Verification of ALADIN/Portugal forecasts

Verification of ALADIN/Portugal forecasts

Margarida Belo (Instituto de Meteorologia, Portugal )

ALADIN Orography and portuguese stations

>1250m

>300m

>1550m

6 9 11 6

5 6 16 9

6 4 4

1 3 8 00

3 8 6

3 2 5 9 7

1 0 42 4 5

2 4 69 8

72 5

B ra g a n c aV .C aste lo

V .R ea lP o rto

V iseu

P .D o u ra d a sC o im b ra

C .B ran c o

C .C arv o e iro P o rta leg re

L isb o aE v o ra

B e jaS in es

F aroS ag re s

-9 .5 0 -9 .0 0 -8 .5 0 -8 .0 0 -7 .5 0 -7 .0 0 -6 .5 0

L O N G IT U D E

3 7 .0

3 7 .5

3 8 .0

3 8 .5

3 9 .0

3 9 .5

4 0 .0

4 0 .5

4 1 .0

4 1 .5

4 2 .0

LATI

TUD

E

Wind speed(10m)

RMSE

Inland (north and center of

Portugal)

Wind speed

BIAS

12UTC

06UTC

18UTC

06UTC

00UTC

In average, ALADIN slightly underestimate the wind speed in the inland stations of north and center of Portugal

RMSE

West coast

Wind speed

BIAS

12UTC

18UTC

06UTC

00UTC

12UTCIn average, ALADIN overestimate the wind speed in the west coast of Portugal

RMSE

Wind speed (ALADIN versus ECMWF)

BIAS

Examples of good forecasts of wind speed (H+24)

ALADIN exceeds the alert value

(15.3m/s) for the Civil Agency

ECMWF gives a false alarm

ALADIN

Observation

ECMWF

Observed event: wind from N

POD = 0.40 POD = 0.29

Observed event: wind from W

POD = 0.54 POD = 0.37

Observed event: wind from S

POD = 0.36 POD = 0.30

Observed event: wind from E

POD = 0.50 POD = 0.57

Mean sea level pressure

Scatterplot: MSLP

H+24

Winter 2004

ALADIN underestimate the MSLP, mainly in

anticyclonic situations

H+48

fore

cast

- ob

serv

atio

n

fore

cast

- ob

serv

atio

n

observation

Temperature (2m)

RMSE

Inland (north and center of

Portugal)

2m temperature

BIAS

18UTC

12 UTC00UTC

06UTC

18UTC

In average, in the inland stations of north and center of Portugal, ALADIN has a warm bias at 12UTC and 18UTC, whereas has a cold bias at 00UTC and 06UTC.

RMSE

West coast

2m temperature

BIAS

12 UTC

06UTC

00UTC

In average, ALADIN has a warm bias in the west coast of Portugal, stronger in summer months

RMSE

Évora and Beja

2m temperature

BIAS

12 UTC

06UTC

00UTC

12 UTC

00UTC

18UTC

In average, in the inland stations of south of Portugal, ALADIN has a warm bias at 00UTC and 06UTC, whereas has a cold bias at 12UTC and 18UTC.

RMSE

2m Temperature (ALADIN versus ECMWF)

BIAS

Series

August 2003

Castelo Branco: good forecast with both models. Vila Real: ALADIN underestimate T2m.

Bias Td (2m) - ALADINÀs 12UTC

After March 2003, ALADIN is too moist in the beginning of the integration

RMSE

2m Td (ALADIN versus ECMWF)

BIAS

Winter 2002/03

C1 - PA 0.3 mm/6 h (no rain),

C2 - 0.3 mm/6 h < PA 2.0 mm/6 h (light rain),

C3 – 2 mm/6 h < PA 10.0 mm/6 h (moderate rain),

C4 – PA > 10.0 mm/6 h (heavy rain),

Accumulated precipitation (PA) in 6-hours (12-18UTC)

Scores for contingency tablescorrect forecastsPC

all cases

" "" "

correct forecasts correct forecasts of no rain eventCSItotal cases correct forecasts of no rain event

Critical Success Index

number of times that an event was forecastedBiasnumber of times this event was observed

correct forecast of one eventPODtimes that this event was observed

Probability of detection

False Alarm Rationumero de vezes que um evento nao foi observado mas foi previstoFAR

numero de vezes que esse evento foi previsto

ALADIN ECMWF

C 18 8 . 3 %

C 28 . 7 %

C 32 . 5 %

C 40 . 4 %

C 17 5 . 7 %

C 21 4 . 3 %

C 37 . 9 %

C 42 . 2 %

Observed event: no rain (C1)

Observed event: light rain (C2)

C 13 8 . 8 %

C 22 4 . 1 %

C 32 7 . 6 %

C 49 . 5 %

C 14 2 . 2 %

C 22 5 . 0 %

C 32 9 . 7 %

C 43 . 1 %

POD = 0.88

FAR = 0.16

BIAS = 0.91

POD = 0.76

FAR = 0.15

BIAS = 0.89

Winter 2002/03

POD = 0.24

FAR = 0.83

BIAS = 1.39

POD = 0.25

FAR = 0.87

BIAS = 1.89

C 15 1 . 4 %

C 22 1 . 4 %

C 31 6 . 4 %

C 41 0 . 7 %

ALADIN ECMWF

Observed event: moderate rain (C3)

Observed event: heavy rain (C4)

POD = 0.16

FAR = 0.84

BIAS = 1.04

Winter 2002/03

C 12 5 . 9 %

C 22 2 . 2 %

C 33 3 . 3 %

C 41 8 . 5 %

POD = 0.19

FAR = 0.90

BIAS = 1.85

C 14 8 . 1 %

C 21 8 . 5 %

C 32 8 . 4 %

C 44 . 9 %

POD = 0.28

FAR = 0.75

BIAS = 1.12

C 16 3 . 2 %

C 22 6 . 3 %

C 31 0 . 5 %

POD = 0.00

FAR = 1.00

BIAS = 1.00

Summary 1

• In average, ALADIN slightly underestimate the wind speed in the inland stations of north and center of Portugal.

• In average, ALADIN overestimate the wind speed in the west coast of Portugal.

• ALADIN underestimate the MSLP, mainly in anticyclonic situations.

Summary 2• In average, in the inland stations of north and

center of Portugal, ALADIN has a warm bias at 12UTC and 18UTC, whereas has a cold bias at 00UTC and 06UTC.

• In average, ALADIN has a warm bias in the west coast of Portugal, stronger in summer months.

• In average, in the inland stations of south of Portugal, ALADIN has a warm bias at 00UTC and 06UTC, whereas has a cold bias at 12UTC and 18UTC.