on the wall. 6z GEFS actually accelerated things a bit relative to the last few runs previously.

Trend for strong southern stream shortwaves rolling across the country the last 2 months is clear. Have to think odds of a widespread big dog storm is higher than normal when you add in the trend of HL blocking. Still maybe less than 50-50 odds, but still above normal.

Bob, I agree that I think we'll get there eventually. Whether it's on Dec 29 like the GEFS thinks, some compromise of Jan 3rd-ish, or probably Jan 7 or after as EPS might suggest (via extrapolation), I don't know. I'd probably chicken out and lean toward a compromise of the first few days of January if I had to pick. One thing I came across in reading this morning is that there's a pretty huge snow cover deficit in Eastern Europe and western Russia. Always a bit of chicken-and-the-egg situation, but that might help bolster the Scandanavian ridging that keeps reloading the east -NAO and occasionally west -NAO and can be seen clearly on your CFS map above.

GEFS and Eps diverge significantly after D10 as has been said, but they’re very similar at D10. One subtle difference between them at D10 is the one that loads a good pattern for us on the GEFS and bad on the Eps. On the Eps at D10, the TPV is stronger and slightly more NW (poleward) relative to the GEFS. GEFS has the TPV a bit weaker and then moves it southward over Hudson Bay after D10. Eps keeps it at high latitudes and leaning toward Alaska. The tropical forcing and the wave 2 hit on the strat vortex peaking around Xmas suggest an evolution like to GEFS should happen eventually, but wouldn’t be surprised if it’s after the new year and not a few days before like the GEFS has.

Based on the forecast I’d wager we end the month +1-2F. Depends how many torch days we get. What’s indisputable is that our warm days are almost always warmer than the cold days are cold .

Yes. Think it happened early this year.

I can’t get plots for this while I’m on my phone, so it’s just memory, but I think GEFS picked up the early Novie EPO period and the secondary one in late Nov/early Dec earlier than Eps.

BWIs new asphalt tarmac certainly seems to be having an influence.

^thats certainly been true for the EPS in the last 8 weeks. GEFS has sniffed it out from range more accurately it seems. GEFS can rush it though.

Actually by the end of the GEFS run its a good pattern for snow, and it’s a step or two away from a VERY good pattern for snow

Don’t scare the weenies Bob. 12z GEFS looks pretty good towards NYE actually. Faster transition to a workable Pac than previous runs as well.

While I’m here in California, I’m facing west and huffing and puffing as often as I can to weaken the Pac puke flood. You’re welcome.

Yup, looks like 5-6 cold+dry days coming up and then a week of AN Pac puke and then probably things start reshuffling. It is nice that we are seeing the exit door from the wretched Pac open before we even walk through the entrance. But need some patience for the next 2 weeks. With the clear tendencies toward HL blocking and an active pattern this year so far, I remain pretty bullish on at least an “average” winter snowfall wise.

^thats a weak amplitude wave however. If those strat forecasts are right, we could get an EPO driven arctic shot just before New Years due to the strong wave 2 hit on the strat PV.

You mean 2 W Elkridge?? That’s me... At least sometimes, my neighbor also gets reported as 2 W Elkridge. Definitely looks like the fall line was a drop off as usual. I’m about to drive to BWI, so will be interesting to see the falloff.

BWI and IAD numbers seem paltry. They both adjusted up last week, so maybe they will again.

It would with a +PNA probably. With a -PNA battling a SE ridge, it could set up overrunning (and cutters...).