where we are and where we’re going: ncep’s central computing system emc’s numerical modeling...
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Where We Are and Where We’re Going:NCEP’s Central Computing System EMC’s Numerical Modeling
Mesoscale Modeling Geoff DiMego
301-763-8000 ext7221
24 June 2003
NCEP
Where the Nation’s climate and weather services begin
TOPICS
• NCEP’s Central Computing System (CCS)
• What we do with it (current model suite)
• Stuff made for Alaska by Meso Eta, HRW etc• Latest Bundle of Changes for Meso Eta (8 July)
• What we want to do with it (future plans)
• Weather Research and Forecasting (WRF)
• The North American Regional Reanalysis
Central Computer System (CCS)• Initial 3 year base period followed by
two 3 year option periods– Each three year period contains an upgrade
• Total of 6 major increases through 2010 providing guaranteed performance (initially 2.5x then 8x…) over our current computer
• 70% for use on weather + 30% for climate– Previously 90% for weather + 10% for climate
• Installed Sept 02 at IBM Gaithersburg, MD
• Accepted Dec 02, OPS switchover May 03
Central Computer System (CCS)Phase / Increase
Date
Processors
Clock Speed
Memory Disk Space Tape Storage
Current 2432 375MHz 1216 MB 30 TB 200 TB
Phase I / 2.5x
May 2003
1408
1.3GHz
1408 MB 42 TB 1250 TB
Phase II / 8.0x
June 2004
2752 1.8+1.3GHz
2752 MB 84 TB 2500 TB
Six Increases in Weather Portion of CCS
Bad News – Development has filled its half
Production
Development
Proposed NCEP Production SuiteWeather Forecast Systems
Version 1.2 January 15, 2003
0
20
40
60
80
100
0:00 0:30 1:00 1:30 2:00 2:30 3:00 3:30 4:00 4:30 5:00 5:30 6:00
6 Hour Cycle
Pe
rce
nt
Us
ed
HawaiiFIREWXCOFSRUCEDASWavesGFSensHUR/NWMGFSfcstGFSanalETAfcstETAanalSREFGDAS
Wx Production Suite Made Up of Four Uniform Cycles per Day
NCEP Model Suite-GlobalRun Slot #/day
Mission & (Notes) Domain (h/v)
Fcst Range
Resolution (h/v)
Global Forecast System (GFS)
4/day
Global general weather and aviation guidance to 15 days (winds, temp, rainfall)
Boundary + initial conditions for Eta,Waves
Initial conditions for ensemble generation
Supports Model Output Statistics
Hurricane tracks
global
30 km
384 55 km/ 64l
75 km/ 42l after day 3
Global Data Assimilation System (GDAS) 4/day
Provides best guess for GFS analysis
Verification & validation
(3-D Variational 6-hr update frequency with digital filter)
global
30 km
9
6 hr update
55 km/ 64l
Global Ensemble
2/day
Probabilistic rainfall (QPF) and general weather to 15 days
(10 members with initial condition perturbations generated from bred modes)
global
50 km
360 100km/28l
200km/28l after day 7
NCEP Model Suite-Ocean/WavesRun Slot #/day
Mission & (Notes) Domain (horiz)
Fcst Range
Resolution (horiz/v)
Global Wave
2/day
Marine safety global 126 1.25x1.0 long/lat
Northwest Atlantic Waves 2/day
Marine safety region 126 0.25x0.25 long/lat
Alaskan Waves
2/day
Marine safety region 126 0.5x0.25 long/lat
Ice Drift
1/day
Marine safety bi-polar 384 190 km
ROFS
1/day
Marine safety region 48 10 km nearshore to 20 km offshore/ 19L
NCEP Model Suite-RegionalRun Slot #/day Mission & (Notes) Domain
(h/v)Fcst Range
Resolution (h/v)
NGM 2/day Used for Model Output Statistics No.America
20 km48 83km/16l
Meso Eta (aka early)
4/day
North America High Resolution early guidance on precipitation, general weather & domestic aviation (strategic); provides HiResWindow lateral boundaries and is used for Model Output Statistics
North America
25 km
84 12km/60l
