The GEFS ensemble model has always had a negative AAM (Atmospheric Angular Momentum) bias. This means that the model slows down momentum, both tropically and extra tropically. This is why GEFS (and GFS) are known for wild cut-off low scenarios and other out-of-the-blue scenarios. The below image demonstrates the negative bias of the GEFS model, in accords to the topic of momentum.
Victor Gensini also runs a similar plot for the GEFS AAM predictions. However he runs his through a bias-correction model to improve the results. However the latest adaptation of FV3 has seemingly messed up this bias-correction. Standby for an improvement of it.
The below details provide access to a database of current AAM/GWO observations.
http://gsdmsolutions.com/~gsdm/clim/aam.rean.shtml
un = gsdm01
pw = gu3st#1
- DAILY DATA
- Vertically-integrated 5-day running mean: 1968-1997 Climatology
- Plots show some of the features: MJO, SUB-MONTHLY, & RAPID TRANSITIONS.
- ( Plots contain data through (MM/DD/YYYY) = 09/26/2018 )
- PLOTS
- Data Files
- AAM data file (Updated: Friday, 28-Sep-2018 08:35:48 CDT)
- AAM 1-21 data file (Updated: Friday, 28-Sep-2018 08:35:50 CDT)
- TAUC data file (Updated: Friday, 28-Sep-2018 08:35:57 CDT)
- TAUF data file (Updated: Friday, 28-Sep-2018 08:35:57 CDT)
- TAUG data file (Updated: Friday, 28-Sep-2018 08:35:57 CDT)
- TAUM data file (Updated: Friday, 28-Sep-2018 08:35:57 CDT)
- TEND data file (Updated: Friday, 28-Sep-2018 08:36:00 CDT)
- TEND (1-21) data file (Updated: Friday, 28-Sep-2018 08:36:02 CDT)
- TRANSP data file (Updated: Friday, 28-Sep-2018 08:36:00 CDT)
- MONTHLY DATA
- Vertically-integrated: 1968-1997 Climatology
- Plots show some of the features: ENSO, QBO, & TRENDS.
- ( Plots contain data through 08/31/2018 )
- PLOTS
You require the login details to access the above links.
CFS GWO and AAM projections can also be found at the Victor Gensini site here.
An Andrea Winters run website shows the current GEFS forecast projection of the North Pacific jet stream
