Weather Reports Flashcards
Radar weather reports (SD)
- radar detects precipitation only:
- snow, rain, thunderstorms
- heights are MSL
- example “TLX 1935 LN 8 TRW++ 86/40 164/60 20W C2425 MTS 570 AT 159/65 AUTO ^M01 ON3 PM34 QM3 RL2=”
TLX - location and time (TLX Oklahoma City)
LN - echo pattern
- May be LN= line; AREA; CELL
8 - coverage in tenths of an area
TRW++ - type and intensity
- thunderstorm (T) and very heavy rain showers (RW++)
86/40 164/60 - range and distance from station
- lines and areas defined by two sets
- cells defined by one
20W - width of the pattern
- example 20NM wide, 10NM each side of the line marked by above
C2425 - movement for cells
- example cells moving from 240 at 25kts
MTS 570 AT 159/65 - maximum top
- example 57,000ft 159 degrees @65NM
- MT for radar; MTS for radar+satellite
AUTO - automated report
^M01 - used for preparing radar summary chart
PIREP (pilot weather reports)
- contact flight watch 122.0 to give PIREP
- only way to know icing and turbulence conditions
2 types of PIREP
1. UA- regular (routine)
2. UUA- urgent
Format (info you report)
1. Where you are
2. Time
3. Altitude
4. Aircraft type
5. Weather conditions
6. Visibility
7. Turbulence
8. Icing
AIRMETS (WA)
- valid for 6 hours
- updated every 6 hours
- concerns smaller aircraft
- TANGO= turbulence low level wind shear
- SERRIA= IFR conditions mountain obscurations
- ZULU= icing conditions, icing level
- reports
1. Moderate icing; turbulence
2. Surface winds 30 KTS or more
3. Ceilings <1,000ft
4. Visibility 3SM
5. Extensive mountain obscurations
SIGMETS (WS)
- valid for 4 hours
- updated every 4 hours; 20 minutes past the hour
- reports non-convective weather potentially hazardous to all aircraft
- reduced visibility < 3SM
- severe icing
- severe turbulence
- clear air turbulence
- dust and sand storms
- volcanic ash and eruptions
Convective SIGMETS (WST)
- valid for 2 hours
- issued every hour; 55 minutes past the hour regardless if there is any convective activity or not
- convective SIGMETS imply but never state; sever turbulence, icing, and low level wind shear
- special issue can come anytime
- reports
1. Severe and embedded thunderstorms
2. Winds are always >/= 50KTS
3. Hail at surface more than 3/4” diameter
4. Tornados
5. Line of thunderstorms
TAF (terminal aerodrome forecast)
- same codes as METARS
- covers 5 mile radius based on the center of the airport runway complex
- TAF are built using METAR data and monitored for accuracy by a weather forecaster. If METAR data is missing or not complete, a TAF may not be issued
- issued 4 times a day 0000Z, 0600Z, 1200Z, 1800Z
- valid for 24 hours for each issuance
- no temperature
FA (area forecast)
- general weather conditions over a wide region covering several states
- issued 3 times a day
- valid for 18 hours; 12 hour forecast and 6 hour categorical
- amendments (AMD) when AIRMETS, SIGMETS, and convective SIGMETS are issued
- 4 parts to an FA
1. Communications and heading section - ID’s the office
- date and time of issuance
- product name
- valid times
- states covered
2. Precautionary statement - lets you know immediately if and where any IFR conditions, mountain obscurations or thunderstorms hazards exist
- heights for the most part are given in AGL
3. Synopsis (valid for 18 hours) - location and movement of weather
4. VFR clouds and weather (12 hour forecast) - clouds and weather significant to VFR
- summary of sky conditions, cloud height, visibility, and winds >30 KTS
- it concludes with a categorical outlook valid for 6 hours
FD (winds and temps aloft forecasts)
- winds and temperature for certain altitudes
- issued 2 times daily
- valid 24 hours
- no winds forecasted within 1,500ft of the station
- if code says 9900 winds are light and variable less than 5 KTS
- if code is 0000 wind is calm
- chart starts at 3000ft no temperature at 3000ft
- used to determine possible areas of icing
- no temperature within 2500ft of station
- all temperatures above 24000ft are below 0 so no signs (+/-) will be given
- there are 6 areas in the continental United States
- Arizona falls under SLC
In-flight weather: EFAS (en-route flight advisory service)
- call flight watch on 122.0
- available from 5,000ft AGL- 17,500ft MSL
- open from 6 AM to 10 PM local time
FSS (flight service station)
- use FSS if unable to get EFAS
- Prescott 122.2/122.6
TWEB (transcribed weather en-route broadcast)
- transmitted continually over NDB and VOR
- identified by a T with a circle around it on a chart
- updated 4 times a day valid for 12 hours
- range 50 NM (25NM on each side of NDB/VOR)
HIWAS (hazardous in-flight weather advisory)
- transmitted over VOR
- identified by H with a circle around it on a chart
- transmits AIRMETS, SIGMETS, and convective SIGMETS
- range 50 NM (25NM on each side of VOR)
AWOS (automated weather observing system)
- automated weather gathering system
- can receive it out to 25NM and up to 10000ft AGL
- reports minute by minute
1. AWOS A: Altimeter
2. AWOS AV: altimeter + visibility
