Snow Reports
FAQ
Help!!
Log in to snowHeads to make it MUCH better!
Registration's totally free, of course, and makes snowHeads easier to use and to understand, gives better searching, filtering etc. as well as access to 'members only' forums, discounts and deals that U don't even know exist as a 'guest' user. (btw. 50,000+ snowHeads already know all this, making snowHeads the biggest, most active community of snow-heads in the UK, so you'll be in good company)..... When you register, you get our free weekly(-ish) snow report by email. It's rather good and not made up by tourist offices (or people that love the tourist office and want to marry it either)... We don't share your email address with anyone and we never send out any of those cheesy 'message from our partners' emails either. Anyway, snowHeads really is MUCH better when you're logged in - not least because you get to post your own messages complaining about things that annoy you like perhaps this banner which, incidentally, disappears when you log in :-)
Username:-
Password:
Remember me:
👁
durr, I forgot...
Or:
Register
(to be a proper snow-head, all official-like!)
GFS Ensembles question
snowHeads Forum Index
>>>
Snow Reports - weather - snow conditions
Prev topic
::
Next topic
Poster:
A snowHead
Poster:
A snowHead
Having now become completely addicted to checking the GFS ensemble runs I opened it up for my early morning fix and saw a thick green line which I haven't seen before which is labelled as GFS-Hauptlauf on the 850hPa temp 6h Niederschlag chart. Anyone tell me that this signifies?
brian
brian
Guest
BGA
, the Hauptlauf (high run in german I think) is the operational run (ie. the one you actually see on the charts).
Prior to March last year, it used to appear as the thick blue line, but GFS was then upgraded to run at a higher resolution (on a 0.5 degree grid rather than 1 degree). However, I think it's only the operational that runs at the higher res (hence hauptlauf) whereas the rest of the ensemble members are at the old 1 degree resolution. When this change came in the operational went missing from the ensemble charts. It looks like Wetterzentrale have got round to putting it back.
btw, the thick blue line now shows as "control run", I think that it's what was the old operational run (ie. the input unmodified but at the coarser resolution) but I'm not 100% sure of that.
Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
Thanks for that
brian
, does that mean that the operational line gives a better indication as to the forecast? My current, highly amateur, method of interpreting the charts is first to see how closely the runs are grouped together to get an indication of the confidence of the forecast, then to use the grey 'mittel' (?mean) line to give me an idea of forecast conditions. Should I now pay more attention to the hauptlauf line?
You need to
Login
to know who's really who.
You need to
Login
to know who's really who.
brian
, Hauptlauf would be main run
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
Quote:
does that mean that the operational line gives a better indication as to the forecast
The starting conditions for the operational run are considered to be those which most closely model the current state of the atmosphere. If you need to make a deterministic forecast using the GFS it is best IMHO to use the operational run to do so. The ensembles should be used to gauge the level of confidence in the forecast. In other words, if most of the ensemble members support the operational run, confidence in the solution is increased.
One thing to look out for is when the operational run and control run diverge from each other. This in my experience suggests that a new pattern is breaking and you should follow the subsequent GFS runs closely.
Terms and conditions
Privacy Policy
FAQ
Poster: A snowHead
