Pub Date : 2023-02-17DOI: 10.15191/nwajom.2023.1102.
Anthony C. Bernal Ayala, Jordan J. Gerth, T. Schmit, S. Lindstrom, James P. Nelson
A parallax shift is a displacement in the apparent navigated position of a feature that arises because of its perspective from the viewing platform and is also a function of the feature height. For Geostationary Operational Environmental Satellite (GOES) imagery, this shift is especially apparent away from the satellite subpoint. Users should understand the degree of this shift when combining GOES Advanced Baseline Imager (ABI) imagery with other data, such as radar and lightning. However, it can be challenging, especially at spatial resolutions around the cloud/storm scale. This article explores parallax displacement for both uniform and computed cloud-top heights. Parallax shift will be shown using two case studies. The first case is from 7 September 2021, in which northern Illinois hailstorms are examined using ground-based Level II NEXRAD radar data, GOES-16 ABI imagery, and Geostationary Lightning Mapper data. The second case, on 9 April 2021, examines an eruption of the La Soufrière volcano on St. Vincent from the differing perspectives of GOES16 and -17. The discussion of these cases will show how parallax is an apparent displacement that will vary depending on what satellites are used for observation, where the phenomenon is with respect to the satellite, and the height of the phenomenon being analyzed. Newer satellite instruments with finer spatial resolutions and improved georeferencing will maximize data usability at more extreme angles and require users to account for the accompanying enhanced parallax shift. Even at lesser angles, parallax displacement is an important consideration for many meteorological and other applications.
{"title":"Parallax Shift in GOES ABI Data","authors":"Anthony C. Bernal Ayala, Jordan J. Gerth, T. Schmit, S. Lindstrom, James P. Nelson","doi":"10.15191/nwajom.2023.1102.","DOIUrl":"https://doi.org/10.15191/nwajom.2023.1102.","url":null,"abstract":"A parallax shift is a displacement in the apparent navigated position of a feature that arises because of its perspective from the viewing platform and is also a function of the feature height. For Geostationary Operational Environmental Satellite (GOES) imagery, this shift is especially apparent away from the satellite subpoint. Users should understand the degree of this shift when combining GOES Advanced Baseline Imager (ABI) imagery with other data, such as radar and lightning. However, it can be challenging, especially at spatial resolutions around the cloud/storm scale. This article explores parallax displacement for both uniform and computed cloud-top heights. Parallax shift will be shown using two case studies. The first case is from 7 September 2021, in which northern Illinois hailstorms are examined using ground-based Level II NEXRAD radar data, GOES-16 ABI imagery, and Geostationary Lightning Mapper data. The second case, on 9 April 2021, examines an eruption of the La Soufrière volcano on St. Vincent from the differing perspectives of GOES16 and -17. The discussion of these cases will show how parallax is an apparent displacement that will vary depending on what satellites are used for observation, where the phenomenon is with respect to the satellite, and the height of the phenomenon being analyzed. Newer satellite instruments with finer spatial resolutions and improved georeferencing will maximize data usability at more extreme angles and require users to account for the accompanying enhanced parallax shift. Even at lesser angles, parallax displacement is an important consideration for many meteorological and other applications.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48550406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-16DOI: 10.15191/nwajom.2023.1101
J. Ott, Matthew Stalley
Strong wind in the lower levels of the atmosphere near major airports can impact normal air traffic control (ATC) operations with respect to the horizontal spacing of aircraft. This is known in the ATC community as wind compression. Wind compression occurs when a strong wind from a specific direction and speed (at critical altitudes) impact normal ATC operations. The impact of wind compression becomes most noticeable when the spacing between aircraft decreases near or below minimal acceptable limits. Previous attempts to forecast wind compression have been unsuccessful. Wind shear calculations, time, height wind forecasts, and maximum winds below a certain altitude, such as 3050 m (10 000 ft), do not adequately convey the impact of wind compression. These methods are insufficient because they do not account for the flight profile of the numerous arrival routes that aircraft must travel to land at major airports. The Terminal Radar Approach Control (TRACON) Wind Compression Tool assists aviation forecasters in determining which arrival routes are impacted and the specific layers of the approach that are susceptible to wind compression. This program (1) diagnoses five different layers on an arrival route that may have potential wind compression impacts and (2) forecasts the onset and end of a compression event, the altitudes impacted, and the relative strength of the wind compression. Key information using the wind forecast from three National Weather Service models is condensed for each model hour and is placed into a timeline forecast.
