Use of Ensemble Forecast

Robert MureauKNMI

Marco Nolet

Reading 16 june 2005

Content Simple EPS verification First guess 5 day forecast New EPS plume product

Simple verification T2m (T00/T12) Ensemble mean Oper Forecaster

Winters 97-04

Summers 97-2003

T00 1997-2004 T+132

T12 1997-2004 T+144

T00 T+228

T12 T+240

Day 5 Tmin dec 1999- 2004

Day 5 Tmax Dec 1999-2004

Marco Nolet

Error Tmax De Bilt (day 1-5)

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Jan-

72

Jan-

73

Jan-

74

Jan-

75

Jan-

76

Jan-

77

Jan-

78

Jan-

79

Jan-

80

Jan-

81

Jan-

82

Jan-

83

Jan-

84

Jan-

85

Jan-

86

Jan-

87

Jan-

88

Jan-

89

Jan-

90

Jan-

91

Jan-

92

Jan-

93

Jan-

94

Jan-

95

Jan-

96

Jan-

97

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Bias

MAE1234

5

Climate

Climate

Tmax 1972-2002

Dag 5 Tmax: Overschrijdingen per maand

0

10

20

30

40

50

60

70

80

Jan-

81

Jan-

82

Jan-

83

Jan-

84

Jan-

85

Jan-

86

Jan-

87

Jan-

88

Jan-

89

Jan-

90

Jan-

91

Jan-

92

Jan-

93

Jan-

94

Jan-

95

Jan-

96

Jan-

97

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Pe

rce

nta

ge

>2

>2

>3

>4

>5

1981-2002

Dag 5 Tmin: Overschrijdingen per maand

0

10

20

30

40

50

60

70

80

Jan-

81

Jan-

82

Jan-

83

Jan-

84

Jan-

85

Jan-

86

Jan-

87

Jan-

88

Jan-

89

Jan-

90

Jan-

91

Jan-

92

Jan-

93

Jan-

94

Jan-

95

Jan-

96

Jan-

97

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Per

cen

tag

e

>2

>2

>3

>4

>5

Conclusions verification part No real trends in rms Bias control and ens mean are similar Gap opens at day 3 ? Ensemble mean best deterministic

value for money (but very safe)

First guess 5 day forecast

First Guess Table First guess 5 day forecast ( including

error margins ) Probabilities of events Special link with probabilities of severe

weather events

Table internet table

New EPS plot layout