Section 3

Chapter 3

3.1 METAR

METAR

  • Roughly translated from the French as Aviation Routine Weather Report
  • On July 1 1996 the METAR format was adopted for global standardization
  • Provides common frame of reference for international flights

METAR

  • 2 Types:
  • METAR comes out hourly from H+45 to the top of the hour
  • SPECI which is non routine and comes out when special conditions exist… see table 3-1

Types of Observations

  • Manual Observation
  • Done by a human
  • Automated Observation
  • Automated surface observing system (ASOS)
  • Automated Weather Observing System (AWOS)
  • Augmented Observation
  • Human oversight, including tower personnel
  • AUTO is not used when the wx dude gets involved

METAR

  • Type of Report
  • Station ID
  • Date/Time
  • Modifier
  • Wind
  • Visibility
  •  
  • Weather
  • Sky condition
  • Temp/Dew point
  • Altimeter
  • Remarks

METAR DECODED

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO

TYPE OF REPORT

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  •  
  • SPECI KMWH 282021Z 00000KT 2SM BR OVC009 01/M01 A3076 RMK AO2 CIG 003V011 T00111011
  • Designates if it is a METAR or SPECI

ICAO IDENTIFIER

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • ICAO identifier, K = continental U.S.

DATE AND TIME

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • 30 = day of the month, 1456Z indicates time the report was issued in Zulu

MODIFIER

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • AUTO will be absent if the report is taken by or augmented by a human.

MODIFIER

  • METAR  KSMP  301456Z  COR VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • COR will be present if a corrected report has been sent out.

WIND

  • METAR KSMP 301456Z  AUTO 09026KT 1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020 T10221028  58004  TSNO
  • The first three digits are direction, last two or three digits are velocity in knots. Direction is True and which way it is FROM

WIND

  • METAR KSMP 301456Z  AUTO  08012G25KT 040V120  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Wind gust is a rapid speed change of 10kts or more.
  • To be reported as variable, direction must vary 60˚ or more and speed greater than 6kts. If speed is less than 6, then VRB will be reported.

WIND

  • METAR KSMP 301456Z  AUTO  00000KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • If calm, then it will be reported as 00000KT

VISIBILITY

  • METAR KSMP 301456Z  AUTO  VRB06KT  M1/4SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Automated stations use an M to indicate “less than”

VISIBILITY

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Visibility is reported in Statue Miles.
  • P6SM means visibility greater than 6 statue miles.

RVR

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  R32R/3000V4500FT SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • R denotes the group, 32R the runway, 3000V4500FT the visual range 3000 variable to 4500.

RVR

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  R32R/M0600FT SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • RVR is coded from 600’ to 6000’. P or M indicates Above or Below those limits (R32R/M0600FT)

PRESENT WX GROUP

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Intensity qualifiers: (-) = light, none = ( )
  • moderate, (+) = heavy.
  • Weather is inside a 5 mile radius.
  • VC for 5-10 mile radius.
  • See table 3-2 for descriptors.
  • BR is vis 5/8 to 6 miles, FG is less than 5/8.

PRESENT WX GROUP

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Descriptor qualifiers MI=shallow, PR=partial, BC=patches, DR=low drifting, BL=blowing, SH=showers, TS=t-storm, FZ=freezing.

PRESENT WX GROUP

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  TSB05E45  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Thunderstorm began 5 min after the hour and ended 45 min after the hour.

SKY CONDITION

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • OVC = overcast, BKN = broken, SCT = scattered, FEW = few, SKC = from a human, CLR = from a machine at or below 12,000. OVC020 clouds are 2000 AGL. See table 3-3.

SKY CONDITION

  • Height is reported in AGL
  • Cloud type may be reported TCU, CB, ACC
  • VV = Vertical Visibility, VV001
  • Ceiling is broken or overcast
  • If the sky is obscured VV is the ceiling
  • Sky is broken into 8ths Table 3-3

Sky Cover

  • The abbreviation CLR will be used at automated stations when no layers at or below 12,000 feet are reported
  • The abbreviation SKC will be used at manual stations when no layers are reported.
  • Any layer amount less than 1/8 is reported as FEW.