{"title":"An Air Traffic Control Wind Compression Forecasting Tool for the TRACON Environment","authors":"J. Ott, Matthew Stalley","doi":"10.15191/nwajom.2023.1101","DOIUrl":"https://doi.org/10.15191/nwajom.2023.1101","url":null,"abstract":"Strong wind in the lower levels of the atmosphere near major airports can impact normal air traffic control (ATC) operations with respect to the horizontal spacing of aircraft. This is known in the ATC community as wind compression. Wind compression occurs when a strong wind from a specific direction and speed (at critical altitudes) impact normal ATC operations. The impact of wind compression becomes most noticeable when the spacing between aircraft decreases near or below minimal acceptable limits.\u0000Previous attempts to forecast wind compression have been unsuccessful. Wind shear calculations, time, height wind forecasts, and maximum winds below a certain altitude, such as 3050 m (10 000 ft), do not adequately convey the impact of wind compression. These methods are insufficient because they do not account for the flight profile of the numerous arrival routes that aircraft must travel to land at major airports.\u0000The Terminal Radar Approach Control (TRACON) Wind Compression Tool assists aviation forecasters in determining which arrival routes are impacted and the specific layers of the approach that are susceptible to wind compression. This program (1) diagnoses five different layers on an arrival route that may have potential wind compression impacts and (2) forecasts the onset and end of a compression event, the altitudes impacted, and the relative strength of the wind compression. Key information using the wind forecast from three National Weather Service models is condensed for each model hour and is placed into a timeline forecast.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47825286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-13DOI: 10.15191/nwajom.2022.1004
Todd A. Murphy, Tessa M. Stetzer, Lauren Walker, T. Fricker, Brad Bryant, C. Woodrum
On 12 April 2020, a tornadic quasi-linear convective system (QLCS) produced two EF-3 tornadoes in Ouachita Parish, Louisiana in close proximity to instrumentation operated by the University of Louisiana Monroe’s (ULM) Atmospheric Science program. In addition to the in situ environmental information, a high-resolution aerial damage survey was conducted by the ULM Unmanned Aerial Systems program. In this paper, these datasets are used to provide a comprehensive environmental and storm-scale analysis of the tornadic QLCS through northern Louisiana. In addition, we discuss the importance of aerial damage surveys, and how Doppler radar-derived tornado intensity estimates compared to the damage survey.
