csnavywx

It's dwindling. We got our adjustment w/nw but it just wants to dig for oil at this point. Needed a bit more time and space to make it work. The suppression out front didn't help either. There are a multitude of reasons to never trust triple phasers and this just adds to it. Better chance of getting some consolation snow if you're out on the beaches ofc, but will take quite a feat to get it back at this point.

The biggest source of spread has been the placement, tilt and shape of the primary max +PV/advection lobe as it comes into the upper Midwest. Most earlier solutions were emphasizing the middle of the axis to develop the primary PV later on, but generally this process favors the far end of the trough axis. Not really shocking to see it trend that way. I have my feelings about the NAM too, but given the sensitivity of the setup, models are still almost certainly still underdispersed wrt the true spread of the probability space, so seeing some notable dprog/dt on that feature is a good thing and shouldn't be tossed out of hand, at the very least.

18Z Euros moved the right way with it. One or two more nudges and it'll be in a great spot. Creeping down to 96hr out now, so mildly bullish.

Don't get too caught up on where exactly the QPF is landing right now. The important thing is getting it close enough. It will have the best baroclinic energy right near the start of the coastal's life, and the explosive deepening (>30mb/18hr) means there's going to be some serious reorientation of the precip shield and banding as it does this. Not really possible to nail that kind of thing down at this distance.

Exactly what we're looking for here, trend wise.

It can be. Just needs to tuck that vort more cleanly when it's over the Midwest. AIGFS and GFS have been doing that. EC OP too, but more erratically.

Highly non-linear cutoff here. Modeling is almost certainly underdispersed atm.

Partially, yes.

Yes, the last frame of that forecast trend loop shows a local vorticity maximum over Southern Michigan that becomes the primary later. The AI models and GFS are mostly favoring the far western portion of the axis instead. Sloppy as it is, the EC has slowly been heading that way since the 00Z run. If it mostly consolidates on the far end (west) of the trough axis then that gives the entire system considerably more room to develop.

If the meat of that developing advection lobe continues to trend west along the major axis here, the surface depiction will change in a hurry. Notable improvement at H5 already (in the same direction as the GFS/AIGFS, even if the ECAIFS only nudged a bit initially). Holding it back right now a bit is the trend in the lobe over SE Canada.

Both the EC-AI and AIGFS are tucking a stronger advection lobe in the far major axis of the NS trough instead of evenly distributing it along the length. The stronger and better oriented that is, the better the chance of getting this oriented correctly as it picks up the other two shortwaves.

I know folks are doing the Euro vs. GFS thing, but it's more like AI vs. non-AI at this point, esp when looking at these 500mb charts. Maybe that changes this run, but interesting to note how resistant they've been to totally caving offshore.

12Z GFS/AIGFS:

AI-GFS and EC-AIFS are on top of each other on this morning's 6Z run. Not much room to maneuver from here though. Gonna be a tough one unless we can get a faster tuck, neg tilt or a slightly stronger/amped and separated northern stream wave.

E. Shore -- overdid snow (flipped early), about right with sleet and rain flip. Inshore -- overdid snow, underdid sleet (flipped early), about right with ZR (0.3-0.4 IMBY). We got the heavy rain showers (as freezing rain) but the CAD ended up chasing the precip out, so very little/no ZR on eastern shore. We did indeed get some light snow today over the inshore areas w/ the big upper trough. All in all, not too bad. Flipping sleet 2-3 hours earlier would've almost entirely corrected this to reality, so B/B-.

Run to run variability seems to have calmed down somewhat. A hold through tomorrow gets me bullish.

Triple phaser. Great if it works, but as always, delicate with timing. Suspect there will be some changes until Wed. So far, so good on trends. Plenty of cold air, so there's a chance of staying snow even if it gets fairly close. Suspect the main fail modes are a phase miss (and we get some consolation snow a la last Feb) via being too progressive or it overamps and we have to deal with a narrow mixing zone.

Continuing off of @Terpeast's trend GIF from yesterday:

Eh. It did pretty well. Took an extra 12-24hr to snap in, but had the right general idea not long after.

The EC-AIFS *was* really good with the last system from this distance (it had locked into a large mix zone and virtually nailed all of the major features by this point), but I would say that the initial interaction is more delicate on this one has a tighter timing window. Prob need to be sub-100hr for equivalent. Would really like to see the AIGFS come on board.

Really cool triple phaser. However, it's a triple phaser. Powerful but delicate setup, so your expectations should be very guarded as there's quite a bit of dprog/dt even 3 days out right now. Here's a quick chart to help you manage your expectations should guidance continue to show it working out:

Finally ended down here. Getting power flickers and still hearing the occasional branch crash outside. Will get a proper radial measurement in the morning. Headed to bed.

The NAM's ability to get thermals right is very useful. As was the fact that CAMs were useful today with the embedded heavy rain showers. Can always use other guidance for precip amounts.

Chef's kiss. (Watch til the end)

It's another tool in the toolbox. I am personally *very* pleased with the EC-AIFS and AIGFS with the last storm. Helped me keep my sanity when every other piece of guidance was insisting on washing out the CAD here today, against every bone in my body. Anyways, link is here: WeatherNext 2.0 Model Viewer