Two things to watch for the upcoming week

[Terpeast]

Yesterday, I said I would write up a forecast for Sunday's storm, but that was when the models were trending west with the track. However, the Sunday threat is dead for DC area - stick a fork in it, it's done. But you all knew that already

Now the next things to watch are:

1. The monday-tuesday clipper. I don't think DC is going to get much out of that, if any. My current thinking is that it's going to be a super fast moving system courtesy of the Pacific jet slamming into the west coast, and it will likely be moisture starved. If it slows down a bit, however, DC could potentially get an inch or so if the track is right. The Apps and westward will probably see more, on the order of 2-4".

2. The system for xmas eve through xmas day. This system could be the result of lee cyclogenesis once a strong jet streak passes over the Rockies. It's track is still uncertain, but it will probably be an east-to-west moving system. With cold northerly flow across the Great Lakes and NE, it would be pretty difficult for this system to cut to the lakes. Not impossible, but difficult. What remains to be seen is the exact position of the polar vortex, how the downstream block behaves, the strength of the western/plains ridge and how much it amplifies the upper level s/w associated with this system, and whether how much it taps into Gulf moisture.

Should be an interesting week!

[Ian]

On Tue you don't see a scenario like what just happened possible? Clippers are always tough to nail down till the shorter range but it seems there is potential and I think the fact that there was one in earlier Dec that went south argues for another moving somewhere across the area. Right now it looks fairly juicy west of the apps though the models may be overdoing it... obviously we want whatever we can get there so we have more get over the hills.

[aldie 22]

I think the clipper delivers

[mdsnowlover]

I woiuld not expct to much from the clipper, as the one yesterday underperformed, and the fast flow and the mountains take away from anything coming from the west. As far as the xmas eve/day event, I,m not excited at all, about that until we come to thursday and the models are showing something . After the dismal predictions of the models for this sunday event, hoping for something next weekend is a bit farfetched to me. I,m a realist and I doubt this will happen either.

[Avdave]

I woiuld not expct to much from the clipper, as the one yesterday underperformed, and the fast flow and the mountains take away from anything coming from the west. As far as the xmas eve/day event, I,m not excited at all, about that until we come to thursday and the models are showing something . After the dismal predictions of the models for this sunday event, hoping for something next weekend is a bit farfetched to me. I,m a realist and I doubt this will happen either.

underpeformed? Maybe up there but down here between 2-3 inches fell when most were going for an inch to inch and a half. WE did pretty good down this way.

[aldie 22]

I woiuld not expct to much from the clipper, as the one yesterday underperformed, and the fast flow and the mountains take away from anything coming from the west. As far as the xmas eve/day event, I,m not excited at all, about that until we come to thursday and the models are showing something . After the dismal predictions of the models for this sunday event, hoping for something next weekend is a bit farfetched to me. I,m a realist and I doubt this will happen either.

I'm a pretty negative/pessimistic dude....I think I can learn some things from you though...I'm just sayin

[Ji]

I think the clipper delivers clouds

agree

[WinterWxLuvr]

I woiuld not expct to much from the clipper, as the one yesterday underperformed, and the fast flow and the mountains take away from anything coming from the west. As far as the xmas eve/day event, I,m not excited at all, about that until we come to thursday and the models are showing something . After the dismal predictions of the models for this sunday event, hoping for something next weekend is a bit farfetched to me. I,m a realist and I doubt this will happen either.

Can't go along with that. I guess it depends upon where you are and what you were expecting. Here, in NVA, about Tuesday, I thought a good result would be a dusting. Turned out to be much better. I'll gladly take another just like it this week.

[WinterWxLuvr]

agree

Did you get snow yesterday?

[Avdave]

Did you get snow yesterday?

Yes, about 2 inches fell

[Analog96]

Yesterday, I said I would write up a forecast for Sunday's storm, but that was when the models were trending west with the track. However, the Sunday threat is dead for DC area - stick a fork in it, it's done. But you all knew that already

Now the next things to watch are:

1. The monday-tuesday clipper. I don't think DC is going to get much out of that, if any. My current thinking is that it's going to be a super fast moving system courtesy of the Pacific jet slamming into the west coast, and it will likely be moisture starved. If it slows down a bit, however, DC could potentially get an inch or so if the track is right. The Apps and westward will probably see more, on the order of 2-4".

2. The system for xmas eve through xmas day. This system could be the result of lee cyclogenesis once a strong jet streak passes over the Rockies. It's track is still uncertain, but it will probably be an east-to-west moving system. With cold northerly flow across the Great Lakes and NE, it would be pretty difficult for this system to cut to the lakes. Not impossible, but difficult. What remains to be seen is the exact position of the polar vortex, how the downstream block behaves, the strength of the western/plains ridge and how much it amplifies the upper level s/w associated with this system, and whether how much it taps into Gulf moisture.

Should be an interesting week!

I believe you mean the Christmas system would be WEST to EAST moving, not East to West.

[Ian]

Yesterday's clipper did underperform to the south I suppose but people should have expected mixing in some places especially in retrospect. Overall I think the precip mass y-day afternoon was less than modeled.. but we got good accum early.

