Weather Types - aspenflyingclub.com · • BECMG 0610 P6SM NSW – Gradual change in weather (over...
Transcript of Weather Types - aspenflyingclub.com · • BECMG 0610 P6SM NSW – Gradual change in weather (over...
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Sport / Private Ground School
Lesson 7
Weather Products
Weather Types
• Text Weather– Current Conditions
– Forecasts
• Graphical Weather– Current Conditions
– Forecasts
Text Weather Notes
• Winds are reported in reference to true north– 30015G24 (300° @ 15 knots with Gusts to 24 knots)
• Visibility reported in statute miles (SM)– 6SM (6 Statute Miles)– P6SM (greater than 6 SM)
• Ceiling is the lowest broken or overcast layer (more than 50%)– Clear: < 1/8– Few: 1/8 to 2/8– Scattered: 3/8 to 4/8– Broken: 5/8 to 7/8– Overcast: > 7/8
• In controlled airspace, VFR conditions exist with a visibility of at least 3sm and a ceiling of at least 1,000’ AGL
Current Conditions
• METAR– MEteorological Terminal Aviation Routine Weather Report or METeorological Aerodrome Report.
– Aviation Routine Weather Report
– Updated at least once per hour, normally at 55 minutes past the hour
• PIREP– Produced by Pilots
– Actual conditions
– Normal Pilot Reports (UA)
– Urgent Pilot Reports (UUA)• Disseminated by ATC
METAR
METAR KAPA 270153Z 04008KT 10SM SCT060 BKN070 07/M03 A3007 RMK AO2 SLP188 T00671028
• Conditions at KAPA: Observed 0153 UTC 27th of the month• Winds: From the NE (40 degrees) at 8 knots • Visibility: 10 or more miles• Clouds: Scattered clouds at 6000 feet AGL; broken clouds at 7000 feet AGL • Temperature: 7°C• Dewpoint: ‐3°C• Altimeter: 30.07 inches Hg • Remarks:
– A02: Automated station with precipitation discriminator– SLP188: Sea level pressure in millibars 1018.8 mb– T00671028: Temperature/dewpoint in tenths °C 6.7/‐2.8
Pilot Report (PIREP)
PUB UA /OV PUB/TM 0114/FL400/TP B737/TB OCNL MOD CHOP 400/RM CONT LGT CHOP AWC‐WEBWNCO
• PUB UA: Pueblo routine report• OV PUB: Location in relation to Pueblo• TM 0114: Time 0114Z• FL400: Flight level 400 (40,000’)• TP B737: Type Boeing 737• TB OCNL MOD CHOP 400: Turbulence, occasional moderate chop at 40,000’• RM CONT LGT CHOP AWC‐WEBWNCO: Reported via Aviation Weather
Center’s web‐based PIREP system
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Printed Weather Forecasts
• TAF: Terminal Aerodrome Forecast– Published 4 times per day
• FA: Area Forecast– Published 3 times per day
• FD: Winds & Temp Aloft Forecast– Published 2 times per day
• AIRMET: Airman’s Meteorological Information– Published every 6 hours
• SIGMET: Significant Meteorological Information– Published when a pilot makes a report
• Convective SIGMET– Published As‐Needed
Terminal Aerodrome Forecast (TAF)
• Usually valid for 24hr period
• Updated four times a day
• Cumulonimbus (CB) are the only type of cloud included on a TAF
• Max visibility reported as P6SM (greater than 6 SM)
TAF Forecast Modifiers(sample)
• FM1900 07010KT P6SM SCT012 BKN020
– Rapid change in weather (within 1 hour)
• BECMG 0610 P6SM NSW
– Gradual change in weather (over 2 hours)
• TEMPO 1923 VRB08G18KT 3SM TSRA
– Temporary change in weather
• PROB30 0004 2SM TSRA OVC010CB
– Probability Forecast when probability is 30 ‐ 39%
TAF Example
KAPA 012059Z 0121/0218 07007KT P6SM SCT010 OVC020
TEMPO 0121/0201 3SM ‐SN BR BKN010 OVC020
FM020100 10007KT 5SM ‐SN BR SCT008 BKN015 OVC025
TEMPO 0201/0205 2SM ‐SN BR BKN007
FM021000 VRB05KT P6SM VCFG SCT015 BKN050
FM021300 18006KT P6SM FEW030 SCT060
FM021700 14008KT P6SM FEW060 SCT120
Aviation Area Forecast (FA)
• Use to determine wx conditions between reporting stations and over several states.
