Meteorology/Severe Storms

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Meteorology/Severe Storms

Type

Earth Science

Category

Study

Event Information

Latest Appearance

2024

Forum Threads

2024	2021	2020	2017	2014
2011

Question Marathon Threads

2024	2020	2017	2014

This page refers to a topic of Meteorology which is currently in rotation for the 2024 season. It was last in rotation during the 2021 season.

Severe Storms

Severe Storms is focused on the study of Severe Weather that affects the United States. It can be split into three main groups: Thunderstorms, Hurricanes, and Winter Storms. For all pages pertaining to this topic, see Category:Severe Storms.

Thunderstorms

Main article: Severe Storms/Thunderstorms

Thunderstorms can occur anywhere that warm, moist air meets cooler air. They are common along cold fronts where the warm air moves rapidly upward and condenses, which forms cumulonimbus clouds. Lightning, thunder, and rain are associated with thunderstorms, and severe storms may be accompanied by heavy rain, strong winds, hail, and on occasion, tornadoes.

Hurricanes

Main article: Severe Storms/Hurricanes

Hurricanes are tropical cyclones, storm systems which have a large, low-pressure center around which thunderstorms converge. Tropical cyclones are called hurricanes in the Atlantic and eastern Pacific Oceans, but elsewhere in the world are called typhoons or simple "cyclones". They spin counterclockwise in the northern hemisphere and clockwise in the southern hemisphere due to the Coriolis force. Hurricanes often produce many thunderstorms with heavy rain and strong winds. They may also produce tornadoes and damaging storm surge. Hurricanes usually form over large bodies of warm water, and will become weaker if they travel over land, mainly because they lose the warm water energy source.

Winter Storms

Main article: Severe Storms/Winter Storms

Winter storms can produce precipitation such as snow, sleet, or freezing rain, rather than the rain and hail thunderstorms produce. These storms can happen outside of the winter season, but this is extremely rare. Some of the key dangers of all winter storms include hypothermia and frostbite due to the cold, and also car accidents due to unsafe road conditions. The types are: Blizzards and Severe_Storms/Winter_Storms#Nor'easters, Lake-effect Snow.

Mudslides

Main article: Severe Storms/Mudslides

Mudslides develop when water rapidly accumulates in the ground and results in a surge of water-saturated rock, earth, and debris. Mudslides usually start on steep slopes and can be activated by natural disasters.

Mid-latitude Cyclones

Main article: Severe Storms/Mid-latitude Cyclones

Extratropical cyclones, widely referred to as mid-latitude cyclones, are synoptic scale low pressure systems that form between 30° N and 60° N latitudes or 30° S and 60° S latitudes. Cyclogenesis is a term used to describe the intensification or development of a cyclone and is commonly used to describe the life cycle of a mid-latitude cyclone. The different stages of Cyclogenesis are: Stationary stage, Wave stage, Open stage, Occluded stage, and Dissipation stage.

Atmospheric Rivers

Main article: Severe Storms/Atmospheric Rivers

Atmospheric rivers are narrow bands of enhanced water vapor transport. They are often found in the warm sectors of mid-latitude cyclones that form over water. The warm sector can also entrain moisture from oceanic regions. Atmospheric rivers are narrow (about 100km) and travel quickly (85mph at core). ARs are responsible for almost all (>90%) of the global north-south transport of water vapor. The evidence surrounding the impacts and effects ARs have on weather patterns is substantial, and will continue to increase as NOAA and other important weather organizations conduct research on how the rivers function. Climate change can drastically change the effects of atmospheric rivers. For each 1 degree Fahrenheit that the atmosphere heats up, the atmosphere can hold 4% more moisture, so as the effects of climate change increase, so will the size of atmospheric rivers. This allows more rainfall in most places. For example, the Pineapple Express would contain moisture thereby influencing precipitation on the West Coast.

Specific Storms

Based on the 2024 National Rules.

Important Hurricanes/Tropical Storms

Galveston (1900)

Hurricane Galveston was a category 4 hurricane that was first detected at around August 27th and hit Galveston on September 8th. Galveston is the fourth deadliest Atlantic Hurricane on record. The death toll was estimated to be 8,000 to 12,000 deaths. The storm surge reached 15 feet, winds were estimated to be over 130 mph, and there was major destruction. It resulted in lots of destruction. The city was rebuilt, and as a result, they raised the city's elevation and constructed a seawall. It also lead to Houston becoming the main shipping port in Texas.

