tombo82685

https://acd-ext.gsfc.nasa.gov/Data_services/met/qbo/qbo.html

Don't mean to bombard, but you are correct. There is actually a paper out that shows evidence that when you get a rather robust phase 3 mjo that propagates around, like we had last year that it does lead to a SSW if the conditions are favorable. With how weak the PV got in late nov I wonder if we had a more robust mjo signal through phase 3 would it of initiated anything. Though, we really didn't get a strong wave 2 hit on the pv after the wave 1 displacement which is needed usually. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012GL053144

Yea it’s a bit wetter for you. I haven’t kept track of when you guys changeover. I’ve been using the 546thickness as the start looking aloft signal. So 12z run had .25 a little west of dc at 15z Wednesday. This run brings .25 into DC now with 546 thickness exactly the same

You can't go off 850s with this setup, the warming is above 850 in the 700-800mb zone. Best bet is to go off 546 thickness. Once that passes you best to look for a warm nose poking in in that zone.

I think this is counting sleet as snow, in fact it most likely is. Look at the meteogram off the ukmet for DC. It has one tiny window where the 850s are below zero while the rest is above zero. Yet the map above is showing 8-10 there. To me the more logical thing to use that map for is just how much qpf falls as frozen or freezing.

They are colder with a flatter H5 look. Still doesn't support an all snow event but could raise the bar for more thump on the front end and also help you guys out with the overunning event beforehand. Also, the colder 850 with stronger CAD could lead to an icier look too.

No, but I know USweathermodels does. Some people have that so thats what I was asking.

Other way around...Here is what I mean. 0z eps from weatherbell to vista

I'd be careful with those vista snow maps, they are pretty suspect. The weatherbell ones at 0z are much less than what those ones have at 0z. Does anyone have USweathermodels 6z eps snow map to compare?

Nice post. That wave on the front is actually energy from the s/w that delivers a snow storm to the lakes. You can track it. This was from 18z gfs yesterday. Gfs shows how you can possibly get something middle of next week, albeit not a blockbuster. So we have our northern stream s/w diving down through canada Then that same s/w splits into 2. One piece of energy takes the northern route and delivers a snow storm to the lakes. While the other piece of energy dives down into the south. that southern piece of energy then gets stretched out along the arctic front. As of now, the energy isn't that consolidated so it's not a big qpf producer but it's something to watch down the road. If we get a stronger piece of energy along that front then it could develop an area of low pressure along the front to bring a few inches of powder.

Agreed, had the same thought when I saw the eps. Was starting to get a pain in my stomach when I saw the lower hgts shoot to AK but then as it progressed, at least on this run it looks like it's dumping it into the Aleutian trough which should pop a respectable pna ridge out west. You can already see the hgts starting to respond to it in the 14.5-16 day progression. At least for this run of the eps it was encouraging, and is more of a canonical nino look for February, but the LR has been bouncing a lot.

Do you think that could just be a follow up wave along the front if it's strung out?

Here is the comparison from 0z to 6z euro. As someone mentioned slower, but there also seems to me atleast there is a bit more press down in hgts from the tpv lob swinging through

I know we all want what the ukmet shows, and that is a non phase with the tpv lobe that swings around. Here are the last 3 runs of the euro, including the 18z run. Can see each run of the euro continues to delay the northern stream interaction and almost tries to make it just a separate southern stream wave by itself. Can also see in response to the pac nw low the ridge in the west is losing amplitude and rolling over pushing east. Just thought I would share

This is what it has, I always thought it was a sounding. But I guess not.

weatherbell I believe has a skew-t kind of sounding

Yup, those WAA snows can certainly have an over performing snow band. Thats where your best shot of good ratios would be too as you would get better lift in the DGZ combined with cold air a loft.

Yup, you're basically trading in one for the other possibly. The models this morning seem to be timing the strongest push of confluence with overunning snows thus drier look there at least from m/d line north. They then move that tpv streamer out a bit faster allowing hgts to recover for possible coastal impacts. I would still like to see better bundling of energy at base of the trough on the euro. I don't like how it's so strung out. Also need to increase wave spacing between the tpv streamer and coastal to allow for even better hgt rises. At least in your case it's not like we are asking for a coastal shift of 500 miles. 100 miles north would make a big differences and still within realm of possibilities at 3.5-4 days

I think you guys are good for 2-4 at the very least IMO. What you also have to consider is, the coastal impact is still 3.5-4 days away about a day later than the overunning setup. These Canadian impulses are fickle, any sort of changing of the handling of the tpv and pieces of energy rotating around in regards to speed and strength can make for a big difference downstream.

Couple images from 0z eps to 6z eps. Hitting a bit more on coastal impacts

This is the comparison between 6z gfs and 6z euro. Euro hangs a ton of energy back which just flattens the flow combined with the stronger tpv streamer which also compresses hgts. Gfs bundles the energy better at the base of the trough, combined with weaker tpv streamer (though trended a bit stronger at 6z from 0z) allow hgts to bend back towards the coast allowing for a closer coastal pass.

The 18z gfs made sense to me honestly. There is a piece of energy that goes from the GOA over the ridge and then kind of phases in with the TPV. If you look at the 12z gfs to the 18z gfs this streamer is a bit stronger and causes a bit more of a southward press of the confluence negating the stronger s/w effects. You can see the hgt lines in New england are a bit further south. The question is will it be right or wrong. That piece of energy isn't in a data rich area. The evaporation of the precip makes sense. When you have a CAD setup, what usually happen? We have a big high that funnels down cold dry air east of the apps, thus lots of virga usually due to the low dew points. So the tandem of downsloping effect combined with very dry air causes the precip shield to get eaten up IMO. Thats why places west of the apps are wetter because they aren't experiencing the CAD effects like we are.

here is your h5 vort look on 18z compared 12z. Notable stronger southern s/w. Also h5 mslp and hgts. Stronger low, higher hgts out ahead. Also, the area circled for people further north on the 12z run had that jet streak that dove south and compressed the hgt field. This run doesn't have that feature. The hgt field is a tad lower in new england, but without that jet streak it may allow hgts to recover in time for a push north and west more.

just started right now

yea they run the eps out to hr 144 for off hr runs