1. Weather Services
CHAPTER 7

2. Content Aviation Weather Reports/Forcasts
Reading Weather Reports/Forcasts
TAF, FA, METAR, FD, Pireps
Surface Weather Charts
Weather Depiction charts
Windshear avoidance

3. WEDNESDAY QUIZ ASA CHAPTER 7 EVERY QUESTION IS FAIR GAME.
APPOXIMATELY 73 QUESTIONS
QUIZ WILL BE 14 OF THE ABOVE QUESTIONS
STUDY!!!!!!!

4. Reading Assignment Jeppesen Chapter 7 Gleim chapter 8 *****
ASA CHAPTER 7
AIM section 7
AC 00-45G Aviation Weather Services
PHAK CHAPTER 12
FMH-1 Section 12

5. Aviation Weather Reports and Forecasts (215)
Where can one obtain weather information?
FSS WXBRIEF, TWEB (transcribed weather broadcast on NDB/VOR), PATWAS (pilot’s automatic telephone weather answering service, 50nm), TIBS (Telephone information briefing service, routes on demand service

6. Aviation Weather Reports and Forecasts
Already in flight HIWAS (hazardous inflight weather advisory service, over VOR’s Airmets/Sigmets)
EFAS (enroute flight advisory service, or flight watch, mHz)enroute weather PIREPS
Radio, Television, Internet, ATIS, Tower, DUATS etc..

7. How to get a good briefing
Call FSS WX-Brief,
Identify yourself as a pilot
Tell them about your flight
Type of flight, type of briefing as well as VFR or IFR, Aircraft number or your name, aircraft type, departure point, route of flight, destination, flight altitude(s), estimated time of departute, estimated time en route or estimated time of arrival

8. Types of weather briefings
Standard briefing includes everything
Abbreviated briefing - used to supplement information you already have
Outlook briefing - when the briefing is 6 hours or more in advance of proposed departure

9. METAR METAR= Meteorological Aviation Routine weather report
In 1996 US converted to the ICAO and the World Meterological Organization form of aviation weather reporting.
Each country is allowed to make modifications to the code to use in that particular country
In the U.S. visibility is in statute miles, runway visual range in feet, wind speed in knots, and altimeter setting in inches of mercury

10. METAR Elements of a METAR 1. Type of Report 2. ICAO station identifier
3. Date and time of report
4. Modifier (as required)
5. Wind
6. Visibility
7. RVR
8. Weather
9. Sky conditions
10. Temp/DPT
11. Altimeter
12. Remarks

11. GLEIM SUPPLEMENT METAR

12. METAR
METAR KMWH Z COR 24015KT 3/4SM R28/2400FT +TSRA BKN008 OVC015CB 26/25 A2985 RMK TSB32RAB32
METAR KEPH Z COR 22015G25KT 3/4SM R28L/2600FT TSRA OVC010CB 18/16 A2992 RMK SLP045 T

13. METAR

14. METAR (226 & 200AFD)
METAR’s are issued normally 5-10minutes before the hour every hour
Ceiling is defined as the lowest broken or overcast layer or vertical visibility into a surface based obstruction
Indefinite ceiling VV006
Temperature below zero prefixed with a M

15. METAR (226 & 200AFD)
A01-Automated station with out precipitation discrimination
A02- with precip discrimination
VC in vicinity of airport 5-10 SM
METAR’s are reports (a moment of time) not a forecast
FMH-1 SECTION 12

16. TAF (255 & 200AFD) Used to be called a FT
Is a forecast of the expected weather conditions at an airport during a specific period (24hrs to 30 hours)
Issued four times a day for hrs periods (00Z, 06Z, 12Z, 18Z)

17. GLEIM TAF SUPPLEMENT

18. TAF (255 & 200AFD)
Example:
TAF AMD KMWH Z 0622/ KT P6SM VCSH SCT007 BKN020 OVC050 TEMPO 0622/0701 5SM BR BKN007 OVC015 FM KT P6SM SCT080 OVC150

19. TAF (255 & 200AFD)
Example:
TAF AMD KYKM Z 0620/0718 VRB04KT P6SM VCSH OVC025 TEMPO 0620/0624 -RA OVC018 FM VRB04KT P6SM VCSH SCT025 OVC050 TEMPO 0700/0704 -RA OVC025 FM VRB04KT 5SM BR VCSH OVC025 FM VRB03KT 4SM BR VCSH OVC020 FM VRB04KT 6SM -RA BR OVC030

20. FA AVIATION AREA FORECAST (269)
FA is a forecast of general weather conditions over an area the size of several states.
It is used to determine forecast en route weather and to interpolate conditions at airports that do not have TAF’s issued.
FA’s are issued 3 times a day for 6 different areas in the U.S. (00Z, 08Z, 16Z)