Andrew (1992)

Hurricane Andrew was a category 5 hurricane that began as a tropical depression around Cape Verde on August 16th. It became a hurricane on August 22nd, and hit the Straits of Florida and the southern tip of Florida on August 24th. The wind speeds were around 166.8 mph, with one gust reaching 177 mph. Storm-related damage was roughly 26.5 billion in the U.S, and there was lots of criticism over FEMA's handling of the event due to it taking 4 days for them to respond. It lead to 26 direct and 39 indirect deaths. The name is retired. Notably, it is 1 of the 4 category 5 hurricanes that impacted the U.S.

Katrina (2005)

Hurricane Katrina was a category 3 hurricane when it made landfall on the Gulf Coast, and a category 5 hurricane in the Gulf of Mexico before weakening slightly before landfall. It occurred from August 23rd to August 31st. It is ranked as the costliest disaster in U.S. History. When it made landfall in Florida, it was around 74-95 mph, before later strengthening to cat. 3 at 115 mph, and then later becoming one of the most powerful Atlantic storms on record, at around 170 mph. There were over 1,800 fatalities and it costed the U.S. around $125 billion. Affected areas were generally from New Orleans to Mobile, Alabama. Notably, in New Orleans, Katrina showed a devastating failure of the levees that were meant to be protecting it, as the its winds at landfall overran the levee system.

Sandy (2012)

Hurricane Sandy was a category 3 hurricane that later weakened to a category 1. It occurred between the 22nd and 29th of October. It hit Cuba, the Bahamas, and New England areas due to the path of the Jet Stream. the highest winds were around 115 mph, total fatalities were 254 people, and the damage it caused was 68.7 billion USD, making it the seventh-costliest tropical cyclone on record. Climate change may have effected the Hurricanes strength, as the two main factors in the storm's creation were temperatures and blocking patterns, which are both becoming more frequent due to global warming.

2021 Hurricanes/Tropical Storms

Fred

Hurricane Fred was a category 3 hurricane that formed on the 11th of August, 2021. It dissipated on the 20th. Fred originated from a tropical wave first noted on August 4th. The remnant low was on August 17. The highest winds were 65 mph or 100km/h. The lowest pressure was 991 mbar. 7 fatalities were recorded and the total damage done was $1.3 billion (2021) USD.

Grace

Henri

Ida

2022 Hurricanes/Tropical Storms

Fiona

Ian

Nicole

2023 Hurricanes/Tropical Storms

Limited to any "Major" Hurricanes

Blizzard of March 1888

Dust Bowl of the 1930s

Tornado Outbreaks

Xenia Ohio Tornado Outbreak (1974)

April 2011 Tornado Outbreaks

Great Flood of 1993

Storm of the Century (1993)

Other

Analysis of Data from 2021-2024 U.S. Blizzards, Droughts, Floods, Tornado Outbreaks & Heat Waves (Heat Domes)
Analysis of Data from 2021 - 2024 World-Wide (non-U.S.) Tropical Severe Weather, Floods, & Heat Waves.

Scales for Measuring Severe Weather Events

There are several ways to measure specific types of severe storms. Most are measured using a scale system. Hurricanes use the Saffir-Simpson scale, while tornadoes use the Enhanced Fujita Scale. It is also important to know the Fujita Scale, an older version of the Enhanced Fujita Scale.

Saffir-Simpson Scale

The scale is a 1-5 rating system based on a hurricane's maximum sustained wind speed.

Saffir-Simpson Hurricane Scale
Category	Wind Speed (mph)	Wind Speed (knots)	Comments
5	>/= 156	>/= 135	Catastrophic damage will occur: A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
4	131-155	114-134	Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
3	111-130	96-113	Devastating damage will occur: Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
2	96-110	84-95	Extremely dangerous winds will cause extensive damage: Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.
1	74-95	65-83	Very dangerous winds will produce some damage: Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.
Tropical Storm	39-73	34-64	Not a direct classification.
Tropical Depression	0-38	0-33	Not a direct classification.

Fujita Scale

The Fujita scale (also known as the F-scale) is a system that categorizes tornado intensity based wind speeds, and can be used to infer on the damage they cause. It is now outdated.