COSMO General Meeting Zurich, 2005 Institute of Meteorology and Water Management Warsaw, Poland- 1 - Verification of the LM at IMGW Katarzyna Starosta,

Institute of Meteorology and Water ManagementWarsaw, Poland - 1 -

COSMO General MeetingZurich, 2005

Verification of the LM at IMGW

Katarzyna Starosta, Joanna Linkowska, Andrzej Mazur

Institute of Meteorology and Water Management



Contents:

Verification of surface parameters using 56 SYNOP stations

Verification of precipitation using 308 rain gauges

Verification of upper-air parameters using 3 TEMP stations.



Verification of surface parameters using 56 SYNOP stations

Katarzyna Starosta, Joanna Linkowska

Institute of Meteorology and Water Management, Poland



• The results of verification surface continuous parameters from January 2005 to June 2005 will be presented. Following meteorological elements were analysed: 2m temperature, 2m dew point temperature, sea level pressure, 10m wind speed.

• The meteorological variables forecasted by the model were compared with synoptic data from 56 Polish synoptic stations. Mean error (ME) and root mean square error (RMSE) were calculated using 12 forecast range (every 6 hours) for a 72 hour forecast starting at 00 UTC. The error estimators were calculated for all stations and for the whole country area.

0 10 20 30 40 500

5

10

15

20

25

30

35

40

45

50

LOCATION OF SYNOPTIC STATIONS



RMSE, ME, Temperature 2m[C], January-June 2005

-3

-2

-1

0

1

2

3

4

5

6

6 12 18 24 30 36 42 48 54 60 66 72

forecast range [h]

ME

RM

SE

JAN FEB MAR APR MAY JUN I II III IV V VI



RMSE, ME, Dew point temp. 2m [C], January-June 2005

-3

-2

-1

0

1

2

3

4

5

6

6 12 18 24 30 36 42 48 54 60 66 72

forecast range [h]

ME

R

MS

E




RMSE, ME, Pressure [hPa], January-June 2005

-3

-2

-1

0

1

2

3

4

5

6

6 12 18 24 30 36 42 48 54 60 66 72

forecast range [h]

ME

R

MS

E




RMSE, ME, Wind speed, [m/s], January-June 2005

-3

-2

-1

0

1

2

3

4

5

6

6 12 18 24 30 36 42 48 54 60 66 72

forecast range [h]

ME

R

MS

E




ME, 1-day, Temperature [C], January-June 2005

-3

-2

-1

0

1

2

3

6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24

JAN FEB MAR APR MAY JUN

hours/months

ME

ME, 1-day, Dew point temperature [C], January-June 2005.

-3

-2

-1

0

1

2

3

6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24


hours/months

ME



ME, 1-day, Pressure [hPa], January-June 2005

-3

-2

-1

0

1

2

3

6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24


hours/months

ME

ME, 1-day, Wind speed [m/s], January-June 2005

-3

-2

-1

0

1

2

3

6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24 6 12 18 24


hours/months

ME



ME, Temperature 2m [C], 36h-forecast, June 2005.

-3

-2

-1

0

1

2

3

4

5

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53

synoptic stations

ME

ME, Dew point temp.2m [C], 36h forecast, June 2005

-3

-2

-1

0

1

2

3

4

5

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52

synoptic stations

ME



ME, Pressure [hPa], 36h-forecast, June 2005

-3

-2

-1

0

1

2

3

4

5

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53

synoptic stations

ME

ME. Wind speed [m/s], 36-h forecast, June 2005

-3

-2

-1

0

1

2

3

4

5

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53

synoptic stations

ME



1. The 2 m temperature:

• A monthly and seasonal variation for the scores of temperature is observed.

• The mean error is negative in the winter and positive in spring and the summer.

• In the summer we observed the large diurnal amplitude of mean error and amplitude of RMSE with maximum value during a day.

2. The dew point temperature:

• The monthly variation of mean error is observed.The bias is negative in January, positive in the summer and diurnal amplitude in the spring.

• The RMSE increased with the forecast time.

Conclusions



3. The sea level pressure:

• The RMSE increased with the forecast time.

• The error is smaller in the summer and higher in the winter.

• The ME is quite smooth (about zero in the winter and negative in the summer).

4. The 10 m wind speed:

• The ME is mostly positive and increases with the forecast time.

• The RMSE is quite smooth, bigger in the winter than the summer (with daily amplitude in the summer).

Conclusions



Verification of precipitation using 308 rain gauges

Katarzyna Starosta, Joanna Linkowska


Poland



The results of verification of 24-h accumulated precipitation from January 2004 to June 2005are presented below.

For precipitation we calculated indices from the contingency table for 24-h accumulated forecast data and data from 308 rain gauge stations for 3 day forecast range (1-day, 2-day, 3-day). For verification of precipitation following thresholds of 0.5, 1, 2.5, 5, 10, 20, 25, 30 mm were used.

For each threshold the following scores were calculated: FBI (Frequency bias index), POD (Probability of detection of event), PON (Probability of detection of non-event), FAR (False alarm rate), TSS (True skill statistics), HSS (Heidke skill score), ETS (Equitable skill score).

