Natural Disasters Week 8

  • For thunderstorms, the lifted air has to become less dense than the air around it to keep is rising

  • It has to stay warmer than the surrounding air or it will stop rising and stary sinking again

  • IF a Rising Air Parcel is Unsaturated

    • It Cools More Quickly than the Surrounding Air

    • Reaches the same Temperature/Density as Surrounding air

    • Then it stops rising.

    IF an Air Parcels is Saturated

    • Water Vapor Condenses as it Rises

    • The Parcel Cools Slower than an Unsaturated Air Parcel

    Then IF

    • The rising saturated air parcel Cools Faster than surrounding Ai

    • Water Condenses Into Clouds but no Thunderstorms

    • (System Stabilizes)

    OR

    • Rising saturated air parcel Stays Warmer than surrounding Air

    • It keeps rising and Thunderstorms Can Occur!

LIMBS

  • LIFT - do I have less dense air that can rise over dense air?

  • INSTABILITY - Do I have colder/denser air aloft, so that my rising less dense air keeps rising?

  • MOISTURE - Relatively high humidity

  • BOUNDARIES - Do I have clear boundaries between two distinct air masses that don’t mix well (cold fronts)

  • SHEAR - Do I have strong winds flowing in different directions, especially lower and upper winds?

Types of thunderstorms

  • Single cell - convection cells or orographic lifting, fairly shortly lived

  • Multicell - strung along a distinct line formed by cold fronts (most rain in Midwest

  • Supercell - contains partially strong rotating updraft, 30 miles wide

  • vertical wind shear - condition where adjacent air mass winds differ in speed

Lightning

  • Electrons from atoms flow into our body making the skin negatively charged relative to the object you touch

  • Particles move around in the clouds making them larger

  • Electrostatic potential frows until it drives electrons across the air

PROFESSOR GOING TO SACREMENTO

Derechos

  • Widespread long windstorms

  • Product of concentrated strong winds by downdraft

  • Happens when conditions pf down burst keeps happening in the same spot

Hurricanes

  • Deadliest storms on earth

  • Most costly natural hazard in the U.S.

  • Large tropical storm spiraling around

  • The eye is a cloud free circular area

  • The eye wall is a dense upward flowing rapidly spiraling

  • Spiral rainbands arc shaped cloud banks of tall, aligned thunderstorms

  • Intensity can increase and decrease

  • Storm lines bulge or shrink

  • Eye walls contract and regenerate