CAPE

it really is a disease.

Bit of a tradeoff. The stronger/closer 50-50 low is largely what's damping the wave/ keeping it more suppressed on the mean. Not really worth doing more analysis, as there are many more model cycles to go.

HH GEFS is further southeast with the low and a bit weaker. Decreased spacing wrt both the 50-50 low and the next wave out west are the most obvious reason on the mean. After thoroughly enjoying a 120, I'm not at all interested in poring over the members for further detail. The mean still implies frozen into the MA. On to the next run.

It phases with what's left of the 50-50 from the Jan 4th wave, which then reinforces the positive h5 heights over GL. That's the basic mechanism of an atmospheric block, and what keeps it sustained for a period of time.

Only subtle differences in the upper levels and the overall evolution for the Jan 7th event the last 2 GFS runs. Nice to see such consistency in back to back op runs at this stage.

Ends up mostly rain but another step in the right direction for that period, which looked like a pure cutter with mild rain a couple runs ago.

That's a legit block with surface HP wedging south.

This is probably somewhere between a squirrel and a moose.

This is pretty.

I get it. I am 'hunting' snow chances. Don't care if its a squirrel or a moose. All good.

lol we know dude.

I made a post focusing on number 2, which I believe to be the biggest difference on the 12z run compared to the previous few, where the resulting surface low was weak and easily damped as it moved further NE into the upper confluence zone on the back side of the 50-50 vortex. A bit more spacing there helps, but we need a deep surface low to make this work. The 50-50 feature has been there, and has looked impressively strong. Yes it will vary somewhat from run to run.

Hell no dude. Pay attention. That's not a real -NAO. It was enhanced by an extension of the WAR!

A strong 50-50 low is good, but the orientation/position is important. Improvement there on the 12z run. Also improvement out west. Both relatively subtle, but gained some spacing on both ends. To me the biggest difference has to do with the shortwave itself, resulting in a deeper surface low.

lol I'm not going anywhere. I just do my thing, and read the posts I find value adding.

The shortwave is stronger/sharper, with just enough interaction at the right time with NS vorticity. Also a bit more separation from the 50/50-ish vortex.

I think I need a break. The Bob Chill variety.

You heard it. That pattern can't work. Pray/root hard for a ++NAO.

He is probably referring to this period when the trough digs into the central US and forces a ridge up into eastern Canada. The NAO ridge is established prior to that occurring though.

Pretty close match to the EPS h5 look for that timeframe. More impressive -NAO signal on the EPS though.

A bit further north than the previous 2 runs. 7 days out so still uncertainty on the exact details. Potential for a moderate event for parts of the region with some spacing adjustments.

6z GEFS has the precip a bit further north, but the signal for frozen is modest and focused more in the western higher terrain. The basic problem(s) as currently modeled imo- the tendency for the wave to weaken/be suppressed due to the close proximity of the previous wave that strengthens into a southward displaced 50-50 feature, while the deepening trough out west forces a developing ridge just to the north/west of the low as it tracks towards the coast. That also tends to shunt it offshore to our south and somewhat limits available cold.

Not sure what you are looking at lol. It is the same general idea as the GFS, but it has more of a 50-50 trough with TPV energy feeding into it. It progresses NE a bit as the low approaches so a bit more spacing.

Be interesting to see the GEFS members. Didn't quite work out this run, but this is an improvement wrt cold air feed from the north as the low approaches. The classic surface HP locked in southern Canada with confluence on the west side of that vortex. Need more spacing between our wave and that vortex though, otherwise it damps as it runs into the upper confluence/convergence region.

Storm ran into a wall on our doorstep. Too much of a good thing up top. Wave dampens. That '50-50' vortex is a beast and a bit too far southwest. Need more spacing.