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John M. Brown

Affiliation/Employer
Federal
Partner Affiliation
gsl
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Publications

Corresponding Articles: 64

John M. Brown authored and/or contributed to the following articles/publications.

An Intercomparison of T-REX Mountain-Wave Simulations and Implications for Mesoscale Predictability

Numerical simulations of flow over steep terrain using 11 different nonhydrostatic numerical models are compared and analyzed. A basic benchmark and five other test cases are simulated in a two-dimensional framework using the same initial state, which is based on conditions during Intensive Observation Period (IOP) 6 of the Terrain-Induced Rotor...

John M. Brown

A Comparison of Model and Observed Turbulent Kinetic Energy Within Coastal Barrier Jets Forced by Landfall Cyclones

The Rapid Refresh (RR) is a 1-h data assimilation system at 13-km grid spacing, which provides mesoscale guidance for short-range forecasts. Among the many significant weather phenomena, the RUC is relied upon for the prediction of turbulence and high speed wind events by the marine and aviation industries. The Rapid Refresh (RR) forecast model ...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

2010 results from the 3km HRRR - verification, case study assessment, and HRRR-based convective probabilistic forecasts (HCPF)

The High Resolution Rapid Refresh (HRRR) is a 3-km, convection resolving model, run hourly in real-time at the Global System Division (GSD) of the NOAA Earth System Research Laboratory (ESRL). The WRF-ARW-based HRRR is run out to fifteen hours over a domain covering the entire continental United States (CONUS), using initial and boundary conditi...

John M. Brown

An investigation of simulated low-level jets produced by different PBL schemes in the WRF-ARW as verified against tower data

The prediction of winds between 50 and 150 m above ground level (AGL) is crucial for the design, operation, and maintenance of wind farms. The lack of standard observations in this layer makes the development and verification of numerical weather prediction models difficult for wind energy purposes. Specifically, this data limitation has resulte...

John M. Brown

A Comparison of Model and Observed Turbulent Kinetic Energy within Coastal Barrier Jets Forced by Landfalling Cyclones

The coastal region of western North America frequently experiences intense orographically enhanced wind and rainfall when cyclones make landfall. The prefrontal lowlevel winds can undergo upstream deceleration and deflection in the coastal regions, producing strong barrier jets (Macklin et al. 1990; Overland and Bond 1993 and 1995; Loescher et a...

John M. Brown

Use of lightning data to enhance radar assimilation within the RUC and Rapid Refresh models

An ongoing research effort within NOAA ESRL/GSD has focused on incorporating lighting data into the RUC and Rapid Refresh analysis systems. For both systems, lightning data are converted to proxy radar reflectivity data using simple assumptions. Within the RUC, latent heating-based temperature tendency fields are then created, which are used to ...

John M. Brown

Assimilation of radar reflectivity data using a diabatic digital filter within the Rapid Update Cycle

For the past four years, The ESRL Global Systems Divisions has produced probabilistic thunderstorm likelihood forecasts by applying statistical post-processing techniques to timelagged ensembles of Rapid Update Cycle (RUC) model output. Since March of 2005, these forecasts have been distributed in real-time to the Aviation Weather Center (AWC) a...

John M. Brown

Statistical modeling of downslope windstorms in Boulder, Colorado

Downslope windstorms are of major concern to those living in and around Boulder, Colorado, often striking with little warning, occasionally bringing clear-air wind gusts of 35–50 m s1 or higher, and producing widespread damage. Historically, numerical models used for forecasting these events had lower than desired accuracy. This observation prov...

John M. Brown

The RTMA Background - Hourly Downscaling of RUC Data to 5-KM Detail

The Real-Time Mesoscale Analysis is designed to provide the best 5-km gridded estimate of current surface and near-surface conditions on an hourly basis in support of National Weather Service activities and the NWS National Digital Forecast Database (NDFD). Even with availability of increasingly dense mesonet observations, the RTMA must incorpor...

John M. Brown

FIM: A vertically flow-following, finite-volume icosahedral model

Global Spectral models have gained almost universal acceptance in the last several decades. However, drawbacks of high-resolution spectral models in terms of operation counts and communication overheads on massive parallel processors have led, in recent years, to the development of new types of grid-point global models discretized on geodesic gr...

