Measurements and Model Improvement: Insight into NWP Model Error Using Doppler Lidar and Other WFIP2 Measurement Systems

Journal Article · 01 December 2023 · Monthly Weather Review

DOI: https://doi.org/10.1175/MWR-D-23-0069.1 · OSTI ID:2228541

Banta, Robert M. ^[1]; Pichugina, Yelena L. ^[1]; Brewer, W. Alan ^[2]; Balmes, Kelly A. ^[3]; Adler, Bianca ^[4]; Sedlar, Joseph ^[3]; Darby, Lisa S. ^[5]; Turner, David D. ^[6]; Kenyon, Jaymes S. ^[7]; Strobach, Edward J. ^[1]; Carroll, Brian J. ^[1]; Sharp, Justin ^[8]; Stoelinga, Mark T. ^[9]; Cline, Joel ^[10]; Fernando, Harindra J. S. ^[11]

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1. a CIRES, University of Colorado Boulder, Boulder, Colorado, b NOAA/Chemical Sciences Laboratory, Boulder, Colorado
2. b NOAA/Chemical Sciences Laboratory, Boulder, Colorado
3. a CIRES, University of Colorado Boulder, Boulder, Colorado, c NOAA/Global Monitoring Laboratory, Boulder, Colorado
4. a CIRES, University of Colorado Boulder, Boulder, Colorado, d NOAA/Physical Systems Laboratory, Boulder, Colorado
5. f LDWX LLC, Boulder, Colorado
6. e NOAA/Global Sciences Laboratory, Boulder, Colorado
7. a CIRES, University of Colorado Boulder, Boulder, Colorado, e NOAA/Global Sciences Laboratory, Boulder, Colorado
8. h Sharply Focused LLC, Portland, Oregon
9. j Vaisala, Seattle, Washington
10. i NOAA Tropical Program Coordinator, Silver Spring, Maryland
11. g University of Notre Dame, Notre Dame, Indiana

Abstract Doppler-lidar wind-profile measurements at three sites were used to evaluate NWP model errors from two versions of NOAA’s 3-km-grid HRRR model, to see whether updates in the latest version 4 reduced errors when compared against the original version 1. Nested (750-m grid) versions of each were also tested to see how grid spacing affected forecast skill. The measurements were part of the field phase of the Second Wind Forecasting Improvement Project (WFIP2), an 18-month deployment into central Oregon–Washington, a major wind-energy-producing region. This study focuses on errors in simulating marine intrusions, a summertime, 600–800-m-deep, regional sea-breeze flow found to generate large errors. HRRR errors proved to be complex and site dependent. The most prominent error resulted from a premature drop in modeled marine-intrusion wind speeds after local midnight, when lidar-measured winds of greater than 8 m s ⁻¹ persisted through the next morning. These large negative errors were offset at low levels by positive errors due to excessive mixing, complicating the interpretation of model “improvement,” such that the updates to the full-scale versions produced mixed results, sometimes enhancing but sometimes degrading model skill. Nesting consistently improved model performance, with version 1’s nest producing the smallest errors overall. HRRR’s ability to represent the stages of sea-breeze forcing was evaluated using radiation budget, surface-energy balance, and near-surface temperature measurements available during WFIP2. The significant site-to-site differences in model error and the complex nature of these errors mean that field-measurement campaigns having dense arrays of profiling sensors are necessary to properly diagnose and characterize model errors, as part of a systematic approach to NWP model improvement. Significance Statement Dramatic increases in NWP model skill will be required over the coming decades. This paper describes the role of major deployments of accurate profiling sensors in achieving that goal and presents an example from the Second Wind Forecast Improvement Program (WFIP2). Wind-profile data from scanning Doppler lidars were used to evaluate two versions of HRRR, the original and an updated version, and nested versions of each. This study focuses on the ability of updated HRRR versions to improve upon predicting a regional sea-breeze flow, which was found to generate large errors by the original HRRR. Updates to the full-scale HRRR versions produced mixed results, but the finer-mesh versions consistently reduced model errors.

• Sponsoring Organization: USDOE Office of Environmental Management (EM)
• OSTI ID: 2228541
• Journal Information: Monthly Weather Review, Journal Name: Monthly Weather Review Vol. 151 Journal Issue: 12; ISSN 0027-0644
• Publisher: American Meteorological SocietyCopyright Statement
• Country of Publication: United States
• Language: English