1 cosmo gm, athens/2007 | e. zala; d. leuenberger update on weather-situation dependent cosmo-7...
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1 COSMO GM, Athens/2007 |
E. Zala; D. Leuenberger
Update on Weather-Situation Dependent COSMO-7 Verification against Radar Data
Results of 2006
Emanuele Zala, Daniel Leuenberger
MeteoSwiss
2 COSMO GM, Athens/2007 |
E. Zala; D. Leuenberger
Data Sets and Methodology
RADAR• Radar: 24h precipitation sums
from 06 UTC to 06 UTC• MeteoSwiss network composite
„rain“ product• horizontal resolution: 2x2km• visibility-, clutter- and bias-
corrected
COSMO-7 model:• +06h to +30h precipitation sums
from all 00UTC runs• horizontal resolution 7x7km
BIAS correction map of radar dataagainst rain gauges(Long-term corrections)
3 COSMO GM, Athens/2007 |
E. Zala; D. Leuenberger
Data Sets and Methodology
RADAR fields mapped on COSMO-7 grid:
Radar grid (2x2km) LM grid (7x7km)
4 COSMO GM, Athens/2007 |
E. Zala; D. Leuenberger
Weather Type Classification
• subjective• mainly based on 500hPa geopotential/winds • classes:
year low high flat N NE E SE S SW W NW
2004 35 99 58 14 10 1 7 13 50 46 31
2005 36 108 54 18 20 1 4 7 57 35 25
2006 20 91 41 17 9 0 6 7 75 49 50
5 COSMO GM, Athens/2007 |
E. Zala; D. Leuenberger
Weather Class „LOW“ (20 days)
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Weather Class „HIGH“ (91 days)
7 COSMO GM, Athens/2007 |
E. Zala; D. Leuenberger
Weather Class „FLAT“ (41 days)
8 COSMO GM, Athens/2007 |
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Weather Class „NORTH“ (17 days)
9 COSMO GM, Athens/2007 |
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Weather Class „SW“ (75 days)
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E. Zala; D. Leuenberger
Weather Class „WEST“ (49 days)
11 COSMO GM, Athens/2007 |
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Weather Class „NW“ (50 days)
12 COSMO GM, Athens/2007 |
E. Zala; D. Leuenberger
Conclusions
• Smaller biases in weak advection
• Overestimation on upstream side of topography
• Tendency to underestimation in flat terrain
• Special: SW-flow: Large underestimation over Jura mountains and Swiss Plateau
• Similar results in 2004 and 2005