John M. Brown

Numerical Simulations of the wake of Kauai

This study uses a series of numerical simulations to examine the structure of the wake of the Hawaiian island of Kauai. The primary focus is on the conditions on 26 June 2003, which was the day of the demise of the Helios aircraft within Kauai's wake. The simulations show that, in an east-northeasterly trade wind flow, Kauai produces a well-def...

John M. Brown

Assimilation of lightning data into RUC model convection forecasting

Lightning data have been used experimentally as part of the NOAA Rapid Update Cycle (RUC) assimilation method for improving cloud/hydrometeor/convection initialization. Lightning data can be used to supplement initial information on existence of convection, along with radar and satellite data and a short-range background model forecast. Radar re...

John M. Brown

Development of FAA national ceiling and visibility products: Challenges, strategies, and progress

The complex physical processes controlling ceiling and visibility (for example, the formation, evolution and motion of low cloud, precipitation and fog) and the diverse seasonal and geographic influences that modulate these controls across the continen-tal U.S. and Alaska yield an extremely difficult analysis and forecast problem. This same phen...

John M. Brown

Modeling of mountain waves in T-REX

John M. Brown

Statistical Modeling of Downslope Windstorms in Boulder, Colorado

Downslope windstorms are of major concern to those living near the Boulder, Colorado area, often striking with little warning, bringing clear air wind gusts of 35-50 m/s or higher, and producing widespread damage across the city. Models used for forecasting these dangerous events are often not accurate. Hence, there is a need to apply different ...

John M. Brown

Cloud and hydrometeor analysis using metar, radar, and satellite data within the RUC/Rapid Refresh Model

Aviation users have a strong need for accurate short-range forecasts of sensible weather parameters including clouds, fog, ceiling and visibility and precipitation. Modelbased predictions of these parameters are the main source of guidance beyond a few hours and these predictions depend critically on the accurate initialization of cloud and hydr...

John M. Brown

Numerical simulation of the wake of Kauai with implications for the Helios flights

John M. Brown

CYCLED SNOW STATE IN RUC COUPLED DATA ASSIMILATION SYSTEM (CDAS)

John M. Brown

EXAMINATION OF THE PERFORMANCE OF SEVERAL MESOSCALE MODELS FOR CONVECTIVE FORECASTING DURING IHOP

John M. Brown

Performance of real-time and post-IHOP mesoscale models in determining storm type and evolution for the IHOP-2002 experimental period

John M. Brown

Cloud/Hydrometeor Initialization in the 20-km RUC Using GOES and Radar Data

John M. Brown

The 20-km RUC in Operations

John M. Brown

PROBABILISTIC CONVECTION INITIATION FORECASTS IN SUPPORT OF IHOP DURING THE 2002 SPC/NSSL SPRING PROGRAM

John M. Brown

Cloud/Hydrometeor Initialization in the 20-km RUC Using Radar and GOES Data

John M. Brown

Cloud/Hydrometeor Initialization in the 20-km RUC Using Radar and GOES Data

John M. Brown

Visibility Forecasts from the RUC20

John M. Brown

A preliminary examination of the performance of several mesoscale models for convective forecasting during IHOP

John M. Brown

THE 20-KM VERSION OF THE RUC

A new version of the Rapid Update Cycle (RUC) with 20-km resolution and significant changes in model and assimilation techniques is being implemented at NOAA’s National Centers for Environmental Prediction (NCEP) in summer 2001. The RUC, a high-frequency mesoscale analysis and forecast model system, has become a widely used source for short-rang...

John M. Brown

COMPARISONS OF RUC 20-KM AND 40-KM FORECASTS FOR 24 MAY 2000

John M. Brown

Fine-scale comparison of TOMS total ozone data with model analysis of an intense Midwestern cyclone

High-resolution (similar to 40 km) along-track total column ozone data from the Total Ozone Mapping Spectrometer (TOMS) instrument are compared with a high-resolution mesoscale numerical model analysis of an intense cyclone in the Midwestern United States. Total ozone increased by similar to 100 DU (nearly 38%) as the TOMS instrument passed o...