• Helpful in determining wx at airports w/o TAFs
FA Notes
• Four Sections– Heading (valid times)
• Synopsis: 18 hours
• VFR Clouds and Weather: 12 hours
• Outlook: 6 hours
– Precautionary Statements
– Synopsis
– VFR Clouds and Weather
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FA Sample
000
FAUS45 KKCI 012045
FA5W
SLCC FA 012045
SYNOPSIS AND VFR CLDS/WX
SYNOPSIS VALID UNTIL 021500
CLDS/WX VALID UNTIL 020900...OTLK VALID 020900‐021500 ID MT WY NV UT CO AZ NM .
SEE AIRMET SIERRA FOR IFR CONDS AND MTN OBSCN. TS IMPLY SEV OR GTR TURB SEV ICE LLWS AND IFR CONDS. NON MSL HGTS DENOTED BY AGL OR CIG.
FA Sample
SYNOPSIS...BROAD UPR LVL TROF WILL CONT OVR WRN US DURG FCST PD WITH MOIST FLOW FROM PAC ESEWD ACRS AREA. UPR LVL LOW PRES SYS OVR ERN PAC NR 45N/140W WILL MOVE SEWD TOWARDS AREA. BY 15Z UPR LVL LOW PRES SYS WILL OVR CSTL SXNS OF NRN CA.
FA Sample
CO
MTNS AND WEST...
SERN PTNS...OVC080‐100 TOPS FL180. WDLY SCT ‐SHSN LWRG VIS 3‐5SM. BECMG 0609 SCT100 SCT150.
OTLK...VFR.
REST OF AREA…BKN‐SCT080 TOPS 120‐140. ISOL ‐SHSN. BECMG 0306 SCT100 SCT150. OTLK...VFR.
ERN PLNS/FOOTHILLS...OVC050‐070 LYRD FL200. OCNL ‐SN BR LWRG VIS 3SM. OTLK...MVFR CIGS BR.
Winds Aloft Forecast (FD)
• Winds given in true direction; speed shown in knots
• First 2 digits: wind direction
• Next 2 digits: wind speed *
• Last 2 digits: temp°C (neg above 24k’)• 9900 = light and variable
• No winds are forecast within 1,500 ft AGL
• No temperatures within 2,500 ft AGL
Winds Aloft Forecast (FD)
** Winds between 100 and 199kts are displayed by subtracting 50 to the two‐digit wind direction and adding 100 from the 2‐digit velocity.
So, 7701 = winds 270@101 (subtract 50 from direction, add 100 to velocity)
AIRMET: In‐flight Aviation WX Advisories
• Warn of weather conditions which are particularly hazardous to small, single‐engine aircraft (moderate icing, moderate turbulence, sfc winds 30kts, ceiling < 1,000’, vis < 3sm)
– Sierra: IFR, Mountain obscuration
– Tango: Turbulence, winds, LLWS
– Zulu: Icing and freezing levels
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AIRMET: In‐flight Aviation WX Advisories
AIRMET ICE...WY UT CO AZ NM FROM CYS TO SNY TO GLD TO 50W LBL TO 30ESE TBE TO 60WSW LBB TO 50N ELP TO 50N SSO TO 40NE PHX TO 30NE DRK TO 50ESE JNC TO 20W CHE TO CYS MOD ICE BTN FRZLVL AND FL180. FRZLVL SFC‐080. CONDS CONTG BYD 03Z ENDG 06‐09Z.
SIGMET
• Warn of weather hazards such as severe icing, which concern all aircraft
– Severe turbulence
– Dust storms
– Sand storms
– Volcanic Eruptions
Convective SIGMET
• Warn of convective weather hazards
– Tornadoes
– Embedded thunderstorms
– Hail ¾” or greater in diameter
CONVECTIVE SIGMET 5C VALID UNTIL 0555Z LA AR TX FROM 20SE ELD‐MLU‐20N LFK‐30W GGG‐20SE ELD AREA TS MOV FROM 29035KT. TOPS TO FL230.
OUTLOOK VALID 270555‐270955 FROM 30NE JAN‐40ENE MCB‐40SE LFK‐60WSW GGG‐30NE JAN WST ISSUANCES POSS. REFER TO MOST RECENT ACUS01 KWNS FROM STORM PREDICTION CENTER FOR SYNOPSIS AND METEOROLOGICAL DETAILS.
