Transcript Presentation at 15th NWP Conference

Real-time Storm-scale Forecast
Support for IHOP 2002 at CAPS
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Ming Xue1,2, Keith Brewster1, Dan Weber1
Kevin Thomas1, Fanyou Kong1, Eric Kemp1
[email protected]
Center for Analysis and Prediction of Storms (CAPS)1
School of Meteorology2
University of Oklahoma
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)
 Convection Initiation (CI)
 Boundary Layer (ABL) Processes
 Water Vapor Instrumentation and Data Assimilation Research
IHOP_2002 Operations Domain
and Instrumentation Sites
IHOP Related Research at CAPS
•
CAPS is supported through an NSF grant to
 Contribute to the IHOP field experiment and
 Perform research using data collected
•
Emphases of our work include
 Optimal Assimilation of and the
 Qualitative assessment of the impact of
 Water vapor and other high-resolution observations on
storm-scale QPF.
Goals of CAPS Realtime Foreacst
 To provide additional high-res NWP support for the
real time operations of IHOP
 To obtain an initial assessment of numerical model
performance
 To identify specific data sets and cases for
extensive retropective studies
CAPS Real Time Forecast
Domain
183×163
273×195
213×131
CAPS Real Time Forecast
Timeline
Model Configuration
•
ARPS 5.0 of CAPS was used with following options:
o
Nonhydrostatic dynamics with vertically-stretched terrain-following grid
o
Domain 20 km deep with 53 levels. First level 10m AGL.
o
4th-order advection, simple positive definite scheme for water and TKE.
o
3 ice-phase microphysics (Lin-Tao)
o
New Kain-Fritsch cumulus parameterization on 27 and 9 km grids
o
NCSA Long and Short Wave Radiative Transfer scheme
o
o
1.5-order TKE-based subgrid scale turbulence closure and PBL
Parameterization
2-layer soil and vegetation model
Data 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
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 Grid
Computational 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 Alphabased 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 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 Page
http://ihop.caps.ou.edu
Example: Animation of Page Precipitation
Rate at 1 hour intervals
May 12, 2002
NCEP Hourly Precip
ARPS 9 km Forecast – Precip rate
12 Hour forecast valid at 00 UTC
May 17, 2002
NCEP Hourly Precip
ARPS 9 km Forecast – Comp. Ref.
Initial Condition at 12 UTC
June 15, 2002
NCEP Hourly Precip
ARPS 3 km Forecast – Comp. Ref.
11 hour forecast valid at 02 UTC
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