{"title":"Analysis of the 12 April 2020 Northern Louisiana Tornadic QLCS","authors":"Todd A. Murphy, Tessa M. Stetzer, Lauren Walker, T. Fricker, Brad Bryant, C. Woodrum","doi":"10.15191/nwajom.2022.1004","DOIUrl":"https://doi.org/10.15191/nwajom.2022.1004","url":null,"abstract":"On 12 April 2020, a tornadic quasi-linear convective system (QLCS) produced two EF-3 tornadoes in Ouachita Parish, Louisiana in close proximity to instrumentation operated by the University of Louisiana Monroe’s (ULM) Atmospheric Science program. In addition to the in situ environmental information, a high-resolution aerial damage survey was conducted by the ULM Unmanned Aerial Systems program. In this paper, these datasets are used to provide a comprehensive environmental and storm-scale analysis of the tornadic QLCS through northern Louisiana. In addition, we discuss the importance of aerial damage surveys, and how Doppler radar-derived tornado intensity estimates compared to the damage survey.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44727066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-28DOI: 10.15191/nwajom.2022.1003
N. Hampshire, T. Ryan, Chad Gravelle
Tornadoes in eastern Texas generally track to the east as predominant westerly upper flow acts on their parent storms. However, an examination of tornadoes from 2000 to 2018 finds that 22% of all tornadoes in the region move in much more northward directions. These tornadoes’ parent storms develop in the open warm sector prior to the arrival of a main linear forcing mechanism (e.g., front, dryline). In fact, some of the more notable tornado outbreaks in recent years across Texas have occurred from northward-moving thunderstorms. This bifurcation of storm/tornado motions is important to understand for forecasting, warning, and messaging of these events. The results show these tornadoes typically occur eastward of large, slow moving, mid to upper-level long-wave troughs and underneath the left quadrant exit-region of an upper-level jet streak. The composite pattern also shows that a low-level jet in eastern Texas, a surface low centered in west-central Texas, and a warm/stationary front extending northeast of the surface low were common for these events. The typical air mass was indicative of weak instability, low convective inhibition, and high shear. Radar analysis of the northerly moving, tornadic storms showed mesocyclonic circulations with smaller diameters and lower rotational shear when compared with tornadic storms that moved in an easterly direction.
{"title":"An Analysis of Northward-Moving Tornadoes within an Open Warm Sector Across Eastern Texas","authors":"N. Hampshire, T. Ryan, Chad Gravelle","doi":"10.15191/nwajom.2022.1003","DOIUrl":"https://doi.org/10.15191/nwajom.2022.1003","url":null,"abstract":"Tornadoes in eastern Texas generally track to the east as predominant westerly upper flow acts on their parent storms. However, an examination of tornadoes from 2000 to 2018 finds that 22% of all tornadoes in the region move in much more northward directions. These tornadoes’ parent storms develop in the open warm sector prior to the arrival of a main linear forcing mechanism (e.g., front, dryline). In fact, some of the more notable tornado outbreaks in recent years across Texas have occurred from northward-moving thunderstorms. This bifurcation of storm/tornado motions is important to understand for forecasting, warning, and messaging of these events. The results show these tornadoes typically occur eastward of large, slow moving, mid to upper-level long-wave troughs and underneath the left quadrant exit-region of an upper-level jet streak. The composite pattern also shows that a low-level jet in eastern Texas, a surface low centered in west-central Texas, and a warm/stationary front extending northeast of the surface low were common for these events. The typical air mass was indicative of weak instability, low convective inhibition, and high shear. Radar analysis of the northerly moving, tornadic storms showed mesocyclonic circulations with smaller diameters and lower rotational shear when compared with tornadic storms that moved in an easterly direction.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47208494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-18DOI: 10.15191/nwajom.2022.1002
Matthew Anderson, D. Schneider, Jeremy L. Buckles, D. Bodine, A. Reinhart, Martin A. Satrio, T. Maruyama
Storm-scale interactions with rough terrain are complex. Terrain has been theorized to impact the strength of low-level mesocyclones. Surface roughness and modifications of the surrounding environment also may impact tornadogenesis or tornado intensity. The Mountainburg, Arkansas EF2 tornado on 13 April 2018 traveled along a path with minor variations in intensity and elevation throughout most of the nearly 19-km (11.8 mi) damage path as the storm moved along a river valley. A detailed damage survey showed that the tornado then made an abrupt ascent of more than 200 m (656 ft) in the last 2 km (1.2 mi) before dissipating. By examining model soundings and conducting a detailed terrain analysis, this study examines what role terrain may have had in channeling the momentum surge and enhancing the low-level vorticity to influence tornadogenesis. Other storm-scale factors are investigated to determine their potential impact on the demise of the tornado. The differential reflectivity column is studied to determine if the updraft was weakening. The relative position of the tornado and mesocyclone also are examined as the tornado ascended the terrain and dissipated to determine whether the change in elevation impacted the overall strength of the storm and to evaluate whether the storm was undergoing a traditional occlusion cycle. Finally, a large-eddy simulation model is used to explore physical changes in a tornado encountering terrain similar to the Mountainburg, Arkansas, tornado near its demise.
