weather graphics
TRANSCRIPT
Graphic Weather Products & How to Read Them
Graphic Wx Products
• Quickly access large-scale weather patterns• Identify trends• Predict wx that might occur over time• Identify areas of IFR wx at a glance• See where IFR conditions are forecast within the
next 12-24 hours
Required Graphics
• Surface Analysis Chart• Weather Depiction Chart• Radar Summary Chart• 12/24 Hour Significant Weather Prognostic Chart• Winds & Temps Aloft Chart
Surface Analysis
Surface Analysis• Depicts an analysis of the current surface
weather• Computer prepared every 3 hours• Shows;
o Areas of pressureo Frontso Temperatureso Dew pointso Wind Directions & Speedso Local Weathero Visual Obstructions
Station Model
• Created by computer• Mainly on surface-
weather maps• Winds are true
direction• Temp/Dew point is in
Fahrenheit
So What Do I Need To Know?
• A good source for general weather information over a wide area.
• Depicts the actual position of fronts, pressure patterns, temperatures, dew point, wind, weather, and obstructions to vision at the valid time of the chart.
• When the Isobars are close the pressure gradient is greater meaning wind velocities will be stronger.
• Dashed lines indicate a weak pressure gradient.
Weather Depiction
Wx Depiction• Derived from METAR’s• Prepared every 3 hours beginning at 0100Z by a
computer• Used for flight planning• Displays
o Major frontso Areas of pressureo Graphic display of IFR, MVFR, VFRo Shows a modified station model
Modified Station Model
• Sky Conditions• Cloud height or ceiling• Weather• Obstructions to visibility• Same as Surface Analysis
So What Do I need To Know?
• Some may be automated• Bases shown are the lowest layer
Radar Summary
Radar Summary (SD)• Computer generated• Published hourly, 35 minutes past the hour• Displays areas of precipitation as well as the
characteristics of the precipitation.
SD• NA – No information
Available• NE – No echoes• Height of tops in
hundreds of feet MSL• Movement of cells
depicted by arrow
So What Do I Need To Know?
• The only charts that show lines and cells of thunderstorms
• You can determine the tops and bases of echoes, the intensity of the precipitation, and the echo movement.
• Most effective when used in combination with other charts, reports, and forecasts.
Satellite Wx Pictures
Composite Moisture Stability Chart
• Four Panels showing stability, precipitable water, freezing level, & average relative humidity conditions.
• Computer generated• Obtained from upper air observations• Updated twice daily• Stability = Potential for thunderstorms• You will not find this chart anywhere in the
current system
Constant Pressure Analysis Chart
Composite Moisture Stability Chart
Low Level Significant Weather Prog Chart
Prog Charts
• SFC to FL240 (400 Millibar)• 12/24 hour forecast, and 36/48 forecast• Issued four times daily• Valid time is printed on it
Prog ChartsUpper Panels Lower Panels
• Shows forecasted significant weathero Non-convective turbulence
(dashed lines)o Freezing levels (zigzag lines)o IFR (solid lines)o MVFR (scalloped lines)
• Forecast surface wxo Pressure systemso Frontso Precipitation
High-Level Significant Weather Prog Chart
Issued 4 times a day
High level Prog• Domestic & International Flights• FL240 – FL600• Presents a forecast for;
o Thunderstormso Tropical cycloneso Squall Lineso Moderate or greater turbulenceo Wide spread dust storms & sandstormso Tropopause heighto Location of jet streamso Volcanic activity
Convective Outlook Chart
Convective Graphics
Conv. Outlook
• Issued five times daily• Convective Activity• Hail• Tornadoes• Winds
Hail
Tornado
Winds
Forecast Winds & Temperatures Aloft Chart
FD
• 12 hour forecasts valid at 0000Z & 1200Z daily• Read same as station model winds• 99 for calm winds with no arrow• Temps are shown in Celsius