real-time storm-scale forecast support for ihop 2002 at caps ming xue 1,2, keith brewster 1, dan...

Real-time Storm-scale Forecast Real-time Storm-scale Forecast Support for IHOP 2002 at CAPSSupport for IHOP 2002 at CAPS

Ming XueMing Xue1,21,2, Keith Brewster, Keith Brewster11, Dan Weber, Dan Weber11 Kevin ThomasKevin Thomas11, Fanyou Kong, Fanyou Kong11, Eric Kemp, Eric Kemp11

mxue@ou.edumxue@ou.edu

Center for Analysis and Prediction of Storms (CAPS) Center for Analysis and Prediction of Storms (CAPS)11

School of MeteorologySchool of Meteorology22 University of Oklahoma University of Oklahoma

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IHOP_2002 (International H2O Project 2002)

• A field experiment that occurred over the Central Great Plain between 5/13 – 6/25/2002

• Science Objectives and Components

Quantitative Precipitation Forecast (QPF)Quantitative Precipitation Forecast (QPF)

Convection Initiation (CI) Convection Initiation (CI)

Boundary Layer (ABL) Processes Boundary Layer (ABL) Processes

Water Vapor Instrumentation and Data Assimilation Water Vapor Instrumentation and Data Assimilation ResearchResearch

IHOP_2002 Operations Domain IHOP_2002 Operations Domain and Instrumentation Sitesand Instrumentation Sites

IHOP Related Research at CAPSIHOP Related Research at CAPS

• CAPS is supported through an NSF grant to

Contribute to the IHOP field experiment and Contribute to the IHOP field experiment and

Perform research using data collectedPerform research using data collected

• Emphases of our work include

Optimal Assimilation of and theOptimal Assimilation of and the

Qualitative assessment of the impact of Qualitative assessment of the impact of

Water vapor and other high-resolution observations Water vapor and other high-resolution observations on storm-scale QPF.on storm-scale QPF.

Goals of CAPS Realtime ForeacstGoals of CAPS Realtime Foreacst

To provide additional high-res NWP support To provide additional high-res NWP support for the real time operations of IHOPfor the real time operations of IHOP

To obtain an initial assessment of numerical To obtain an initial assessment of numerical model performancemodel performance

To identify specific data sets and cases for To identify specific data sets and cases for extensive retropective studiesextensive retropective studies

CAPS Real Time Forecast CAPS Real Time Forecast DomainDomain

273×195

183×163

213×131

CAPS Real Time Forecast CAPS Real Time Forecast TimelineTimeline

Model ConfigurationModel Configuration

• ARPS 5.0 of CAPS was used with following options:

o NonhydrostaticNonhydrostatic dynamics with dynamics with vertically-stretched terrain-following vertically-stretched terrain-following gridgrid

o Domain 20 km deep with Domain 20 km deep with 53 levels. First level 10m AGL.53 levels. First level 10m AGL.

o 4th-order advection4th-order advection, simple positive definite scheme for water and , simple positive definite scheme for water and TKE. TKE.

o 3 3 ice-phase microphysicsice-phase microphysics (Lin-Tao) (Lin-Tao)

o New Kain-Fritsch cumulus parameterizationNew Kain-Fritsch cumulus parameterization on 27 and 9 km grids on 27 and 9 km grids

o NCSA Long and Short Wave NCSA Long and Short Wave Radiative TransferRadiative Transfer scheme scheme

o 1.5-order TKE-based subgrid scale turbulence closure and PBL 1.5-order TKE-based subgrid scale turbulence closure and PBL ParameterizationParameterization

o 2-layer 2-layer soil and vegetation modelsoil and vegetation model

Data and Initial ConditionsData and Initial Conditions

• Initial conditions produced by ARPS Data Analysis System (ADAS) with cloud / diabatic initialization

• Eta forecast for BC of CONUS grid and first guess for IC analysis

• Rawinsonde and wind profiler data: Used on CONUS and SPmeso grids

• MDCRS (aircraft observations): All grids.

• METAR (surface observations): All grids.

• Oklahoma, Western TX and ARM Mesonets: All grids

• Satellite: IR cloud-top temperature used in cloud analysis.

• CRAFT Level-II and NIDS WSR-88D data: Reflectivity used in cloud analysis on SPmeso and SPstorm grids, and radial velocity used to adjust the wind fields.

Cloud Analysis in the Initial ConditionsCloud Analysis in the Initial Conditions

• Windband Level-II data from 12 radars (via CRAFT) and Level-III (NIDS) data from 12 others in the CGP were used in a cloud analysis procedure that analyzes qv, T and microphysical variables

• The cloud analysis also used visible and infrared channel data from GOES-8 satellite and surface observations of clouds

Example of Initial Condition on 3km Example of Initial Condition on 3km GridGrid

Computational IssuesComputational Issues

• The data ingest, preprocessing, analysis and boundary condition preparation as well as post-processing were done on local workstations.

• The three morning forecasts were made on a PSC HP/Compaq Alpha-based clusters using 240 processors.

• The 00 UTC SPstorm forecast was run on NCSA’s Intel Itanium-based Linux cluster, also using 240 processors.

• Perl-based ARPScntl system used to control everything

• Both NCSA and PSC systems were very new at the time. Considerable system-wide tuning was still necessary to achieve good throughput. A factor of 2 overall speedup was achieved during the period.

• Data I/O was the biggest bottleneck. Local data processing was another.

Dissemination of Forecast ProductsDissemination of Forecast Products

• Graphical products, including fields and sounding animations, were generated and posted on the web as the hourly model outputs became available.

• A workstation dedicated to displaying forecast products was placed at the IHOP operation center.

• A CAPS scientist was on duty daily to evaluate and assist in the interpretation of the forecast products.

• A web-based evaluation form was used to provide an archive of forecast evaluations and other related information.

• The forecast products are available at http://ihop.caps.ou.edu, and we will keep the products online to facilitate retrospective studies.

CAPS IHOP Forecast PageCAPS IHOP Forecast Pagehttp://ihop.caps.ou.edu

Example: Animation of Page Precipitation Rate at 1 Example: Animation of Page Precipitation Rate at 1 hour intervalshour intervals

May 12, 2002May 12, 2002

NCEP Hourly Precip ARPS 9 km Forecast – Precip rate

12 Hour forecast valid at 00 UTC

May 17, 2002May 17, 2002

NCEP Hourly Precip ARPS 9 km Forecast – Comp. Ref.

Initial Condition at 12 UTC

June 15, 2002June 15, 2002

NCEP Hourly Precip ARPS 3 km Forecast – Comp. Ref.

11 hour forecast valid at 02 UTC

Future Work (where real fun starts)Future Work (where real fun starts)

• Multi-scale QPF Verification under way

• Simulation Studies of Selected Cases

• IC and BC Sensitivity Studies using the Forecast Model and its Adjoint

• Continuous Data Assimilation Studies (including radar and GPS data) using 3DVAR and later 4DVAR

• Study of Data Impact

• Studies of Physical Processes using Model Data Sets