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#1427784 - 10/07/2017 22:38 Imminent EC and GFS upgrades
Ken Kato Offline
Weatherzone Addict

Registered: 05/03/2012
Posts: 4681
I've posted this elsewhere but will post it here as well since some people in other states might be interested.

The next EC upgrade is still on track to become operational from the 12z run tomorrow (Tuesday).

This will be followed by the next GFS upgrade next Wednesday.

Over the last month or so, I've been comparing the upgraded pre-operational EC version with the current version for 24hr precip for our region (I haven't looked at the upgraded ensemble version yet though).
To me at least, the upgraded version seems to be a bit LESS accurate (and more erratic) in placement and intensity of rainfall for this region.
But that's from a subjective point of view and it only includes a small sample size (mainly stratiform rain) so I don't know if this will be the same over the coming months or for thunderstorms.

The objective skill stats from when it's been undergoing trials suggest that on average, the majority of parameters such as temps, winds, etc at various levels have shown some improvement for various regions of the world including AU/NZ while some have remained unchanged or deteriorated slightly such as in the tropics.
TC track performance was very slightly improved at short range while TC intensity has tended to be a bit lower which shows up as an improvement at longer ranges.

The deep convection scheme has also been upgraded.

Some other technical details of the changes to the model below including the use of more sounding data from extra satellite sensors:

" Assimilation
Improved humidity background error variances directly from the EDA like for all other variables.
Revised wavelet filtering of background error variances and revised quality control of drop-sonde wind observations in 4DVAR to improve tropical cyclone structures.

Observations
Increased use of microwave humidity sounding data by adding new sensors (SAPHIR, GMI 183 GHz channels).
Activation of 118 GHz channels over land from MWHS-2 instrument on-board FY-3C.
Harmonised data usage over land and sea-ice for microwave sounders (adding MHS channel 4 over snow, adding some ATMS channels, lower observation errors for MHS data over land).
Improved screening of infrared observations for anomalously high atmospheric concentrations of hydrogen cyanide (HCN) from wildfires.
Improved quality control for radio occultation observations and radiosonde data.

Model
New, more efficient radiation scheme with reduced noise and more accurate longwave radiation transfer calculation.
New aerosol climatology based on ‘tuned’ CAMS aerosol re-analysis including dependence on relative humidity.
Increased super-cooled liquid water at colder temperatures (down to -38C) from the convection scheme.
Visibility calculation changed to use ‘tuned’ CAMS aerosol climatology. "

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#1438270 - 21/10/2017 07:18 Re: Imminent EC and GFS upgrades [Re: Ken Kato]
Flowin Offline
Weather Freak

Registered: 15/10/2017
Posts: 65
Loc: Pinjarra Hills, Qld
What do think now Ken, after some three months in action with the upgraded models?
And I don't mean is any model better than another, but is the upgrade notably better than previous.


Edited by Flowin (21/10/2017 07:20)
_________________________
Models are for estimating and gauges are for knowledge.

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#1441853 - Yesterday at 10:19 Re: Imminent EC and GFS upgrades [Re: Ken Kato]
Ken Kato Offline
Weatherzone Addict

Registered: 05/03/2012
Posts: 4681
Sorry I was meaning to respond to this earlier but time's gotten away from me.

My first (subjective) impressions has been that in EC's case, it's not too different to before. This is consistent with the objective skill stats for it. Obviously it's shown some improvement when it was being trialled before it became operational though.
On average, it's been really good with many of the day to day aspects such as timing and extent of enhanced shower activity coming onto the coast, general placement of convective and stratiform precip, etc.

As for GFS, it's been atrocious in terms of both placement of precip and intensity (but again, I'm not sure if it's any worse than it used to be). There's been a number of precip and convective events in recent months here where it's done things like not putting any precip along the central/northern NSW coast and southern SE QLD coast (in reality, storms blew up all over the place along parts of that strip), putting a big weird bullseye of significant rainfall over the Sunshine Coast for multiple runs but nowhere else (in reality, it was the opposite with the southern SE QLD coast getting more thunderstorm precip than the north), consistently putting a 500-700mm bullseye over the Sunshine Coast when only 100-250mm eventuated (a lot closer to other models), etc etc.
GFS thermodynamics such as those displayed in soundings and CAPE fields seem to still be good though.

Of course, there'll be times when GFS beats other models including EC so it's always good to look at all of them - this is just speaking on average.

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#1441858 - Yesterday at 11:12 Re: Imminent EC and GFS upgrades [Re: Ken Kato]
teckert Offline
Weatherzone Moderator

Registered: 27/05/2001
Posts: 17524
Loc: NE suburbs, Adelaide, South Au...
TBH I am fed up with GFS and its substandard results compared to EC in particular. If anything its getting worse.
Thank goodness we can now get a lot of quality EC model outputs for free on the web..

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#1441920 - Yesterday at 20:25 Re: Imminent EC and GFS upgrades [Re: Ken Kato]
Flowin Offline
Weather Freak

Registered: 15/10/2017
Posts: 65
Loc: Pinjarra Hills, Qld
Model are just estimates and you can't criticise them for that.
But without any models we would be worse off.
So we need to have measuring effort of what occurs to improve the models.
Judging what the models say is the challenge.
_________________________
Models are for estimating and gauges are for knowledge.

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