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Current and future convective-scale model forecasts from NCEP. Matthew Pyle with major contributions from Jacob Carley. Outline. Overview of current and future higher-resolution NWS operational modeling systems Current mix of deterministic, 4-5 km grid spacing models
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Current and future convective-scale model forecasts from NCEP Matthew Pyle with major contributions from Jacob Carley
Outline • Overview of current and future higher-resolution NWS operational modeling systems • Current mix of deterministic, 4-5 km grid spacing models • The future NAM rapid refresh (NAMRR) system • Recent case highlighting CI difficulties with current operational models, but hopeful signs from the NAMRR. • Operational target for 2018: high resolution, frequently updating ensemble-based modeling systems.
Current NWS higher-resolution models over CONUS • 4 km NAM CONUS nest • NEMS/NMMB model • 4x/day to 60 h • Currently with a light amount of parameterized convection • HiresWindow • 5.15 km WRF-ARW, 4.0 km WRF-NMM • 1-2x/day to 48 h • No parameterized convection 00Z,12Z 06Z
NWS operations by end of FY14 (knock on wood) • HiresWindow • ~4.1 km WRF-ARW, 3.5 km NMMB • Full CONUS grid 2x/day to 48 h • No parameterized convection • 3 km HRRR • WRF-ARW model • 24x/day to 15 h • Radar-derived heating profiles • No parameterized convection • 4 km NAM CONUS nest • NEMS/NMMB model • 4x/day to 60 h • Microphysics retuned for cnvc • No parameterized convection • Reduced moisture/cloud diffusion 00Z,12Z
Future plans: NAMRR • NAMRR: NAM Rapid Refresh (to complement RAP/HRRR in future rapid refresh ensembles) • Development of hourly NDAS/NAM cycling capabilities on NOAA R&D machine Zeus: • Part of DOE-funded wind energy projects: WFIP/POWER • Cycling 12 km NAM and 4 (3) km CONUS nest • Hybrid ensemble-3DVar via GDAS EnKFmembers • Cloud analysis and diabatic digital filter initialization with radar-derived temperature tendencies; building on GSD’s expertise in these areas. Courtesy Jacob Carley
CurrentNDAS/NAM configuration for a single, arbitrary cycle • Experimental NAMRR configuration for 12 hourly cycles Courtesy Jacob Carley
June 29-30, 2012 Derecho - NAMRR Test • 4 Hour Forecast valid 22 UTC Obs Ops NAM 4 km Poor forecast from Ops NAM 4 km CONUSNEST NAMRR 4 km NAMRR 3 km Much improved forecast from NAMRR 4 km CONUSNEST Additional improvement with NAMRR 3 km CONUSNEST Courtesy Jacob Carley
June 29-30, 2012 Derecho - 27 Hr Forecast NAMRR Test with 3 km CONUSnest • Significant improvement at longer lead times with 3 km NAMRR relative to Ops • 4 km Ops NAM CONUSnest • Fhr=27 • 3 km NAMRR CONUSnest • Fhr=27 • Observations (0630/03Z) Courtesy Jacob Carley
Recent 15 Aug case highlighting the difficulties Hail to 1.75” 60+ MPH winds 21Z-00Z ...CENTRAL/WRN KS TO NW TX THROUGH EARLY TONIGHT... SOME AMPLIFICATION OF THE FLOW REGIME IS EXPECTED TODAY AS THE MIDLEVEL RIDGE BUILDS NEWD FROM THE ROCKIES TO THE NRN HIGH PLAINS...WHILE A DOWNSTREAM SHORTWAVE TROUGH DIGS SSEWD FROM THE WY/NEB/SD BORDER TO KS/OK OVERNIGHT. THE SURFACE RESPONSE TO THIS SHORTWAVE TROUGH WILL CONSIST OF A WEAK LEE CYCLONE WHICH WILL DEVELOP SSEWD FROM THE NE CO BORDER THIS AFTERNOON TO NW TX BY FRIDAY MORNING. ON THE MESOSCALE...A WEAKENING MCV WILL PROGRESS SEWD FROM SW KS TO WRN OK...AS ANOTHER MCV /WITH AN ONGOING CONVECTIVE CLUSTER/ MOVES SEWD FROM SW/S CENTRAL NEB TO N CENTRAL/NE KS THIS AFTERNOON. CONVECTION WITH THE NEB MCV SHOULD WEAKEN SOME THIS MORNING...BUT THE LINGERING OUTFLOW BOUNDARY WILL PROVIDE A LOW-LEVEL FOCUS FOR STORM INITIATION INTO NRN KS BY EARLY-MID AFTERNOON. LIKEWISE...THE WRN EDGE OF THE OUTFLOW WILL INTERACT WITH THE WEAK LEE CYCLONE NEAR THE KS/CO BORDER BY MID AFTERNOON...WHEN DAYTIME HEATING/MIXING WILL HAVE LARGELY REMOVED CONVECTIVE INHIBITION. NEW THUNDERSTORM DEVELOPMENT WILL OCCUR BY MID AFTERNOON ALONG THE AFOREMENTIONED BOUNDARY...WITH STORMS SPREADING SWD/SSEWD THROUGH THE AFTERNOON/EVENING...