0 10 20 30 40 500

5

10

15

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25

30

35

40

45

50

LOCATION OF RAIN GAUGE STATIONS





0.5 1 2.5 5 10 15 20 250

20

40

60

80

100%

Indices for 24h accumulated precipitation, May 2004

0.5 1 2.5 5 10 15 20 250

20

40

60

80

100

%

PODPONFARHSSETS

0.5 1 2.5 5 10 15 20 250

20

40

60

80

100

%

THRESHOLDS [mm]

I day

II day

III day



0.5 1 2.5 5 10 15 20 25 300

20

40

60

80

100%

Indices for 24h accumulated precipitation, May 2005

0.5 1 2.5 5 10 15 20 25 300

20

40

60

80

100

%

PODPONFARHSSETS

0.5 1 2.5 5 10 15 20 25 300

20

40

60

80

100

%

THRESHOLDS [mm]

I day

II day

III day



FREQUENCY BIAS INDEX, JANUARY - DECEMBER 2004

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC0

0.5

1

1.5

2

2.5

3F

BI

THRESHOLD 0.5 [mm]


12345678

THRESHOLD 10 [mm]

FB

I

MONTHS

I dayII dayIII day



FREQUENCY BIAS INDEX, JANUARY - JUNE 2005

JAN FEB MARCH APRIL MAY JUNE0

0.5

1

1.5

2

2.5

3F

BI

THRESHOLD 0.5 [ mm]

JAN FEB MARCH APRIL MAY JUNE0

0.5

1

1.5

2

2.5

3

FB

I

MONTHS

THRESHOLD 10 [ mm]

I dayII dayIII day




20

40

60

80

100%

THRESHOLD 0.5 [ mm]


20

40

60

80

100

%

PODPONFARHSSETS


20

40

60

80

100

%

MONTHS

INDICES FOR 24h ACCUMULATED PRECIPITATION, JANUARY - DECEMBER 2004




20

40

60

80

100%

THRESHOLD 10.0 [ mm]


20

40

60

80

100

%

PODPONFARHSSETS


20

40

60

80

100

%

MONTHS

I day

II day

III day

INDICES FOR 24h ACCUMULATED PRECIPITATION, JANUARY - DECEMBER 2004



JAN FEB MAR APR MAY JUN0

20

4060

80100

%THRESHOLD 0.5 [mm]


20

40

60

80100

%

PODPONFARHSSETS


20

40

60

80100

%

MONTHS

I day

II day

III day

INDICES FOR 24h ACCUMULATED PRECIPITATION, JANUARY - JUNE 2005




20

4060

80100

%THRESHOLD 10.0 [mm]


20

40

60

80100

%

PODPONFARHSSETS


20

40

60

80100

%

MONTHS

I day

II day

III day

INDICES FOR 24h ACCUMULATED PRECIPITATION, JANUARY - JUNE 2005



1. The model overestimates the amount of precipitation.

2. The precipitation forecast quality in the period from January to June in 2005 are better than in 2004.

3. The plots of indices for 24-h accumulated precipitation for threshold 0.5 mm in 2005 show smaller variability than in 2004.

4. The quality of the forecast does not deteriorate significantly in subsequent days of the forecast.

Conclusions



Verification of upper-air parameters using 3 TEMP stations.

Andrzej Mazur


Poland



Monthly mean ME/RMSE at standard pressure levels (1000, 850, 700, 500, 400, 300, 250 and 200 hPa)...

Subject:

of height, temperature, wind velocity and relative humidity...

at three Polish upper-air stations: Leba, Legionowo, Wroclaw



Temperature ME (observed-predicted) - Leba station

Left - year 2003 Right - year 2004

Forecast: +12 hours

Temperature ME (observed-predicted) - Legionowo stationTemperature ME (observed-predicted) - Wroclaw station



Wind speed ME (observed-predicted) - Leba stationLeft - year 2003 Right - year 2004

Forecast: +12 hours

Wind speed ME (observed-predicted) - Legionowo stationWind speed ME (observed-predicted) - Wroclaw station



Standard level height ME (observed-predicted) - Leba station


Forecast: +12 hoursForecast: +24 hoursForecast: +36 hoursForecast: +48 hoursForecast: +60 hours



Relative humidity ME (observed-predicted) - Leba station


Forecast: +12 hoursForecast: +24 hoursForecast: +36 hoursForecast: +48 hoursForecast: +60 hours



•Forecasts are “surprisingly” good as far as temperature and wind speed are concerned (ME about ±1° and ±1m/s, respectively).•Model still seems to be “too wet” (ME about 30%, in extreme case - relative error ~50%).•However, this looks like it improved, comparing results for 2003 with these for 2004•The quality of forecast - which is naturally expected tendency - decreases monotonously with time - especially for relative humidity. For other parameters this tendency is not so clearly seen.

CONCLUSIONS



THANK YOU FOR YOUR ATTENTION

Documents

COSMO General Meeting Zurich, 2005 Institute of Meteorology and Water Management Warsaw, Poland- 1 - Verification of the LM at IMGW Katarzyna Starosta,