Lesson 16 Weather Services

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Private Pilot Ground School

 

Grant County Wx

762-5082

METAR

Type of Report

Station ID

Time

Wind

Visibility

Weather

Sky condition

Temp / Dew point

Altimeter

Remarks

PIREPS

Denoted by UA or UUA for urgent

All altitudes are MSL unless otherwise noted

Turbulence LGT, MDT, SVR

Icing CLR, RIME

AREA FORECAST

Covers large geographical areas

12 hour forecast with a 6 hour outlook

  1. Hazards and Flight precautions
  2. Synopsis
  3. Icing
  4. Turbulence
  5. VFR clouds and Wx

TAF

Issued 4 times a day

Good for 24 hours

  1. Type
  2. Location
  3. Date / time
  4. Valid period
  5. Forecast
  6. Probability forecast
  7. Temporary conditions
  8. Forecast change groups

WEATHER DEPICTION CHART

Shows:

  1. Total sky cover
  2. Cloud height or ceiling

WEATHER DEPICTION CHART

  1. Wx and obstructions to vision
  2. Visibility

less than 6 miles then an entry is made

IFR less than 1000 and 3 mi (hatched)

MVFR 1000 to 3000 3 to 5 mi

VFR greater than 3000 vis greater than 5 mi

RADAR SUMMARY CHART

Shows:

type of precipitation

intensity

trend

configuration

coverage

echo tops and bases

movement

severe wx watch area

  1. Tornadoes
  2. Severe thunderstorms

EFAS

122.0

Available everywhere

Seattle Flight Watch

WINDS AND TEMPS ALOFT

Come out twice daily

Good for time specified on the chart

Temps above 24,000 are all negative

No winds forecast within 1500′ AGL

No temps forecast for the 3000′ level or within 2500′ AGL

9900 Light and variable

Decode exercise

LOW LEVEL PROG

Surface to 24,000

4 times a day

Lower panels 12 and 24 hour surface

Upper panels 12 and 24 hour surface to 400 mb (24,000)

SHOWS:

Fronts

Pressure systems

Speed of frontal movement

Isobars

Forecast precip and or thunderstorms

Precipitation type

Dash dot lines encircle showers and T storms

Solid lines encircle continuous or intermittent precip

Shading indicates precip over half or more of area

LOW LEVEL PROG

UPPER PANELS SHOW:

IFR

MVFR

Turbulence- T storms always imply moderate or greater turb.

Fz levels depicted in 4000′ intervals

TWEB

Route forecast and synopsis

Sky cover cloud bases, tops, visibility, wx and obstructions to vision

25 miles either side of route

MSL bases and tops

SIGMET (all aircraft)

Severe icing

Severe or extreme turb

Dust storms, sandstorms, or volcanic ash with vis less than 3 miles

Volcanic eruption

Valid up to 4 hours

AIRMETS (light aircraft)

Moderate icing

Moderate turbulence

Sustained wind of 30 kts or more on surface

Ceilings less than 1000 and vis less than 3 mi over 50% of the area

Mountain obscurement

Valid up to 6 hours

SURFACE ANALYSIS

Provides a ready means for locating pressure systems and fronts

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