Eta Data Assimilation System (EDAS)
4/day
Provides best guess for Meso Eta analysis
Verification & validation
(3-D Variational 3-hr update frequency )
North America
25 km
12
3hr update
12km/60l
Short Range Ensemble Forecast (SREF) system
2/day
Probabilistic rainfall (QPF), precip type and general weather and its uncertainty
(15 members = 10 Eta + 5 RSM, initial condition perturbations generated from bred modes)
North America
25 km
63 48km/60l for Eta
48km/28l for RSM
NCEP Model Suite-RegionalRun Slot #/day
Mission & (Notes) Domain (h/v)
Fcst Rng
Resolution (h/v)
HiResWindow4 large nests/day
4 small nests/day
High Resolution Window runs of Nonhydrostatic Meso Model (NMM) for daily high resolution test guidance from next generation mesoscale system for everyone in US when fewer than two Hurricane runs are being made
Alaska 0z, Western US 6z, CentralUS 12z, EasternUS 18z, Hawaii 00+12z Puerto Rico 06+18z25 km
48 8 km/60l
10km/60l in Alaska
IMET / Fire Weather 4/day
Runs of Nonhydrostatic Meso Model (NMM) to support IMETs and SPC etc for Fire Weather
Selectable ¼ of large nest
48 8 km/60l
Homeland SecurityOn demand!
Run of Nonhydrostatic Meso Model (NMM) to support run of HYSPLIT
Selectable ¼ of large nest
48 4 km/60l
Hurricane
4/day
Hurricane track & intensity guidance for TPC warnings (up to 4 storms)
75o x 75o 126 18/55km/ 42l
Rapid Update Cycle (RUC) 24/day
Tactical/hourly Aviation Guidance for FAA, domestic aviation and NCEP’s AWC and SPC
CONUS20 km
3 & 12 (0,3…21)
20 km / 50l
Meso Eta Alaskan Output Grid #21645 km Polar-stereographic
Contents identical to 40 km CONUS grid #212
Meso Eta Alaskan Output Grid #21722.5 km Polar-stereographic
Contents identical to 20 km CONUS grid #215
Meso Eta Alaskan Output Grid #24211.25km Polar-stereographic
Contents identical to 12 km CONUS grid #218
Grids 216, 217 + 242 MUCH Better Than Original AWIPS Grids 207&214
207, 214 216, 217 & 242
Except for its vertical longitude which screws up IPFS & NDFD!
Grids 221 + 104 Cover Alaska
90 km Polar-stereographic
NGM-look-alike
32 km Lambert
Full complement
Grids 243 Covers Eastern Pacific0.4 deg by 0.4 deg lat-long with content
same as 40 km CONUS grid #212
Map of current BUFR sites in Alaska
49 original
38 new
Graphics Available from Web Site http://www.emc.ncep.noaa.gov/mmb/meteograms/
Surface Meteogram Vertical Time Section
Nonhydrostatic Mesoscale Model (NMM)• Model used for runs at grid spacings less than 10 km:
Homeland Security, HiResWindow and Fire Weather • See Janjic, Gerrity,and Nickovic, 2001 for model
equations, solution techniques & other test results [MWR,Vol. 29, No. 5, 1164-1178]
• Highly refined version of nonhydrostatic option released in May 2000 upgrade to NCEP’s workstation Eta http://wwwt.emc.ncep.noaa.gov/mmb/wrkstn_eta/
• NMM retains full hydrostatic capability– Incorporate nonhydrostatic effects through where =(1/g) dw/dt
– Then split prognostic equations into:• hydrostatic parts plus • corrections due to vertical acceleration
– Set to zero to run in hydrostatic mode
Nonhydrostatic Mesoscale ModelFeature Comparison With Meso Eta
Feature Meso Eta Model Nonhydrostatic Meso Model
Dynamics Hydrostatic Hydrostatic plus complete nonhydrostatic corrections
Horizontal grid spacing
12 km E-grid 8 or 4 km E-grid
Vertical coordinate
60 step-mountain eta levels
60 hybrid sigma-pressure levels
Terrain Unsmoothed silhouette with lateral boundary set to sea-level
Unsmoothed grid-cell mean everywhere
Physics (BMJ convection, turbulence etc) have been tweaked in NMM.
