Oceanography and Atmospheric Sciences and Meteorology Commons^™

Evaluation Of Windninja Simulations In Canyons And Complex Terrain, Marc Buchs

Master's Theses

This study describes a validation of the surface wind model WindNinja conducted over different types of complex terrain. WindNinja is one of many software tools first responders use to better understand wind flow over such terrain. One approach to receive a higher resolution wind field to account for local terrain effects is to downscale numerical weather prediction model output with the help of WindNinja. 2 km resolution Weather Research and Forecasting model (WRF) output was used as input for our WindNinja simulations. We tested the surface wind model for two case sites in California characterized by canyons of different terrain …

Interactions Between A High Intensity Wildfire And An Atmopsheric Hydraulic Jump In The Case Of The 2023 Lahaina Fire, Clifford Dw Ehrke

Master's Theses

On 8 August 2023, a grass fire that started in the city of Lahaina, Hawai’i, grew into the deadliest wildfire in the United States since 1918. This wildfire offers a unique opportunity to explore the impact of high heat output on an atmospheric hydraulic jump and a downslope wind event. We conducted two WRF-SFIRE simulations to investigate these effects: one incorporating fire–atmosphere feedback and the other without it. We compare these WRF-SFIRE simulations to all available data regarding the fire event, including high resolution satellite data, weather station data from other parts of Maui and the Hawaiian Archipelago, and official …

A Uas-Centered Investigation Of Vorticity Characteristics And Cold Pool Structure Across Forward And Left-Flank Boundaries In Supercells, Mark R. De Bruin

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Supercell internal boundaries are the locus of tornadogenesis; thus, understanding the characteristics of these boundaries, particularly in terms of vorticity, is important for identifying the role they play in tornado formation. Insight into the overall characteristics of internal boundaries and their possible role in tornadogenesis have been driven by studies reliant on numerical modeling-based experiments. Observational studies often neglect above-surface conditions or, when these observations are made, lack the spatial resolution to resolve boundary characteristics. During TORUS (Targeted Observation by Radars and UAS of Supercells) 2019 and TORUS-LItE (TORUS Left-flank Intensive Experiment) 2023, uncrewed aircraft systems (UAS) and mobile mesonets …

2025 July - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

Hi All,

The main story for July was the high heat and humidity that spread across the state for the second half of the month. Most counties in the state saw at least 1 day with a heat advisory or extreme heat warning issued by the National Weather Service due to a combination of high temperatures and humidity that sent heat index values above advisory/warning criteria. The western half of the state saw higher heat index values and were impacted by the heat wave for a longer period of time than the eastern half of the state. Some part of …

Influence Of Tropical Cyclones, Southwest Monsoon, And Tropical Cyclone-Enhanced Southwest Monsoon On Rainfall Variability Over The Western Coast Of The Philippines, Alwin Bathan, Lyndon Mark Olaguera, Faye Abigail T. Cruz, Jose Ramon T. Villarin, Joel T. Maquiling, Maria Obiminda L. Cambaliza, John A. Manalo, Jun Matsumoto

SOSE Affiliate: Manila Observatory

This study investigates the processes driving interannual variability of rainfall over the western coast of the Philippines during the peak southwest monsoon (SWM) months (July–September) from 1961 to 2022. Specifically, it describes how tropical cyclones (TC), SWM, and TC-enhanced SWM influence SWM rainfall variability. Rainfall measurements from 11 stations along the western coast of the Philippines were classified into three types: direct TC rainfall (PD), indirect TC rainfall (PI), and SWM rainfall (PSM). The yearly contributions of PD, PI, and PSM to SWM rainfall were estimated to be 15.4 %, 33.1 %, and 51.5 %, respectively. Furthermore, four rainfall variability …

2025 June - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

Hi All,

The main story of June 2025 was the first major heat wave of the year that sent temperatures into the mid-to-upper 90’s and heat index values over 100°F for most locations in the state from June 22nd to 28th. This included the first day of the year with a high over 90°F for many parts of the state. The National Weather Service offices covering Tennessee issued heat advisories for most counties in the state for at least 1 day during this period and several areas of West and Middle Tennessee had multiple days in a row with these …