21. FA REGIONS

22. FA AVIATION AREA FORECAST (269)
FA is comprised of four sections:
1 Communication and product header section
2. A precautionary statement section
3. Synopsis section
4. VFR Clouds/WX section

23. FA AVIATION AREA FORECAST (269)
The area we are in is the SFO San Francisco area
1. Communication and Product header
Identifies the office for which the FA is issued, the date and time of issue, the product name, the valid times, and the states and/or areas covered by the FA
2. Precautionary statements. Three statements are in all FA’s

24. FA AVIATION AREA FORECAST (269)
See airmet sierra for IFR conds and mtn obscn.
TSTMS IMPLY PSPL SVR OR GTR TURBC SVR ICG LLWS AND IFR CONDS.
NON MSL HGTS ARE NENOTED BY AGL OR CIG.

25. FA AVIATION AREA FORECAST (269)
Synopsis - brief summary of the location and movement of fronts, pressure systems, and circulation patterns for an 18-hr. period
VFR Clouds and Weather - contains a 12 hr. specific forecast, followed by a 6 -hr outlook giving a total forecast of 18hr
(pg 271 overhead or DUAT example)

27. In-Flight WX advisories (278)
Are forecasts that advise en route aircraft of the development of potentially hazardous weather
Three different kinds of in-flight wx advisories
1. Convective SIGMET (WST)
2. SIGMET (WS)
3. AIRMET (WA)

28. In-Flight WX advisories (278)
All heights are MSL unless stated CIG
Convective SIGMET (WST) - Are issued for any of the following
A severe thunderstorm due to 1. Surface winds greater than or equal to 50kt, 2. Hail at the surface greater than or equal to 3/4 in. in diameter, 3. Tornadoes, 4. Embedded thunderstorms, 5. Line of thunderstorms, or 6. TS greater or = to VIP intensity level 4 affecting 40% or more of an area 3000 square miles.

29. In-Flight WX advisories (278)
Convective SIGMET (WST) - implies severe or greater turbulence, severe icing, and low-level wind shear
Issued for eastern (E), central (C), and western (W) United States.
Bulletins are issued hourly at H+55
Each new bulletin is identified with a number
The text of the bulletin’s forecast is valid for up to 2 hours. (Pg 281)

30. In-Flight WX advisories (278)
SIGMET (WS)- advises of nonconvective weather that is potentially hazardous to all aircraft
1. Severe icing, 2. Severe or extreme turbulence or clear air turbulence not associated with a TS
3. Dustorms, sandstorms, or volcanic ash lowering surface visibilities to below 3SM
4. Volcanic eruption
The maximum forecast period is 6 hrs.

31. In-Flight WX advisories (278)
Identified by alphabetic designators which inlude November through Yankee but exlude Sierra and Tango
First issuance of a SIGMET with be labeled UWS (urgent weather SIGMET)

32. In-Flight WX advisories (278)
Example
UWS
SIGMET PAPA 1 VALID UNTIL
AR LA MS
FROM STL TO 30N MEI TO BTW TO MLU TO STL OCNL SVR ICING 90 TO 130 EXPCE.
FRZLVL 80 E TO 120 W. CONDS CONTG BYD 2100Z

33. In-Flight WX advisories (278)
AIRMET (WA)- are advisories of significant weather phenomena but describe conditions at intensities lower than those which trigger SIGMETs.
Are bulletins issued on a scheduled basis every 6 hrs. Issued for: moderate icing, Moderate turbulence, sustained surface winds of 30 kt. Or more, IFR clouds and visibilites affecting over 50% of the area at one time, extensive mountain obscurement

34. In-Flight WX advisories (278)
AIRMET - have fixed alphanumeric designators of:
ZULU for icing
TANGO for turbulence
SIERRA for IFR and mountain obscuration
Pg 284 example

35. WINDS ALOFT FORECAST FD(285)
Forecasts are made twice a day based on 00Z and 12Z data for use during specific time intervals
Can be both an observation or a forecast.
Valid for a specific time
Gives winds at 3000ft, 6000ft, 9000ft, 12,000ft, 18,000ft, 24,000ft, 30,000ft, 34,000ft etc.
example winds and temperature at 9,000ft are written as
= winds 270 degrees true and 25 knots temperature 0 degrees C

36. WINDS ALOFT FORECAST FD(285)
No winds are forecast within 1500ft of station elevation, also no temperature are forecast for the 3,000ft level or for any level within 2,500 ft of station elevation. Above no negative C
If wind speed is over 100 knots (or from knots) the wind speed will have 50 added to the direction
Example wind 230 degrees T at 150 knots =7350
Wind less than 5 kt codedas 9900 light and variable (Show duat example)

