Users meeting Summary Performance of the Forecasting System 1

1
Users meeting SummaryPerformance of the
Forecasting System (1)

• Main (deterministic) model
• Outstanding performance last winter over NH
• Excellent results and consistent upward trend for
  Europe as measured by ANC Z500hPa
• The average lead over an ensemble of centres has
  been maintained, as confirmed by gain
  statistics, however, some centres have also
  progressed significantly
• EPS
• Performance continues to improve, recent changes
  to the forecasting system had a positive impact
• Upward trends in performance are reflected in
  RPSS scores for Z500 and in skill scores for
  weather parameters

2
Users meeting SummaryPerformance of the
Forecasting System (2)

• Severe weather event prediction
• Tropical cyclone forecasts have improved
  significantly last year, providing generally good
  guidance
• Core pressure is underestimated, better in higher
  resolution
• Bias towards slow movement
• Delineating the TC in the analysis is important,
  bogussing should be re-considered
• Some overconfidence in strike probabilities
• First steps towards verification of the EFI
• Station verification of extreme precipitation
  events over Europe using the EUMETNET/ECSN
  Climate Atlas
• Self-calibrating properties of the EFI provide
  improved guidance over raw model probabilities
• Example of successful indication of freak waves
  in analysis and forecast

3
Users meeting SummaryPerformance of the
Forecasting System (3)

• Weather parameters
• One day gain per decade in predictive skill of
  moderate amounts of precipitation
• Same improvements cannot be demonstrated for
  large amounts
• Up-scaled precipitation analysis based on high
  resolution observing network is used for
  verification in delayed mode
• Provides more reliable and robust results
  obtained at the scale of the model
• Reduced frequency bias in particular for small
  amounts compared with verification results
  obtained when using scattered SYNOP network
• Problems with treatment of low level clouds
  during persistent inversions over central Europe
  in winter, improved boundary layer cloud scheme
  was introduced in April 2005 and will help
  alleviate these deficiencies
• Some evidence of positive trend in T2m forecasts
  over North America and parts of Europe
• Episodes of strong low level inversions and
  extreme cold conditions over Europe in February
  contribute to larger errors

4
Users meeting SummaryPerformance of the
Forecasting System (4)

• Monthly forecasts
• Operational since October 2004, dissemination was
  added spring 2005
• ROC area score indicates skill in T2m over
  persistence for days 12-18, to a lesser extent
  for days 19-32
• Good predictions of transition between flow
  regimes last winter
• Outer quintiles for T2m are skilful
• Meteo France finds moderate skill in T2m
  forecasts for week 3 over France

5
Users meeting SummaryPerformance of the
Forecasting System (5)

• Seasonal forecasts
• Predictions of the monsoon precipitation for JJA
  2004 verified well
• Good representation of ocean currents in tropical
  Pacific
• Over the West Pacific basin the forecast
  predicted successfully higher tropical storm
  activity than the climatology over the Atlantic
  the forecast has not been as good
• Dry conditions over the Iberian Peninsula were
  consistently predicted since November 2004
• Potential benefit from multi-model system
  reduced rms error and improved correlation, eg
  for NINO3 SST forecasts

6
Users meeting SummaryDevelopment of the
Forecasting System(1)

• Cy29r2 end June, to include
• 3-hourly EPS post-processing to 132 hours
• Near-real-time hindcast runs to create model
  climate for EFI
• Plans to implement higher resolution forecasting
  system in autumn 2005 (T799L91/T399L62)
• First test data in Mars end June
• E-suite data in Mars from mid-July
• Test dissemination by arrangement early September
• Information on web
• Unified system (VAREPS) with extension to 15 days
  end 2005
• VAREPS to merge with monthly forecast early 2006
• Seasonal forecast system3

7
Users meeting SummaryDevelopment of the
Forecasting System(2)

• Product development
• Extended EPSgrams for Unified System
• Global and regional multi parameter EFI maps
• Prototypes of combined multi-model seasonal
  products
• New monthly forecast products, eg synoptic view
  of temperature and flow anomalies
• Additional archiving from monthly forecasting
  system
• Weekly anomalies
• Terciles
• Additional verification from monthly system on
  web
• Fields from up-scaled precipitation data to be in
  MARS

8
Users meeting SummaryUse and evaluation in
Member States (1)

• Users report on a wide range of applications and
  usage of medium and extended range products
• Early delivery system improved the usefulness of
  the forecasts, also in the early stages of the
  forecast range
• Presentation of probabilistic forecast
  information to the public
• On the web (DK, NL,), EPS spread expressed as
  range, probabilities used for exceeding
  thresholds
• Weather scenarios are presented for days 7-9 (DK)
• Newspaper (S,..)
• On TV (NL, S..)
• Several case studies of successful severe weather
  event forecasts (HUN, DWD, N,)
• Influence of weather data (T, precipitation,
  wind) on energy markets, probabilistic
  information is used to create level of confidence
  
• Weather risk applications

9
Users meeting SummaryUse and evaluation in
Member States (2)

• Limited area ensemble prediction (COSMO-LEPS,
  LAMEPS)
• Encouraging results were reported from several
  applications
• Aiming at downscaled severe weather event
  prediction
• Use of LAMEPS output in Eurorisk project, storm
  surge model, input to hyrdological models (N)
• Ensemble prediction
• Ensemble mean is found useful for point forecasts
• Benefits of probabilistic forecast information
  was emphasized
• EFI used to alert forecasters (e-mail sent
  automatically (SUI))
• Probability forecasts under development for
  locations along the Finnish coast
• Meteo France plans to study the skill in
  predicting weather regimes in the monthly
  forecasts
• Used as input for hydrological forecasts (river
  discharge)
• Experimental use of new CAPE parameter (NL)
• Automatic generation of weather alarms for
  forecasters (NL)

10
Users meeting SummaryUse and evaluation in
Member States (3)

• Other issues
• IRI reported on the potential benefit of extended
  range forecasts for predicting rainfall in
  regions epidemically affected by malaria
  outbreaks
• MetO reported on significant problems with the
  generation of convective snowfall over the North
  Sea in north-easterly flow in late winter 2005
• MetO further investigated the verification
  results for early warnings, previously
  experienced anomalies in the results with a
  maximum in skill disappear when applying
  verification procedures which are more in line
  with standard NWP procedures
• KNMI presented a web catalogue of high impact
  weather events, using ERA-40 as a documentary

11
Users meeting SummaryUser requirements

• Medium range forecasting system
• Provide 3-hourly post-processing from the EPS
• Consider the development and extension of
  suitable products to 15 days with the planned
  extension of the forecast range
• Develop suitable products for the unified
  forecast system
• Requirement for hindasts/learning sample prior to
  model upgrades

12
Users meeting SummaryUser requirements (2)

• Monthly forecasting system
• Increase the number of members (from currently 5)
  in the hindcast ensembles
• Time of the runs and the delivery should be
  reviewed
• Multi-model seasonal forecasting system
• Develop combined and calibrated multi-model
  products
• Standardize the hindcast periods
• Standardize the reference periods for anomalies
• Standardized toolbox for verification is of
  interest
• Support for time critical applications run at the
  Centre by Member States

13
Users meeting SummaryUser requirements (3)

• Requests for products
• Timely updating of products on the web is
  important
• Extend the range of web products
• Global EFI products to be made available to WMO
  members
• CAPE parameter in future ERA
• Times of product delivery to be reviewed after
  the implementation of the planned upgrades in
  2005/early 2006