Recent 15 Aug case highlighting the difficulties14Z-02Z radar loop
9 h forecasts of 1000 m AGL REFD valid 0815/21Z Operational and parallel 4-5 km models 15/21Z
12h forecasts of 1000 m AGL REFD valid 0816/00Z Operational and parallel 4-5 km models 16/00Z
15h forecasts of 1000 m AGL REFD valid 0816/03Z Operational and parallel 4-5 km models 16/03Z
12Z NAMRR nest, f06 13Z NAMRR nest, f05 15/18Z
12Z NAMRR nest, f07 13Z NAMRR nest, f06 15/19Z
12Z NAMRR nest, f08 13Z NAMRR nest, f07 15/20Z
12Z NAMRR nest, f09 13Z NAMRR nest, f08 15/21Z
12Z NAMRR nest, f10 13Z NAMRR nest, f09 15/22Z
12Z NAMRR nest, f11 13Z NAMRR nest, f10 15/23Z
12Z NAMRR nest, f12 13Z NAMRR nest, f11 16/00Z
14Z NAMRR nest has same general idea as the 13Z, but a bit slower and more diffuse. 15/21Z
Lessons from this event but not specific to this event • Analyses are critical • NAM analysis constrained the current operational high-resolution guidance (forecast similarities across models with very different dynamics and physics) • Use of radar reflectivity and cloud analysis in an hourly cycle reduces model “blind spots” to observational trends. • Time-lagging within a rapidly updating modeling system may smooth cycle-to-cycle variability; quantify confidence in outcomes at a given time. • Relying on a single deterministic forecast rarely is a good idea.
Schedule • HRRR in 2014 • NAMRR in 2015-16 time frame • 2016-18: multiple RAP/HRRR and NAMRR members, updated hourly to 24 h, every 6 h to 48-60 h • All contingent on sufficient computing power and human power to make it happen • Ensembles complete their “take over” of the modeling world – from extended range global runs down to short duration, high spatial resolution forecasts.
Projected WCOSS Phase 1 End State in 2015 Current ~200 Megaflop machine High Resolution Rapid Refresh [HRRR] Courtesy Geoff DiMego
Projected WCOSS Phase 2 End State in 2018 (2 Petaflop - ~10x current computing power) S R E F S R E F S R E F S R E F Hurricane Hurricane Hurricane Hurricane RTOFS RTOFS RTOFS RTOFS GEFS GEFS GEFS GEFS GDAS GDAS GDAS GDAS GFS NAMext NAMext NAMext NAMext GFS GFS GFS Rapidly updating storm scale ensembles and data assimilation NMMB Storm Scale Ensemble members within CONUS and/or Alaska NMMB HRRRE members CONUS, Alaska, Hawaii, Puerto Rico ARW HRRRE members CONUS and Alaska Convective Allowing Data Assimilation – NMMB Convective Allowing Data Assimilation – ARW CFSv3 Courtesy Geoff DiMego
Current EMC quasi-ops • “SPC” run • 4.0 km WRF-NMM • 2x/day to 36 h • No parameterized convection • Older versions of dynamics & physics – more convectively “hyperactive” 00Z,12Z 06Z 00Z,12Z
14Z NAMRR nest has same general idea as 13Z, but a bit more diffuse.
21h forecasts of 1000 m AGL REFD valid 20130815/21Z Operational and parallel 4-5 km models
24h forecasts of 1000 m AGL REFD valid 20130816/00Z Operational and parallel 4-5 km models
12Z HRRR, f09 13Z HRRR, f08 15/21Z
13Z HRRR, f11 12Z HRRR, f12 16/00Z