SEVERE SEVERE WEATHER WEATHER PROJECTPROJECT

Severe ThunderstormsSevere Thunderstorms

Thunderstorm produce one or more Thunderstorm produce one or more of the following conditions: high of the following conditions: high winds, hail, flash floods, and winds, hail, flash floods, and tornadoes. tornadoes.

TornadoTornado Wind moving in 2 directions causes a Wind moving in 2 directions causes a

layer of air in the middle to spinlayer of air in the middle to spin Spinning column is turned vertical Spinning column is turned vertical

due to strong updraftsdue to strong updrafts Low central pressureLow central pressure A funnel cloud forms at the bottom of A funnel cloud forms at the bottom of

a cumulonimbus clouda cumulonimbus cloud Once it touches ground it is a tornadoOnce it touches ground it is a tornado Tornadoes occur in only 1% of all Tornadoes occur in only 1% of all

thunderstorms. thunderstorms.

HurricanesHurricanes

Large, rotating tropical weather Large, rotating tropical weather systemsystem

Most powerful storms on EarthMost powerful storms on Earth Occur at 5-20 degrees latitude N and SOccur at 5-20 degrees latitude N and S Need warm water to formNeed warm water to form Winds spiral in towards intense low-Winds spiral in towards intense low-

pressure storm centerpressure storm center Categories 1-5Categories 1-5

BlizzardsBlizzards Blizzards are severe winter storms that Blizzards are severe winter storms that

pack a combination of blowing snow and pack a combination of blowing snow and wind resulting in very low visibilities. wind resulting in very low visibilities.

While heavy snowfalls and severe cold often While heavy snowfalls and severe cold often accompany blizzards, they are not required. accompany blizzards, they are not required.

Sometimes strong winds pick up snow that Sometimes strong winds pick up snow that has already fallen, creating a blizzard. has already fallen, creating a blizzard.

Officially, the National Weather Service Officially, the National Weather Service defines a blizzard as large amounts of defines a blizzard as large amounts of falling OR blowing snow with winds in falling OR blowing snow with winds in excess of 35 mph and visibilities of less excess of 35 mph and visibilities of less than 1/4 of a mile for an extended period of than 1/4 of a mile for an extended period of time (greater than 3 hours).time (greater than 3 hours).

FloodFlood

Flooding is when the water level in a Flooding is when the water level in a creek, river, lake or the sea rises and creek, river, lake or the sea rises and covers land that is usually dry. covers land that is usually dry.

While some floods occur without While some floods occur without problem, others are devastating, problem, others are devastating, causing large-scale destruction and causing large-scale destruction and significant loss of life.significant loss of life.

Flooding is experienced all over the Flooding is experienced all over the world and in some countries such as world and in some countries such as Bangladesh, flooding occurs regularly.Bangladesh, flooding occurs regularly.

WildfireWildfire

Any uncontrolled, non-structure fire Any uncontrolled, non-structure fire that occurs in the wilderness. that occurs in the wilderness.

Wildfires differ from otherWildfires differ from other fires only fires only by their extensive size; the speed at by their extensive size; the speed at which it spreads out from its original which it spreads out from its original source; its ability to change source; its ability to change direction unexpectedly; and to jump direction unexpectedly; and to jump gaps, such as roads, rivers and fire gaps, such as roads, rivers and fire breaks.breaks.

LightningLightning

An electric discharge that occurs An electric discharge that occurs between a positively charged area and between a positively charged area and a negatively charged area. a negatively charged area.

Lightning can occur between two Lightning can occur between two clouds, between Earth and a cloud or clouds, between Earth and a cloud or between two parts of the same cloud.between two parts of the same cloud.

When lightning strikes, energy is When lightning strikes, energy is released, which causes air to expand released, which causes air to expand and rapidly send out sound waves and rapidly send out sound waves (thunder).(thunder).

Pick a StormPick a Storm

HurricanesHurricanes AndrewAndrew RitaRita KatrinaKatrina HugoHugo IvanIvan GalvestonGalveston WilmaWilma

BlizzardsBlizzards HalloweenHalloween Great Blizzard of Great Blizzard of

'49'49 Armistice Day Armistice Day

BlizzardBlizzard

Pick a StormPick a Storm TornadosTornados

St. PeterSt. Peter HugoHugo Tri-StateTri-State April 3-4, 1974: April 3-4, 1974:

Super OutbreakSuper Outbreak The Natchez The Natchez

Tornado on May 7, Tornado on May 7, 18401840

The St. Louis/East The St. Louis/East St. Louis Tornado on St. Louis Tornado on May 27, 1896May 27, 1896

The Gainesville The Gainesville Tornado on April 6, Tornado on April 6, 19361936

South MinneapolisSouth Minneapolis

FloodsFloods 1997 Red River 1997 Red River

FloodingFlooding 2009 Red River 2009 Red River

FloodingFlooding 2010 Flooding2010 Flooding Flooding in Flooding in

another countryanother country 2010 Tennessee2010 Tennessee

WildfireWildfire Boundary Waters Boundary Waters

Canoe Area (BWCA)- Canoe Area (BWCA)- various yearsvarious years

California-focus on California-focus on one or in generalone or in general

Hinkley FireHinkley Fire