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Why is MD&E important?
Model development and enhancement is
the basis for improving aviation weather
products.
The quality of model output governs the
quality of information on turbulence, icing,
convection, ceiling, visibility, and
precipitation.
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Model Development and Enhancement
Report - 4 December 2001
•
•
•
Rapid Update Cycle (RUC) - Stan Benjamin
Meso-Eta Model - Geoff DiMego
Weather Research and Forecasting Model
(WRF) - Tom Schlatter
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The 20km Version of the
Rapid Update Cycle
Stan Benjamin
Georg Grell
Steve Weygandt
Tracy Lorraine Smith
Tanya Smirnova
Barry Schwartz
Dongsoo Kim
Dezso Devenyi
Kevin Brundage
John M. Brown
Geoff Manikin – NCEP/EMC
FAA Aviation Weather
Program Management Review
Key goals for 20km RUC
• Take advantage of increased computer power
→ higher spatial resolution
• Focus on improving RUC performance for
• QPF, especially for convective precipitation
• Surface forecasts
• Cloud/icing 3-d fields
-----------------------------------------------------------Incorporate new advances
in model and assimilation techniques
Assimilate new observational data
Eliminate bugs, design weaknesses
4
Subset of full domain
40km RUC
Model terrain elevation
Contour interval - 200 m
20km RUC
5
40km RUC
40 levels
20km RUC
50 levels
800
1600
2400
3200
RUC native coordinate levels
W-E vertical cross-section
- Pacific – WA
6h fcsts valid 0000 UTC 24 Feb 2001
10 new levels
7 – upper levels – 330 – 500 K
6
3 – lower levels – 270 – 290 K
RUC20 Testing Since May 2001
- Ongoing real-time 1-h cycle at FSL and NCEP
- Retrospective period tests – full 1-h cycle
- Feb 2001 at NCEP and FSL
- May 2000 at FSL
-Examination of verification against
- precipitation, radar
- surface observations
- rawinsonde observations
- Web page products – daily look at maps
for both RUC20/40 analyses and forecasts
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RUC20 Modifications Since May 2001
-Forecast model
- revisions to convective parameterization
- use of GOES cloud-data to prompt convective initiation
- revised vertical advection / hybrid isentropic-sigma
coordinate movement
-Analysis
- 3dVAR found to give slightly poorer wind forecasts
for 3h period (not at 12h)
-Decision made to introduce OI analysis within
3dVAR framework, defer 3dVAR analysis
implementation for ~3 months after RUC20 impl.
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1200 UTC
4 Dec 2001
Denver, CO
rawinsonde
obs
Comparison of
obs sounding vs.
grid point soundings
for RUC40 vs. RUC20
Better near-surface fit to obs
with RUC20
40km - OI
20km – mod OI
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RUC40 – operationa
RUC20 – test
3-h wind forecasts – 4 Dec 2001
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Initial RUC cloud analysis
technique
Goal – Improve RUC precipitation, cloud, icing forecasts
• Combines
• GOES/NESDIS cloud-top pressure
(sounder single field-of-view)
• RUC 1-h hydrometeor fcst (cloud water, ice,
snow/rain/graupel) as first guess
• Performs cloud clearing and cloud building
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3h 20km RUC cloud-top fcst
w/ GOES cloud assimilation
Verification
Cloud-top pressure
based on NESDIS product
Effect of GOES data on
3-h RUC cloud forecasts
1800 UTC
Tues 2 Oct 2001
3h 40km RUC cloud-top fcst
No GOES cloud assimilation
