Review and warm up Kahoot first and fourth period Weather mapping review activity Read the directions carefully. Only use dry erase markers or highlighters on the maps. Make sure that you show the maps to Mrs. Chapel so she can get a grade for you. You have 10 minutes

Radar MeteorologyM. D. Eastin Basic Concepts of Doppler Radar Doppler Shift: A frequency shift in electromagnetic waves due to the motion of scatters toward or away from the observer. Doppler radar: obtains weather information (wind and precipitation) based upon returned energy.. It emits a burst of energy. If the energy strikes an object (rain drop, bug, bird, etc), the energy is scattered in all directions. A small fraction of that scattered energy is directed back toward the radar

Radar MeteorologyM. D. Eastin Doppler shift is negative (lower frequency, red shift) for objects moving away from the radar (positive v r ) Doppler shift is positive (higher frequency, blue shift) for objects moving toward the radar (negative v r ) These “color” shift conventions are often translated to radar displays: Basic Concepts of Doppler radar Red: Moving away from radar Blue/Green: Moving toward radar

Satallite mapping: Dozens of satellites keep a constant watch over the earth each day. Some are geosynchronous (stay in the same position over the earth) while others orbit around the earth.

Severe Storms Most Violent weather is associated with low pressure systems because air of different properties mixes there Thunderstorms Tornadoes Hurricanes Winter Storms

How do tornadoes form? Scientists aren’t entirely sure Associated with low pressure system Associated with supercells which contain a deep and persistent rotating updraft called a mesocyclone. An updraft is upward moving air currents, and a downdraft is downward moving air currents. Creating a tornado: 1.Air rotates because of wind shear-winds at different altitudes spin in different speeds 2.Rising air within the thunderstorm updraft tilts the rotating air from horizontal to vertical.

Tornado Alley - The Midwest! A cP air mass from Canada meets a mT air mass from the Gulf of Mexico forming a supercell. A supercell is a giant, self-sustaining storm that can spawn tornados. Most tornadoes occur in May.

In 2006, the NWS introduced the Enhanced Fujita Scale, an updated version of the F-scale

Watch vs. Warning Watch=conditions are favorable for a tornado Warning=tornado has been sited or indicated by weather radar Hazards? Flying debris

Tornado Safety… 1.Move to a pre-designated shelter – to a basement if possible. 2.Move to an interior room/hall, lowest floor, under sturdy furniture. (A bath tub is safest!) 3.Stay away from windows. 4.Get out of vehicles! 5.Don’t try to outrun a tornado. 6.If outside, lie flat in a ditch or depression. 7.Abandon a mobile home for a shelter.

Where don’t you want to be when a tornado strikes?

How many does NC have per year? Approximately 16

On radar, often big tornadoes are seen with a “hook echo”

Hurricanes Hurricane: Atlantic and East Pacific Typhoon: West Pacific Cyclone: Indian Ocean Intense Low-Pressure Systems Need 60 m (200 feet) of ocean water at 26.5 C or warmer to form

Formation Regions

When to expect Hurricane season is June through November Peak is in September

Typical Paths

Tropical Cyclones… 1.A tropical cyclone can be described as a…  Large, rotating, low pressure storm  Form near equator where air is warm and moist 2.We call these storms…  hurricanes 3. Tropical cyclones derive a tremendous amount of energy from…  Warm, tropical oceans

Tropical Cyclones… 4.Which direction do tropical cyclones turn in the northern hemisphere?  Counterclockwise  It is a low pressure system! Fran, 1996, Cape Fear, NC Name was retired!

Classifying Hurricanes… 4. A hurricane runs out of energy a.When it moves over land b.When it moves over cold water Need warm water for energy Decay rapidly over land Lose strength over cold water Can still cause destructive flooding long after cyclonic structure is gone Degenerate into low pressure systems

Classifying Hurricanes… 3. The Saffir-Simpson Scale… a.Categories 1 – 5 b.Category that does the most damage – 5 c.Wind speed of a cat 5? > 155 mph

Classifying Hurricanes… 1. What scale is used to classify hurricanes?  Saffir-Simpson 2. What are the four characteristics of a hurricane described by the scale? a.Wind speed – how high? b.Air pressure – how low? c.Potential for damage – how much?! d.Storm surge

Hurricane Watch vs warning A hurricane poses a possible threat within the next 36 hours Hurricane conditions expected within 24 hours

Hurricane Hazards… Wind Pressure Flying Debris Storm Surge Flash Flooding Tornadoes

Hurricane Safety Best plan is to evacuate Towns have voluntary evacuation during a watch, and some switch to mandatory during a warning. Plan early in advance If you choose to stay: Board all windows Prepare Flashlights, avoid candles Stay tuned to radio Stay indoors

How many does North Carolina get? a tropical cyclone makes landfall along the coastline about once every four yearslandfall

Hurricane and tornado posters You have the rest of the period to finish your posters

Closure Obtain a map analysis worksheet Turn the worksheet in as you leave. This is a grade