ESRL – Some Recommendations for Mesoscale Ensemble Forecasts Consolidate all NCEP regional...

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ESRL – Some Recommendations for Mesoscale Ensemble Forecasts • Consolidate all NCEP regional storm-scale model runs perhaps under HRRRE (or other) banner (including NAM- nest, Hi-Res Windows, SPC runs, Fire-Weather nests) • David Dowell on CAMs – Weisman 1997 -Grid spacing should be ≤ 4km – Increased realism of convective structures from 4 to 3 to 2km (Weisman, Kain, others) • Recommend – use 3km, better to add ensemble members and retain 3km dx. – Another advantage for 3km (for now): much research experience now available with 3km (NCAR, ESRL, WoF for outer next.) • Question – Use ARW and NMMB equally? (ESRL and EMC have assumed yes for now for HRRRE). • No difference in ARW vs. NMMB run time at same res. – Therefore run both at same resolution. Mesoscale Ensembles Toward 2020 – Stan, David Dowell, Curtis, Steve Weygandt

Transcript of ESRL – Some Recommendations for Mesoscale Ensemble Forecasts Consolidate all NCEP regional...

Page 1: ESRL – Some Recommendations for Mesoscale Ensemble Forecasts Consolidate all NCEP regional storm-scale model runs perhaps under HRRRE (or other) banner.

ESRL – Some Recommendations for Mesoscale Ensemble Forecasts

• Consolidate all NCEP regional storm-scale model runs perhaps under HRRRE (or other) banner (including NAM-nest, Hi-Res Windows, SPC runs, Fire-Weather nests)

• David Dowell on CAMs– Weisman 1997 -Grid spacing should be ≤ 4km– Increased realism of convective structures from 4 to 3 to 2km (Weisman, Kain,

others)• Recommend – use 3km, better to add ensemble members and retain 3km

dx.– Another advantage for 3km (for now): much research experience now available

with 3km (NCAR, ESRL, WoF for outer next.)• Question – Use ARW and NMMB equally? (ESRL and EMC have assumed yes

for now for HRRRE).• No difference in ARW vs. NMMB run time at same res.

– Therefore run both at same resolution.

Mesoscale Ensembles Toward 2020 – Stan, David Dowell, Curtis, Steve Weygandt

Page 2: ESRL – Some Recommendations for Mesoscale Ensemble Forecasts Consolidate all NCEP regional storm-scale model runs perhaps under HRRRE (or other) banner.

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2019?High-Resolution Rapid Refresh

ENSEMBLE (HRRRE)• Each member of NARRE contains 3 km nests

– CONUS/Gulf/Carib, Alaska, Hawaii nests– The two control runs initialized with radar data & other hi-res obs

• This capability puts NWS/NCEP[+OAR/ESRL] in a position to – Provide NextGen Enroute AND Terminal guidance – Provide PROBABILITY guidance with full Probability Density

Function specified, hence uncertainty information as well– Provide a vehicle to improve assimilation capabilities using hybrid (4d-

ens-var) technique with current & future radar & satellite– Address Warn-on-Forecast as resolutions evolve towards ~1 km

• NAM nests are extensions of the 00z, 06z, 12z & 18Z runs.

• HRRRE requires an increase in HPCC funding over and above that required for the NARRE

From Geoff DiMego, Dec 2011, NCEP Model Review

Page 3: ESRL – Some Recommendations for Mesoscale Ensemble Forecasts Consolidate all NCEP regional storm-scale model runs perhaps under HRRRE (or other) banner.