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40km RUC
20km RUC w/ cloud analysis
3h 20km RUC cloud-top fcst
w/ GOES cloud assimilation
Verification
Cloud-top pressure
based on NESDIS product
Cloud-top forecast verification
- correlation coefficient between forecast
and NESDIS cloud-top product
- much improved cloud forecasts even at 12h
28 Sept – 2 Oct 2001
13
Changes to MM5/RUC microphysics with 20km RUC
Bug fixes
Changes for formation of ice and graupel
- result – less “ice friendly”
Change in time step from 10 min to 2 min
40km operational
RUC at NCEP
Result:
• More realistic
supercooled liquid water
• Improved precip type
20km test RUC w/
microphysics fixes
SW-NE vertical
cross-section
across WA
/Olympic
Peninsula into BC
and Alberta 12h forecast valid
0300z 5 January
2001
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RUC 2m temp (oC) bias verified
against METARS ( 01152-01205 )
Less bias with RUC20
g
RUC20
RUC40
2
2
R UC20
R UC40
analysis
1
bias (f - o)
1
bias (f - o)
)
3
3
0
-1
Analysis
-2
0
3-h fcsts
-1
3h fcsts
-2
-3
-3
0
300
600
900
1200
1500
cycle (U TC )
(
g
1800
0
2100
300
600
900
1200
1500
1800
2100
cyle (UTC)
)
3
3
R UC20
R UC40
2
RUC20
RUC40
2
1
1
bias (f - o)
bias( f - o)
(
0
6-h fcsts
-1
6h fcsts
-2
0
12-h fcsts
-1
12 fcsts
-2
-3
-3
0
300
600
900
1200
cycle (U TC )
1500
1800
2100
15
0
300
600
900
1200
cycle (U TC )
1500
1800
2100
24h precipitation verification - R UC 40 vs. RU C 20
- vs. N CEP 24h precipitation analysis
(20 M arch - 15 April 2001)
0.4
Equitable threat score
0.35
RUC 40 - ets
RUC 20 - ets
0.3
0.25
0.2
0.15
0.1
0.05
0
0
0.5
1
threshold - in
1.5
2
Bias - precipitation forecasts - R UC 40 vs. RU C 20
(20 M arch - April 2001)
1.2
Precipitation verification
RUC40 vs. RUC 20
1
Bias
0.8
Clear superiority of 20km RUC,
especially for heavier precipitation
events
0.6
0.4
RUC 40 - bias
RUC 20 - bias
0.2
16
0
0
0.5
1
threshold - in
1.5
2
Precipitation verification
RUC40 vs. RUC 20
Clear superiority of 20km RUC,
especially for heavier precipitation
events
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40km RUC
20km RUC
NCEP/CPC
24h precip
analysis
24h precipitation
40km RUC vs. 20km RUC
24h period ending 12z 25 Sept 2001
(Two 12h fcsts summed)
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20km vs. 40km RUC
- verification against raobs
3h, 12h forecasts – 25 Nov – 3 Dec 2001
RMS/s.d. differences
20km
40km
RUC20 –
Slightly better or
equal 3h wind
forecasts
Consistently
improved 12h wind
forecasts
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Summary - the 20km RUC
• Schedule for implementation
–
–
–
–
Current – real-time testing at NCEP and FSL
Retrospective period test – Feb 2001, July 2001, May 2000
January-February 2002 – field test for RUC users
Implementation – early 2002, 3dVAR follows by ~ 3 months
• 20 km/50 level 1 hr version
– with model improvements including cloud microphysics,
convection, land-surface
– Improved optimal interpolation analysis, cloud/hydrometeor
analysis using satellite combined with explicit cloud fcsts in RUC
– Improvements in warm- and cold-season precipitation and
cloud/icing forecasts, also in surface forecasts
• 10 km RUC – testing at FSL in 2002 w/ current RUC
and WRF models
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RUC web site - http://ruc.fsl.noaa.gov - 20km test RUC products
N
C
E
P
Model Development & Enhancement
NCEP / EMC Components
Geoff DiMego
Geoff.DiMego@noaa.gov
FAA / AWRP Review
4 December 2001
Where the Nation’s climate and weather services begin
Topics
