Weather

• Type of report
• METAR - Hourly Observation
• SPECI - Special, unscheduled report

Station Identifier

• Date and Time of Report
• 011955Z - 01 Day, 1955Z time

• Report Modifier
• (None) - manual station or manual input at automated station
• AUTO - Totally Automated Stations
•  - AO1 without a precipitation discriminator
•  - AO2 with a precipitation discriminator
• COR - Corrected METAR to replace previous report

• Wind
• 22015G25KT - 220° 15 kts Gust 25 kts
• 180V250 - 180° varying 250°

• Visibility
• 3/4SM - 3/4 Statute Miles

• Runway Visual Range
• R17L/2600FT - Runway 17L 2600 Feet

Present Weather

Sky Condition

• Temperature/Dewpoint
• Degrees Celsius

• Altimeter
• 2992 = 29.92" HG

Remark

• PIlot REPort
• Pilots are encouraged to make reports of unexpected weather conditions

• Terminal Aerodrome Forecast
• An estimate of what the weather will be in the future at a specific airport

24 hours

4 times a day

Cumulonimbu (CB)

• Aviation Area Forecast

• covers general weather conditions over a wide region
• good info for en route weather

Six regions for the 48 Contiguous States

• Winds and Temperature Aloft Forecast

• Provides an estimate of:
• wind direction in relation to true north
• wind speed in knots
• Temperature in Celsius

Hurricane Advisory

When a hurricane is at least 300 NM offshore but threatens a coast line

Convective Outlook

A national forecast of thunderstorm activity covering two 24 hour periods (day 1 & day 2)

Severe Weather Watch Bulletin

• Defines areas of possible sever thunderstorms or tornadoes.
• Preliminary message called alert severe weather watch (AWW) is sent.

Alert Severe Weather Watch

Preliminary message for Severe weather watch bulletin (WW)

• Airman's Meteorological Information
• Warn of weather conditions which are particularly hazardous to small, single-engine aircraft
• For all aircraft

Every 6 hours with amendments as necessary

• Light to moderate turbulence.
• Surface winds >= 20kts

• Mountain obscuration or IFR conditions
• Vis < 3 miles
• Ceiling <1,000 ft
• affecting > 50% of area

• light to moderate icing
• freezing levels

• Significant Meteorological information
• Warn of weather hazards which concern all aircraft
• Severe Icing
• Turbulence
• Clear Air Turbulence (CAT)
• Dust and Sandstorms
• Volcanic Ash

• Warn of weather hazards including:
• tornadoes
• embedded Thunderstorms
• hail 3/4 inch or greater in diameter

• Eastern (E) US
• Central (C) US
• Western (W) US

• 1-800-WX-Brief Telephone brief and file flight plan
• DUATS: Direct User Access Terminal. Online service to allow users to receive weather and file flight plans.

• Automated Weather Observing System (AWOS)
• Automated Surface Observing System (ASOS)

Center Weather Advisory

Unscheduled weather advisory to alert pilots of existing or anticipated adverse weather conditions within the next 2 hours

The temperature at which air is completely saturated.

boundary between 2 air masses.

• Warm air is replacing cold air.
• Poor visibility
• Moves at slow speed.
• Slope of a warm front is very gradual and may extend up over cool air for several hundred miles ahead of the front.

• Cold air is moving to displace warmer air
• Dense and stable air moves along surface and forces less dense, warm air upward.
• Showers and poor visibility

• No movement
• Opposing forces of two masses are relatively balanced

• Cold fronts are usually fast moving ad often catch up to and merge w/ a slower moving warm front
• When cold and warm fronts merge they create an occluded front (temp in each front influences which type of front and weather are created.

Fast-moving cold front is colder than the air ahead of the slow-moving warm front

The air ahead of the slow-moving warm front is colder than the air within the fast-moving

• Unstable conditions
• a lifting force
• high moisture levels

• Cumulus - lifting action initiates the vertical movement of air, continuous updrafts
• Mature - greatest intensity and precipitation begins
• Dissipating - downdrafts that eventually weaken the storm

• Severe turbulence
• lightning
• hail
• tornadoes