Simulations Of Differential Reflectivity Columns In Quasi-Linear Convective Systems, Devon Jacob Healey

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Much research over the past decade has revealed that dual-polarization radar is a powerful tool in furthering our understanding of severe storm dynamics and subsequently improving warning strategies for these hazardous events. However, there are currently very few studies examining a particularly prolific severe convective storm mode with dual-polarization radar: quasi-linear convective systems (QLCSs). These storms can occur in any season of the year throughout most of the contiguous United States and can have immense societal impacts. Warning for the hazards produced by QLCSs is currently a significant operational challenge, therefore, research is needed to see if applying dual-polarization radar …

Investigating The Role Of Aerosols In Extreme Precipitation Events Along The Gulf Coast Of The U.S.A., Wenjia Cao

LSU Doctoral Dissertations

Atmospheric aerosols have been found to influence tropical cyclone (TC) and flood event development. In this study, the Weather Research and Forecasting model is applied to investigate specific microphysical impacts and aerosol sensitivity to heavy precipitation and TC events in the U.S. Gulf Coastal area. The Thompson aerosol-aware scheme with regular and adjusted aerosol concentration scenarios is used to quantify precipitation, wind field, horizontal/vertical structures, and track variations, by aerosol mixing ratio. In general, results for the three storms analyzed (the 2016 Baton Rouge, Louisiana, flood event (Chapter 2); Hurricane Harvey in 2017 (Chapter 3); and an idealized storm event …

Estimating The Future Frequency Of Bonnet Carré Spillway Openings, Kayla Thomas

LSU Master's Theses

In the 2010s, the Bonnet Carré Spillway (BCS) in southeastern Louisiana, U.S.A., experienced an unprecedented uptick in openings to mitigate the possibility of flooding, including a record double-opening in 2019. Both the environmental consequences of BCS openings associated with nutrients that run from the Mississippi River into Lake Pontchartrain and the synoptic-scale meteorological conditions that necessitate these openings are poorly understood. With the unexpectedly frequent openings in recent years and the ever-present threat of climate change, it is vital to consider the future shift of synoptic-scale climate patterns and how it can relate to BCS openings. Understanding the potential for …

An Investigation Into The Inclusivity, Methodology, And Education Of Severe Weather In K-12 Schools, Stephen Holden Wooten

Theses and Dissertations

Schools are a focal point in the lives of everyone in the community, especially teachers, parents, and students. Investigating the connection between these individuals and tornadoes by identifying shortcomings in education, training, and emergency procedures can induce more effective and informed decision-making for future encounters. This study evaluated the inclusivity of tornado protocols for students with disabilities, uncovered where parents prefer their child to shelter in early dismissal situations and clarified how extensively natural hazard education and tornado drills are covered in schools. Two surveys and semi-structured interviews were used to obtain responses from earth science teachers, K-12 guardians, and …

Atmospheric Turbulence Education Effects On Flight Anxiety, Megan A. Hanna

Theses and Dissertations

This study examines the effect of turbulence education on flight anxiety. A pre-post methodology measured students’ anxiety levels before and after a study abroad flight, using an educational video during the pre-flight survey to change their feelings. The Flight Anxiety Situations (FAS) questionnaire assessed anxiety at three survey points: pre-video, post-video, and post-flight. Qualitative analysis using Friedman’s test and the Wilcoxon Signed-rank test, indicated that turbulence education effectively decreased generalized and anticipatory flight anxiety, particularly in non-phobic students. Text analysis of open-ended responses suggested increased scientific knowledge post-video helped students apply technical atmospheric processes to their feelings. Turbulence education was …

Evaluating Rainfall Sensitivity Over Land To Tropical Cyclone Parameters Using Idealized Wrf, Madison C. Yawn