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•
•
•
Computer status
BUFR sounding(TAF)/FOUS/FD wind
Meso Eta upgrades
Near-Term Plans
IBM SP Upgrade to Phase II
• Phase II to have two equal parts PROD & DEV
• First piece took over ALL of NCEP’s operations
on 7 December 2000 +temporary DEV partition
• Second piece certified in March-April, accepted
June 2001 - dedicated entirely to DEV
• First piece dedicated entirely to PROD in
September 2001
• There is now VERY HIGH utilization on BOTH
partitions
Status of Next Computer
Procurement
Action
Completion
RFI phase
Release of RFP
Award contract
Equipment delivery
System acceptance
Fully operational
July 2001
September 2001
Spring 2002
Summer 2002
Winter 2002
July 2003
Meso Eta hourly soundings (BUFR) for
TAF support
http://www.emc.ncep.noaa.gov/mmb/meteograms/
Graphics Available from Web Site
http://www.emc.ncep.noaa.gov/mmb/meteograms/
Surface Meteogram
Vertical Time Section
Additions to Meso Eta output for
TAF and aviation users
• Added 38 Alaskan sites for hourly BUFR
output from Meso Eta runs 12z 24 April 2001
• Extend 00z+12z FOUS Bulletins to 60 hours
12z 15 May 2001 (for FBWTG)
ftp.ncep.noaa.gov/pub/nws/nmc/etafous/
• Added 27 sites to KWBC and added 28 sites
to CWAO Canadian FD wind bulletins and all
FD winds generated from full resolution grid
12z 30 May 2001
Meso Eta Modeling Plans 2001
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
22km/50lvl
Extend
00z+12z
runs to
84 hr
“Hi Res
Window”
Nested
Meso Eta
runs when
no tropical
storms
12 km / 60 level
22 km / 50 level
•Re-tune 3D-VAR
•Assimilate Precip
•Upgraded LandSurface Model
Short Range Ensemble Forecast System
•Upgrade 3DVAR
•Replace gridscale cloudPrecip scheme
•Mod precip assimilation
scheme
Millenium Blizzard Bust for DC
•Heavy snow predicted
for DC area but none fell
•Tiger Team Called For
•Solutions Found Before
Tiger Team Convened
• Needed better SST
• Needed better 3DVAR
•Tiger Team convened
anyway - report available
http://www.nws.noaa.gov/ost/ppdindex.htm
•Better SST implemented
30 January 2001
•Better 3DVAR
implemented 24 July 2001
84 hour Extension 17 April 2001
• 00z & 12z Meso Eta 22 km runs extended
from 60 hours out to 84 hours
– separate job normally completes before AVN starts
• Restart capability
• Lateral boundary conditions for HiResWindows
• Correct problem with 10 m wind diagnosis
Jan 2001
Eta
EtaX
With fixed code
Obs
Nested Meso Eta “HiResWindow”
• Year-round concept of “HiResWindow” runs:
– Highest priority is GFDL hurricane model run on
up to 4 tropical storms during hurricane season
– Run nested Meso Eta during other seasons and
when there is no (few) tropical storm(s)
• Nested runs with higher resolution provide
• Better guidance overall in precipitation, surface
winds and surface temperatures especially where
driven by complex terrain or coastlines
• Preview of upcoming changes
ftp://ftp.ncep.noaa.gov/pub/emc/wd20er/caftinfo3/v3_document.htm
HiResWindow Fixed-Domain Nested Runs
• Users want routine runs
they can count on at the
same time every day
• 00Z : Alaska-12 &
Hawaii-10
• 06Z : Western-10 &
Puerto Rico-10
• 12Z : Central-10 &
Hawaii-10
• 18Z : Eastern-10 &
Puerto Rico-10
• This gives everyone a
daily high resolution
run when no hurricane
http://www.emc.ncep.noaa.gov/mmb/mmbpll/nestpage/
Example of Improved Precip
Forecast with 10km Central Nest
Verification
22km Operational
10km Central Nest
Short Range Ensemble Forecast (SREF) System
in Real-Time Test & Evaluation Status at NCEP 29
