16 th Conference on Aviation, Range, and Aerospace Meteorology 10 January 2013 High-Resolution Rapid Refresh (HRRR) Model and Production Advancements for 2013 with Targeted Improvements for Reliable Convective Weather Guidance in the National Airspace System NOAA/ESRL/GSD/AMB Curtis Alexander, Steve Weygandt, Stan Benjamin, David Dowell, Tanya Smirnova, Eric James, Patrick Hofmann, Ming Hu, John Brown, and Georg Grell
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16th Conference on Aviation, Range, and Aerospace Meteorology
10 January 2013
High-Resolution Rapid Refresh (HRRR) Model and Production Advancements for 2013 with
Targeted Improvements for Reliable Convective Weather Guidance in the
National Airspace System
NOAA/ESRL/GSD/AMB
Curtis Alexander, Steve Weygandt, Stan Benjamin, David Dowell, Tanya Smirnova, Eric James, Patrick Hofmann, Ming Hu, John Brown, and Georg Grell
3 km/15 min reflect assimilation3 km cloud cycling3 km land-surface cycling
RAP and HRRR Changes 2013
3-km Interp
2013: Cycled Reflectivity at 3 km
GSI 3D-VAR
Obs
Cloud Anx
DigitalFilter
1 hr
fcs
t
HMObs
ReflObs
18 hr fcst
3-km Interp
GSI 3D-VAR
Obs
Cloud Anx
DigitalFilter
1 hr
fcs
t
HMObs
ReflObs
18 hr fcst
GSI 3D-VAR
Obs
Cloud Anx
DigitalFilter
HMObs
ReflObs
18 hr fcst
3 km HRRR
13z 14z 15z13 km RAP
15 hr fcst1 hr pre-fcst
Refl Obs
1-hr Reduction In Latency for 14z HRRR
Latent Heating (LH) Specification
Obse
rved 3
-D R
adar
Reflect
ivit
y
Tim
e (
min
)
-60
-45
-30
-15
0
-60 -45 -30-15 0Model Pre-Forecast Time (min)
Temperature Tendency (i.e. LH) = f(Observed Reflectivity)LH specified from reflectivity obs applied in four 15-min periodsThe observations are valid at the end of each 15-min pre-fcst periodNO digital filtering at 3-kmHour old mesoscale obsLatency reduced by 1 hr
LH = Latent Heating Rate (K/s)p = PressureLv = Latent heat of vaporizationLf = Latent heat of fusionRd = Dry gas constantcp = Specific heat of dry air at constant pf[Ze] = Reflectivity factor converted to
rain/snow condensatet = Time period of condensate formation
(600s i.e. 10 min)16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 15
Many options for weighting LH specification vs model LHTwo approaches including:(a)100% specification for the entire pre-forecast hour (b) Time-varying with linear ramp down to 0% specification at 1 hr
Option (b) permits more “free model” behavior before additional DA
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 16
Latent Heating (LH) Specification
0-h fcstwithout 3-km
radar DA
Obs0000 UTC11 June
2011
0-h fcstwith 3-kmradar DA(fixed)
0-h fcstwith 3-kmradar DA(ramp)
Benefit from pre-forecast 3-km model integration
1-h fcstwithout 3-km
radar DA
Obs0100 UTC11 June
2011
1-h fcstwith 3-kmradar DA(fixed)
1-h fcstwith 3-kmradar DA(ramp)
Convective systems more mature even by 1-hr
3-day retrospective period 09-12 June 2011 (36 runs)Forecasts every 2 hours
> 25 dBZ Composite ReflectivityEastern half of US
Upscaled to 40-km grid
With 3-km fixed radar DAWith 3-km ramp radar DAWithout 3-km radar DA
Bias = 1.0
Native3-km grid
Greatly improved CSI and BIAS between 0-1 fcst hr
Benefit persists until 4 hrsVery similar skill at longer lead times
HRRR Reflectivity Verification
14-day retrospective period June 2011 (160 runs)Forecasts every 2 hours
> 25 dBZ Composite ReflectivityEastern half of US
Upscaled to 40-km grid
With 3-km ramp radar DAWithout 3-km radar DA
Bias = 1.0
Native3-km grid
Greatly improved CSI and BIAS between 0-1 fcst hr
Benefit persists until 4 hrsVery similar skill at longer lead times
HRRR Reflectivity Verification
0-h fcstwithout 3-km