Theses and Dissertations

Tropical cyclones (TCs) are extreme weather events impacting the United States nearly every year. These events often cause severe damage due to the associated responses they produce including storm surge and rainfall, and the accurate estimation of these TC hazards is necessary to support coastal engineering, risk assessment, and emergency management activities. Evaluating TC-driven hazards is often done in combination with numerical models to simulate how environmental interactions alter the physical processes and responses of these storms. The purpose of this study was to simulate synthetic TC events using the Advanced Weather Research and Forecasting (WRF) model to understand how …

Real-Time Enhanced Tornado Warning Product Guidance Based On Tornado Debris Signature Height And Population Density, Alexander Cooke

Theses and Dissertations

This research aims to develop an operational program for enhancing real-time tornado warning capabilities by integrating tornado debris signature (TDS) analysis with population impact assessment. The proposed Python-based tool will ingest Level II radar data to identify and analyze TDS, estimating tornado intensity based on maximum TDS height. For high-intensity tornadoes, the program will project the potential impact area using storm motion vectors and integrate this with population density data. The system will assess whether the situation meets National Weather Service criteria for enhanced warning products, providing forecasters with rapid, objective guidance for critical warning decisions. The program’s performance will …

Influence Of Horizontal Grid Spacing On Numerical Weather Prediction Simulations Of Clear Air Turbulence, Kailah Rose Gordon

Theses and Dissertations

The focus of this research was to analyze the influence of horizontal grid spacing on numerical simulations of kinetic and thermal forced clear air turbulence (CAT) by quantifying uncertainty using a resolution ensemble. Previous studies indicated that microscale (< 1km) spatial resolutions are necessary to resolve turbulent kinetic energy (TKE) with low uncertainty. Six case studies of moderate or greater CAT, from pilot reports, were simulated at six horizontal grid spacings including 1, 2, 4, 8, 16, and 32km using the Weather Research and Forecast (WRF) Model. Results showed that grid spacing does influence the magnitude of uncertainty; however, the relationship between the grid spacings varied with the type of CAT being simulated and the addition of the cumulus parameterization scheme for grid spacings greater than 4km. Overall, higher precision was found between convective resolutions (1-4km), indicating that microscale resolutions are not necessary to precisely simulate TKE for CAT forecasts.

The Role Of Enso Diversity In Modulating Tornadic Activity In The United States, Davis Boyd Newton

Theses and Dissertations

Tornado activity in the United States is influenced by large-scale climate patterns, especially by the El Niño-Southern Oscillation (ENSO). While prior research has explored ENSO’s impact on severe weather, the influence of ENSO flavors, Central Pacific (CP) and Eastern Pacific (EP), on tornadic activity remains understudied. Using tornado records, reanalysis data, and sea surface temperature anomalies, we assess how convective available potential energy (CAPE), wind shear, and jet stream dynamics influence tornado frequency and distribution. Results indicate that CP La Niña years had significant increases in tornado frequency, particularly across the Midwest, Central Plains, and Southeast. EP ENSO years had …

Integrating Case Studies With Meteorologists’ Insight: Assessing Meteorologists’ Perception And Utilization Of Composite Indices, Brianna Marie Salazar

Theses and Dissertations

Meteorologists from sectors, including broadcast, academia, and operations, use derived composite indices such as 0-1km and 0-3km energy helicity index (EHI), effective-layer supercell composite parameter (SCP), fixed-layer and effective layer significant tornado parameter (STP), in addition to other resources, when developing severe local storm forecasts. This study utilizes the Weather Research and Forecasting (WRF) model to create simulations of composite indices for two tornado-producing events: 31 March 2023 and 3 May 1999. With modifications to geographical location, these simulated scenarios are then utilized in the survey to gauge how meteorologists assess where tornado potential is highest. Additionally, a combination of …

Patterns In Tropical Cyclone Intensity And Frequency Since 1960, Ramie E. Thompson