{"title":"Terrain Effects on the 13 April 2018 Mountainburg, Arkansas EF2 Tornado","authors":"Matthew Anderson, D. Schneider, Jeremy L. Buckles, D. Bodine, A. Reinhart, Martin A. Satrio, T. Maruyama","doi":"10.15191/nwajom.2022.1002","DOIUrl":"https://doi.org/10.15191/nwajom.2022.1002","url":null,"abstract":"Storm-scale interactions with rough terrain are complex. Terrain has been theorized to impact the strength of low-level mesocyclones. Surface roughness and modifications of the surrounding environment also may impact tornadogenesis or tornado intensity. The Mountainburg, Arkansas EF2 tornado on 13 April 2018 traveled along a path with minor variations in intensity and elevation throughout most of the nearly 19-km (11.8 mi) damage path as the storm moved along a river valley. A detailed damage survey showed that the tornado then made an abrupt ascent of more than 200 m (656 ft) in the last 2 km (1.2 mi) before dissipating. By examining model soundings and conducting a detailed terrain analysis, this study examines what role terrain may have had in channeling the momentum surge and enhancing the low-level vorticity to influence tornadogenesis. Other storm-scale factors are investigated to determine their potential impact on the demise of the tornado. The differential reflectivity column is studied to determine if the updraft was weakening. The relative position of the tornado and mesocyclone also are examined as the tornado ascended the terrain and dissipated to determine whether the change in elevation impacted the overall strength of the storm and to evaluate whether the storm was undergoing a traditional occlusion cycle. Finally, a large-eddy simulation model is used to explore physical changes in a tornado encountering terrain similar to the Mountainburg, Arkansas, tornado near its demise.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49635746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-04DOI: 10.15191/nwajom.2022.1001
A. Ellis, S. Keighton, Stephanie E. Zick, Andrew S. Shearer, Casey E. Hockenbury, Anita Silverman
Winter mixed-precipitation events across the mid-Atlantic region of the United States from 2013–2014 through 2018–2019 were used to analyze common short-term model forecasts of vertical atmospheric thermal structure. Using saturated forecast soundings of the North American Mesoscale (NAM), higher-resolution nested NAM (NAMnest), and the Rapid Refresh models—corresponding with observed warm-nose precipitation events (WNPEs)—several thermal metrics formed the basis of the analysis of observed and forecast soundings, including Bourgouin positive and negative areas. While the three models accurately forecast the general thermal structure well during WNPEs, a warm bias is evident within each. Well forecast are maximum and minimum temperatures within the warm nose and surface-based cold layer, respectively, but the cold layer is commonly too thin for each of the models, and the warm nose is regularly too thick, particularly within NAM and NAMnest forecasts. Forecasts of a cold layer that is too shallow tend to coincide with observations of stronger synoptic-scale upward motion, a deeper cold surface-based layer, and a higher isentropic surface. Forecasts of a warm nose that is too thick tend to coincide with observations of weaker upward motion, a shallower cold surface-based layer, and a lower isentropic surface across the region. Two-thirds of precipitation-type estimates from model soundings agreed with those derived from observed soundings, with the remaining third predominantly representing a warm bias in precipitation type.
