Transcript The THORPEX Interactive Grand Global Ensemble (TIGGE) and plans for a Global Interactive Forecast System (GIFS) - an introduction Richard Swinbank, with thanks to the.

The THORPEX Interactive Grand Global
Ensemble (TIGGE) and plans for a Global
Interactive Forecast System (GIFS)
- an introduction
Richard Swinbank,
with thanks to the GIFS-TIGGE working group,
THORPEX IPO and other colleagues
TIGGE
THORPEX Interactive Grand Global Ensemble
 A major component of THORPEX: a World Weather
Research Programme to accelerate the improvements
in the accuracy of 1-day to 2-week high-impact
weather forecasts
 GEO task WE-06-03 – “TIGGE and the Development
of a Global Interactive Forecast System for Weather”
Objectives:
 Enhance collaboration on ensemble prediction, both internationally
and between operational centres & universities.
 Facilitate research on ensemble prediction methods, especially
methods to combine ensembles and to correct systematic errors
 Enable evolution towards a prototype operational system, the “Global
Interactive Forecast System”
TIGGE data
 Ten of the leading global forecast centres are providing regular
ensemble predictions to support research on predictability,
dynamical processes and development of probabilistic forecasting
methods.
 TIGGE data is made available for research after a 48-hour delay.
Near real-time access may be granted for specific projects
through the THORPEX International Project Office.
TIGGE infrastructure
 Data collected in nearreal time (via internet) at
central TIGGE data
archives
Predictability
science
academic
Applications
NHMS
users
 Could be implemented at
relatively little cost
 Can handle current data
volumes (approaching
400 GB/day) within
available network and
storage capabilities
NCAR
ECMWF
EPS 1
EPS 2
CMA
EPS n
Summary of TIGGE database
Centre
Ensemble
members
Output data
resolution
Forecast
length
Forecasts
per day
Fields
(out of 73)
Start date
BOM
33
1.50º x 1.50º
10 day
2
55
3 Sep 07
CMA
15
0.56º x 0.56º
10 day
2
60
15 May 07
CMC
21
0.9º x 0.9º
16 day
2
56
3 Oct 07
CPTEC
15
0.94º x 0.94º
15 day
2
55
1 Feb 08
ECMWF
51
N200 (Reduced
Gaussian)
N128 after day 10
15 day
2
70
1 Oct 06
JMA
51
0.56º x 0.56º
9 day
1
61
1 Oct 06
KMA
17
1.00º x 1.00º
10 day
2
46
28 Dec 07
Météo-France
11
1.50º x 1.50º
2.5 day
2
62
25 Oct 07
NCEP
21
1.00º x 1.00º
16 day
4
69
5 Mar 07
UKMO
24
0.83º x 0.55º
15 day
2
71
1 Oct 06
Some nice features of TIGGE that
demanded a lot of effort
 All data are archived at native resolution (on native grid
when possible)
 Data are interpolated on any limited-area lat-lon grid
defined by the user just before download
 Field names, definitions, units, accumulation times,
etc… are fully standardized
 Data gaps are continuously monitored and every effort
is made to repair them quickly
 Data can be obtained either in GRIB2 or NETCDF
format (only from NCAR at the moment)
 More functionalities will be installed (e.g. access to
single point data, automatic requests, local calculation
and plot generation, etc…) depending on user numbers,
requests and funding
6
TIGGE-LAM:
TIGGE for limited-area models
The TIGGE-LAM panel, chaired by Tiziana Paccagnella (ARPASIM), supports the development of the Limited Area Model
Ensemble Prediction System component of TIGGE.
This Panel works in close coordination with the GIFS-TIGGE WG, in
liaison with pre-existing LAM EPS initiatives and in coordination with
the THORPEX regional committees.
Aims:
 encourage a coordinated approach to LAM EPS for the mutual
benefit of WMO members;
 facilitate the interoperability of the different modelling systems
contributing to TIGGE;
 coordinate the archiving of limited-area ensemble forecasts – the
three TIGGE archive centres have agreed to host a sub-set of high
priority data;
 contribute to the definition of scientific issues related to LAM EPS
and particularly to TIGGE-LAM and propose specific initiatives to
address these issues to advance LAM EPS.