37. FD GLEIM

38. PIREPS UA(245)
PIREPS (UA) - observations from pilots in the cockpit. Provide the only means of directly observing cloud tops, icing, and turbulence.
Trasmitted in a prescribed format
/OV = LOCATION, /TM = TIME, /FL = ALTITUDE/FLIGHT LEVEL, /TP = AIRCRAFT TYPE, /SK = SKY COVER, /WX = FLIGHT VISIBILITY AND WEATHER, /TA = TEMPERATURE, /WV = WIND, /TB = TURBULENCE, /IC = ICING, /RM = REMARK

39. PIREP

40. PIREPS UA(245) The letter “UUA” identify an urgent PIREP Example
UA/OV MWH/TM 1600/FL100/TP B19/SK024 BKN 032/042 BKN-OVC/WX FV02 R H/ TA -12/WV 27020/TB LGT/IC LGT-MDT RIME /RM MDT RAIN

41. GLEIM UA FIGURE

42. Surface Analysis Chart (296)
Transmitted every 3 hours
Valid with the time of the plotted observations
Shows pressure systems (L & H)isobars in 4mb/hpa intervals, Fronts, wind speed, sky cover, cloud type, sea level pressure, temperature, present weather, dew point, 6 hour precipitation, pressure tendency, pressure change in last 3 hours, squall lines, troughs and ridges

43. Surface Analysis Chart (297)
Picture of chart on 297 or duat/adds example

44. SURFACE ANALYSIS CHART

45. STATION MODEL AND SYMBOLS

46. Weather Depiction Chart (305)
Is computer prepared from METARs.
Gives a broad overview of the observed flying category conditions at the valid time of the chart
First one is issued at 1zulu and is then transmitted at 3 hour intervals, and is valid at the time of the plotted data
Gives total sky cover, cloud height or ceiling, weather and obstructions to vision, visibility, analysis (if IFR, MVFR, or VFR)
Good chart for initially sizing up the general weather picture

47. WEATHER DEPICTION GLEIM

48. Weather Depiction Chart (305)
Show chart of Page 307
Or Duat example

49. RADAR SUMMARY CHART

50. PHAK RADAR SUMMARY

51. Low level significant weather prog chart (317)
Is a four-panel chart
The two lower panels are 12 and 24 hr. surface prognostic charts
The two upper panels are 12 and 24 hours prognostic charts of significant weather from the sureface to 400 mb/hPa (24,000ft MSL)
The charts show conditions as they are forecast to be at the valid time fo the chart

52. PROG CHARTS

53. GLEIM SIGNIFICANT PROG CHART

54. Low level significant weather prog chart (317)
This chart is issued 4 times daily with the 12 and 24 hour forecasts based on the 0000Z, 0600Z, 1200Z, 1800Z synoptic data
The two surface prog panels use standard symbols for fronts, significant troughs, and pressure centers. Also outlines areas of forecast precipitation and/or thunderstorms a. solid lines continuous or intermittent (stable air) precipitation. B. Dash-dot lines show showers and TS (unstable air precip)

55. Low level significant weather prog chart (317)
Symbols indicate the type of precipitation
The upper panels depict IFR, MVFR, turbulence, and freezing levels. There is a legend in the center of the chart which explains the methods of depiction.

56. Low level significant weather prog chart (317)
show chart on page 318

57. Wind Shear (42)
Wind shear - generates eddies between two wind currents of differing velocities.
A. The difference may be in wind speed, wind direction, or in both
May be associated with either a wind shift or a wind speed gradient at any level in the atmosphere

58. Wind Shear (42) Four conditions are of special interest.
1. Wind shear with a low-level temperature inversion
2. Wind shear in a frontal zone,
3. Clear air turbulence at high levels associated with a jet sstream or strong circulation
4. Micro burst with a thunderstorm

59. Wind Shear (42)
Temperature inversion - climbing or descending through the inversion can cause airspeed to slow or increase, this relative wind fluctuations can cause the aircraft to reach its critical angle of attack and stall. (101) Especially if climbing into a strong tailwind above.
If landing approach is into the wind above the inversion, when the headwind is lost descending through the inversion may induce a stall.

60. Wind Shear (42)
Good rule of thumb when ever gusty winds are encountered or wind shear suspected at have the gust factor or half the difference in wind speed to your climb or approach speed.
This gives a margin or safety if and when your enter turbulence or cross wind shear.
Winds 10G30 add 10 knots to your approach speed.

61. Private PTS You need to know METAR, TAF AND FA Surface analysis chart
Radar summary chart
Winds and temperature aloft chart
Significant weather prognostic chart
Convective outlook chart.
AWOS, ASOS, and ATIS reports

62. USEFUL LINKS www.duat.com www.duats.com http://aviationweather.gov/