Student Scholarship

Tropical cyclones, also known as hurricanes or typhoons, are defined as organized storm systems that form in the warm waters around the equator (NOAA, 2024). This happens due to the combination of warm waters, light winds, and preexisting weather conditions. In the last 50 years, tropical cyclones have accounted for approximately 800,000 deaths and an economic loss of $1.4 trillion USD due to their resulting damages (WMO, 2024). Research in this field includes studies that encompass a variety of time scales including from 85 to 150 years on a global or regional level and studies that focus on more recent …

2025 May - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

Hi All,

For May 2025, the main weather/climate stories were the continued pattern of severe weather impacting Tennessee as well as Chattanooga recording their wettest May in the 147-year weather history of the city. Starting with the record rainfall in Chattanooga, the Chattanooga airport weather station recorded a total of 12.02-inches of rainfall over May 2025, 8.08-inches above normal and 0.02-inches above the previous record wettest May in 1929. Many other areas of East Tennessee and the Cumberland Plateau also had well above normal rainfall this month, but they were emerging out of a drought from last fall and winter …

Radar Precursors To Severe Weather Reports In Left-Moving Supercells, Eric A. Carothers

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

While much research has examined dual-polarimetric signatures of right-moving supercells, very little has been done with left-moving supercells. Given that left-moving supercells are thought to be disproportionate producers of large hail, understanding their internal dynamics is vitally important. This study examines differences and trends in the dual-polarimetric signatures of left-moving supercells to identify precursors to severe weather reports. A dataset of left-moving supercells associated with severe weather reports was created. These storms are processed with an automated analysis algorithm that identifies and quantifies the polarimetric signatures in each storm. A method for analysis of differences and trends in their dual-polarization …

A Synoptic Analysis Of Hurricane Andrew, Alice E. Schipper, Mark R. Sinclair

Student Works

Hurricane Andrew was a historic Category 5 storm that made landfall in southern Florida on the morning of 24 August 1992. Andrew’s landfall brought massive destruction, with entire neighborhoods in the city of Homestead, Florida destroyed. There were 250,000 people left homeless in the US over its entire track, and cost US$25 billion in damage, the costliest hurricane in United States history up to that point. A synoptic analysis was completed to study the tropical and subsequent extratropical phases of this destructive storm. During Andrew’s tropical phase it was found that strong vertical shear initially impeded development. As this dissipated, …

Identifying Saharan Air Layer Events And Their Relationship To Instability And Rainfall Patterns In The Tropical North Atlantic Ocean, Charles H. Dolce

LSU Master's Theses

Every year, strong North African winds across the Sahara loft dust particles and advect them westward within the Saharan Air Layer (SAL). These plumes of dust often reach the Caribbean Sea and can heavily affect regional weather patterns by suppressing convection. When concentrations are high, decreased rainfall can yield negative societal and ecological impacts, potentially leading to drought. The Puerto Rican early rainfall season (ERS), spanning from 1 April through 31 July, overlaps with Saharan dust migration periods, and systematically detecting instances of SAL activity near the island is important for understanding longer-term drought-forcing trends in the region.

Corridors of …

2025 April - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

Hi All,

April was a very active weather month across Tennessee! Consequently, this is one of our longer monthly reports. The main weather and climate stories for April 2025 were the deadly severe weather, extreme rainfall and associated flooding, and record-setting heat that all occurred in the first week of the month. A series of weather systems set up across the central U.S. in the first week of April, with warm, moist air funneled into Tennessee from the Gulf. This pattern produced severe thunderstorms, heavy rainfall, and high temperatures from April 2nd to 6th. The series of storms began on …

Characterizing Rainfall Variability Within A Series Of Storms Over Northern California In February 2017, Parker Jan Malek

Dissertations and Theses

In February 2017, a series of storms with associated atmospheric rivers (ARs) made landfall in the US state of California, dropping large amounts of precipitation over the Sierra Nevada Mountains and their western foothills. The rainfall from these ARs, long, narrow bands of water vapor that transport large amounts of water vapor from the tropics to the mid-latitudes, instigated the near-failure of the Oroville Dam located at the southeastern edge of the Feather watershed outside the city of Oroville in the state's Central Valley. This case study provides a synoptic and mesoscale diagnosis of the drivers of rainfall pulses that …