Convective SIGMET
Convective SIGMET
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Graphic Reports
• Surface analysis chart
• Weather depiction chart
• Radar summary chart
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Surface Analysis Charts
• Shows areas of high and low pressure
• Shows Temperatures and Dew Points
• Published every 3 hours
Cold Front
Warm Front
Stationary Front
Occluded Front
Weather Depiction Chart
• A station circle shows the visibility, cloud height or ceiling, and weather and/or obstructions to vision
• For flight planning, the weather depiction chart is most useful for determining general weather conditions and quickly locating areas of adverse weather
Station Model Weather Depiction Chart
Published every 3 hours
Radar Summary Chart
• Depicts the location of precipitation, as well as direction and speed of movement of radar returns
• Individual t‐storm cells as well as lines of thunderstorms are depicted on radar summary charts
• Since radar only reflects precipitation, it does not detect cloud formations
• Published once per hour
Radar Summary Chart
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Graphic Forecasts
• Low‐level prog. chart
• Severe weather outlook chart
• Winds and temperature aloft chart
Low Level Significant Weather Prog Chart
• Low‐level = below 24,000’
• Helps you avoid areas of:– Low visibility
– Low ceilings
– Significant turbulence
– Icing conditions
4 – Panel Prog Chart12 hour forecast 24 hour forecast
Turbulence,Freezing levels, IFR/MVFR
Surface Prognostics
Legend
Significant WX Panels
Ceiling < 1,000’ and/or vis < 3sm
Moderate or greater turbulence
Ceiling 1‐8k’ and/or vis 3‐5sm
Freezing level MSL
Surface Prog Panel Severe Weather Outlook Chart
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Winds and Temperatures Aloft Chart Pre‐Flight Weather Services
• 1‐800‐WX‐BRIEF
• DUATS
• Internet/Commercial services
– Skyvector.com
– Pilotweb.nas.faa.gov/pilotweb
WX Brief
• Standard Briefing: provides the most complete info concerning weather for your flight. Briefer assumes you have not received any preliminary info
• Abbreviated Briefing: update information from other sources or an earlier briefing
• Outlook Briefing: for departures six or more hours in the future
WX Brief
Standard Briefing Info Needed
– Type flight: VFR
– Aircraft ID: 1277K
– Aircraft Type: AAT4
– Departure: Centennial Airport (APA)
– Departure Time: 1600Z; or in 30 minutes
– Cruising altitude: 8,000’
– Route of Flight: 15nm to the southeast
– Destination: Returning to APA
– Est time en route: 1 ½ hours
DUATS
• Direct User Access Terminal
• Online method of receiving wx briefings and filing flight plans
• www.duat.com
• www.duats.com
• Free service (pilot certificate req)
Internet / Commercial Sources
www.aviationweather.gov
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In‐Flight Weather Sources
• Flight Watch (EFAS)
• Transcribed Weather Broadcast (TWEB) – Alaska only
• Hazardous In‐flight Weather Advisory Service (HIWAS)
• Automated Weather Observing System (AWOS)
• Automated Surface Observation System (ASOS)
Flight Watch
• Enroute Flight Advisory Service (EFAS)
• EFAS provides actual wx info, including thunderstorms which might affect your route
• 122.0 between 5,000’AGL and 18,000’ MSL
• “Denver Flight Watch, Gobosh 1277K, Falcon VOR”
TWEB
• Available only in Alaska
• Transcribed Weather Broadcast
• Continuous broadcast of local area weather conditions and forecasts, advisories, winds aloft, NOTAMS, etc
• Broadcast over select VORs
• A “T” in the upper right corner indicates NAVAID with TWEB
HIWAS
• Hazardous In‐flight Weather Advisory Service
• AIRMETs, SIGMETs, Convective SIGMETs, Urgent PIREPs
AWOS / ASOS
• Automated Weather Observing System/Automated Surface Observation System
• Provide real‐time weather info:
– Altimeter, wind, temp/dewpoint, visibility, cloud, ceiling
– ASOS adds even more data including precip type and intensity
Additional Resources
• Aviation Weather (AC 00‐6A): http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2000‐6A%20Chap%201‐3.pdf
• Aviation Weather Services (AC 00‐45G): http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC‐0045G_chg1_fullDocument.pdf
• AIM Chapter 7