14: Thunderstorm Hazards
- Page ID
- 46101
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Alison Nugent and David DeCou
By the end of this chapter, you should be able to:
- Identify the different types of precipitation (rain, snow, graupel, hail, etc.)
- Describe how hail forms and why it is difficult to predict
- Summarize how lightning occurs with respect to thunderstorm ice processes
- Discuss the various types of hazards from thunderstorms (gust fronts and outflow winds, precipitation, thunder and lightning, tornadoes)
- Identify radar hook echoes that suggest tornado hazards and discuss the process of warning the public about a tornado threat
- 14.1: Introduction
- This page covers thunderstorms, emphasizing their characteristics, including thunder, lightning, and associated precipitation. It details the potential hazards like damaging winds, hail, heavy rain, and tornadoes. The discussion focuses on the dangers of severe weather and its impact on human activities, while also noting the visual phenomena that thunderstorms can create. The chapter aims to explore hazardous weather linked to thunderstorms.
- 14.2: Precipitation and Hail
- This page discusses thunderstorms, highlighting their deep convective clouds that generate intense rainfall, with rates up to 1000 mm per hour. It explains the coexistence of ice crystals and droplets, leading to phenomena like graupel and hail. Graupel is formed from supercooled droplets, while hailstones develop through droplet accretion, necessitating strong updrafts.
- 14.3: Gust Fronts
- This page explains gust fronts in thunderstorms, emphasizing the impact of downdrafts that create boundaries between cold and warm air. It details how gust fronts lead to temperature drops and wind shifts. The page also covers downbursts and microbursts, highlighting their significance as intense downdrafts capable of causing substantial wind damage to structures and aircraft, despite their small size.
- 14.4: Lightning
- This page explains lightning as an electrical discharge in thunderstorms, mostly occurring within clouds, with only 20% reaching the ground. It heats the air to 30,000°C, creating thunder, which can be timed from the flash. Lightning results from charge separation in clouds, due to interactions between graupel, hail, and supercooled droplets. Thunderstorms need these ice phase processes for both lightning and thunder.
- 14.5: Tornadoes
- This page discusses supercell storms as rotating thunderstorms capable of producing tornadoes due to wind shear. It emphasizes the complexities of tornado forecasting, which involves issuing Watches and Warnings based on atmospheric conditions and recognizing radar signatures like hook echoes. Tornadoes are classified using the Enhanced Fujita scale based on damage.
- 14.6: Keeping Yourself Safe
- This page focuses on storm hazards, stressing the seriousness of severe weather's unpredictability. It outlines key safety measures like avoiding flooded areas and seeking shelter during storms. The chapter promotes proactive emergency planning due to the limited time for reactions. Additionally, it encourages readers to think about storm logistics, including the impacts of hail and lightning distances, underscoring the necessity for preparedness against severe weather events.