{"title":"Analysis of Model Thermal Profile Forecasts Associated with Winter Mixed Precipitation within the United States Mid-Atlantic Region","authors":"A. Ellis, S. Keighton, Stephanie E. Zick, Andrew S. Shearer, Casey E. Hockenbury, Anita Silverman","doi":"10.15191/nwajom.2022.1001","DOIUrl":"https://doi.org/10.15191/nwajom.2022.1001","url":null,"abstract":"Winter mixed-precipitation events across the mid-Atlantic region of the United States from 2013–2014 through 2018–2019 were used to analyze common short-term model forecasts of vertical atmospheric thermal structure. Using saturated forecast soundings of the North American Mesoscale (NAM), higher-resolution nested NAM (NAMnest), and the Rapid Refresh models—corresponding with observed warm-nose precipitation events (WNPEs)—several thermal metrics formed the basis of the analysis of observed and forecast soundings, including Bourgouin positive and negative areas. While the three models accurately forecast the general thermal structure well during WNPEs, a warm bias is evident within each. Well forecast are maximum and minimum temperatures within the warm nose and surface-based cold layer, respectively, but the cold layer is commonly too thin for each of the models, and the warm nose is regularly too thick, particularly within NAM and NAMnest forecasts. Forecasts of a cold layer that is too shallow tend to coincide with observations of stronger synoptic-scale upward motion, a deeper cold surface-based layer, and a higher isentropic surface. Forecasts of a warm nose that is too thick tend to coincide with observations of weaker upward motion, a shallower cold surface-based layer, and a lower isentropic surface across the region. Two-thirds of precipitation-type estimates from model soundings agreed with those derived from observed soundings, with the remaining third predominantly representing a warm bias in precipitation type.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46614673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-09DOI: 10.15191/nwajom.2021.0908
B. Holloway
Coastal flooding occurs when saltwater inundates normally dry land and the resulting impacts can range from minor flooding of low-lying areas along the coast, to significant damage to property and structures. Previous research consistently suggests that if sea-level rise continues to increase along the East Coast of the United States, coastal flooding will occur more frequently. In order to document the history of coastal flooding along the southeastern Georgia and southeastern South Carolina coast, a coastal flood event database was created for National Ocean Service tide gauges located in Charleston Harbor, South Carolina and Fort Pulaski, Georgia. Trends from the data show that coastal flooding is occurring more frequently with time at both tide gauges, particularly over the last five to ten years. Because of the increased frequency and worsening impacts of tidal flooding, a tide forecast tool is implemented operationally in an effort to improve deterministic tide forecasts. This study extends the dataset used in the Charleston Harbor forecast tool, expands the tool to Fort Pulaski, and compares the synoptic category forecast equations to an all-inclusive equation that does not differentiate by synoptic category. Results show that there is virtually no difference in the forecast accuracy between the all-inclusive forecast equation and the specific forecast equations based on synoptic category. Furthermore, the all-inclusive forecast equation can be implemented operationally, will help improve deterministic tide forecasts, and will likely aid in the decision-making process for Coastal Flood Watches, Warnings, and Advisories issued by the National Weather Service office in Charleston, South Carolina.
{"title":"A Coastal Flood Event Database for the Southeastern Georgia and Southeastern South Carolina Coast and the Operational Implementation of a Tide Forecast Tool","authors":"B. Holloway","doi":"10.15191/nwajom.2021.0908","DOIUrl":"https://doi.org/10.15191/nwajom.2021.0908","url":null,"abstract":"Coastal flooding occurs when saltwater inundates normally dry land and the resulting impacts can range from minor flooding of low-lying areas along the coast, to significant damage to property and structures. Previous research consistently suggests that if sea-level rise continues to increase along the East Coast of the United States, coastal flooding will occur more frequently. In order to document the history of coastal flooding along the southeastern Georgia and southeastern South Carolina coast, a coastal flood event database was created for National Ocean Service tide gauges located in Charleston Harbor, South Carolina and Fort Pulaski, Georgia. Trends from the data show that coastal flooding is occurring more frequently with time at both tide gauges, particularly over the last five to ten years. Because of the increased frequency and worsening impacts of tidal flooding, a tide forecast tool is implemented operationally in an effort to improve deterministic tide forecasts. This study extends the dataset used in the Charleston Harbor forecast tool, expands the tool to Fort Pulaski, and compares the synoptic category forecast equations to an all-inclusive equation that does not differentiate by synoptic category. Results show that there is virtually no difference in the forecast accuracy between the all-inclusive forecast equation and the specific forecast equations based on synoptic category. Furthermore, the all-inclusive forecast equation can be implemented operationally, will help improve deterministic tide forecasts, and will likely aid in the decision-making process for Coastal Flood Watches, Warnings, and Advisories issued by the National Weather Service office in Charleston, South Carolina.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44396749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-10DOI: 10.15191/nwajom.2021.0907