Hybrid versus Step (Eta) Coordinates
ground MSL
ground
Pressure domain
Sigma domain
= 0
= 1 = 1
Ptop Ptop = 0
NMM vertical domain compared to Eta
18 pressure layers, model top still at 25-hPa
42 sigma layers between surface about 420 hPa
1st layer interface above 420 hPa is bottom of first fixed pressure layer
420 hPa
NMM 60 –Layer Distribution
18 layers
42 layers
HiResWindow Fixed-Domain Nested Runs• Users want routine runs
they can count on at the same time every day
• 00Z : Alaska-10 & Hawaii-8
• 06Z : Western-8 & Puerto Rico-8
• 12Z : Central-8 & Hawaii-8
• 18Z : Eastern-8 & Puerto Rico-8
• This gives everyone a daily high resolution run when fewer than 2 hurricane runs needed
Alaska Nest = AWIPS grid #249
http://www.emc.ncep.noaa.gov/mmb/mmbpll/nestpage/
Terrain Used in Eta-12 and Eta-10Eta-12 Eta-10
NMM terrain would not be restricted to discrete values like the Eta’s step mountain terrain.
HRW NMM Alaskan Output• Grid #249 10 km Polar-stereographic• BUFR soundings for anonymous ftp from NCEP
ftp://ftpprd.ncep.noaa.gov/pub/emc/mmb/mmbpll/alaska10.t00z/bufrsnd/
• Output for anonymous ftp from NCEP server ftp://ftpprd.ncep.noaa.gov/pub/emc/mmb/mmbpll/alaska10.t00z/
• Output for anonymous ftp from TOC server ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnt/MT.meso_CY.00/RD.20030621/PT.grid_DF.gr1_AR.alaska10/
• Web displays of Alaskan Nest (Meso Eta vs HiResWindow vs NCAR WRF) On left of page, sweep down through parameters, 2-m temperature and 10-m wind fields have northern and southern regional display options http://wwwt.emc.ncep.noaa.gov/mmb/mmbpll/hiresw.alaska10/
12 km Meso Eta vs 10 km NMM On Web
12 km Meso Eta vs 10 km NMM vs 10 km WRF On Web
On Call Emergency Response
• SDM receives request for run with specs of release and initiates run into production where it may preempt existing or future production runs
• 4 km NMM run produces hourly output• Hourly output drives 4 km HYSPLIT run to
describe atmospheric spread of hazardous material (designed for radiological accidents)
• HYSPLIT output sent to WFO & emergency managers
• No output of the NMM meteorological fields (yet)
26 Selectable 4 km domains for homeland security response
Fire Weather / IMET Support Run
• SDM receives request for run via coordination call with Boise, WR, SPC etc.
• Runs are made within dedicated run slots at 00z, 06z, 12z and 18z running over the top of the Meso Eta
• 8 km NMM run produces 3 hourly output grids• Output grids (look just like HiResWindow) picked up
by WR, clipped to relevant subregion and prepared for transmission to the IMET laptops using same FX-NET procedure developed for Olympics. SPC gets grids directly.
26 Selectable 8 km Domains For Fire Weather / IMET Support Identical To
4 km Homeland Security Domains
Fire Weather / IMET Run Output• The firewx grids are available out to 48 hours on the
TOC ftp server (tgftp.nws.noaa.gov) under the following format:/SL.us008001/ST.opnl/MT.nmm_CY.{CC}/RD.