May 2001
• 5 Meso Eta Model members
• 5 Regional Spectral Model members
• 2 pairs of perturbations come from separate Meso Eta and
RSM breeding cycles
• Domain is full North American continent
• Resolution is 48 km / 45 levels
• Forecast range is 63 hours
• Forecasts initialized at 21z + 09z so that SREF results are
completed before 00z + 12z Meso Eta runs begin
• This allows SREF guidance to be used by forecasters
together with the Meso Eta runs
Short Range Ensemble Forecast (SREF)
Webpage from which all products are linked:
http://lnx48.wwb.noaa.gov/SREF/SREF.html
Summer Change Package - 24 July, 2001
• 3DVAR analysis upgrade
– better balance & parameter retuning
• Assimilation of observed precipitation
– uses hourly gauge & radar estimates
– better soil moisture & precip forecasts
• Upgrades to land-surface physics
ftp://ftp.ncep.noaa.gov/pub/emc/wd20er/caftimay01/v3_document.htm
http://www.emc.ncep.noaa.gov/mmb/mmbpll/spring2001/tpb/
Dec 2000 OPS ETA
Storm total precip (in) at 12Z 12/31/01
ETA w/new SST (Feb 2001 OPS ETA)
July 2001 OPS ETA
Fall Change Package - 27 November 2001
• Resolution increases
– Horizontal from 22 km to 12 km
– Vertical from 50 levels to 60 levels
•
•
•
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3DVAR analysis changes - to use AMSU-B
New gridscale cloud+precip scheme
Upgrades to precip assimilation scheme
Maintain product content & timeliness
ftp://ftp.ncep.noaa.gov/pub/emc/wd20er/cafti12km/v3_document.htm
http://www.emc.ncep.noaa.gov/mmb/mmbpll/eta12tpb/
Horizontal resolution increase from
22 km to 12 km
22-km terrain
12-km terrain
ÿþýüûúùø÷ùöõüôóü÷ùòñûõð÷ïùîíúìùëïôðõêúíð÷ùÿ÷ûéïüôïôùèõêôù
öëùòìü÷ïôùöõõðîí÷ùôïùðùøöö
New Gridscale Cloud & Precipitation
Scheme for Meso Eta
• Developed by Brad Ferrier (FAA supported)
• Full complexity of Reisner (scheme in RUC) but
with same low cost of Zhao (current scheme in
Meso Eta)
• Like Reisner, it simulates the variation of 6
species of water: (vapor, cloud droplets, small ice
crystals, rain drops, snow, graupel/sleet)
• Like Zhao, it uses only 2 prognostic variables
(vapor, total condensate)
Summary of improvements from new
gridscale cloud&precip scheme
• Predicts rain, freezing rain, snow, graupel, and / or
sleet and improves forecasts of precipitation type
• Reduces the overprediction of light precipitation
amounts (over Pacific) and overprediction of upperlevel cloud amounts
• Reduces grid-scale precipitation bulls-eyes and
eliminates excitation of fast-moving external
gravity waves
7 April Example of Impact of New Cloud
Scheme on Low, Middle and High Cloud
Old Zhao Scheme
New Ferrier Scheme
high
middle
low
QPF for May 4-5 Case with 10
km Central Nest
ÿþýüûúùø÷ø
øüûúùø÷ø
QPF for May 4-5 Case with 10
km Central Nest
ÿþýüûúùø÷øüýúþøü÷ø
ÿøøýüùüøú
èéïûíýù õðî êýù ûðþþð÷ùí÷ù ùóþù
÷ïôúô ùíôùéðþùðõéí
ôûüõï ôûìïþïù
Surface winds 22km vs 12km
In 2002, 3DVAR will use WSR-88D Radial Velocity
in Hourly Updates in EDAS
Sample Distribution of Processed 88D Radial Velocity Data
~ 5 km processing of an hour’s worth of scans
In 2002 HiResWindow Nests Will Be 8km and Use
Janjic Nonhydrostatic Meso Model Then WRF
Cold Bubble Test
Warm Bubble Test
t
t
In 2002, a Semi-Lagrangian WRF
Model Prototype will be completed
at NCEP
• High order compact differencing
• Unstaggered (A) grid
•
•
•
•
•
Semi-Implicit in time
Forward trajectories with cascade interpolation
Radiative upper boundary condition
Terrain following hybrid vertical coordinate
Runge-Kutta (3rd & 4th order) time integration