Zoey Rosen, Makenzie J. Krocak, J. Ripberger, Rachael N. Cross, Emily D. Lenhardt, Carol L. Silva, H. Jenkins‐Smith
Forecasters are responsible for predicting the weather and communicating risk with stakeholders and members of the public. This study investigates the statements that forecasters use to communicate probability information in hurricane forecasts and the impact these statements may have on how members of the public evaluate forecast reliability. We use messages on Twitter to descriptively analyze probability statements in forecasts leading up to Hurricanes Harvey, Irma, Maria, and Florence from forecasters in three different groups: the National Hurricane Center, local Weather Forecast Offices, and in the television broadcast community. We then use data from a representative survey of United States adults to assess how members of the public wish to receive probability information and the impact of information format on assessments of forecast reliability. Results from the descriptive analysis indicate forecasters overwhelmingly use words and phrases in place of numbers to communicate probability information. In addition, the words and phrases forecasters use are generally vague in nature -- they seldom include rank adjectives (e.g., “low” or “high”) to qualify blanket expressions of uncertainty (e.g., “there is a chance of flooding”). Results from the survey show members of the public generally prefer both words/phrases and numbers when receiving forecast information. They also show information format affects public judgments of forecast reliability; on average, people believe forecasts are more reliable when they include numeric probability information.
{"title":"Communicating Probability Information in Hurricane Forecasts: Assessing Statements that Forecasters Use on Social Media and Implications for Public Assessments of Reliability","authors":"Zoey Rosen, Makenzie J. Krocak, J. Ripberger, Rachael N. Cross, Emily D. Lenhardt, Carol L. Silva, H. Jenkins‐Smith","doi":"10.15191/nwajom.2021.0907","DOIUrl":"https://doi.org/10.15191/nwajom.2021.0907","url":null,"abstract":"Forecasters are responsible for predicting the weather and communicating risk with stakeholders and members of the public. This study investigates the statements that forecasters use to communicate probability information in hurricane forecasts and the impact these statements may have on how members of the public evaluate forecast reliability. We use messages on Twitter to descriptively analyze probability statements in forecasts leading up to Hurricanes Harvey, Irma, Maria, and Florence from forecasters in three different groups: the National Hurricane Center, local Weather Forecast Offices, and in the television broadcast community. We then use data from a representative survey of United States adults to assess how members of the public wish to receive probability information and the impact of information format on assessments of forecast reliability. Results from the descriptive analysis indicate forecasters overwhelmingly use words and phrases in place of numbers to communicate probability information. In addition, the words and phrases forecasters use are generally vague in nature -- they seldom include rank adjectives (e.g., “low” or “high”) to qualify blanket expressions of uncertainty (e.g., “there is a chance of flooding”). Results from the survey show members of the public generally prefer both words/phrases and numbers when receiving forecast information. They also show information format affects public judgments of forecast reliability; on average, people believe forecasts are more reliable when they include numeric probability information.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49111192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-01DOI: 10.15191/nwajom.2021.0906
M. Splitt, Morgan Hennard, Pierre Bougeard
Understanding barriers to submitting pilot weather reports (PIREPs) has been the focus of recent attention in the general aviation community. The goal is to help increase the submission frequency of these reports, which are valuable for aviation operations and situational awareness. Additionally, the perception of the quality of these reports by pilots can impact the level of trust users have in the data. This study aims to evaluate aspects of the reporting frequency and quality of PIREPs particularly from the general aviation perspective. PIREPs were subjected to a range of logical, qualitative, and quantitative tests. Commercial applications are shown to improve the data quantity transmitted in the reports, particularly the non-mandatory sections such as sky and weather conditions, as well as to help alleviate some of the transcription errors. Reported times of the PIREPs indicate impacts from rounding that may limit the utility of the data in some instances. Analysis of individual geophysical measurements show varying quality with potential gaps noted in the icing type assessment and a bias towards higher turbulence intensity reporting, though air temperature compares well to independent data.
