12z GFS is nuts with arctic air... 474dm heights

[Valkhorn]

I'll let the graphics speak for themselves





The -30C isotherm is huge in the last 90 hours or so, and mean heights as low as 474dm.

My take is that the GFS is trying to grasp at the obvious cross-polar flow setting up but it's not clicking. I think the GFS is still out to lunch but I do think it's pretty spot on with the cold air intrusion in Canada. The trouble with this model is it isn't really reading the patterns and I'm afraid what it's forecasting is just its bias.

I thought I'd show this for spits and giggles. Take your bets folks on how low the GFS is going to go with heights this winter. My guess is it'll try to get to 470dm or lower in the next few weeks and the -40C line will rear its ugly head in the north of Canada on the GFS long range runs.

Any bets for a -50C line in January? C'mon, it's the GFS... place your bets

[Fishmn]

The GFS is usually -15F off in the winter months in the long range. I'm suprised that anyone even tries to give it creedance. Its still nice to look at though. Ah if it could verify once, I'd be a happy camper. There has to be at least once in its history that its been accurate that far out, but I cant remember it.

[Valkhorn]

Indeed, it is interesting to look at

I sometimes think the GFS is just "odd" in the winter months. It knows what it's trying to say but the words get stuck halfway. So, it ends up being discombobulated by the end of the run

[RNS]

I'll let the graphics speak for themselves





The -30C isotherm is huge in the last 90 hours or so, and mean heights as low as 474dm.

My take is that the GFS is trying to grasp at the obvious cross-polar flow setting up but it's not clicking. I think the GFS is still out to lunch but I do think it's pretty spot on with the cold air intrusion in Canada. The trouble with this model is it isn't really reading the patterns and I'm afraid what it's forecasting is just its bias.

I thought I'd show this for spits and giggles. Take your bets folks on how low the GFS is going to go with heights this winter. My guess is it'll try to get to 470dm or lower in the next few weeks and the -40C line will rear its ugly head in the north of Canada on the GFS long range runs.

Any bets for a -50C line in January? C'mon, it's the GFS... place your bets

I wouldin/t place bets on the GFS at that range...it has a severe cold bias...and as a result has a tendency to blow things out of proportion with regard to the amount of cold air present in any given location. the second thing is the models run-to-run consistency and long range skill...both of which lack. IOW...the model is very inconsistent in the meadium range...and is normally too cold. the ECM (european model) skill is much higher in the MR. not to mention the ECM has fewer biases (aside from the fact that it likes to hold back energy in the southern branch).

[Valkhorn]

Well of course I'm not taking this as something set in stone. I just thought it was something funny to share

[Guest]

I would not use the 384 hr GFS to blow the snot out of my nose

[Chris the Weather Man]

I would not use the 384 hr GFS to blow the snot out of my nose

LOL!! Good One DT!