multimedia resources: nwp resources and new wrf training dr. william r. bua, project scientist,...
TRANSCRIPT
Multimedia Resources: NWP Resources and new WRF
Training
Dr. William R. Bua, Project Scientist,
UCAR/COMET
Talk Outline• Introduction
– Demystifying the NWP “black box” as a tool for understanding the atmosphere
• Training on NWP on MetEd– NWP Model matrix
• Nuts and bolts of NWP (PCU 1)• Specific model “architecture” (PCU 2)• Case studies (PCU 3)
– Other content• Teletraining, webcasts, NWP modules
• Multiple levels of content available– Introduction to meteorology – NWP/synoptic case study for advanced courses
• WRF: An NWP infrastructure, not a specific model!
NWP Then….
• When I was an undergraduate at dear old State (Penn State)….– Forecasting was an art, supported by science– Existing tools (1970s)
• Barotropic model (2 layers, 380km)• Primitive Equation model (PE), 2.5°, 8 layers ran
out to 84 forecast hrs with barotropic ext to 144 hrs, was NH only until 1974, then global domain
• Limited-area Fine Mesh (LFM, 190.5km, 6 layers)– 24 hours in 1974, 48 hours by 1976
• No biosphere modeling, soil modeling; fluxes were determined using crude energy balance methods
…and NOW
• Now, forecasting is a science [NWP]; the art is in its use– Global Forecast System (GFS) at T382 (about 50km
equivalent), 64 levels run to 384 hours, 4 layer soil model, predicted cloud water; ensemble forecasts based on GFS
– Climate Forecast System (CFS) T62 (about 310km equivalent), 28 levels run out 9 months, coupled to a global ocean model
– North American Mesoscale (NAM) Weather Research and Forecast (WRF) non-hydrostatic mesoscale model (NMM), 12km, 60 levels, 4 layer soil model
What May Be Common to Both
• NWP is a black box to many students (and forecasters, unfortunately)– Meteorological cancer* from unquestioning use of
NWP
• Teaching is not just for meteorologists …– But for the non-meteorological public as well
• Multimedia is a good tool for demystification– Reaches people through visual, auditory, and even
kinesthetic (e.g. VISITView, drawing/ participation by students) methods, “interactions”
– Examples of some of these will follow
* Snellman, L., National Weather Digest, 16, 1991.
Multimedia NWP Training Materials
• Many hours of training on generic NWP and model-specific architecture– Dynamics– Precipitation microphysics– Radiation and turbulence– Data assimilation– Post-processing
• Material was developed for training experienced NWS meteorologists rather than students– Assumes knowledge of acronyms, jargon/short hand,
concepts that may not hold for students– Material can be parsed out for use in the classroom,
especially graphics and some learning objects
MetEd NWP Topic: Everything NWP on COMET• Special interest
column on left– Currently contains
WRF, ensembles, marine modules, new on-line lecture on radar
• Featured materials– Operational model
matrix– NWP Distance
Learning Course
• List of Available Modules– Many topics,
multimedia methods– Most rated 2-3 in
difficulty
http://meted.ucar.edu/topics_nwp.php
Special interestFeatured materials
Available modules
Case Studies
Ready-made Lecture Materials
• Case studies− Many would be appropriate for advanced topics− Example will be shown later
• Ready-made lecture materials
http://meted.ucar.edu/nwp/pcu2/
NEW ITEMS!
Aged “What’s New”PCU-1 PCU-2
http://meted.ucar.edu/nwp/pcu2
Other Links of Interest
PCU-1 PCU-2
Model Post-Processing
Model Physics: Radiative Processes
Model Physics: Precipitation and Clouds
Model Data Assimilation
Example of introductory ideas re: NWP
• Take apart the model diagram (maybe a simplified version of it….) in model fundamentals
• Example:– The effect of using grid
points in NWP models– Example issue:
• Effect of resolution of feature depiction
• Effect of resolution on movement of feature
Grid point concepts: discretization and horizontal resolution
http://meted.ucar.edu/nwp/pcu1/ic2/1_4_3.htm
Grid point concepts: discretization and horizontal resolution
Example of introductory ideas re: NWP
• Take apart the model diagram in model fundamentals
• Example:– The effect of using grid
points in NWP models– Example issue:
• Effect of resolution of feature depiction
• Effect of resolution on movement of feature
Introduction to Physical Processes:
http://meted.ucar.edu/nwp/pcu1/ic1/2_2.htm
∆x
Sub-grid scale Sub-grid scale convectionconvection
Processes Required in Convective Parameterization (CP) schemes
NWP Model Specifics
USGS Vegetation Type,NESDIS Vegetation Fraction
Case Studies
• Good tools for inquiry about NWP from a pedagogical and operational meteorology perspective
• Possible inquiries:– Why did model not predict the weather event?– Why did model predict a weather event that
did not occur?– How will new version of model (or entirely new
model, like NAM NMM WRF) perform?
Case Study
http://meted.ucar.edu/nwp/pcu3/cases/06jan02/frameset.htm
What is taught with the case study?
• Started with a poor forecast• Did inquiry as to what went wrong
– Brings in initial condition errors– Inquiry results: what did the ensemble prediction system (Short-
Range Ensemble Forecast or SREF for this case) forecast?– Brings in importance of the initial SREF perturbations including
the true initial state: Did it include what seems to be the true state?
