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- Author or Editor: Jonathan Blaes x
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Abstract
In this study, several analyses were conducted that were aimed at improving sustained wind speed and gust forecasts for tropical cyclones (TCs) affecting coastal regions. An objective wind speed forecast analysis of recent TCs affecting the mid-Atlantic region was first conducted to set a benchmark for improvement. Forecasts from the National Digital Forecast Database were compared to observations and surface wind analyses in the region. The analysis suggests a general overprediction of sustained wind speeds, especially for areas affected by the strongest winds. Currently, National Weather Service Weather Forecast Offices use a software tool known as the Tropical Cyclone Forecast/Advisory (TCM) wind tool (TCMWindTool) to develop their wind forecast grids. The tool assumes linear decay in the sustained wind speeds when interpolating the National Hurricane Center 12–24-hourly TCM product to hourly grids. An analysis of postlandfall wind decay for recent TCs was conducted to evaluate this assumption. Results indicate that large errors in the forecasted wind speeds can emerge, especially for stronger storms. Finally, an analysis of gust factors for recent TCs affecting the region was conducted. Gust factors associated with weak sustained wind speeds are shown to be highly variable but average around 1.5. The gust factors decrease to values around 1.2 for wind speeds above 40 knots (kt; 1 kt = 0.51 m s−1) and are in general insensitive to the wind direction, suggesting local rather than upstream surface roughness largely dictates the gust factor at a given location. Forecasters are encouraged to increase land reduction factors used in the TCMWindTool and to modify gust factors to account for factors including the sustained wind speed and local surface roughness.
Abstract
In this study, several analyses were conducted that were aimed at improving sustained wind speed and gust forecasts for tropical cyclones (TCs) affecting coastal regions. An objective wind speed forecast analysis of recent TCs affecting the mid-Atlantic region was first conducted to set a benchmark for improvement. Forecasts from the National Digital Forecast Database were compared to observations and surface wind analyses in the region. The analysis suggests a general overprediction of sustained wind speeds, especially for areas affected by the strongest winds. Currently, National Weather Service Weather Forecast Offices use a software tool known as the Tropical Cyclone Forecast/Advisory (TCM) wind tool (TCMWindTool) to develop their wind forecast grids. The tool assumes linear decay in the sustained wind speeds when interpolating the National Hurricane Center 12–24-hourly TCM product to hourly grids. An analysis of postlandfall wind decay for recent TCs was conducted to evaluate this assumption. Results indicate that large errors in the forecasted wind speeds can emerge, especially for stronger storms. Finally, an analysis of gust factors for recent TCs affecting the region was conducted. Gust factors associated with weak sustained wind speeds are shown to be highly variable but average around 1.5. The gust factors decrease to values around 1.2 for wind speeds above 40 knots (kt; 1 kt = 0.51 m s−1) and are in general insensitive to the wind direction, suggesting local rather than upstream surface roughness largely dictates the gust factor at a given location. Forecasters are encouraged to increase land reduction factors used in the TCMWindTool and to modify gust factors to account for factors including the sustained wind speed and local surface roughness.
Abstract
Nearly 100 North Carolina State University (NCSU) students have participated in a unique, highly structured internship course conducted by the National Weather Service (NWS) Weather Forecast Office (WFO) in Raleigh, North Carolina. Here, we explore the impact that this course has had on their professional development and career trajectories. As of this writing, the course has been running for 17 years; this paper provides an update on how the course has changed over time, and information concerning participant outcomes. Changes include a reduction in class size to allow for more individualized mentoring, and the addition of experiences outside of the WFO. The course serves as a compelling selling point in student recruiting for the Department of Marine, Earth, and Atmospheric Sciences (MEAS), and participation also helps to ensure that the curriculum is adequately preparing students for positions in the NWS. The NWS benefits from a pool of potential employees that will require less spin-up time if hired; additionally, some NCSU graduates have participated in similar student volunteer programs at their respective offices once hired.
Abstract
Nearly 100 North Carolina State University (NCSU) students have participated in a unique, highly structured internship course conducted by the National Weather Service (NWS) Weather Forecast Office (WFO) in Raleigh, North Carolina. Here, we explore the impact that this course has had on their professional development and career trajectories. As of this writing, the course has been running for 17 years; this paper provides an update on how the course has changed over time, and information concerning participant outcomes. Changes include a reduction in class size to allow for more individualized mentoring, and the addition of experiences outside of the WFO. The course serves as a compelling selling point in student recruiting for the Department of Marine, Earth, and Atmospheric Sciences (MEAS), and participation also helps to ensure that the curriculum is adequately preparing students for positions in the NWS. The NWS benefits from a pool of potential employees that will require less spin-up time if hired; additionally, some NCSU graduates have participated in similar student volunteer programs at their respective offices once hired.
