Meteorology 1950 - Today

1 Aug 2018

1st Lt Libby Haynes

Capt Kim Mevers

What is meteorology? Is it important to you?

• Meteorology is the science of the atmosphere… embracing both weather and climate.• It is concerned with physical, dynamical and chemical state of the earth’s atmosphere.

• Does weather affect your day to day life?• What you wear everyday

• Do you bring an umbrella/rain jacket

• How much water to drink

• What to pack on vacation

• Can we fly today? Wind limits, thunderstorm?

Weather’s impact on the outcome of war

• Napoleon’s Army – Invasion of Russia in 1812• 600,000 invaded East to Russia

• -40C temperature killed over 450,000 Soldiers

• Operation Barbarossa – 1941• Adolf Hitler’s attempt to invade the Soviet Union

• Prior to the invasion – weather forecasters predicted -24C degrees temperatures outside of Moscow

• Started their advancements in June

• October - still 250 km from Moscow

• December – Reached the capital

• Underprepared with limited winter clothes and forced to retreat

Weather’s impact on the outcome of war

• D-Day Landings - 1944• Critical decisions about when to send the allied forces

across the channel were made based on weather forecasts

• Having broken the Enigma code – Allies were able to decode German weather observations

• German forecasting thought weather conditions would remain unsuitable on the 6th of June for an allied assault

• Allied forces had sufficient extra information – advised that conditions would be marginal but sufficient to launch

https://www.metoffice.gov.uk/learning/weather-and-history/weather-and-war

Forecasting in the 1950s

Route Forecast

Narsarsuaq International Airport Air Force Base

Narsarsuaq International Airport

Left: Goose Bay, Labrador, June of 1954

175-1 Weather Forecast

Hazards – Icing, Turbulence, Thunderstorm

Real-Time Weather Tool

Layers of the Atmosphere

Troposhpere- Most airplanes fly- Weather - Deeper at the equator than poles, due to earth’s spin- 80% of Earths Atmosphere my mass- 14.7 psi at the surface

Stratosphere - Some special aircraft can fly- Flelix Baumgartner’s sky dive record- Ozone layer - 1/1000th of sea level pressure

Mesosphere- Burns up most meteors heading to earth

Thermosphere- International Space Station

Atmospheric Pressure

In the Tropopause –- Temperature decreases with altitude… why?

Experiment: - Demonstration: The force of gravity vs. atmospheric pressure- What happens to the card and why?

Pilots and weather forecasters use a standard lapse rate- 2C per 1000 ft

- Experiment: Air Rising

How Clouds Form

• Convection: Clouds develop out of the process of changing moisture from a gas to liquid• Solar Radiation

• 1. Sun heats the ground and air immediately above it

• 2. The warm air becomes lighter and the flow of air carries this warm air upward

• 3. Air cools as it rises and the amount of water vapor it can hold decreases

• 4. Water vapor condenses and clouds develop

• 3 Ingredients in cloud formation:• Moisture

• Instability (Lifting Motion)

• Heat the surface / Cool the top

• Experiment – Create a cloud

Definitions

• Condensation – process of converting water vapor to liquid

• Dew Point – the temperature at which the air becomes saturated with water vapor

• Humidity – amount of water vapor in the air• 100% humidity = Temperature / Dew point difference

is 0

• Precipitation – general term given to various types of condensed water vapor

• Relative Humidity – amount of water vapor in the air compared to its water vapor capacity at a given temperature

• Saturation – the condition of a parcel of air holding as much water vapor as it can at the air temperature at that time

• Water cycle – continuous movement of water as it circulates between the Earth and its atmosphere

Sources of Lift

Frontal SystemBehind a Cold Front Ahead of a Warm Front

Types of Clouds

3 Primary Types of Clouds:

- Cumulus (heaped or piled)- Looks like cotton balls- Puffy, with vertical development

- Stratus (sheets or layers)- Looks like a white blanket- Widespread, typically covering a

large area- Not much vertical development

- Cirrus (curly or fibrous)- Wispy, thin and typically you can

see threw- Made entirely from ice droplets

Types of Clouds

Cloud Altitudes:

- Low-Level Clouds- Surface – 6,500 ft- Observing technique: 3 fingers or

larger- Formed by rain droplets

- Mid-Level Clouds- 6,500 to 20,000 ft- Observing technique: 2 finger rule- Formed by rain droplets

- High-Level Clouds- Over 20,000- Formed by ice crystals

Special Types of Clouds

- Cumulonimbus- Thunderstorms- Anvil Head - Stratosphere

- Wave/Roll Cloud- Severe Turbulence- Very similar to ocean waves- Created by strong winds going

across a mountain range

- Lenticular Clouds- Severe to extreme turbulence- Created by winds going over a

mountain range

METAR - Observing Clouds

• Clear –• Coded: CLR• No Clouds in the sky

• Few –• Coded: FEW• 1/8 – 2/8 of the sky covered (0-25%)

• Scattered –• Coded: SCT• 3/8-4/8 of the sky covered (25-50%)

• Broken –• Coded: BKN• 5/8-7/8 of the sky covered (50-90%)

• Overcast –• Coded: OVC• 8/8 of the sky covered, no clear sky can be seen (100%)

What cloud is this?

What cloud is this?

Cumulus

What cloud is this?

What cloud is this?

Stratus

What cloud is this?

What cloud is this?

Cirrocumulus

CirrusCirrostratus

What cloud is this?

What cloud is this?

Cumulonimbus with Anvil

Cumulonimbus

Stratocumulus

What is this image showing?

H

L

Snow

Cumulus Clouds

High Pressure = Good weather

Darkness… Why?

What is this image showing?

H

L

Snow

Cumulus Clouds

High Pressure = Good weather

Darkness… Why?

April 1, 1960 – TIROS-1 Television Infrared Observation Satellite

Infrared satellite (ir)

- MEASURES TEMPERATURE OF CLOUD TOPS

- COLDER IS BRIGHTER (HIGHER CLOUDS)

- WARMER IS DARKER (LOWER CLOUDS)

- USES FOR IR

- CONVECTION (I.E. THUNDERSTORM)

STRENGTH

- AFTERNOON DRYLINES

- TROPICAL STORM DEVELOPMENT

- APPROACH OF COLD AIRMASSES (I.E.

POLAR VORTEX)

- HURRICANE STRENGTH AND ANALYSIS

Applications of Satellite products

CA Coast: Marine Layer

Mexico -> KS: High Clouds

Dakotas/NE: Low Clouds

Dust Storm on Satellite

HTTPS://WWW.YOUTUBE.COM/WATCH?V=KAKZXSUMQLY&FEATURE=YOUTU.BE

Hurricane analysis via satellite imagery

- ADVANTAGES

- TRACKING FOR DAYS IN ADVANCE

- STRENGTHENING/WEAKENING

- SHEAR

- DRYLINES

Questions