Comparison of RMS errors
Courtesy Mio Matsueda
Comparison of RPSS N. hem Z500
z at 500hPa (cf_as_an)
10 categories, cases 20061201-20070228_N90, area n.hem
ecmwf ukmo jma
z at 500hPa (cf_as_an)
10 categories, cases 20071002-20071115_N45, area n.hem
ecmwf ukmo ncep msc jma cma bmrc kma
1
ON07
(45c)
Ranked Probability Skill Score
0.9
0.8
0.7
0.6
0.5
0.4
ECMWF
UKMO
NCEP
MSC
JMA
CMA
BMRC
KMA
DJF07
(90c)
0.9
Ranked Probability Skill Score
1
0.8
0.7
0.6
0.5
0.4
0.3
0.3
0.2
0.2
0.1
0 z at 500hPa (cf_as_an)
010 categories,
1 2 3 cases
4 520070328-20070528_N62,
6 7 8 9 10 11 area
12 n.hem
13 14 15 16
0.1
1
1
Ranked Probability Skill Score
0.8
0.7
0.6
JJA07
(84c)
0.9
Ranked Probability Skill Score
AM07
(62c)
0.9
0.8
0.7
0.6
0.5
0.5
0.4
0.4
0.3
0.3
0.2
0.2
0.1
0
0z at 1500hPa
2 (cf_as_an)
3
4
5
6
7
8
9 10 11 12 13 14 15
10 categories, cases 20070607-20070831_N84,
area n.hem
fc-step
(d)
ecmwf ukmo jma cma bmrc
fc-step (d)
ecmwf ukmo ncep jma
0.1
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
fc-step (d)
from Park et al, 2008
0
0
1
2
3
4
5
6
7
8
fc-step (d)
9
10
11
12
13
14
15
Multi-model combination: MSLP & T2m
Brier skill-scores of multi-model
combination of bias-corrected
ECMWF, Met Office and NCEP
forecasts.
Mean Sea Level Pressure and
500 hPa (not shown) show only
small benefits from combining
different models
2m temperature shows more
benefit (1-5 days improvement in
lead time)
More sophisticated weighting led
to only small additional skill
Courtesy Christine Johnson
MSLP > mean
T2m > mean
T2m > 90 %
Comparison of extra-tropical cyclone tracks
Ensemble mean error:
Position
(verified against ECMWF
analyses)
Ensemble mean error –
Propagation speed
Propagation speed bias
Courtesy Lizzie Froude
Applications: flood prediction
Predictions with a 5-day lead-time for a flood event on River
Jiu in Romania
from Pappenberger et al, 2008
MJO forecast comparison
Mio Matsueda
Towards the Global Interactive Forecast
System (GIFS)
 Many weather forecast situations are low probability but high risk
– unlikely but catastrophic. Probabilistic forecasting is a powerful
tool to improve early warning of high-impact events.
 The objective of the GIFS is to realise the benefits of THORPEX
research by developing and evaluating probabilistic products to
deliver improved forecasts of high-impact weather.
 As a first step, the GIFS-TIGGE working group set up a pilot
project for the exchange of real-time tropical cyclone predictions
using “Cyclone XML” format.
GIFS concept
 GIFS is planned to
use global-regionalnational cascade
pioneered by the
WMO Severe
Weather Forecast
Demonstration
Project (SWFDP)
 Further development
and evaluation of
products will be done
in conjunction with
SWFDP and other
regional pilot projects.
In-Situ
Observations
EPS1
Airborne
Observations
EPS2
Satellite
Observations
EPS3
Generate
Products
Regional
Centre
National
Centre
users
National
Centre
users
users
National
Centre
users
GIFS development
 GIFS-TIGGE WG has initiated a GIFS development
project
 Develop products, based on TIGGE ensembles,
focused on forecasts of
 Tropical cyclones
 Heavy precipitation
 Strong winds
 Collaborate with WMO Severe Weather Forecast
Demonstration Project (SWFDP) and other FDPs and
RDPs to provide an environment for the evaluation of
prototype products
 Need to engage with users to ensure products
address needs of operational forecasters and end
users.
GIFS development project interactions
GIFS development project interactions
SERA group
Joint Working Group
on Verification
GIFS-TIGGE
Working group
SWFDP
Southern Africa
Other THORPEX
and WWRP
WGs
GIFS-DP
THORPEX
Regional
committees
NW Pacific TC
Project
Future subprojects
Other pilot projects
Operational
forecast
community
Research
community
SW Pacific
Tropical cyclone products
from MRI/JMA http://tparc.mri-jma.go.jp/cyclone/
New tropical cyclone product:
Strike probability time-series at a city
(available after next major update)
Courtesy Tetsuo Nakazawa
Forecasting TC genesis
strike probability 5-7 days ahead
Courtesy David Richardson / ECMWF
Summary
 Since October 2006, the TIGGE archive has been
accumulating regular ensemble forecasts from leading
global NWP centres.
 The archive is a tremendous resource for the research
community at large, and in particular the science
working groups of THORPEX.
 Products to enhance the prediction of high-impact
weather, starting with tropical cyclones, will form the
basis of the development of the Global Interactive
Forecast System.
 GIFS products will be developed & evaluated in
conjunction with SWFDP and other regional projects.
TIGGE website: http://tigge.ecmwf.int