Urban Heat Dynamics In Pune: The Influence Of Land Cover And Local Climate, Arpit Tiwari, Preethi Nanjundan, Ravi Ranjan Kumar, Ananya Karmakar, Satyaban Bishoyi Ratna

Northeast Journal of Complex Systems (NEJCS)

Urban areas with high population density and extensive infrastructure development have been experiencing an increasing strain on the local heat budget, leading to a surge in heat-related illnesses and discomfort. This study examined the impact of climate and land use as heat islands in Pune, India, from 2012 to 2023 at six different locations representing varying degree of urbanization. Satellite land cover observations revealed that 55.17% of the total area was urbanized in the city itself, which was limited to 44.8% in 2012. This urbanization has significantly impacted the increasing tendency of maximum temperature (T_max; 0.13℃ to 1.63℃ …

2025 March - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

Hi All, March and April were very eventful weather months across the state. We're starting to work through April data but below are the highlights for March. March continued the pattern of extremes in weather that Tennessee has seen in 2025, with high winds and fires, record-setting rainfall, and severe storms impacting the state. Several small to moderate sized grass, brush, and forest fires popped up around the state driven by days with high winds and low relative humidity in early March. One of the largest fires was in Sevier County, where the Pittman Center/Webb Mountain fire burned over 1,000 …

Spatiotemporal Prediction Of Atmospheric Events Through Recurrent Deep Learning Model, Brian W. F. Popick

Theses and Dissertations

The main contributions of this research is to add to the growing library of literature on the use of deep learning algorithms for the spatiotemporal prediction of dangerous atmospheric and hydrologic phenomena. Specifically, we develop novel attention-based and non-attention-based recurrent neural network frameworks to produce short-range sequential forecasts for lightning and tornado occurrences. Additionally, we introduce methods that account for and include error in the model tuning process to generate more reliable models. Furthermore, we have created a lightweight spatiotemporal tornadic prediction dataset that we plan to make publicly available. The first component of this research develops three novel spatiotemporal …

Evaluating Weather Effects On Sortie Generation Using Discrete Event Simulation, Markus Case

Theses and Dissertations

United States Air Force (USAF) operations rely on sortie generation, a complex system involving aircraft maintenance, operational planning, munitions, security forces, and aircrew. Failures in any of these areas can jeopardize a mission, and extreme weather events such as lightning, high winds, and snow further complicate operations. This thesis examines the impact of extreme weather on sortie generation, focusing on developing a data-driven discrete-event simulation (DES) to predict generation timelines and identify high-risk areas. The model allows users to adjust key inputs, including the month, number of aircraft, processing times, and personnel/equipment availability. By simulating real-world conditions, the model helps …

2024 Nhc Verification Report Preview: Atlantic Basin, John Cangialosi, Jon Martinez

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

The National Hurricane Center (NHC) is nearing completion of the post-analysis of the 2024 Atlantic and eastern North Pacific basin tropical cyclones. The annual NHC Verification Report uses the post-analyzed information to verify the accuracy and biases of NHC forecasts and real-time model guidance, and the 2024 report will be available in the spring on NHC’s website - https://www.nhc.noaa.gov/verification/. This short review provides some of the preliminary highlights of NHC’s 2024 forecast performance in the Atlantic basin, which is based on a combination of post-analyzed and real time best track data. If interested in the forecast verification for individual …

2025 February - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

Hi All,

February 2025 brought a wide range of weather to Tennessee including severe storms, snow, flooding, and large temperature fluctuations. Warm temperatures in the first week of the month brought a taste of spring after a much colder than normal January across the state, with high temperatures climbing into the upper 70’s for many locations on February 4th. This warm airmass set the stage for severe weather to impact northern areas of the state on February 6th, with six reports of tornadoes (four EF1 tornadoes and two EF2 tornadoes). Cooler and wetter weather then returned to the state for …

2025 January - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.