John M. Brown

Forecasting downslope windstorms at Boulder, Colorado: The empirical-statistical approach revisited

John M. Brown

Case study verification of RUC/MAPS fog and visibility forecasts

John M. Brown

Validation of long-term precipitation and evolved soil moisture and temperature fields in MAPS

John M. Brown

An evaluation of day 3 to day 7 forecasts from several models for potential significant winter season events over Colorado

John M. Brown

Mesoscale circulation growth under conditions of weak inertial instability

The hypothesis that inertial instability plays a role in the upscale development of mesoscale convective systems (MCSs) is explored by sampling environments that supported the growth of MCSs in the Preliminary Regional Experiment for STORM (Stormscale Operational and Research Meteorology) (PRE-STORM) network with high quality special soundings. ...

John M. Brown

A collaborative effort toward a future community mesoscale model (WRF)

John M. Brown

Comparison of skin temperatures from the MAPS/RUC Forecast Model and from GOES-8

John M. Brown

Progress on FIM development toward membership in the North American Ensemble Forecast System

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

100 Years of Progress in Forecasting and NWP Applications

Over the past 100 years, the collaborative effort of the international science community, including government weather services and the media, along with the associated proliferation of environmental observations, improved scientific understanding, and growth of technology, has radically transformed weather forecasting into an effective global a...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Improving Wind Energy Forecasting through Numerical Weather Prediction Model Development

The primary goal of the Second Wind Forecast Improvement Project (WFIP2) is to advance the state-of-the-art of wind energy forecasting in complex terrain. To achieve this goal, a comprehensive 18-month field measurement campaign was conducted in the region of the Columbia River basin. The observations were used to diagnose and quantify systemati...

John M. Brown
Institutions National Oceanic and Atmospheric Administration - NOAA Earth System Research Laboratory - ESRL National Center for Atmospheric Research - NCAR

A Description of the MYNN-EDMF Scheme and the Coupling to Other Components in WRF–ARW

The Mellor–Yamada–Nakanishi–Niino (MYNN) (Nakanishi and Niino 2001, 2004, 2006, and 2009) scheme was first integrated into the Advanced Research version of the Weather Research and Forecasting Model (WRF-ARW) version 3.1 (Skamarock et al. 2008) by Mariusz Pagowski of the National Oceanic and Atmospheric Administration (NOAA) Global Systems Divis...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Assimilating Differential Reflectivity Columns into the High-Resolution Rapid Refresh Using Latent Heating Forcing

The High Resolution Rapid Refresh (HRRR) assimilates radar reflectivity information in order to skillfully forecast convection. This assimilation is done using an empirical relationship between reflectivity and latent heat release from hydrometeor condensation and freezing to update the temperature tendency field. The temperature tendency field ...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Application of the High-Resolution Rapid Refresh (HRRR) to the Bay Area Advanced Quantitative Precipitation Information Project

The Bay Area Flood Protection Association has just recently begun funding the Physical Sciences Division and Global Systems Division (GSD) of NOAA’s Earth System Research Lab (NOAA-ESRL), as well as the NOAA Cooperative Institute for Research in the Atmosphere (CIRA), to design and build a specialized nowcast / forecast system for the 9 Californ...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Addressing Common Cloud - Radiation Errors from ~4-hour to 4-week Model Prediction

Cloud-radiation representation in models for subgrid-scale clouds is a known gap from subseasonal-to-seasonal models down to storm-scale models applied for forecast duration of only a few hours. NOAA/ESRL has been applying common physical parameterizations for scale-aware deep/shallow convection and boundary-layer mixing over this wide range of ...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

An Evaluation of a Hybrid, Terrain-Following Vertical Coordinate in the WRF-based RAP and HRRR Models

A new hybrid, sigma-pressure vertical coordinate was recently added to the Weather Research and Forecasting (WRF) model in an effort to reduce numerical noise in the model equations near complex terrain. Testing of this hybrid, terrain-following coordinate was undertaken in the WRF-based Rapid Refresh (RAP) and High-Resolution Rapid Refresh (HRR...