radar DA
Obs1800 UTC29 May 2011
0-h fcstwith 3-kmradar DA(ramp)
Benefit from pre-forecast 3-km model integration
0-h fcstwith fully
cycled 3-km DA
6-h fcstwithout 3-km
radar DA
Obs0000 UTC30 May 2011
6-h fcstwith 3-kmradar DA(ramp)
6-h fcstwith fully
cycled 3-km DA
Fully Cycled 3-km DA shows improved structures
CoSPA: Collaborative effort: ESRL/GSD, NCAR/RAL, MIT/LLProvide 0-8 hr thunderstorm intensity and echo top guidance to aviation community
HRRR 15 UTC 08 July 20116 hr forecast valid 21 UTC
VIL
Ech
o T
op
CoSPA 17 UTC 08 July 20114 hr forecast valid 21 UTC
ObservationValid 21 UTC 08 July 2011
Blend with CIWS
HRRR (and RAP) Future MilestonesHRRR MilestonesHRRR Forecasts for Aviation
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 23
New HRRR ET Diagnostic
Calibration of echo tops to produce improved bias
Current 2012 HRRR ET Diagnostic
(1) In each column starting from the top model level, locate the height of the first model level (if any) where HRRR reflectivity ≥ 18 dBZ
Proposed new HRRR ET Diagnostic
(1) In each column starting from the top model level, locate the height of the first model level (if any) where HRRR reflectivity ≥ 18 dBZ
(2) If and only if (1) is satisfied, repeat search through model column and locate the height of the first model level whereHRRR reflectivity ≥ 11 dBZ
(3) Interpolate between modellevel height identified in (2) and height of next level
above to estimate exact 11 dBZ height
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 24
HRRR 4 hr forecast
Observation01z 21 June 2012
Old2012
Echo Tops (kft)
New HRRR ET Diagnostic
Current 2012 low bias in echo tops
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 25
NEW2012
New HRRR ET Diagnostic
HRRR 4 hr forecast
Observation01z 21 June 2012
Echo Tops (kft)
Calibration of echo tops to produce improved bias
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 26
HRRR ET Diagnostic VerificationEastern US 03-km BIAS 344 runs 08-25 July 2012
25 kft 30 kft
35 kft 40 kft
Optimal Optimal
OptimalOptimal
New ETOld ET
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 27
HRRR ET Diagnostic VerificationEastern US 40-km CSI 344 runs 08-25 July 2012
25 kft 30 kft
35 kft 40 kft
New ETOld ET
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 28
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 37
• Current – 1 computer running HRRR– NOAA/ESRL – Boulder– Current reliability: 97% for last 12h months
(allowing up to 3h gaps)
• 2013-14 – 2 computers running HRRR – interim solution– Boulder – computer 1– Fairmont, WV – computer 2– Expected reliability to increase further to 98.5-99% via coordination of
downtimes for Boulder vs. Fairmont computers
• Est. 2015 – NCEP running HRRR– NOAA/NCEP computing budget – will allow no increase before 2015
• Conclusion: Interim HRRR computing for 2012-14 on 2 sites to provide “real-time experimental” HRRR from NOAA for NWS, FAA, DOE/energy users
HRRR Transition to NCEP
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 38
• Moist bias reduced in 2012 RAP and HRRR– Reduced false alarms, lower precipitation bias– GSI enhancements and WRF upgrade to v3.3.1– Reflectivity diagnostic consistent with microphysics
• Science: Focus on 3-km assimilation for 2013– 3-km variational analysis– 3-km non-variational cloud analysis– 3-km radar reflectivity data assimilation
• Technical: Reduced latency for 2013 (2-3 hrs now)– Approximate 1-hr reduction in execution time (1-2 hrs)– Faster post-processing with parallelization– Direct GRIB2 generation
Summary and Plans
16th ARAM Conf 10 Jan 2013High-Resolution Rapid Refresh 39