# Presentation: 649206

## MSC Ensemble Prediction System – an update

- Richard Verret, Normand Gagnon,
- Stéphane Beauregard, Jacques Hodgson,
- Benoit Archambault
- Canadian Meteorological Center
- Meteorological Service of Canada

## Outline

- Current and proposed EPS set-up at CMC.
- Basic products.
- NAEFS products.
- Conclusions.

## Canadian EPS - current set-up

**96 perturbed analyses based **
**on Ensemble Kalman filters**

**One 16-day control integration**
**with SEF model**

**Selection of 16**
**initial conditions**

**Spread**
**inflation**

**Products**

**Integration done twice a day (00 and 12 UTC)**

**Mean**

**Eight 16-day integrations**
**with SEF model**

**Eight 16-day integrations**
**with GEM model**

**resolution ~150 km**

**T149 L28**

**1.2° L28**

## Canadian EPS - proposed set-up

**96 perturbed analyses based **
**on Ensemble Kalman filters**

**One 16-day control integration**
**with GEM model**

**Selection of 20**
**initial conditions**

**Spread**
**inflation**

**Products**

**Integration done twice a day (00 and 12 UTC)**

**Mean**

**Twenty 16-day integrations**
**with GEM model**

**resolution ~100 km**

**0.9° L28**

## GZ-500 hPa

## TT-850 hPa

## CRPS TT-850 hPa

- January 2006

- CRPS GZ-500 hPa
- January 2006

## CRPS UU-500 hPa

- January 2006

- CRPS VV-500 hPa
- January 2006

## May 12 2006 00 UTC

**May 12 2006 00 UTC**
**120-h**
**Valid May 17 2006 00 UTC**

## Probability of 24-h precipitation amounts

**May 7 2006 00 UTC – 96- to 120-h**
**Probability of 24-h precipitation amounts**
**Valid 00 UTC May 11 2006 – 00 UTC May 12 2006**

**calibrated**

**Probability of 24-h precipitation amounts**

## Bayesian Model Averaging

**Prepared at 00 UTC May 19 2006**

## Slide 12

## NAEFS Grand Ensemble (principles)

- Global ensembles:
- NOAA, MSC, NMS of Mexico: official accord signed in November 2004.
- ECMWF and UKMetO, via Thorpex research program.
- Other partners (FNMOC, AFWA, JMA) may join at a later time.
- Advantages:
- Larger ensemble allowing better PDF definitions (super-ensemble).
- Improved probabilistic forecast performance.
- Seamless suite of forecast products across international boundaries and across different time ranges (1-14 days).
- Minimal additional costs – levering computational resources.
- Synergy with NCEP on R&D work.
- Collaborative product development.
- Contingency with another national NWP Centre.
- Problems:
- Combination of multi-model ensembles into a super-ensemble.
- Real time exchange (operational considerations).

## NAEFS Grand Ensemble (deliverables)

- Raw data exchange (00 and 12 UTC runs).
- 00 and 12 UTC production runs.
- ~ 50 selected variables.
- 6-hourly output frequency.
- GRIB2 format.
- Basic products:
- Using same algorithms/codes.
- Bias correction algorithm.
- Weighted combination of members.
- Forecast products in terms of climatological anomalies.
- Week 2 (days 8 to 14) forecasts based on the combined MSC/NCEP ensembles.
- Center specific end products.
- Evaluation and feedback for improvements:
- Verification using same approaches

## NAEFS set-up

- CMC:
- 16 members + 1 control
- Multi-model:
- 8 GEM – 1.2° L28
- 8 SEF – T149 L27
- Perturbed Kalman filter data assimilation cycles.
- Integration done two times a day (00 and 12 UTC) out to 16 days.
- To come:
- 20 GEM members
- 0.9° L28

- NCEP:
- 14 members + 1 control
- Single model:
- GFS – T126 L28
- Ensemble Transform breeding method.
- Integration done four times a day (00, 06, 12, 18 UTC) out to 16 days.
- To come:
- 20 GFS members
- T190 L28