DRAFT Storm Prediction Center Desired Numerical Guidance Attributes

2015 2017 2022•North America Short-Range Mesoscale Ensemble: 12-15 km ~30 member multi-model/multi-physics/multi-IC ensemble with EnKF/hybrid DA, run every 6 hrs with forecasts to 84 hrs

•North America Short-Range Mesoscale Ensemble: 12-15 km ~40 member multi-model/multi-physics/multi-IC ensemble with EnKF/hybrid or newer-state-of-the-art DA, run every 6 hrs with forecasts to Day 4*

•Global Mesoscale Ensemble Forecast System: 10-12 km global domain 40-50 member ensemble with advanced state-of-the-science DA, run every 6 hrs with forecasts to Day 7-10*

•CONUS Storm Scale Ensemble Forecast (SSEF): 4 km CONUS ~10 member multi-model/multi-physics/multi-IC storm scale ensemble with EnKF/hybrid DA, issued every 6-hrs with forecasts to 48-60 hrs*

•CONUS Storm Scale Ensemble Forecast (SSEF): 3 km CONUS ~15 member multi-model/multi-physics/multi-IC storm scale ensemble with EnKF/hybrid or newer state-of-the-art DA, issued every 6-hrs with forecasts to 48-60 hrs*

•CONUS SSEF: 2 km CONUS 30-50 member multi-model/multi-physics/multi-IC storm scale ensemble with advanced state-of-the-science DA, issued every 6-hrs with forecasts to 48-60 hrs*

•Movable domain update SSEF: 2-3 km movable regional domain ~7 member storm scale ensemble with EnKF/hybrid run every 2-4 hrs with forecasts to 15-18 hrs*, focused on “severe weather of the day” areas

•Movable domain update SSEF: 2 km movable regional domain 10-15 member storm scale ensemble with EnKF/hybrid or newer state-of-the-art DA ,run every 1-2 hrs with forecasts to 18-24 hrs*, focused on “severe weather of the day” areas

•Movable domain update SSEF: 1 km movable regional domain 20-30 member storm scale ensemble with advanced state-of-the-science DA run every 1 hr with forecasts to 18-24 hrs*, focused on “severe weather of the day” areas

•Stormscale 3D Analysis: 4 km EnKF/hybrid DA, CONUS storm scale analysis updated every 1-hr.

•Stormscale 3D Analysis: 2 km EnKF/hybrid or newer state-of-the-art DA, CONUS storm scale analysis updated every 15 min

•Stormscale 3D Analysis: 2 km EnKF/hybrid or newer state-of-the-art DA, CONUS storm scale analysis updated every 5 min

•Appropriate RAP (HRRR), Global deterministic / ensemble, and CFS capacities

•Appropriate RAP (HRRR), Global deterministic / ensemble, and CFS capacities

•Stretch Goal - Warn-on-Forecast Prototype Ensemble: Develop <1 km multi-WFO domain 10-20 member nested SSEF, advanced state-of-the science DA, run as needed every 5-10 min with forecasts to 1-2 hrs*

*Model and data assimilation (DA) complexity will be impacted strongly by High Performance Computing capabilities.

Desired Attributes of NOAA Operational Numerical Guidance System

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Page 4: ESRL – Some Recommendations for Mesoscale Ensemble Forecasts Consolidate all NCEP regional storm-scale model runs perhaps under HRRRE (or other) banner.

DRAFT Storm Prediction Center Desired Numerical Guidance Attributes

2015 2017 2022•North America Short-Range Mesoscale Ensemble: 12-15 km ~30 member multi-model/multi-physics/multi-IC ensemble with EnKF/hybrid DA, run every 6 hrs with forecasts to 84 hrs

•North America Short-Range Mesoscale Ensemble: 12-15 km ~40 member multi-model/multi-physics/multi-IC ensemble with EnKF/hybrid or newer-state-of-the-art DA, run every 6 hrs with forecasts to Day 4*

•Global Mesoscale Ensemble Forecast System: 10-12 km global domain 40-50 member ensemble with advanced state-of-the-science DA, run every 6 hrs with forecasts to Day 7-10*

•CONUS Storm Scale Ensemble Forecast (SSEF): 4 km CONUS ~10 member multi-model/multi-physics/multi-IC storm scale ensemble with EnKF/hybrid DA, issued every 6-hrs with forecasts to 48-60 hrs*