John M. Brown

Stratiform Cloud-Hydrometeor Assimilation for HRRR and RAP Model Short-Range Weather Prediction

Accurate cloud and precipitation forecasts are a fundamental component of short-range data assimilation/model prediction systems such as the NOAA 3-km High-Resolution Rapid Refresh (HRRR) or the 13-km Rapid Refresh (RAP). To reduce cloud and precipitation spinup problems, a nonvariational assimilation technique for stratiform clouds was develope...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

A Description of the MYNN Surface-Layer Scheme

The surface-layer scheme controls the degree of coupling between the model surface and the atmosphere. Traditionally, surface-layer schemes have been developed to be paired with certain planetary boundary layer (PBL) schemes, but this singular pairing is too narrow in scope for modern physics suites, since the surfac...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Improvement of Mountain Wave Turbulence Forecast in the NOAA’s Rapid Refresh (RAP) Model with Hybrid Vertical Coordinate System

Spurious mountain-wave features have been reported as false alarms of light-or-stronger numerical weather prediction (NWP)-based cruise level turbulence forecasts especially over the western mountainous region of North America. To reduce this problem, a hybrid sigma-pressure vertical coordinate system was implemented in NOAA’s operational Rapid ...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Advancing Science and Services during the 2015/16 El Niño: The NOAA El Niño Rapid Response Field Campaign

Forecasts by mid-2015 for a strong El Niño during winter 2015/16 presented an exceptional scientific opportunity to accelerate advances in understanding and predictions of an extreme climate event and its impacts while the event was ongoing. Seizing this opportunity, the National Oceanic and Atmospheric Administration (NOAA) initiated an El Niño...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

A Performance Comparison between Multiphysics and Stochastic Approaches within a North American RAP Ensemble

A stochastic parameter perturbation (SPP) scheme consisting of spatially and temporally varying perturbations of uncertain parameters in the Grell–Freitas convective scheme and the Mellor–Yamada–Nakanishi–Niino planetary boundary scheme was developed within the Rapid Refresh ensemble system based on the Weather Research and Forecasting Model. Al...

John M. Brown
Institutions National Center for Atmospheric Research - NCAR National Oceanic and Atmospheric Administration - NOAA

Radiance Preprocessing for Assimilation in the Hourly Updating Rapid Refresh Mesoscale Model: A Study Using AIRS Data

This study describes the initial application of radiance bias correction and channel selection in the hourly updated Rapid Refresh model. For this initial application, data from the Atmospheric Infrared Sounder (AIRS) are used; this dataset gives atmospheric temperature and water vapor information at higher vertical resolution and accuracy than ...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Diagnostic fields developed for hourly updated NOAA weather models

This document describes methods for diagnosing non-prognostic variables from explicit prognostic variables from hourly updated NOAA models. Many of these diagnostics have been developed for specific forecast applications for downstream forecast users over the years; these variables have been output from the Rapid Update Cycle (RUC) model prior t...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

A North American Hourly Assimilation and Model Forecast Cycle: The Rapid Refresh

The Rapid Refresh (RAP), an hourly-updated assimilation and model forecast system, replaced the Rapid Update Cycle (RUC) as an operational regional analysis and forecast system among the suite of models at the NOAA National Centers for Environmental Prediction (NCEP) in 2012. The need for an effective hourly-updated assimilation and modeling sys...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

A Vertically Flow-Following Icosahedral Grid Model for Medium-Range and Seasonal Prediction. Part I: Model Description

A hydrostatic global weather prediction model based on an icosahedral horizontal grid and a hybrid terrain-following/isentropic vertical coordinate is described. The model is an extension to three spatial dimensions of a previously developed, icosahedral, shallow-water model featuring user-selectable horizontal resolution and employing indirect ...

