CAPE

So yeah, enough with the NAM posts trying to glean anything useful on the lead up to a threat that's a week out lol.

It's an urban myth.

12km NAM is useless, even when it is in its wheelhouse. It's going to be junked in the near future.

They look nearly identical at h5 and the surface. The sensible weather outcome on both the 0z and 12z ens runs for this region are essentially the same. Did I just repeat myself? Feels like I just repeated myself.

Almost identical to 0z. womp womp lowlands, congrats western highlands, NW burbs still in the game.

12z EPS is essentially the same as 0z for our region.

The shade of blue(red) indicates the height anomaly for a given area.

The general answer is we need anomalous cold given the average high temps are well into the 50s.

Rain was pretty underwhelming here. 0.27" according to my gauge. I'll take it. Rather be on the dry side this time of year if it isn't going to snow.

Still a week out, and its very unlikely the guidance has this nailed down with all the moving parts. If the general idea holds or degrades over the next couple days, then it is probably time to focus on the week of the 13th.

If the GFS idea is more correct, the low tracks well NW into the GLs and becomes occluded. As the trough becomes established in the east there will be additional energy dropping into the trough. Might be a sneaky chance of something for the 14-15th. eta- 6z GEFS is suggesting a bit of a following wave for the 14th.

The 0z and 6z GEFS have trended towards the op run, with significant NS energy dropping south as the Pac ridge amplifies, digging a trough out west. The HH GEFS yesterday still had a pretty favorable look, with much of that energy captured by the Pacific trough, allowing a wave to eject east. The EPS is better, but we probably need a bit more help with the NAO than is currently modeled. I want to see some wicked confluence to our NE. As things stand now, the lowlands can forget about significant frozen. The interior/western highlands are favored, and the NW burbs are somewhere in between the 2.

This winter has been a ratter, and it is getting late. Ji is right that there is a pretty big difference between getting a storm on March 11 vs. having to wait a week. It can work out, but the hostile for snow curve is getting pretty steep especially for the lowlands.

Carve out the avocado trough, then get a wave riding the thermal boundary. That's money. Too bad its basically Spring by then lol.

Avocado cold!

When we have a threat in the LR I typically pore over the 0z ens runs early in the morning with my coffee. This morning things looked quite good for snow especially from your area westward. Lets see where we are on the means after tonight's 0z runs.

There is nothing really useful about this "block". Its orientation is shifted 90 degrees from ideal, as it links with the amped ridge in front of that monster trough. Essentially a full latitude ridge.

Nothing is etched in stone. My observations are specific to this run/recent runs. In general though, everyone has seen this movie play out over and over this winter and it always ends the same. Thus the pessimism. Pattern is somewhat more favorable, and given all the chaos, there is no reason to think the timing and degree of interaction between the key waves is nailed down by guidance 7 days out. Plenty of time.

There's time at least lol. Could happen.

Everything is harder with an active NS, and we still are in a Nina. We really fucking need a Mod Nino with sustained NA blocking next winter.

Game over right here. The energy associated with that vorticity lobe stuck between/underneath the 2 blocks has to dig south, and it phases in.

It's really not good at that point. There are variations in character/orientation with all these indices, and they don't exist in isolation. The NS is very chaotic in this pattern- so many wave interactions.

On earlier runs the NS energy rotating down underneath the ridge bridge was largely able to escape west- absorbed by the Pacific trough, while a healthy piece of vorticity ejected eastward. Recent runs have a more amped EPO ridge, forcing most of that energy southward, significantly amplifying the trough and inhibiting a wave from ejecting.

With weed a drink or 2 will do. Need food at the ready.

Already done. George was correct.