## EPS-grams

**EPS-grams**

**CMC**

**NCEP**

**NAEFS**

## Mean and standard deviation

**CMC**

**NCEP**

**NAEFS**

**May 10 2006 00 UTC**
**24- to 48-h**
**24-h precipitation amounts**
**Valid May 12 2006 00 UTC**

**Available for:**
** ****24-h precipitation amounts**
** ****10 m wind speed**
** ****2 m temperature**
** ****Mean sea level pressure**
** ****500 hPa geopotential heights**
** ****1000-500 hPa thickness**
** ****200 hPa wind speed**

**Mean and standard deviation**

##  Available for:

**CMC**

**NCEP**

**NAEFS**

**May 18 2006 00 UTC**
**0- to 120-h**
**Probability 24-h precipitation amounts**
**exceeding 10 mm at least once**
**Valid 00 UTC May 18 2006 – 00 UTC May 23 2006**

**non calibrated**

** ****Available for:**
** ****Precipitation amounts:**
** ****<**** 0.2 mm**
** ****> 2 mm**
** ****> 5 mm**
** ****> 10 mm**
** ****> 25 mm**
** ****10 m wind speed:**
** ****> 15 km/h**
** ****> 50 km/h**
** ****> 90 km/h**
** ****Minimum temperature:**
** ****< 0°C**
** ****< -15°C**
** ****< -30°C**
** ****Maximum temperature:**
** ****> 0°C**
** ****> 15°C**
** ****> 30°C**
** ****Wind chill:**
** ****< -15°C**
** ****< -30°C**
** ****< -40°C**
** ****< -55°C**

**Probability of exceedance over 24-h periods at least once during the specified forecast range**

##  Precipitation amounts:

**May 10 2006 00 UTC**
**0- to 336-h**
**Probability precipitation amounts**
**exceeding 50 mm**
**Valid 00 UTC May 10 2006 – 00 UTC May 24 2006**

**non calibrated**

**Available for:**
** ****Precipitation amounts:**
** ****<**** 0.2 mm**
** ****> 2 mm**
** ****> 5 mm**
** ****> 10 mm**
** ****> 25 mm**
** ****> 50 mm**

**Probability of total precipitation amounts during the specified forecast period**

**CMC**

**NCEP**

**NAEFS**

## Bias correction algorithm

**May 14 2006 00 UTC – 120-h**
**500 hPa GZ CMC ensemble average (contour) / Average bias correction (color)**
**Valid 00 UTC May 19 2006 **

**For multi-model ensemble, the bias correction**
**is applied on each member separately**

## Week 2 product

- Methodology:
- Get temperatures from members debiased toward CDAS reanalyses.
- Average four instantaneous temperatures (00, 06, 12 and 18 UTC) each day for each member.
- Average daily temperatures over seven days (day 8 to 14) for each member.
- Get percentile from reanalysis weekly climatology for each member.
- Count members in each tercile to get probabilities of « above » and « below ».
- « normal » = 1 – (« above » + « below »).
- Calibration of forecasts.

## Slide 22

## End products

**(link to products)**

- NAEFS products

## Slide 24

## Slide 25

## Slide 26

## Slide 27

## End products

- Products – Quebec LAb

## Slide 29

## Slide 30

## Where will we be Tomorrow?

- Increased number of members and resolution of models:
- 20 members,
- ~100 km.
- Stochastic physics.
- Extension of public forecasts:
- Days 6-7 using EPS outputs.
- Usage of EPS outputs for days 3-7.
- Wider usage of NAEFS Grand Ensemble:
- Improved bias correction scheme (1st moment).
- Correction of 2nd moment.
- Member weighting scheme.
- Forecast products in terms of climatological anomalies.
- More end products.

**Notes:**
Séries d’exemple d’utilisation des ensembles

## Where will we be after Tomorrow ?

- Regional EPS :
- 20 members GEM-LAM.
- ~25 km resolution.
- Model perturbations (CAPE).
- Initial condition perturbations.
- Products for decision making processes:
- EPS provides the best source of probabilistic information for decision making.
- Reliability of probabilistic forecasts is required.
- Extreme forecast index.
- Products statistical post-processing:
- Verification
- Calibration

**Notes:**
Séries d’exemple d’utilisation des ensembles

## Slide 33