[WinterWxLuvr]

Yes, about 2 inches fell

I guess 24 hours is a long time for some.

[aldie 22]

agree

Thanks CtBlizz jr.

[usedtobe]

I'm not sure we can even rule out a low going northward to OH for xmas based on all the uncertainty shown on the 1*Z gsf ensemble mean.

Look over the middle of the country and look at the variation of the green lines. Some really show big dips that suggest farily wound up surface lows.

Now look at the surface forecasts and note there are a couple lakes cutters amongst the midst. That may be an extreme looking solution but you can't rule out anything including the much different look of the euro. None of the models have been handling the pattern well

I'm not saying that a lakes cuter is likely but xmas system still is another one that is liable to try most weenies souls. I'm more interested in the clipper and whether we can squeeze out an inch or so. The one caveat is the surface temps will be warmer and any northward shift could even put us where richmond was during the last clipper.

[mitchnick]

I don't know Wes, all the models seem to think that the pinwheel of death, 50/50 should shred anything that tries to come across the mts with its NW flow

Come crunch time, I think we'll be scrounging around for qpf more than colder temps, but in this NINA, it just may be both, but I know qpf will be one of the problems

[usedtobe]

I don't know Wes, all the models seem to think that the pinwheel of death, 50/50 should shred anything that tries to come across the mts with its NW flow

Come crunch time, I think we'll be scrounging around for qpf more than colder temps, but in this NINA, it just may be both, but I know qpf will be one of the problems

The pinwheel of death is the saving grace but if it were to edge eastward a little then we could have mixing issues. I'm not saying that will happen but if we do hold onto the warm advection better,we get more precip but may also gt more warming.

[usedtobe]

Mitchnick,

Looking at the 84 hr vortex position it is hard to picture the system not shearing southward under us and allowing us to say cold enough for snow.

[mitchnick]

The pinwheel of death is the saving grace but if it were to edge eastward a little then we could have mixing issues. I'm not saying that will happen but if we do hold onto the warm advection better,we get more precip but may also gt more warming.

yep, its the ultimate tightrope walk between getting measurable qpf while staying all snow with those suckers

but its all we've got

[mitchnick]

Mitchnick,

Looking at the 84 hr vortex position it is hard to picture the system not shearing southward under us and allowing us to say cold enough for snow.

agree, but look what's left of the rh

no way much of that makes it across the mts

[WVclimo]

I think that the clipper Tuesday will be similar in my area to yesterday's storm, and expect we'll see another 1-1.5" around here. Close enough timing to the last one to take advantage of the current cold pattern in place.

For Christmas Eve, I saw Leesburg mention somewhere that it looked like our first Nina ice event of the season. That agrees with my gut feeling looking at the setup, especially here in a valley west of the Blue Ridge.

[Terpeast]

I'm not sure we can even rule out a low going northward to OH for xmas based on all the uncertainty shown on the 1*Z gsf ensemble mean.

Look over the middle of the country and look at the variation of the green lines. Some really show big dips that suggest farily wound up surface lows.

Now look at the surface forecasts and note there are a couple lakes cutters amongst the midst. That may be an extreme looking solution but you can't rule out anything including the much different look of the euro. None of the models have been handling the pattern well

I'm not saying that a lakes cuter is likely but xmas system still is another one that is liable to try most weenies souls. I'm more interested in the clipper and whether we can squeeze out an inch or so. The one caveat is the surface temps will be warmer and any northward shift could even put us where richmond was during the last clipper.

Interesting. This ensemble run shows a slight NW trend from the previous run I was looking at, if I remember the last run correctly. But also lots of uncertainty at 500 mb with that spaghetti-like green line mess. I agree a lakes cutter shouldn't be ruled out, but could be difficult to achieve if the cold northerly flow remains in place due to that block over Baffin bay. If the low tries to bull its way up into that cold air, we could see a cold-damming icy situation somewhere in the mid atlantic. Or we might see a double-barreled low with redevelopment off the mid atlantic coast - just one other possibility to think about.

[Kevin Druff]

I'm not sure we can even rule out a low going northward to OH for xmas based on all the uncertainty shown on the 1*Z gsf ensemble mean.

No, I'm pretty sure we can rule this out. Surely the gods can't be so cruel as to give us rain on Christmas day 2 years in a row. :sad:

[Jebman]

No, I'm pretty sure we can rule this out. Surely the gods can't be so cruel as to give us rain on Christmas day 2 years in a row. :sad:

I hate rain on Christmas so much, that I would rather have sun and 85 degrees on Christmas with high humidity and hordes of bloodthirsty mosquitoes, than have to endure 35 degrees and depressing rain, heavy at times, melting all of my snow piles.

I hate rain on Christmas. Rain plain sucks huge ugly goat balls. And that's disgusting.

[Jebman]

The really bad thing about this clipper today that is really delivering a ton of clouds over my BY - Is the fact that I'll be lucky to cool below 32 degrees tonight.

Then tomorrow it will be crystal clear with a high in the mid 40s.

All of my snow will be gone by 1pm tomorrow afternoon because of the milder regime. Mark my words. It is going to break my heart.