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

• —Here is a cold winter storm in Jan of 2001
• —This one storm dumped precip from San Diego to Sandpoint ID
• —http://www.aviationweather.gov/satellite

—

—

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

• https://aviationweather.gov/metar