{YYYYMMDD}/PT.grid_DF.gr1_AR.nest{xx} where CC = 00, 06, 12, or 18 YYYYMMDD = the current date xx = 01 - 26 (geographic location)
Filenames follow the convention:
fh.{hhhh}_tl.press_gr.awpreg (hhhh = 0000, 0003, 0006, ... , 0048)
Sample GIF File Denoting Area of Fire Wx Run
8 km versus 4 km Hybrid Terrain
12 km Meso Eta vs 8 km NMM Winds
12 km Meso Eta vs 8 km NMM Winds
Alaska Case Eta-12 vs NMM-417 March 2002
Alaska Case Eta-12 vs NMM-417 March 2002
http://wwwt.emc.ncep.noaa.gov/mmb/SREF/SREF.html
This page will add Alaskan products by
October 2003
Implementation ofEta Upgrade Bundle
Geoff DiMego [email protected]
301-763-8000 ext7221
18 June 2003
NCEP
Where the Nation’s climate and weather services begin
Planned Changes to Eta-12• Upgrades to Gridscale cloud & precipitation (Brad Ferrier)
– Begin proper cycling of total condensate (Eric Rogers)
– Upgrade microphysics and improve cloud - radiation interaction
• Upgrades to 3DVAR analysis (Dave Parrish)
– Add direct analysis of WSR-88D radial velocity from NWS Multicast– Upgrade radiance processing, stop thinning, use NOAA-17 (20x increase)
• Upgrades to Precipitation assimilation (Ying Lin)
– Assimilation of GOES cloud top pressures (w/ Jim Jung)
– Assimilate hourly precip from Stage IV instead of Stage II
• Extend off-time (06z & 18z) runs to 84 hours (Eric Rogers)
• Increase output in both frequency and contenthttp://wwwt.emc.ncep.noaa.gov/mmb/mmbpll/etapllsup12.etax/
http://wwwt.emc.ncep.noaa.gov/mmb/tpb.spring03/tpb.htm
Sample Total Cloud Cover
Before Changes After Changes
Better due to reduced longwave cooling
Sample Distribution of Processed 88D Radial Velocity Data
~ 5 km processing of an hour’s worth of scans
Sample Cloud Top Pressure Field
All NWS RFC’s Stage III are used in Stage IV except AKRFC & NWRFC
Example of new fields postable from Eta Cloud Water Cloud Ice
Rain Snow
Baldwin Type versus Precip Type Direct from Model
Baldwin Diagnosed Precip Type Percent Frozen Direct from Model’s Gridscale Scheme
Bundle Verification Results 24hr QPF
ETS
BIAS
Surface Temperature Response
True for East and West for both 00z and 12z runs.
Bundle Verification Results Sfc RH
Bundle Verification Results Upper-Air
T Z
RH V
24 hr
Bundle Verification Results Upper-Air
T Z
RH V
60 hr
PLANS FOR THE FUTURE
For each of the possible six upgrades/phases of the CCS
contract with IBM
Global Forecast System (GFS)Prediction Model Data Assimilation Phase/YR
T-254 / L64 3D-VAR, AMSU-B, Quikscat Current
T-254 / L64 add 2 passive tracers
Grid point version, AIRS, GOES imagery
I / 2004
45 km / L64 3-D Background error covariance, cloud analysis, minimization
II / 2005
45 km / L64 + improved microphysics
Absorption / scattering in radiative transfer
III / 2006
40 km / L80 Aerosols in radiative transfer, GIFTS IV / 2008
40 km / L80 NPP, integrated SST analysis V / 2009
35 km / L100 Advanced 4DDA, NPOESS, IASI + air quality
VI / 2010
Ensemble ForecastsGlobal Ensemble Short Range Ensemble Forecast Phase/YR
T126/L28 -10 members 48 km 15 members Current
T126/L42 -15 members 28 km 15 members I / 2004
90km/L42-30 members 20 km 20 members II / 2005
90km/L42-50 members 18 km 20 WRF members III / 2006
80km/L64-50 members 16 km 20 WRF members IV / 2008
80km/L64-50 members 14 km 20 WRF members V / 2009
70km/L64-50 members 12 km 25 WRF members VI / 2010