SKY CONDITION CODING

TEMPERATURE/DEW POINT

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Temperature/Dew Point in Celsius
  • M = Minus

ALTIMETER

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Altimeter setting measured in inches of Hg 30.19

REMARKS

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Remarks are used to clarify the conditions specified in the body of the report. Checkout pg 3-18

REMARKS

  • METAR KSMP 301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • AO2 = Precip discriminator, A01=No Precip discriminator
  • PK WND = Highest wind speed since the last METAR in direction, speed and time (PK WND 20032/15)
  • WSHFT = Wind shift and the time. If due to frontal passage then FROPA is entered (WSHFT 30 FROPA)
  • TWR VIS = Vis given by the tower (TWR VIS 1 1/2)
  • VIS 1/2V2 = Variable visibility
  • VIS NE 2 1/2 = Sector visibility
  • VIS 2 1/2 RWY 14L = Vis at a second location
  • OCNL LTGICCG NW, FRQ LTG VC, or LTG DSNT W

REMARKS

  • METAR  KSMP  301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Sea Level Pressure 1025.8  Add a 10 or a 9 whichever will bring the number closest to 1000

REMARKS

  • METAR  KSMP  301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Pecip amount 8/100ths of an inch, 6 hour precip amount .20 inches

REMARKS

  • METAR  KSMP  301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • 6 hour precip amount. 6 is the group indicator, the following 4 digits the amount
  • .20 inches of precip
  • 2.17 inches would code out to 60217

REMARKS

  • METAR  KSMP  301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T00221028  58004  TSNO $
  • Temperature Plus 2.2°C Dew Point Minus 2.8°C 1=minus, 0=plus
  • $ means maintenance is needed

REMARKS

  • METAR  KSMP  301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004  TSNO
  • Pressure tendency 8=steady or increasing then decreasing by 0.04 hectopascals

REMARKS

  • METAR  KSMP  301456Z  AUTO  VRB06KT  1/2SM  SN  FZFG  VV001  M02/M03  A3019  RMK  AO2  SLP258  P0008  60020  T10221028  58004 SHRAB05E15SHSNB20E55 TSNO
  • Rain showers began 0005 and ended 0015 then snow showers began 0020 and ended 0055

AWOS, ASOS, AMOS

  • Automated wx
  • Provides minute by minute wx data
  • Stations are strategically located in the runway complex
  • Uses same technique as humans do for pressure, temp, dew point, wind, and precip accumulation
  • For sky condition uses fixed location time averaging technique
  • Humans use fixed time spatial averaging technique

AWOS, ASOS, AMOS

  • 4 MODES
  • 1. Full time operation
  • 2. Full time operation with local notams
  • 3. Full time operation with manual augmentation and local notams
  • 4. Manual operation
  • Broadcasts ground to air and telephone

AWOS, ASOS, AMOS

  • Ceiling and sky cover
  • Visibility
  • Temp dew point
  • Wind direction, speed and gusts
  • Altimeter setting
  • Remarks, density altitude, variable vis, variable wind direction
  • AMOS only gives info when asked by net.

Chapter 3

3.2 PIREPS/AIREPS

Aircraft Obs and Reports

  • There are 2 kinds
  • –Pilot weather reports
  • Routine and urgent
  • –Aircraft reports
  • Routine and urgent

AIREP

  • These can be reported by the pilot or by sensors onboard the aircraft
  • The AIREP format is used world wide
  • The PIREP format is a U.S. thing

PIREPS

  • The only means of getting:
  • 1. Cloud tops
  • 2. Icing
  • 3. Turbulence
  • 4. Layers
  • 5. In-flight vis
  • They are available on the ADDS site

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • ICAO location Identifier

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Type of Report UA = Routine report, UUA = Urgent report (pg 3-32 for details)

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Location = MWH 070º radial, 15 NM out. OV YKM = directly over nav aid

PIREP

  • MWH UA /OV MWH070015-EAT250010 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Route description = from the MWH 070 rad at 15 NM to the EAT 250 rad at 10 NM

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Time report was taken in Zulu.

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Flight level = 37,000 feet.  FL040 = 4,000 feet MSL

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Aircraft Type  TP UNKN means type is unknown

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Sky cover = Overcast with bases at 4,000 tops at 8,000

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Flight Visibility in statute miles. FV99SM = visibility unrestricted See table 3-7 for restrictions to vis

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Temperature in ºC, M = minus

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Wind direction in mag velocity in knots = 320º at 52 kts

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Turbulence can be classified as Light, Moderate, Severe, and Extreme (Table 3-8)

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /IC LGT RIME /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Icing intensities trace, light, moderate, severe and type rime, clear, mixed. (Table 3-9)