•CONUS Storm Scale Ensemble Forecast (SSEF): 3 km CONUS ~15 member multi-model/multi-physics/multi-IC storm scale ensemble with EnKF/hybrid or newer state-of-the-art DA, issued every 6-hrs with forecasts to 48-60 hrs*

•CONUS SSEF: 2 km CONUS 30-50 member multi-model/multi-physics/multi-IC storm scale ensemble with advanced state-of-the-science DA, issued every 6-hrs with forecasts to 48-60 hrs*

•Movable domain update SSEF: 2-3 km movable regional domain ~7 member storm scale ensemble with EnKF/hybrid run every 2-4 hrs with forecasts to 15-18 hrs*, focused on “severe weather of the day” areas

•Movable domain update SSEF: 2 km movable regional domain 10-15 member storm scale ensemble with EnKF/hybrid or newer state-of-the-art DA ,run every 1-2 hrs with forecasts to 18-24 hrs*, focused on “severe weather of the day” areas

•Movable domain update SSEF: 1 km movable regional domain 20-30 member storm scale ensemble with advanced state-of-the-science DA run every 1 hr with forecasts to 18-24 hrs*, focused on “severe weather of the day” areas

•Stormscale 3D Analysis: 4 km EnKF/hybrid DA, CONUS storm scale analysis updated every 1-hr.

•Stormscale 3D Analysis: 2 km EnKF/hybrid or newer state-of-the-art DA, CONUS storm scale analysis updated every 15 min

•Stormscale 3D Analysis: 2 km EnKF/hybrid or newer state-of-the-art DA, CONUS storm scale analysis updated every 5 min

•Appropriate RAP (HRRR), Global deterministic / ensemble, and CFS capacities

•Appropriate RAP (HRRR), Global deterministic / ensemble, and CFS capacities

•Stretch Goal - Warn-on-Forecast Prototype Ensemble: Develop <1 km multi-WFO domain 10-20 member nested SSEF, advanced state-of-the science DA, run as needed every 5-10 min with forecasts to 1-2 hrs*

*Model and data assimilation (DA) complexity will be impacted strongly by High Performance Computing capabilities.

Desired Attributes of NOAA Operational Numerical Guidance System

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Possible alternative NWP 2-member suite - 2022

Global ensemble – as shown by EMC

• 10-12km global 40-50 member ensemble• runs to Day 14 twice daily (to 7d at 06z, 18z)• hourly assimilation cycle with 24h runs init hourly

Single regional model/assimilation ensemble - SSEF• SSEF (equivalent to HRRRe) – 2-3km• Initialize hourly (or subhourly), run to 24h• Every 6h, run out to 48-60h• 2-3km EnKF/hybrid/other DA• Multi-species microphysics with at least 2-moment rain• Include aerosols/fire/smoke for all runs with aerosol-

aware microphysics• No separate HWRF or fire-weather runs or AQ/dust run• 0.5-1.0km multi-WFO nest where needed (WoF)• SSEF analysis = RUA, no separate products

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From HRRR/HRRRe to WoF• Radar-DFI-LH effective start at 13km/3km• Mesoscale environment via GSI enhancements for RAPv2+ critical

for HRRR• 3km/80-member hourly updated GSI-hybrid data assimilation over

HRRR-CONUS domain plausible– Estimated needed 10,000 cores (Jeff W. / Stan)

• Model design for HRRR – most accurate numerics possible necessary for identification of storm structure (line vs. supercells vs. cell vs. MCS variations)– ARW, less 6th order diffusion, 5th-order vertical advection

• WoF options – discussion with NSSL, ESRL, EMC, U.OK, SPC partners, NCEP/PSR participants– direct nest inside HRRR/HRRRe within same executable– Separate system using HRRR/HRRRe lateral BCs/background 5Mesoscale Ensembles Toward 2020 – Stan, David Dowell, Curtis, Steve Weygandt