North American Early Guidance SystemPrediction Model Data Assimilation Phase/YR12 km Meso Eta partial hourly output
12 km 3DVAR 88D radial velocity, GOES sounder cloud top pressures
Current
12 km Meso Eta, support air quality, new radiation
12 km 3DVAR improve background error covariances
I / 2004
10 km NMM move top to 2mb, enlarge domain
10 km AIRS, GOES imagery & move top to 2mb, hourly updates
II / 2005
10 km WRF improved physics full hourly output
10 km absorption scattering in radiative transfer
III / 2006
10 km WRF 2 member ensemble
10 km WRF 4DDA IV / 2008
10 km WRF 4 member ensemble
10 km aerosols in radiative transfer & reflectivity
V / 2009
8 km WRF 4 member ensemble improved physics
8 km NPP, advanced 4DDA, NPOESS, IASI & air quality (ozone, particulates)
VI / 2010
Planned 15% Expansion in 2005
Hi Res Window & OCERHi Res Window On-Call Emergency Response Phase/YR8 km nested NMM no analysis 4 km nested NMM Current8 km nested NMMwith 3DVAR and top at 2mb
4 km nested NMMwith top at 2mb
I / 2004
8 km WRF6 member ensemble
4 km nested WRFwith improved physics
II / 2005
7 km WRF6 member ensemble
3.5 km nested WRFwith improved physics
III / 2006
7 km WRF10 member ensemble
3.5km nested WRFwith aerosols&reflectivity
IV / 2008
6 km WRF10 member ensemble
3 km nested WRFwith explicit convection
V / 2009
6 km WRF15 member ensemble
3 km nested WRFwith explicit convection
VI / 2010
0
0.005
0.01
0.015
0.02
0.025
0.03
2002 2004 2005 2006 2008 2009 2010
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
2002200420052006200820092010
0
20000
40000
60000
80000
100000
120000
2002 2004 2005 2006 2008 2009 2010
Total Generated by Models at NCEP
Total Transmitted on AWIPS (PROPOSED!)
Ratio of Generated at NCEP to Transmitted on AWIPS
Model Plans Linked To AWIPS•First iteration complete
•Connect model upgrade plans to a (conservative) set of proposed AWIPS product upgrades -ALASKA INCLUDED
•Presented to NWS/OCWWS folks at meeting 10 September
•No second iteration to date.
Why Can’t We Do Better?• Numbers just don't get us there - weather portion of
computer in 2010 is 36x of present capability. If all this is used to increase horizontal resolution alone:– Take the cube root (x,y,t) of that 36 which is 3.3– For Meso Eta: 12km / 3.3 = 3.63km = highest resolution possible
– NO ALLOWANCE for ANY other upgrades (domain, forecast range, vertical resolution, 3DVAR or cost due to additional data sources like radar or satellite, physics upgrades or implementing or increasing membership of ensembles).
• Getting a bigger machine is unlikely since current talk describes FY2004 budget as being extremely LEAN.
• Nesting degrades results.
Weather Research and Forecasting (WRF)• End-to-end Common Modeling Infrastructure
– Observations and analysis– Prediction model– Post-processing, product generation and display– Verification and archive
• For the community to perform research• For Operations to perform NWP• USWRP sponsorship - many partners: NCAR, NCEP,
FSL, OU/CAPS, AFWA, FAA, NSF and Navy• Initial implementation in HiResWindow in 4QFY04• Ensemble approach to be taken instead of single-run
deterministic approach
DynamicCore 1
Dynamic Core 2
DynamicCore N
Accelerates NWS towardWRF SREF end-state objective
Global
ESMF
DA
2
3
N
Init
1
2
3
N
SREF
NOAH Convective Boundary RadiationLand-sfc Schemes Layer Schemes
1
DynamicCore 1
+Dynamic
Core 2...