3. AWOS 1: altimeter, wind, temp, dew point, density altitude
4. AWOS 2: AWOS 1 + visibility
5. AWOS 3: AWOS 2 + cloud and ceiling
6. AWOS 3P: AWOS 3+ precipitation
7. AWOS 3PT: AWOS 3P + thunderstorms/lightening
8. AWOS 4: AWOS 3 + precipitation, freezing rain, thunderstorms, runway sensors
ASOS (automated surface observing system)
- minute by minute observation
- has AWOS 4+ cloud height, intensity, and pressure change
ATIS (automated terminal information system)
- pre-recorded every hour (information comes from METAR)
- broadcast at controlled terminal area
Surface analysis chart
- issued every 3 hours, covering the lower 48
- shows isobars
- isobars show pressure patterns
- spaced at 4 millibar (MB)
- 1013mb= 29.92”hg
Pressure systems - L and H on chart
Fronts - show location and types of fronts
- “Flags” show direction
Troughs and ridges - troughs of low pressure are indicated by thick dashed lines through their center and the word TROF
- Ridges are rarely depicted
Other information - observations from stations depicted by round or square symbols
- round for observations
- square for automated
- helps identify temp, dew point, surface winds
Weather depiction chart
- created from METAR data
- broad overview of flying conditions; “birds eye view”
- valid at time of issue
- issued every 3 hours starting at 01Z each day
Shows - sky cover
- cloud height
- weather and obstructions to visibility
- visibility
- VFR
- ceiling >3k visibility > 5 miles
- no outline
MVFR - ceiling > 1k’ visibility > 3 miles
- non hatched, outline
IFR - ceiling < 1k visibility < 3 miles
- hatched and outlined
- front depicted the same as surface analysis chart
- used to get an idea of General VFR or IFR weather
- great to use before a briefing so you’re able to use breeders information better
Radar summary chart
- computer generated Displays precipitation information - area of coverage - intensity - type - echo tops - cell movements Available hourly at H+35 Symbols used on chart - R for rain - T for thunderstorms Note: this information may not match METARS. Type of precipitation info is generated from automated reports which use computer models to determine precipitation * intensity is displayed with contours - 6 intensity levels are divided among 3 contour levels - contours start with 1-2 at outside area, then 3-4, then 5-6 Echoes configuration - can be listed 3 different ways 1. Area of echoes 2. Single cell 3. Line of echoes
Significant weather prognostic chart
Provides a forecast of weather for various altitudes and forecast times
- low level= surface to FL 240; high level from 24-60
- periods of 12, 24, 36, and 48 hours
US low level significant weather prognostic
- 4 panels showing 12 and 24 hour forecast
- 2 lower panels show surface prognostic charts; 12 and 24 hour
- shows fronts and pressure regions
- troughs drawn by heavy dashed lines
- show precipitation
- areas surrounded by solid line show stable precipitation
- shaded areas show continuous precipitation
2 upper panels show aviation related weather; 12 and 24 hour
- shows forecast flying weather (VFR, MVFR, IFR)
- shows turbulence
- areas bordered by heavy dashed lines
- turbulence with thunderstorms not shown as thunderstorms, implies severe turbulence
Freezing levels:
- surface freezing level depicted by zig zag line
Sever weather outlook chart
- storm warning
- flood warning
- gale warning
- winter weather advisory
- flood advisory
- high surf advisory
- heavy freezing spray warning
- small craft advisory
- brisk wind advisory
- dense fog advisory
- wind advisory
- freezing fog advisory
- winter storm watch
- gale watch
- air quality alert
- special weather statement
- marine weather statement
- hazardous weather outlook
Constant pressure analysis chart
- shows meteorological data at a particular pressure level rather than a particular altitude
- useful for determining winds and temps aloft
- measurements are usually taken by tethered ballon
- each station reports:
1. Height of pressure surface
2. Changes in height over the last 12 hours
3. Temperature
4. Temp dew point spread
5. Wind, direction and speed
Tropopause chart: - shows observed winds, pressure and temp at tropopause
- as shows a forecast for high level significant weather- max winds
- shows a prognosis for tropopause height/vertical wind shear
- shows winds aloft for 34,000ft
Go/no go decision making
Aircraft capabilities
- turbulence; continued flight in moderate or greater turbulence prohibited
- no flight in known icing conditions
- under 200 hours, no more than 25k, gusts of 15kts
- VFR only
- is weather getting better or worse
- fronts approaching or passing
- your comfort level
- importance of mission
Use all available sources to help
- briefer can offer specific suggestions on wether or not to fly but can ask for additional information to help aid in making a decision
- other more experienced pilots not flying should you?
- pressures try to keep outside pressures from influencing your decision
- your pilot in command your decision if final