Abstract
Recent research has improved our knowledge and forecasting of high-shear, low-CAPE (HSLC) severe convection, which produces a large fraction of overnight and cool season tornadoes. However, limited near-storm observations have hindered progress in our understanding of HSLC environments and detection of severe potential within them. This article provides an overview of a research project in central North Carolina aimed toward increasing the number of observations in the vicinity of severe and nonsevere HSLC convection. Particularly unique aspects of this project are a) leadership by student volunteers from a university sounding club and b) real-time communication of observations to local National Weather Service Forecast Offices. In addition to an overview of sounding operations and goals, two case examples are provided that support the potential utility of supplemental sounding observations for operational, educational, and research purposes.
Abstract
Recent research has improved our knowledge and forecasting of high-shear, low-CAPE (HSLC) severe convection, which produces a large fraction of overnight and cool season tornadoes. However, limited near-storm observations have hindered progress in our understanding of HSLC environments and detection of severe potential within them. This article provides an overview of a research project in central North Carolina aimed toward increasing the number of observations in the vicinity of severe and nonsevere HSLC convection. Particularly unique aspects of this project are a) leadership by student volunteers from a university sounding club and b) real-time communication of observations to local National Weather Service Forecast Offices. In addition to an overview of sounding operations and goals, two case examples are provided that support the potential utility of supplemental sounding observations for operational, educational, and research purposes.
The objective of the Coastal and Inland Flooding Observation and Warning (CI-FLOW) project is to prototype new hydrometeorologic techniques to address a critical NOAA service gap: routine total water level predictions for tidally influenced watersheds. Since February 2000, the project has focused on developing a coupled modeling system to accurately account for water at all locations in a coastal watershed by exchanging data between atmospheric, hydrologic, and hydrodynamic models. These simulations account for the quantity of water associated with waves, tides, storm surge, rivers, and rainfall, including interactions at the tidal/surge interface.
Within this project, CI-FLOW addresses the following goals: i) apply advanced weather and oceanographic monitoring and prediction techniques to the coastal environment; ii) prototype an automated hydrometeorologic data collection and prediction system; iii) facilitate interdisciplinary and multiorganizational collaborations; and iv) enhance techniques and technologies that improve actionable hydrologic/hydrodynamic information to reduce the impacts of coastal flooding. Results are presented for Hurricane Isabel (2003), Hurricane Earl (2010), and Tropical Storm Nicole (2010) for the Tar–Pamlico and Neuse River basins of North Carolina. This area was chosen, in part, because of the tremendous damage inflicted by Hurricanes Dennis and Floyd (1999). The vision is to transition CI-FLOW research findings and technologies to other U.S. coastal watersheds.
The objective of the Coastal and Inland Flooding Observation and Warning (CI-FLOW) project is to prototype new hydrometeorologic techniques to address a critical NOAA service gap: routine total water level predictions for tidally influenced watersheds. Since February 2000, the project has focused on developing a coupled modeling system to accurately account for water at all locations in a coastal watershed by exchanging data between atmospheric, hydrologic, and hydrodynamic models. These simulations account for the quantity of water associated with waves, tides, storm surge, rivers, and rainfall, including interactions at the tidal/surge interface.
Within this project, CI-FLOW addresses the following goals: i) apply advanced weather and oceanographic monitoring and prediction techniques to the coastal environment; ii) prototype an automated hydrometeorologic data collection and prediction system; iii) facilitate interdisciplinary and multiorganizational collaborations; and iv) enhance techniques and technologies that improve actionable hydrologic/hydrodynamic information to reduce the impacts of coastal flooding. Results are presented for Hurricane Isabel (2003), Hurricane Earl (2010), and Tropical Storm Nicole (2010) for the Tar–Pamlico and Neuse River basins of North Carolina. This area was chosen, in part, because of the tremendous damage inflicted by Hurricanes Dennis and Floyd (1999). The vision is to transition CI-FLOW research findings and technologies to other U.S. coastal watersheds.