DynamicCore N
Prediction Model Diversity
Initial Condition Diversity
NCEP WRF Ensemble Design:
• In June 2004, computer increase will total 6x• Therefore, establish 6-member ensemble run in place of single HiResWindow run
–2 Control members•NCEP NMM core & NCEP physics, Dx = 8 km•NCAR Mass core & NCAR physics, Dx = 10 km
–4 Additional members • alternative physics or bred mode initial condition perturbations
• Qualify cores and evaluate potential ensemble members according to the WRF Test Plan
Sea-Level Pressure RMSE
0
0.5
1
1.5
2
2.5
3
3.5
3 15 27 39 51 63
Forecast Hour
mil
lib
ars
3 A+B+CModel AModel BModel C
Sea-Level Pressure RMSE
0
0.5
1
1.5
2
2.5
3
3.5
3 15 27 39 51 63
Forecast Hour
mil
lib
ars 15 3x5 Bred
3 A+B+CModel AModel BModel C
850 mb Temperature RMSE
0
0.5
1
1.5
2
2.5
3 15 27 39 51 63
Forecast Hour
deg
rees
C 15 3x5 Bred3 A+B+CModel AModel BModel C
850 mb Relative Humidity RMSE
0
5
10
15
20
25
3 15 27 39 51 63
Forecast Hour
per
cen
t 15 3x5 Bred3 A+B+CModel AModel BModel C
850 mb Wind Speed RMSE
0
1
2
3
4
5
6
7
3 15 27 39 51 63
Forecast Hour
met
ers
per
sec
ond
15 3x5 Bred3 A+B+CModel AModel BModel C
250 mb Wind Speed RMSE
0
2
4
6
8
10
12
14
3 15 27 39 51 63
Forecast Hour
met
ers
per
sec
ond
15 3x5 Bred3 A+B+CModel AModel BModel C
Example of Ensemble Probability Product
Courtesy NOAA-SPC
CAPE > 1000j/kg Prob0-6km Shear >40kts Prob
Conv Precip >0.01” Prob Severe Convection Prob
WRF Test Plan for Summer 2003• Participants: NCEP, NCAR, FSL, AFWA/NAVO-MSRC
• Two Cores: NCAR mass core & NCEP NMM core
• Two physics suites: NCAR suite & NCEP suite
• IC=RUC and Eta – each with bred perturbations• BC=Eta with SREF-based anomalies • Retrospective Runs:2 nests for 30 days in 4 seasons
- Aug/02 Central & West - Oct/02 Alaska & East - Feb/03 West & East - May/03 Central & East
• Real-time Runs at NCEP: Human Forecaster Feedback– 2 nests for 6 weeks each – Jul/Aug West & East– Aug/Sep Alaska & Central
North American Regional Reanalysis
NCEP
Where the nation’s climate and weather services begin
Office of Global Programs
Domain Coverage of NARR
For the Eta, a 32 km run takes 178 times the work of a 190 km run!
190 km 32 km
NARR GOAL: To Improve on NCAR/NCEP Global Reanalysis• Higher resolution 32 km vs T-62 (~180 km)• More frequent updates & ouput 3 hr vs 6 hr• Add precipitation assimilation• Add satellite radiance assimilation• 25 year period 1979-2003• To be perpetuated by NCEP/CPC like CDAS• Production ongoing on NCEP’s old IBM• Completion expected in Fall 2003• Could be source for 2.5 km downscaled climatology
for use in NDFD and IFPS techniques
Downscaling Strategy - A• Correct model bias (on model grid)
– Today’s forecast vs current model history (1-2 months)– Current ensemble mean vs Reanalysis climate mean
• Correct model spread (on model grid)– Today’s forecast vs current model history– Current ensemble spread vs Reanalysis climatological spread
• Apply corrections to all ensemble members• Result: forecast anomaly on model grid, corrected for
climatology• Calculate most probable anomaly from ensemble (error
weighted mean)• Given high resolution, gridded climatology for each
forecast element:– Add most probable anomaly to climatology for downscaled forecast element– Not guaranteed to be physically consistent (like model grids)– Forecast anomaly on model grid needs to be transmitted– High resolution climatology resident at WFOs
Downscaling Strategy – B
• Bias correction directly on NDFD grid– High resolution information still needed from local
climatology
• Can be done locally or centrally– If locally, assumes WFOs receive all ensemble forecast
members
• Neural Network application– Input: ensemble forecasts, lat, lon, elevation, climatology etc– Output: bias corrected ensemble forecasts on NDFD grid– Penalty function: probabilistic measure (e.g. Brier Skill
Score)