– Inquiry results: NO! Why?– Gulf of Mexico had significant convection taking place,
unpredictable effects of convection, etc. Use satellite derived winds (and radiosondes over southeast CONUS!) to see initial problems in wind field, convection in Gulf of Mexico.
• Point: forecasters must (and have the tools to) check the initial conditions in both the deterministic (Eta, GFS) forecast and the ensemble prediction system.
Is THIS W(o)RF?
WHAT IS WRF?• WRF = Weather Research and Forecasting …
infrastructure... not model!• Used for both research and operations
– End-to-end system using a Common Modeling Infrastructure• Data assimilation system (including observation ingest, quality
control, and analysis)• Numerical Weather Prediction model• Post-processing, product generation and display• Verification and archive
• Many partners: NCAR, NCEP, GSD [FSL], OU/CAPS, AFWA, FAA, NSF and Navy
• Shared infrastructure allows research to transition to operations much more rapidly!
• Common postprocessor allows more ensemble options!• WRF plans at NCEP: NAM, RUC, hurricane, SREF
The WRF Infrastructure: Plug and Play Compatibility (NCEP in red)
DATAASSIMILATION
•Gridpoint Statistical Interpolation (GSI)•WRF-VAR•Standard Initiali- zation
NWP NUMERICS:
•Dynamical cores•Advanced Research WRF•Non-hydrostatic Mesoscale Model (NMM)•Can opt for hydro or non-hydrost. for both
•Diffusion and damping options available
NWS PHYSICS:
• Precipitation and cloud physics• 9 options: From no ice (Kessler) to 6-moment (rain/snow/graupel) NCEP uses Ferrier scheme
• Convection•Betts-Miller-Janjic•Kain-Fritch•Grell-Devenyi ensemble
•Radiation•LW:RRTM or GFDL•SW:Dudhia, Chou, or GFDL
•Surface Layer (2 options, both Monin- Obukov based)•PBL (1 local, 2 non-local)•Land surface (thermal only, NOAH, RUC)
http://wrf-model.org/index.php
What is Grid-point Statistical Interopolation? (GSI)• 3d-var• Similar to a grid-point version of Spectral Statistical Interpolation in GFS• Versions of GSI upcoming for GFS, RTMA, RUC, Hurricane WRF, others
What’s in the NAM-WRF?
Assimilation cycle example: 12 UTC model run
NDAS + NAM
NDAS + NAM
NDAS + NAM
AA F3Analysis (early data cutoff) Analysis (late data cutoff) 3-hour forecast
Cycling stays the same!Old NAM-Eta New NAM-WRF
A= Eta 3d-var GSIF3, F84= Eta model WRF-NMMInput data= poor satellite data use better satellite data use, more future types
F84
What COMET Has Available
• Two webcasts (short and long)– Short version
• http://www.meted.ucar.edu/nwp/NAMWRF_short/
– Long version• http://www.meted.ucar.edu/nwp/NAMWRF
• Matrix details to come by end of September
• Teletraining (via VISITView) coming next month
Teasers from Teletraining (comparisons of NAM WRF v NAM Eta)
• Cold Season Examples: – 11-12 February 2006 snow storm
• Warm Season Examples:– Tropical Storm Alberto and Katrina Rerun
• Other Examples– Phase speed (and overamplification?)
problem (late April, early June)
Cold Season: NAM Northeast Storm 2/11-12/06 at 00z2006021200
Cold Season: NAMX Northeast Storm 2/11-12/06 at 00z2006021200
Tropical Storm Alberto: June 2006
• 1st named storm of 2006 season• NAM-Eta did poor job with development and
movement• NAM-WRF did better job earlier in the development,
but was too strong w/cyclone for awhile.– Note: Two previous false alarms from NAM-WRF … this will
likely be a characteristic of model, similar to how GFS behaved in past seasons
• NAM-WRF had precip. after landfall too far inland for a time
• NAM-WRF does *not* have vortex relocation like GFS
Tropical Storm Alberto: Sea Level Pressure Verification
X 996-hPa
X 996-hPa
12z 10 Jun 2006NAM-WRF run
12z 11 Jun 2006NAM-WRF run
Where is it?
12z 13 Jun 2006NAM-WRF run
X 996-hPa
x
X 996-hPa
12z 12 Jun 2006NAM-WRF run
Sea Level Pressure Verification
Hurricane Katrina Rerun (16km)
Verification
12z29Aug
36hr fcst
24hr fcst
Phase Speed Problems at 500-hPaNAM Eta, NAM Eta minus NAM WRF
NAM LOWER NAMX LOWER
verification
12 UTC 8 June 2006, 500-hPa height/vort
NAM Eta
12 UTC 8 June 2006, 500-hPa height/vort
NAM WRF
Summary
• COMET has voluminous NWP training– NWP matrix (generic NWP, operational model specifics)– Case studies– Other multimedia (teletraining, webcasts)
• WRF modeling infrastructure is (and has been) here– A modeling infrastructure, not a single model
• Facilitate tech transfer from research to operations• Plug and play architecture for choices of WRF components• Discussed implementation combination possibilities
– Cold and warm season examples– Phase speed problems
Where To Go for Materials
• MetEd web site (http://meted.ucar.edu, click on NWP topic)
• NWP model matrix (http://meted.ucar.edu/nwp/pcu2)– One stop shop for generic and model specific
NWP
• E-mail to the COMET NWP Training Team– [email protected]– [email protected]