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.
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