Evaluation of simulated precipitation fields of some MAP events: sensitivity experiments

and model intercomparison

(1) LA CNRS/UPS, Toulouse, France

(2) CNRM, Météo-France, Toulouse, France(3) RPN, Montréal, Canada(4) ISAC, CNR, Bologna, Italy(5) University of L ’Aquila, Italy(6) University of Milano, Italy(7) University of Munich, Germany

E. Richard (1), N. Asencio (2), R. Benoit (3), A. Buzzi (4), R. Ferretti (5), F. Lascaux (1), P. Malguzzi (4), S. Serafin (6), G. Zängl (7), J-F. Georgis (1)

1. Sensitivity experiments based upon Meso-NH

IOP2a 17 September 1999:

A short, intense, isolated, convective event

70 mm within 12h

14:00

15:00

16:00

17:00

18:00

19:00

20:00

21:00

22:00

23:00

24:00

RADAR Reflectivity Z 2000mRADAR Reflectivity Z 2000m

OBSERVATIONOBSERVATION MESO-NH COMPUTATIONMESO-NH COMPUTATION

The convective system of MAP - IOP 2a (17 September, 1999, hourly time evolution)

Toce Ticino watershed

ECMWF: OP. ANA ECMWF: OP. ANA 19991999

ARPEGE: OP. ANA. 1999ARPEGE: OP. ANA. 1999 ECMWF: REANALYSISECMWF: REANALYSIS

RADAR OBSERVATIONS

ANA. OP. 1999ANA. OP. 1999 REANALYSISREANALYSIS

850hPa water vapor mixing ratio : 17 September 1999 12UTC

IOP 2a

REANA (NO MAP REANA (NO MAP DATA)DATA)

ECMWF: OP. ANA ECMWF: OP. ANA 19991999

ARPEGE: OP. ANA. 1999ARPEGE: OP. ANA. 1999 ECMWF: OP. ANA. ECMWF: OP. ANA. 20022002

ECMWF: REANALYSISECMWF: REANALYSIS

MAP - IOP2A:

Intense Convection

Strong sensitivity to initial state

Low predictability

RADAR OBSERVATIONS

1. Sensitivity experiments based upon Meso-NH

IOP2a 17 September 1999:

A short, intense, isolated, convective event

70 mm within 12h

2. Model intercomparison : MC2, MM5, MOLOCH,

Meso-NH

IOP2b 20/21 September 1999:

Orographic enhancement of a frontal system

200 mm within 30h

19 Sept. 1999 12:00 20 Sept. 1999 12:00

METEOSAT infrared

The different models:

• MESO-NH 10 KM + 2.5 KM

• MOLOCH 10 KM + 2 KM

• MM5-RE 27 KM + 9 KM + 3 KM

• MM5-E1 18 KM + 6 KM + 2 KM

• MC2 40 KM + 10 KM +2 KM

Initial and boundary conditions from ECMWF operational analyses

From 19 Sep. 12 UTC to 20 Sep. 18 UTC

(30 hours)

MAP - IOP2B - 19-20 Sep. 1999

Intercomparison exercise

4 non-hydrostatic models with horizontal resolution of 2 to 3 km

Initialization based upon ECMWF operational analysis

Accumulated precipitation from the 19th 15 UTC to the 20th 18UTC

Toce-Ticino watershed

Rain gauges

Time evolution of the mean hourly precipitation rate

Radar

Heidke skill scores as a function of precip. class

1h precip. 27h precip.

Comparison with rain gauge measurements (121 points)

Correlation 1h

Correlation 6h

Correlation 27h

Mean Bias

MESONH 0.33 0.49 0.62 + 28 % MOLOCH 0.31 0.47 0.62 - 22 % MM5-RE 0.27 0.43 0.55 - 16 % MM5-E1 0.37 0.53 0.63 + 28 %

MC2 0.30 0.47 0.63 - 32 %

Conclusion: Two contrasted MAP events !!

IOP 2a

– Meso-NH results indicate a srong sensitivity to the analysis

– The best results are not obtained for the « best analysis »

– What is the part of luck ?– Is this conclusion model dependent?– Ideal test for mesoscale assimilation

experiments.

IOP 2b

– Very good consistency of the accumulated precipitation pattern

– Model results over/under estimate the total precipitation by a factor ranging from +30% to -30%

– The bias may be related to the level of smoothing applied to the model orography

– The accuracy of the model precipitation is rather weak for the hourly rainfall but fairly reasonable for the precipitation accumulated over the 30h time period of the event

– Radar derived precipitation are not yet very accurate

The End !

Interested ??

Join the MAP working group on Numerical Modelling

http://www.aero.obs-mip.fr/map/MAP_wgnum

Model Topography : Dx = 2KM

MC2: Max 3483m

MM5: Max 3979m

Sensitivity to the topography

MAX: 512 mm MAX: 435 mm

MEAN: 78 mm MEAN: 74 mm

Heidke skill scores as a function of precip. class

1h precip. 27h precip.

Sensitivity to the topography

Sensitivity to the analysis

ECMWF Op. Analysis MAP Reanalysis

Max: 512 mm Max: 482 mm Mean: 78 mm Mean: 87 mm

Heidke skill scores as a function of precip. class

1h precip. 27h precip.

Sensitivity to the analysis

Time evolution of the correlation coeffecient (wrt rain gauges)

MM5 experiments

Time evolution of the correlation coeffecient (wrt rain gauges)

MM5 experiments

MM5 experiments