In 2002, NCEP will complete its
transition to a WRF common modeling
infrastructure
• Convert Janjic Nonhydrostatic Meso Model to WRF
infrastructure and implement this in the daily Hi-Res Window
runs in NCEP production
• Convert Meso Eta Model to WRF infrastructure and implement
this in the four-per-day continental Meso Eta runs in NCEP
production
• Compare forecast & computer performance of WRF Prototypes
vs These Operational Models with WRF Infrastructure
– Emphasis on REAL-DATA retrospective case studies
– Small and large-domain capabilities examined for nested
and continental requirements of NCEP operations
Development of the WRF Model
ÿ Develop an advanced mesoscale forecast and assimilation system
ÿ Promote closer ties between research and operations
Research:
Design for 1-10 km horizontal grids
Advanced data assimilation and model physics
Accurate and efficient across a broad range of scales
Well-suited for both research and operations
Community model support
51
WRF Project Collaborators
■
Principal Partners:
– NCAR Mesoscale and Microscale Meteorology Division
–
–
–
–
–
■
NOAA National Centers for Environmental Prediction
NOAA Forecast Systems Laboratory
OU Center for the Analysis and Prediction of Storms
Air Force Weather Agency
Federal Aviation Administration
Additional Collaborators:
– NOAA Geophysical Fluid Dynamics Laboratory
–
–
–
–
–
NASA GSFC Atmospheric Sciences Division
NOAA National Severe Storms Laboratory
NRL Marine Meteorology Division
EPA Atmospheric Modeling Division
University Community
52
WRF Development Teams
Numerics and
Software
(J. Klemp)
Working Groups
Dynamic Model
Numerics
(W. Skamarock)
Data
Assimilation
(T. Schlatter)
Standard
Initialization
(J. McGinley)
Analysis and
Validation
(K. Droegemeier)
Community
Involvement
(W. Kuo)
Operational
Implementation
(G. DiMego)
Analysis and
Visualization
(L. Wicker)
Workshops,
Distribution,
and Support
(J. Dudhia)
Data Handling
and Archive
(G. DiMego)
Model Physics
(J. Brown)
Software
Architecture,
Standards, and
Implementation
(J. Michalakes)
3-D Var
(J. Derber)
Model Testing
and Verification
(C. Davis)
4-D Var
(D. Barker)
Ensemble
Forecasting
(D. Stensrud)
Atmospheric
Chemistry
(P. Hess)
Land Surface
Models
(J. Wegiel)
Regional Climate
Modeling
(proposed)
Operational
Requirements
(G. DiMego)
Operational
Forecaster
Training
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Characteristics of Initial WRF Release
(December 2000)
• Parallel implementation on UNIX platforms
• Initial fields interpolated from analyzed gridded data
• Time split Eulerian solver for dynamical core
• Basic set of physics packages
• Model output fields in NetCDF format
Initial data assimilation package: 3DVAR
Expected release: 1st Quarter 2002
Mass-based coordinate for dynamical core
WRF & Release Information: http://wrf-model.org
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Projected Timeline for WRF Project
Development Task
2000
2001
2002
2003
2004
2005-08
Basic WRF model (limited
physics, standard initialization)
Implementation and evaluation
of alternative prototypes
Evaluation of alternative vertical
coordinates
Model physics
3D-Var assimilation system
Simple
Research suite
Basic
Research
Advanced
Advanced
Research quality NWP version
of WRF
4D-Var assimilation system,
ensemble techniques
Basic
Advanced
Testing for operational use at
NCEP, FSL, & AFWA
Diagnosis of operational
performance, refinements
Release and support to community
Operational deployment
55