1September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

The Convective and Orographically-induced Precipitation Study (COPS)

Goal: Advance the quality of forecasts of orographically-induced convective precipitation by 4D observations and modeling of its life cycle

quality

Quantitative Precipitation Forecasting (QPF) and verification

Probabilistic QPF (PrQPF):- Uncertainty- Predictability

forecasts

Focus on:- Nowcasting to short-range QPF- High-spatial and temporal resolution (extensive

research on convection-permitting models)

and

Research at the interface of observations and modeling using the key tool data assimilation:- Model initialization for case studies- Observing system impact studies- Advanced (ensemble) reanalyses for

investigation of model physics and predictive skill

- Predictability Implementation and test of a stochastic EnKF at IPM

convective

Field phase throughout summer from June to August 2007

4D observations

Synergy of state-of-the-art remote sensing and in-situ instruments:- Densified obs., e.g., Joint COPS-D-PHASE (JDC) data set - Upstream and regional observations by 9 aircraft- 5-min Rapid Scan Service of MSG-8 by EUMETSAT- Unique multi-wavelength passive-active sensor synergy- 9-month operation of the ARM Mobile Facility (AMF)- Demonstration of new observing systems, particularly

scanning lidar

-> Data set allows in-depth analysis of process chain

-> Open data policy, available for international research, see www.uni-hohenheim.de/cops with further links

modeling of its life cycle

Unique collaboration with forecast centers, e.g., DWD, Météo-France, Meteo Swiss, UK Met Office, and research centers:- Real-time, multi-model ensemble runs coordinated via WWRP

Forecast Demonstration Project D-PHASE- Case studies with operational and research models

orographically-induced

Low-mountain area:- Located in southwestern Germany/eastern France- Characteristic for the landscape in middle Europe- Area with extreme precipitation prone to flooding

and thunderstorms- Characterized by poor forecast skill

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COPS QJRMS Special Issue

See http://onlinelibrary.wiley.com/doi/10.1002/qj.v137.1s/issuetoc (21 papers)• The COPS Overview Paper (Wulfmeyer et al. QJRMS 2011) has been identified as New Hot

Paper in Geosciences (see http://sciencewatch.com/dr/nhp/2011/11sepnhp/11sepnhpWulf)

• Next COPS Workshop tentatively planned from March 28-30, 2012. Title: „The predictability of convective precipitation in orographic terrain.“ Email sent to ISSC

• Final report in preparation in collaboration with ISSC. Delivery at end of 2011.

3September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

Major COPS Results and Conclusions

1) Logistics:• Surface data collection, harmonization, and quality control• GRIB1 Tigge+ table for CP models, common visualization tools• Common lidar and radar data formats• Air traffic control• Data base

4September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

Major COPS Results and Conclusions

2) Processes:• Evapotranspiration nearly independent of soil moisture, thus mainly controlled by vegetation.• CAPE higher (moisture convergence), CIN lower over mountain ranges.• Thermodynamically-induced flow decisive for convection initiation and modification of frontal systems under all forcing conditions.• Diurnal cycle of precipitation is likely due to a preconditioning of lower troposphere by shallow convection leading to more severe and less to mountain flow-coupled convection in the late afternoon.

5September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

The COPS Summer in Perspective

Diurnal cycle in good agreement with climatology. Phase shift between CI and precipitation maximum amounts to about 10 h (Wulfmeyer et al. QJRMS 2011).

Diurnal cycle of convection initiation (Weckwerth et al. QJRMS 2011). Diurnal cycle of precipitation for June, July,

and August, as well as average.

6September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

IOP4b, June 20, 2007: Meteorological Conditions

Movie of radar, GPS, MSG composite, resolution: 15 min

7September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

Major COPS Results and Conclusions

3) Model performance and verification:• Indications that models overestimate transpiration at low soil moisture (root depth, root water uptake).• Boundary layer to deep over mountains, probably too strong vertical mixing.• Thermodynamically-induced flows partly resolved, vertical wind too

low in convergence zones• Windward-lee effect due to incorrect simulation of flow distorsion in low-mountain regions and resulting displacement of convergence zone triggering CI at wrong locations.• Clear improvement of diurnal cycle of precipitation and QPF by CP models. • Main remaining systematic errors in QPF due to deficiencies of aerosol-cloud-precip microphysics?

8September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

Major COPS Results and Conclusions

Comparison between water vapor DIAL and D-PHASE models

9September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

Meteo Swiss COSMO7 with parameterization of deep convection, 7-km grid resolutionMeteo Swiss COSMO2 without parameterization of deep convection, 2.2 km grid resolution

COPS Precipitation Statistics

COPS precipitation climatology (June to August, 2007). 3-month integrated precipitation of

model - observations.

Convection-permitting models reduce the windward-lee effect and improve the simulation of the diurnal cycle of precipitation.

10September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

The COPS Summer in Perspective

Diurnal cycle of precipitation (Bauer et al. QJRMS 2011).

11September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

First COPS Verification Study of Convection-Permitting (CP) Models

FSS shows consistent superior performance of convection-permitting (CP) COSMO2 over COSMO7 but no clear signal for COSMO-DE (Bauer et al. QJRMS 2011).

Forecast initial time: 0 UTCVerification time period: 6-18 UTC The Fractions Skill Score (FSS, Roberts and Lean MWR 2008) is an example of a fuzzy verification score useful for high-resolution models.

CP

12September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany

Major COPS Results and Conclusions4) Demonstration of new Obs.:

• Water-vapor and temperature lidar provided previously unachieved vertical and temporal resolution as well as accuracy.• GPS STD and tomography very useful for studying moisture variability.• VERA and C-band Doppler radar (partly dual-Doppler) applied for detection of convergence zones. • Combination of ground-based and airborne sensors investigated aerosol-cloud microphysics.• Lidar aerosol data improved the simulation of precipitation during Saharian dust outbreak over COPS area.

• Much more can be exploited with the COPS data set, emphasis should be set on studying ABL and microphysics.

• New lidar technology available for long-term operational measurements.

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Major COPS Results and Conclusions

5) Data assimilation and predictability:• Positive impact of the assimilation of GPS STD on QPF.• Positive impact of Doppler radar and reflectivity.• 3DVAR provides benchmark for DA systems on the CP scale• Orography can increase the predictability of convection.• The lead time is not limited by the lifetime of convective cells but by the lifetime of the forcing conditions leading to convection.• Multi-model ensemble provided improved simulation of convective cells (14 h lead time).

• COPS and D-PHASE data can be used as DA testbed and IMRE but test and comparison of different DA techniques still open.

• More impact studies possible.• COPS-D-PHASE data set unique for verification studies.