PIREP

  • MWH UA /OV MWH070015 /TM 1448 /FL370 /TP  B757 /SK OVC040-TOP080 /WX FV50SM /TA M58 /WV 32052KT /TB  SMOOTH WITH OCSNL MOD CHOP /RM MOUNTAIN WAVE +/-  20K…LAST 30 MILES
  • Remarks clarify items in the body of the report.  LLWS, TORNADO, TS, LTGIC (in cloud), LTGCC, LTGCG, LTGCA (cloud to air)

PIREP

PIREPS

  • All altitudes are MSL unless otherwise noted
  • Distance for visibility is in statute miles
  • Distance for everything else is in nautical miles
  • Time is in Zulu

žChapter 3

žSection 3.3 Radar

žWeather Surveillance Radar

  • žWSR-88D
  • Weather Surveillance Radar – 1988 Doppler
  • žAKA NEXRAD
  • žConsists of 159 (2/17) radar installations
  • žObservation times are not standard
  • Nor are they linked to other radar sites
  • So good for the time listed

žModes of Operation

  • žClear Air Mode
  • Most sensitive
  • Slowest rotation rate
  • Images update every 10 minutes
  • žPrecipitation Mode
  • Less sensitive
  • Faster rotation rate
  • Images update every 4 to 6 minutes

žEcho Intensities

  • žColors represent echo intensities in dBZ
  • žScale goes from -30 (least) to 75 (most)
  • žCheck table 4-1 for ATC terminology based on echoes
  • žValues below 15 dBZ are usually just clouds but may be dust, insects, pollen ect.
  • žThis means values above 15dBZ are probably precip, although may be virga
  • žSnowfall intensity is not show by the table
  • žUsually the higher the return the heavier the snowfall rate

žRadar Mosaics

  • žMultiple radar images combined
  • žThese may be base or composite
  • žIntellicast has my favorite

žBase Reflectivity

  • žRadar is aimed about half a degree above the horizon (0.5°)
  • žShort range to 124 NM
  • žLong range out to 248 NM

žBase Reflectivity

  • žUseful for:
  • žFinding precip probably reaching the ground
  • žThe intensity of precip
  • žCoverage of precip
  • žWhen looped, movement of precip

žBase Reflectivity

  • žFor stratiform precip look for:
  • Widespread coverage
  • Weak reflectivity
  • 39 dBZs or less
  • Slow change when looped
  • žFor cumulus precip look for:
  • Small cells
  • Strong reflectivity
  • High dBZs
  • Can be fast moving and or dissipating

žBase Reflectivity Limitations

  • žBeam Overshoot
  • žCurvature of the earth contributes
  • žUse a mosaic or a closer site

žBase Reflectivity Limitations

  • žBeam Undershoot
  • žHappens at elevations above the base scan close to the station

žBase Reflectivity Limitations

  • žBeam Blockage
  • žMay be minimized by looking at the mosaics

žBase Reflectivity Limitations

  • žGround Clutter
  • žTrees, buildings and stuff
  • žComputer is supposed to eliminate most of this

žBase Reflectivity Limitations

  • žGhost
  • žCaused by
  • insects
  • superrefraction
  • certain settings used on the radar equipment when the real echo is farther out

žBase Reflectivity Limitations

  • žAngels
  • žBats, Birds, Insects
  • žUsually only happens in clear air mode
  • žBase Reflectivity Limitations
  • žAnomalous Propagation
  • žOne of the biggest enemies of radar
  • žChanges in air density can bend the radar
  • žComputer enhancement and use of multiple sites to defeat AP

žBase Reflectivity Limitations

  • žWind farms
  • žIf within 10 NM they cause
  • Beam blockage
  • False echoes
  • High reflectivity values

žComposite Reflectivity

  • žRadar scans through multiple elevations
  • žGives a more complete vertical picture
  • žWhen compared to the base reflectivity you can get an idea of the structure of the precip
  • žHas the same limitations as discussed for the base

žBase vs Composite Reflectivity

  • žEspecially useful for cumuliform cloud structures.
  • žAllows you to develop a vertical picture of intensities

žRadar Coded Message

  • žThe RCM replaced the RAREP, ROB, SD
  • žUpdated every 30 min
  • žBased on the composite reflectivity
  • žIncludes the max echo top for each site
  • žCan show errors when precip is far away

žNew Stuff

  • žProduct update to 5 min
  • žMosaicked Composite Reflectivity
  • žDual Polarization Radar
  • Better at determining what the precip is
  • Including Graupel (snow pellets) and
  • Hail

žTerminal Doppler Weather Radar

  • žUsed for detection of
  • Wind shear (microbursts)
  • Precipitation
  • Winds aloft
  • žThere are 47 TDWR stations at bigger airports

