WxUSAF

I’m down with the GGEM day 10. Let’s go!

Starting to think we should be paying less attention to the WAA front end of next weekends storm and more attention to squeezing some snow out of the ULL as it moves past overnight Sunday into Monday.

We are not going to know anything about storm chances after next weekend for a while, in my opinion. Whether it’s a clipper or something larger the following weekend. Because next weekends storm will have so much control over the flow afterwards. So focusing on next weekend is probably the safe bet for now. I think what we want to root for is something like the Canadian showed today, with a more significant piece of energy Moving out ahead of the main storm. If it could move to our south it could give us a light event and also help drag the boundary further south for the larger storm which would give us a better chance of more front end freezing or frozen precipitation.

EPS has looked better than the GEFS for the last 2-3 runs past D10. I don't hate that. The Dec 1-2 storm looks like it will suck the oxygen out of the room so to speak for a couple days beyond. That makes that trough go more N-S oriented and prevents any follow-on s/w from amplifying out of the southwest. So we might need to wait for the flow to relax a little (barring a clipper in the 3rd-5th timeframe) around the 8th. Then of course it's a question of cold air availability, but getting snow is always a wackamole of issues.

HM seems confident it’s temporary, if it happens. Plus the strat shenanigans.

I agree that’s how it’s looking now past the 7th or so, but things have been very changeable D10+ as we know. Look at the 12z GEFS depiction of the NAO. Even vs a day or two ago, it’s holding onto the Greenland ridging much more. Just a wag since I haven’t looked at individual members, but I get the sense from the mean that there’s probably very wide divergence in solutions in the long range. Still think we got a decent chance of freezing/frozen precip the first week of the month. Beyond that...dunno.

Snow mixing in in Bel Air area per my sister

Yeah, the pattern in the 3rd-5th time frame that I was interested in, now seems entirely northern stream dominated. The ensembles now see a +PNA in that time frame which wasn’t there a few days ago. So a clipper type storm is probably the only option in that window unless the look changes. Which is possible because we’re still 10 days out. I liked the broader, more E-W oriented trough with energy coming out of the southwest. Now it’s more N-S oriented, so colder, but also drier. 6z gfs actually has a clipper in that timeframe.

39 and rain. Almost mid winter form

There’s a strong standing wave over the West Indian Ocean associated with MJO phase 8 and +IOD. It’s not an MJO wave per se, but might force the forcing to behave that way.

HM says don’t jump

Going to be mowing into February it looks like. Maybe throw some seed down?

Yeah I still really like the 3rd-4th period. Eps looks tasty for that time. Ensembles have moved toward more +PNA in that time as well. Might also be worth keeping a small eye on the big December 1 cutter. That airmass is trending colder ahead of the storm and if a piece can break off, the flow will carry it to our south. Overnight gfs and GGEM have a threat of front end frozen/freezing precip.

Euro is quite chilly for the holiday weekend. Cold and windy. Looks like I won’t have to worry about the leftovers that my mother in law stores on her porch spoiling.

Barney Claus comes to visit! I’m banking on the GFS long range cold bias here. That’s just cold and dry and then it lifts out for a cutter. A more modest EPO flex coupled with a 50-50 low could keep the storm track under us with sufficient cold air. Looks like GGEM is going that route.

Yes, also EPO driven.

EPO driven patterns can work for us as we know, but storms are hard to predict and appear at short notice. I’m not sold on the NAO going poof 7-10 days after it arrives. Overnight Eps keeps a bit of it going all the way until 360hrs. GEFS seems good at sniffing out changes in the long range, but typically rushes things. Either way, seems like we’ll have an active pattern with the STJ looking very Nino like and plenty of cold around with the EPO and NAO. That’s a good recipe any time and especially in early December when we need some help. Climo snowfall the first two weeks of December is pretty low, but for now, odds seem better than climo. I still like the 3rd-8th period or so, but remember that we often do better towards the end of a good pattern, not the beginning. FWIW, I’m not sure I’ve ever seen HM honk like this. Well at least not for awhile.

Still got the weeklies this evening to ruin the fun parade

Yeah, that’s the key. Have that ridge onshore and we’re in a decent spot. Throw in a tendency for -NAO and a 50-50 and oh boy...

^I’d take that look in a second. Eps D10 looks very nice and that D15 looks good too. Notice how the NAO breakdown keeps happening at D13+ in each ensemble mean. It’s not getting any closer. Yet at least. And the return of the -EPO for early December is becoming more likely. I also like how the Eps has the EPO ridge axis closer to the west coast. Sign me up.

That’s probably not a terrible equation? I’d be really interested if you actually did a running comparison of that and see how it verified.

BWI: 20.3” DCA: 14.7” IAD: 22.5” RIC: 12.1” SBY: 9.8”

You shouldnt be. As I think @LP08 is alluding to, it’s maybe useful as a quick look on whether a period of time has potential, but that’s it. Especially as we go into winter, our “background” ensemble snow mean through D15 is like 2”.

Email [email protected] for complaints

Speaking of every model run, 0z euro gave us snow D9 and nobody even mentioned it!!?!