John M. Brown
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA

Expanding the High-Resolution Rapid Refresh (HRRR) from Deterministic to Ensemble Data Assimilation, Forecasts and Post-Processing

The 13-km Rapid Refresh (RAP) and 3-km convective-allowing High-Resolution Rapid Refresh (HRRR) are hourly updating weather forecast models that use a specially configured version of the Advanced Research WRF (ARW) model and assimilate many novel and most conventional observation types on an hourly basis using Gridpoint Statistical Interpolation...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Explicit Precipitation-Type Diagnosis from a Model Using a Mixed-Phase Bulk Cloud–Precipitation Microphysics Parameterization

The Rapid Refresh (RAP) and High-Resolution Rapid Refresh (HRRR), both operational at NOAA’s National Centers for Environmental Prediction (NCEP) use the Thompson et al. mixed-phase bulk cloud microphysics scheme. This scheme permits predicted surface precipitation to simultaneously consist of rain, snow, and graupel at the same location under c...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Implementation of a Digital Filter Initialization in the WRF Model and Its Application in the Rapid Refresh

Because of limitations of variational and ensemble data assimilation schemes, resulting analysis fields exhibit some noise from imbalance in subsequent model forecasts. Controlling finescale noise is desirable in the NOAA’s Rapid Refresh (RAP) assimilation/forecast system, which uses an hourly data assimilation cycle. Hence, a digital filter ini...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Modifications to the Rapid Update Cycle Land Surface Model (RUC LSM) Available in the Weather Research and Forecasting (WRF) Model

The land surface model (LSM) described in this manuscript was originally developed as part of the NOAA Rapid Update Cycle (RUC) model development effort; with ongoing modifications, it is now used as an option for the WRF community model. The RUC model and its WRF-based NOAA successor, the Rapid Refresh (RAP), are hourly updated and have an emph...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

Rap and HRRR Model/Assimilation System Improvements for Aviation Weather Applications: Latest Upgrades and Ongoing Work

An operational upgrade of the RAP and HRRR model systems at NCEP is planned for August 2016. This coordinated upgrade (RAP version 3 and HRRR version 2, RAPv3/HRRRv2) includes many enhancements to the data assimilation, model, and post-processing formulations that result in significant improvements to nearly all forecast aspects, including uppe...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

The Mesoscale Predictability Experiment (MPEX)

The Mesoscale Predictability Experiment (MPEX) was conducted from 15 May to 15 June 2013 in the central United States. MPEX was motivated by the basic question of whether experimental, subsynoptic observations can extend convective-scale predictability and otherwise enhance skill in short-term regional numerical weather prediction. Observatio...

John M. Brown
Institutions Earth System Research Laboratory - ESRL National Center for Atmospheric Research - NCAR National Oceanic and Atmospheric Administration - NOAA

The High-Resolution Rapid Refresh (HRRR): An Hourly Updating Convection-Allowing Forecast Model. Part 1: Motivation and System Description

The High-Resolution Rapid Refresh (HRRR) is a convection-allowing implementation of the Weather Research and Forecasting model (WRF-ARW) with hourly data assimilation that covers the conterminous United States and Alaska and runs in real time at the NOAA National Centers for Environmental Prediction. Implemented operationally at NOAA/NCEP in 201...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

The High-Resolution Rapid Refresh (HRRR): An Hourly Updating Convection-Allowing Forecast Model. Part 2: Forecast Performance

The High-Resolution Rapid Refresh (HRRR) is a convection-allowing implementation of the Advanced Weather Research and Forecast model (WRF-ARW) that covers the conterminous United States and Alaska and runs hourly (for CONUS; every three hours for Alaska) in real time at the National Centers for Environmental Prediction. The high-resolution forec...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

A Case Study Investigating the Low Summertime CAPE Behavior in the Global Forecast System

Convective available potential energy (CAPE) is an important index for storm forecasting. Recent versions (v15.2 and v16) of the Global Forecast System (GFS) predict lower values of CAPE during summertime in the continental United States than analysis and observation. We conducted an evaluation of the GFS in simulating summertime CAPE using an e...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA

The 30 December 2021 Colorado Front Range Windstorm and Marshall Fire: Evolution of Surface and 3D Structure, NWP Guidance, NWS Forecasts, and Decision Support

The Marshall Fire on 30 December 2021 became the most destructive wildfire costwise in Colorado history as it evolved into a suburban firestorm in southeastern Boulder County, driven by strong winds and a snow-free and drought-influenced fuel state. The fire was driven by a strong downslope windstorm that maintained its intensity for nearly 11 h...

John M. Brown
Institution National Oceanic and Atmospheric Administration - NOAA