1. Weather Charts

2. Current Weather Products
Observations
Surface Analysis Charts
Constant Pressure Charts
Weather Depiction Charts
Lifted Index Charts
Radar Summary Charts
Forecast Charts
Short Range Surface Prognostic Chart
Low level Significant Weather Prognostic Chart

3. Surface Analysis Chart
Shows the “big picture” – helps plan flights around WX
Depicts
Sea level pressure
Position of highs, lows, ridges and troughs
Position of fronts
Position of boundaries
Overview of winds, temperatures and dew points
Issued every 3 hours
Valid for 6 hours
Available at:

4. Surface Analysis Chart
Low
Sea Level Pressure
–4mb interval lines
- Line below # is pressure trend
Warm front
stationary front
Cold front – Pips show direction of movement
High - Number adjacent is central pressure
Sea Level pressure (first 10 or 9 digits omitted) or ceiling height
Tropical wave
Data
Wind
Temp
Sky cover – If station symbol is square then automated data was used
Dew Point

5. Surface Analysis Chart

6. Surface Analysis Chart

7. Surface Analysis Chart

8. DUATS Surface Analysis Chart

9. Constant Pressure Charts
Similar to the surface analysis chart but at different pressure levels (altitudes will vary)
850 MB chart ≈ 5,000’
700 MB chart ≈ 10,000’
500 MB chart ≈ 18,000’
Provides a 3D view of large areas – interpolate between charts
Data gathered through balloons
Shows winds and temps – can identify jet stream / freezing risks for example
Charts available at:

10. Constant Pressure Charts
X Marks high/low center
Issue date/time
Wind
Level
Contour line area of = height in meters (850 MB omits 1 before and 700 omits 2 or 3 before – which ever makes the number closer to 3,000 meters) e.g. 309 = 3309 meters or 10,754’ – Look at gradients - wind speed proportional to gradients (close = high winds). Contours can be interpreted in the same manner as isobars on the surface chart (e.g. high altitude=high pressure area)
Some charts also show:
isotherms – areas of equal temperature – bold dashed line
isotachs – constant wind speed areas – short fine dashed line with __K

11. Historic (FAA) Constant Pressure Chart
Wind
Latitude
Temp
Height / pressure altitude
Temp – DP spread
Height change / aircraft type
Satellite data
Balloon / Ground station
Data
Temp / Isotherm
Airplane observation
Longitude

12. Duats Constant Pressure Chart

13. Weather Depiction Chart
Broad overview of flying conditions – IFR (<3sm vis;1,000’), MVFR (3 to 5sm vis;1k to 3k ceiling), VFR (>5sm vis; >3,000 ceiling)
Also shows fronts and troughs (except 10 and 23Z)
Prepared 8 X per day

14. Weather Depiction Chart
IFR
MVFR
Precipitation / Vis obstructions
Sky cover
AGL cloud height
Legend
Data

15. Weather depiction Chart Symbols
NB: Symbols are the same as the Surface Analysis Chart

16. DUATS Weather Depiction Chart

17. Radar Summary Chart
Aids in preflight planning by identifying general areas and movement of precipitation and/or thunderstorms
Issued hourly
Shows:
Radar echos
Types of precipitation
Movement of cells
Tops of precipitation
Severe Thunderstorm and Tornado Watch areas
DOES NOT SHOW clouds or fog

18. Radar Summary Chart

19. Radar Summary Chart
Individual cell movement is indicated by an arrow with the speed in knots entered as a number at the top of the arrow head.
Highest echo height in the area is shown above a short line, with the top height displayed.
Severe weather watch areas are outlined by heavy dashed lines, usually in the form of a large rectangular box.

20. NWS Radar Summary Chart

21. Nexrad Radar

22. Lifted Index Chart
Provides plot of the lifted index and K index values
Lifted Index
is a measure of atmospheric stability – it is a comparison of predicted temperature change from the surface (2° saturated or 3° unsaturated) less actual temperature change from the surface to 500mb (18,000 msl +/-)
Positive LI – colder so stable air
Negative LI – warmer so less stable
Zero LI – neutral stability
Becomes more stable with decreased dew point, decreasing surface temperature or increasing 500 mb temperature
Severe thunderstorm guide 0 to -2 weak potential; -3 to -5 moderate potential; ≤-6 Strong potentia;

23. Lifted Index Chart K Index – used mostly by meteorologists
During warm season a large Ki indicates conditions favorable for thunderstorms
In winter temperature terms completely dominate K index
Ki < 20 – No chance of thunderstorms
Ki 20 to 25 – Isolated thunderstorms
Ki 26 – 30 – Widely scattered thunderstorms
Ki 31 – 35 – Scattered Thunderstorms
Ki > 35 – Numerous thunderstorms

24. Lifted Index Chart Lifted Index (LI) Severe Potential K-Index *
Airmass Thunderstorm Probability
0 to -2
Weak
<15
near 0%
15-20
20%
-3 to -5
Moderate
21-25
21-40%
26-30
41-60%
< -6
Strong
31-35
61-80%
36-40
81-90%
>40
near 100%
It is essential to note that an unstable Lifted Index does NOT automatically mean thunderstorms. Look at the synoptic situation and if thunderstorms are expected to develop in the unstable air, this table may be used. * Use caution when applying these values in the western mountainous terrain due to elevation

25. Lifted Index Chart

26. Short Range Surface Prognostic Chart
Surface forecast of pressure systems, fronts and precipitation for two day period – 12, 24, 36 and 48 hours
Uses Surface Analysis chart symbols
Produced 4 x day for 12 and 24 hour periods; twice per day for 36 and 48 hour periods

27. Short Range Surface Prognostic Chart
Shading = >50% coverage; Unshaded precip indicates 30 to 50% coverage
A bold, dashed, grey line is used to separate precipitation within an outlined area with contrasting characteristics
Precipitation
Trough

28. Short Range Surface Prognostic Chart

29. DUATS Low Level Weather Prognostic Chart

30. Low Level Significant Weather Prognostic Chart
Forecast of aviation weather hazards
Preflight use
3 versions (High level (FL250-FL630); mid level (FL100-FL450) and low level (SFC-FL240))
12 and 24 hour panels; additional charts for 30, 36 and 48 hours
Depicts
VFR, MVFR and IFR areas (top panel)
Freezing levels (top panel)
Turbulence (top panel)
Fronts and pressure systems (lower panel)
Available at:

31. Low Level Significant Weather Prognostic Chart

32. Low Level Significant Weather Prognostic Chart

33. Low Level Significant Weather Prognostic Chart

34. DUATS Severe Weather Outlook

35. DUATS Winds Aloft Forecast Chart

36. NWC AirMet / Sigmet Charts
Airmet Zulu - Icing
Airmet Sierra - IFR
Airmet Tango - Turbulence
Freezing levels

37. Freezing Level Chart

38. Icing
SLD (super-cooled large drop - includes freezing drizzle and freezing rain).

39. Turbulence

40. Infrared Satellite Chart

41. Visible Satellite Chart
Day
Night

42. QUESTIONS