Bob Chill

Agree. Looks good to me too. The trough along the west coast showing up d12+ doesn't concern me at all either. Roll that forward and we're right back to a +pna and trough in the east. Looks like once the front clears next week we're in the game for a week+. Holiday will be in ens range soon.... do we ridge out on Xmas or track threats? Beats me...

Yea, this trip isn't as fun tho. My uncle pased so dealing with the service this weekend. He wasn't doing well for a couple years so he's in a better place. On an up note... Literally hit 15 mins of traffic near NYC on the drive and that was it. Left rockville at 1:30 and pulled in here at 8. 370 miles in 6.5 hours... wut?

I'm up in Enfield CT and they got 16" of snow. Huge parking lot piles. Nice snow fix but the 2-4" deal next week in my yard will be more fun.

CMC is the most accurate so far unless the euro takes it up a notch

Didn't see the HH euro control posted. Looks good to me http://imgur.com/a/pZFdaQX

@WxUSAF Scand ridge signal growing.... Technically this is an east based -NAO too... heh

That's the tricky part about split/progressive flow. Two streams are burping shortwaves into fast flow. How each piece plays together is rarely if ever nailed down until inside of 4 days and even that is a stretch. What if the northern stream wave ends up being faster and drags the boundary south as the lagging southern shortwave makes a move? What if the northern stream wave doesn't exist at all? Don't overthink ops outside of 4 days unless a block forms. This is a terrible pattern for medium/long range skill. It's bringing back memories of the 2013-15 stretch where our medium/long range chances vanished regularly but things popped up seemingly out of nowhere in the short/medium range.

Here's the event list for my yard in 2013/14: 11/27: T 12/08: 1.5" snow .25" sleet .20 Ice 12/10: 2.0" 12/14: .25" 01/02: 4.5" 01/21: 6.75" 01/28: .5" 02/09: .5" 02/13: 16.25" (13 front / 3.25 ull) 02/18: 1.0" 02/25: 1.25" 02/26: 2.50" 03/03: 5.50" 03/16: 9.50" 03/25: 3.00" (worst measuring event by me. Two closest trained spotters had 3.6 & 3.8) 03/30: .7" 55.70" Nearly every event on this list is either a clipper type deal or a wave on a front except for 2/13 as that was an organized coastal. Most of the events over 2" were frontal waves with the notables being 12/8, 12/10, 1/2, 1/21, 3/3, 3/16 (not sure about this one). The whole season was mostly progressive waves on fronts. For reasons we'll never fully understand, our area had a bullseye on it from start to finish. I'm not expecting a seasonal repeat of that year again before I'm dead. lol

2013/14 had like 6 of them. Maybe more. 2014/15 had another streak of them. These are "staple events" in a progressive -EPO regime. The margins are razor thin and the bust risk is there right up until close to game time but don't view this "event" as anything "unusual" or "not possible".

There's a couple. Here's the one where you can pull single days (or short periods): https://www.esrl.noaa.gov/psd/data/composites/day/ Here's the monthly/seasonal composites: https://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl

@frd Here's the lead up to the Jan 16 event. It was just a perfectly placed/large west based -NAO. It formed at the perfect time but it was not at the hands of scand ridging.

Excuse my 3rd grade paint skills but this visual is decent. The scand ridge signal is just now showing up but starting to become more prominent. We want it to push all the way into GL and that will force lower heights/confluence/compressed flow in the 50/50 region. That can suppress storm track and allow slower exits of cold highs to our north. I don't remember exactly what happened in 2016 but iirc that was a bootleg/transient west based -NAO block. It could have been at the hands of the scand ridge. I just can't remember. No matter how it shakes out, scand ridging poking poleward is always a net plus in these parts.

We always need the little things to break right. Next week only needs some sort of transient block to keep hp from running east. Right now that's not looking too good and it's all at the hands of the progressive atlantic. Shove the mass of bn heights balled up over GL south and future cold highs to the north meet resistance. Your short list seems reasonable to me. Just keep bringing the chances and it will accidentally snow here.

@WxUSAF Eps starting to show the scand ridge pushing into GL D10-15 like the gefs. That could be the tipping point that turns a so-so but workable pattern into something pretty good. Get that going and we'll prob start seeing 50/50s and/or bn heights in the 50/50 region.

We can work with this spread. Couple look just like the ukie. Becoming more interested in this...

13/14 had like 6 or even more. It was remarkable how many worked out. We started expecting them and we can literally go multiple years without getting hit like that. Southern stream is active now. You can see the connection all the way west of Baja with the front. I'll have to look at ens members and see what's different with the frontal wave solutions that snow but my guess is the front stretches more E-W instead of vertical. You can see that alignment on the gefs member snow maps.

Maybe we're looking too far down the road? Very complicated flow coming up starting middle next week. I'm expecting lots of twist and turns. Just don't have a feel if the turns will be good or not...

We generally score 1 out of 4 legit chances so we're getting a few misses out of the way quickly.

All rain from this in mid december? Lol.

Strong/organized storm = bad. No way around that except remarkable luck with every.single.feature Oddly, the EPS shows the best chance for snow shortly after the front goes through next week. Didn't look into how they got there but around 25% of the eps members drop snow thurs/fri. Could be anafrontal or could be the trailing southern shortwave. Not sure. EPS doesn't like the followup event. Mostly rainers.

Yes, it's been the only long range clue I've liked so far (other than the -AO that disappeared). Seeing the PDO shift positive and having split flow into NA isn't a coincidence. Unless blocking returns we're going to have to hang our whole wardrobe on the Pac helping us out in these parts.

CMC has the same shortwave as the euro but doesn't do anything with it. GFS is by far the most progressive. With pretty big differences through d5 on the gfs/euro/cmc, they all end up in the same general place d7-10. More questions than answers as usual. GEFS insists on more chances down the line so maybe it won't be as painful when the rug gets pulled.

I was speaking about the euro run only. It's a different progression than the gfs. The euro focuses more on the lead shortwave that hits Cali in 3-4 days and lollygags from there. GFS is more progressive and focuses on the next one in line. No sense wasting a bunch of time discussing discrete pieces 6+ days out in time though.

Yes, 3 days until the southern shortwave hits Cali. The TPV dropping down will dictate the track once it clears the intermountain west though. I don't think variations in latitude will make much different. Where the euro gets really complicated is the northern stream digging down and energizing the shortwave. It's really weak/sheared (almost invisible) D7 but winds up as the streams phase. We're going to have to wait awhile before any type of stream interaction can be figured out. Models are not going to do well out in time with the split flow happening along the west coast. All the little pieces are important. Ops generally don't start nailing that stuff down until d4-5 max

The messy phase and trough amplification is ugly as there zero mechanism to lock cold air in. However, the southern shortwave itself can do the job without needing to phase with anything. This one is going to drive us nuts for a while it seems.