Terpeast

Temps likely run a bit warm, but I’d be paying more attention to timing due to the friday PM commute

Nice to see the euro take a step back south, and the gfs is mostly a hold if not a tick north. Let’s see if they tighten up the goalposts. If the storm start time is sunday night, it’s 3.5 days away now. That’s usually the time when models start flushing out any major disagreements with each other, barring a last minute trend.

Love the CAD on the CMC. Sign me up. IAD sounding show a warm nose at 800-825 mb flirting dangerously close to 0C, but stays colder than that. Too early for these details ofc

Ha, not that easy using pivotal on mobile. Fat fingered it

Never mind, Was on a different model page when comparing. Disregard. Sorry.

At 500 it is, but the surface is different

Looks similar to todays 12z gfs

Looks similar to yesterday’s 0z

And confluence actually stronger…!?

84h, closed low about to go neg tilt

Also a bit slower

66. S/w stronger, confluence same, NA vortex a touch west

Verbatim light snow to sleet/ice then dry slot for DC metro

Yep

NAM stronger s/w, but confluence also presses more SW. probably offset each other to some extent Not that this is worth much at this NAM’s range

Now that 18z euro is on TT, I looked at the N Atl vortex and the s/w. Those aren’t huge shifts between 12z and 18z at 500mb. The confluence is still there, but slightly weaker and more east. The s/w is a few dm stronger, but still with a neutral tilt. But the surface difference is dramatic. I do wonder if the Euro is overcorrecting at the surface and blip back a bit south (it won’t go as far south as gfs or icon). In addition, these shifts are typical at 500mb 4-5 days out, and we don’t usually notice these when they are cutters and rainstorms. just my 2 cents

Haven’t been paying attention to that yet. Need to resolve the two waves before that first, then we’ll have a better sense of what the day 10 threat might look like

For now Euro is on its own with the north shift, and it’s just one run. Need to see what 0z models say, and need to see if they start following the euro on the north shift. It may be onto something, or it may be a blip. Many are taking this seriously because Euro is the best performing model.

Between i-66/rt 50 and i-70 were progged to see not more than an inch or so averaged across all models, and we ended up with 3-6” both storms

The two Jan storms last year shifted south within 2 days, but that situation is a little different.

Just now getting a chance to sit down and dig in, but @wxmvpete already did his excellent writeup. I don’t have much to add. Keep it coming!

Looks like a classic N+W event we used to get a lot in the past. I’d take it as long it doesn’t keep trending north (which is still a possibility)

After my daughter goes to bed, I’m going to dig into why the models are diverging. But by then I may not have much to add, you all provide great insights so quickly.

Now the GFS and Euro diverge! Oh boy this is gonna get interesting.

Looks like the typical GFS swings/noise to me. Yes it’s faster, but the NE trough/confluence also moves east accordingly. Almost like they’re dancing in sync. Qpf amounts won’t be figured out until the meso models have their day with it.