{"title":"Survey of General Aviation Pilot Reports (PIREPs) Conformity, Consistency, and Quality","authors":"M. Splitt, Morgan Hennard, Pierre Bougeard","doi":"10.15191/nwajom.2021.0906","DOIUrl":"https://doi.org/10.15191/nwajom.2021.0906","url":null,"abstract":"Understanding barriers to submitting pilot weather reports (PIREPs) has been the focus of recent attention in the general aviation community. The goal is to help increase the submission frequency of these reports, which are valuable for aviation operations and situational awareness. Additionally, the perception of the quality of these reports by pilots can impact the level of trust users have in the data. This study aims to evaluate aspects of the reporting frequency and quality of PIREPs particularly from the general aviation perspective. PIREPs were subjected to a range of logical, qualitative, and quantitative tests. Commercial applications are shown to improve the data quantity transmitted in the reports, particularly the non-mandatory sections such as sky and weather conditions, as well as to help alleviate some of the transcription errors. Reported times of the PIREPs indicate impacts from rounding that may limit the utility of the data in some instances. Analysis of individual geophysical measurements show varying quality with potential gaps noted in the icing type assessment and a bias towards higher turbulence intensity reporting, though air temperature compares well to independent data.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41580945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-03DOI: 10.15191/nwajom.2021.0905
J. Gibbs
Tornadoes produced by quasi-linear convective systems (QLCS) present a significant challenge to National Weather Service warning operations. Given the speed and scale at which they develop, different methods for tornado warning decision making are required than what traditionally are used for supercell storms. This study evaluates the skill of one of those techniques—the so-called three-ingredients method—and produces new approaches. The three-ingredients method is found to be reasonably skillful at short lead times, particularly for systems that are clearly linear. From the concepts and science of the three-ingredients method, several new combinations of environmental and radar parameters emerge that appear slightly more skillful, and may prove easier to execute in real time. Similar skill between the emerging methods provides the forecaster with options for what might work best in any given scenario. A moderate positive correlation with overall wind speed with some radar and environmental variables also is identified. Additionally, mesoscale convective vortices and supercell-like features in QLCS are found to produce tornadoes at a much higher rate than purely linear systems.
{"title":"Evaluating Precursor Signals for QLCS Tornado and Higher Impact Straight-Line Wind Events","authors":"J. Gibbs","doi":"10.15191/nwajom.2021.0905","DOIUrl":"https://doi.org/10.15191/nwajom.2021.0905","url":null,"abstract":"Tornadoes produced by quasi-linear convective systems (QLCS) present a significant challenge to National Weather Service warning operations. Given the speed and scale at which they develop, different methods for tornado warning decision making are required than what traditionally are used for supercell storms. This study evaluates the skill of one of those techniques—the so-called three-ingredients method—and produces new approaches. The three-ingredients method is found to be reasonably skillful at short lead times, particularly for systems that are clearly linear. From the concepts and science of the three-ingredients method, several new combinations of environmental and radar parameters emerge that appear slightly more skillful, and may prove easier to execute in real time. Similar skill between the emerging methods provides the forecaster with options for what might work best in any given scenario. A moderate positive correlation with overall wind speed with some radar and environmental variables also is identified. Additionally, mesoscale convective vortices and supercell-like features in QLCS are found to produce tornadoes at a much higher rate than purely linear systems.","PeriodicalId":44039,"journal":{"name":"Journal of Operational Meteorology","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46562055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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