OceanStWx

You mean the month in which your normal high temp is in the 50s?

But I always grew up with a North Shore and South Shore. So I concede there is a zone between Boston and SE MA.

Precision and accuracy. Models are quite accurate, but they are rarely precise anymore. You aren't going to see run after run of the same solution given both the frequency of runs and model resolution. When your grid scale was 80 km, subtle shifts made little difference to the outcome. When you drill that down to 13 km and start focusing on QPF/snow maps you are going to see some big moves from haves to have nots. There is a reason why the best mets are using the forecast funnel approach (large scale to small, top down). Like mid level magic. It isn't just a term we made up for the picnic tables, it's that modeling frequently overdoes QPF near the low center (with latent heat release) and underestimates forcing via deformation processes (in Canada that reads "DEE-formation PRO-sess-ees").

FV3 is the core, GFS is the name. Still poop emoji.

And Kevin's grew three sizes that day.

Louis just left the board.

Unsurprisingly the changes in that northern stream are driving the wild run to run swings of varying individual pieces of guidance.

That's going to be comparing apples to oranges though until they upgrade the GEFS core too. Right now they are running on separate systems.

I would probably exercise a little caution much outside my little study area, but looking at the 01.00z OKX sounding it would forecast a 35 knot gust, when HWV peaked at 33 knots in the 4 hour window around the launch time. If you wanted to look at model data instead, around 05z the LLJ increased to 81 knots at 925, and the regression spit out 46 knots. HWV peak wind was 46 knots.

I did. We got two balloon launches that had the 45+ knot criteria at 925/850 from a direction other than NW. With the 01.00z 4 hour launch window the regression was 0.5 knots off (27 obs at PWM, 26.5 forecast), and with the 01.12z 4 hour launch window the regression was 5 knots off (41 obs, 36 forecast). I think the results are strong enough that I'm comfortable using it with model data for all parts of the forecast.

The major overhaul was the guts of the model. The idea being to make it easier to perform upgrades in the future. So aside from a few tweaks to schemes and parameterization nothing was fundamentally changed with how the GFS forecasts the weather. I think the grand plan is to crowdsource GFS improvements. They are planning to make the code widely available publicly and allow people to try and make improvements that can then be shared back to NCEP. Color me skeptical about how that's going to work (definitely opens up a back door (front door?) into gov't computers, are programmers going to want some sort of credit for big breakthroughs, etc).

I realize it's expensive to move towards something like the Euro, but honestly given how much money can be saved/lost with weather I'm surprised that we try and pinch (relative) pennies for hybrid 4D EnVar on the FV3.

Yeah, it's always been a progressive/northern stream dominant model. Honestly I think the worst thing they did was release it with the bug in snow accumulation without realizing how much people view those snowfall maps. That spooked the majority of the field into thinking the model got worse. It's really more or less the same model, with only incremental improvements. The thing was it was never really meant to be a model performance upgrade.

Something like the long term average of >= 1" of snow would be best for tracking a "real" snowfall event. BTV 11/18 CON 11/24 ORH 11/26 PWM 11/27 BDL 12/5 BOS 12/11 PVD 12/12