žTerminal Doppler Weather Radar

  • žTDWR vs WSR-88D
  • žResolution is higher
  • TDWR 150 meters (500’) within 135 km (72NM) and 300 m (1000’) beyond 135 km
  • WSR-88D 250 m (820’)and 1 km (.5NM) for surveillance data
  • žBeam width
  • TDWR .55 degrees
  • WSR-88D .95 degrees

žTerminal Doppler Weather Radar

  • žNormally the radar runs in monitor mode (VCP 90) until
  • A region of 20 dBZ echoes located within 24.3 NM from the associated airport with a nominal areal extent of 1.3 NM and an altitude of at least 1.3 NM AGL, or
  • The radar detects windshear or a microburst.
  • žAt which point the radar shifts into hazardous mode (VCP80) to achieve higher rates of data

žTerminal Doppler Weather Radar

  • žThere are 3 categories of products available
  • General Products
  • –Base Reflectivity, Base Velocity, Spectrum Width, Vertically Integrated Liquid, and the Velocity Azimuth Display (VAD) Wind Profile.
  • Precipitation Products
  • –Estimated ground accumulated rainfall
  • Overlay Products
  • –Detailed info for storm cells
  • Radar Messages
  • –Information about the radar status and special product data

ž

—Chapter 3

—Section 3.4 Satellite

—

—GOES-R Series Satellites

  • —GOES (Geostationary Environmental Satellite) sit at 22,000 miles out in geostationary orbit
  • —GOES 16 was Launched in 11/19/2016
  • —GOES-16 observes Earth from the coast of West Africa, to Hawaii, and everything in between.
  • —GOES-17 was launched on 03/01/2018
  • —GOES-17 will cover the west coast of the US and the Pacific to New Zealand
  • —Is the single most important source of wx data

—Spider Lightning

—SATELLITE PICTURES

  • —1. GOES Geostationary Environmental Satellite
  • —visible imagery depends on height thickness and ability to reflect
  • —infrared is heat radiation (high clouds less heat)
  • —2. POES Polar Orbiter Environmental Satellite
  • —They orbit from 124 to 1.240 miles up
  • —Since they are closer the resolution is better, 5/8 of a mile
  • —Not stationary so it can be several hours before it passes over an area

—Satellite

  • —3 different images
  • —Visible
  • —Infrared
  • —Water vapor

—Visible Imagery

  • —The amount of reflected light is referred to as albedo
  • —The band across the top is the albedo in %
  • —Visible imagery has the highest resolution of the 3
  • —It approximates what the eye sees
  • —High thin clouds are grey
  • —Thicker more dense and snow appear whiter

—Infrared Imagery

  • —This is a measurement of temperature
  • —The warmer the more energy
  • —The colors are used to enhance readability
  • —Sort of like the colors on the Coors light bottle enhance drinkability

—Color IR

—https://www.aviationweather.gov/satellite?date=

——Infrared Imagery

  • —Unenhanced decoding
  • —Shades of grey are equated to temp in C
  • —Land is warm
  • —High clouds are cold duh!

—Water Vapor

  • —Displays the quantity of water vapor located from about 700mb (10,000 ft) to 200mb (FL390)
  • —No direct relationship between temp on the chart and the temp of the clouds
  • —Most useful for locations and movements of weather systems, jets and thunderstorms
  • —Shades of red are very dry
  • —Shades of blue or green are moist
  • —Available 24 hours a day

—Water Vapor Imagery

  • —Displays the quantity of water vapor
  • —Good for locating wx systems, jet and TS
  • —Shades of red indicate very dry conditions
  • —Shades of pink, blue and orange indicate lots of moisture
  • —When used with other wx products it may give an idea of what type of clouds to expect

—Using Them Together

—

—

Chapter 3

3.5 Upper-Air Observations

RADIOSONDE OBSERVATIONS

  • A radiosonde is a small instrument package carried aloft by balloon
  • Measures pressure, temp, wind speed/direction and moisture
  • Ascends at about 1,000 ft/min
  • Launched twice daily at 11:00z and 23:00z
  • Takes about 90 minutes to reach 100,000 feet

DROPWINDSONDE

  • Dropped from weather research aircraft
  • Usually dropped over the ocean where meteorological information is highly lacking
  • Measures pressure, temperature, moisture, and the vertical distribution of horizontal wind speed and wind direction
  • They play an important role in improving the forecast of typhoon/hurricane track and intensity.

Chapter 3

3.7.2 METARS on Aviationweather.gov

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