Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010) T Group indicator 0 Indicates the following number is positive; a 1 would be used if the temperature was reported as negative at the time of observation 026 Temperature disseminated to the nearest 10th and read as 02.6 1 Indicates the following number is negative; a 0 would be used if the number was reported as positive at the time of observation 015 Dew Point disseminated to the nearest 10th and read as 01.5
No spaces are between the entries. For example, a temperature of 2.6ºC and dew point of -1.5ºC is reported in the body of the report as 03/M01 and the hourly temperature and dew point group as T00261015. If the dew point is missing only the temperature is reported; if the temperature is missing the hourly temperature and dew point group is not reported.
3.1.3.14.2 Maintenance Data Groups The following maintenance data groups, Sensor Status Indicators and the Maintenance Indicator, are only reported from automated stations.
3.1.3.14.2.1 Sensor Status Indicators Sensor status indicators are reported as indicated below:
• If the Runway Visual Range is missing and would normally be reported, RVRNO is coded
• When automated stations are equipped with a present weather identifier and the sensor is not operating, the remark PWINO is coded
• When automated stations are equipped with a tipping bucket rain gauge and the sensor is not operating, PNO is coded
• When automated stations are equipped with a freezing rain sensor and the sensor is not operating, the remark FZRANO is coded
• When automated stations are equipped with a lightning detection system and the sensor is not operating, the remark TSNO is coded
• When automated stations are equipped with a secondary visibility sensor and the sensor is not operating, the remark VISNO LOC is coded
• When automated stations are equipped with a secondary ceiling height indicator and the sensor is not operating, the remark CHINO LOC is coded
3.1.3.14.2.2 Maintenance Indicator A maintenance indicator, $, is coded when an automated system detects maintenance is needed on the system.
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Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
3.1.4 METAR/SPECI Examples METAR PAHL 031836Z AUTO 07009KT 10SM CLR 13/02 A2980 RMK AO1 PNO
GROUP CODED TRANSLATION Type of Report METAR Aviation Routine Weather Report Station Identifier PAHL United States Huslia, Alaska Date and Time of Report 031836Z 3rd day of the month, 1836 UTC Report Modifier AUTO automated observation with no human augmentation Wind 07009KT Wind from 070 degrees (the east) at 9 knots (10 mph, 4.6 m/s) Visibility 10SM Visibility ten statute miles (16 kilometers) Runway Visual Range [omitted] Present Weather [omitted] There may or may not be significant weather present at this time Sky Condition CLR Sky clear below 12,000 feet AGL Temperature/Dewpoint 13/02 Temperature 13⁰ C (55⁰ F), dewpoint 2⁰ C (36⁰ F) Altimeter A2980 29.80 inches of mercury (1009.2 millibars, 1009.2 hectopascals) Remarks RMK Remarks section designator Automated, Manual, and Plain Language A01 Automated station without a precipitation discriminator Additive and Automated Maintenance Data PNO Tipping bucket rain gauge not operating
METAR KNSI 031656Z VRB03KT 5SM HZ SCT007 21/17 A2989 RMK SLP121 T02060172
GROUP CODED TRANSLATION Type of Report METAR Aviation Routine Weather Report Station Identifier KNSI United States San Nicolas Island, California Date and Time of Report 031656Z 3rd day of the month, 1656 UTC Report Modifier [omitted] Either a manual or an augmented observation Wind VRB03KT Wind variable at 3 knots (4 mph, 1.5 m/s) Visibility 5SM Visibility five statute miles (8.0 kilometers) Runway Visual Range [omitted] Present Weather HZ Haze Sky Condition SCT007 Scattered at 700 feet AGL Temperature/Dewpoint 21/17 Temperature 21⁰ C (69⁰ F), dewpoint 17⁰ C (63⁰ F) Altimeter A2989 29.89 inches of mercury (1012.3 millibars, 1012.3 hectopascals) Remarks RMK Remarks section designator Automated, Manual, and Plain Language SLP121 Sea level pressure 1012.1 hectopascals (1012.1 millibars) Additive and Automated Maintenance Data T02060172 Temperature 20.6⁰ C (69⁰ F), dewpoint 17.2⁰ C (63⁰ F) Section 3: Observed Text Products Page 3-29
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
SPECI KCOT 292020Z AUTO 13009KT 3SM TSRA BR SCT011 BKN028 OVC043 23/21 A2991 RMK AO2 PK WND 13029/2000 LTG DSNT ALQDS P0020
GROUP CODED TRANSLATION Type of Report SPECI Aviation Selected Special Weather Report Station Identifier KCOT United States Cotulla, Texas Date and Time of Report 292020Z 29th day of the month, 2020 UTC Report Modifier AUTO Automated observation with no human augmentation Wind 13009KT Wind from 130 degrees (the southeast) at 9 knots (10 mph, 4.7 m/s) Visibility 3SM Visibility three statute miles (5 kilometers) Runway Visual Range [omitted] Present Weather TSRA BR Thunderstorm, moderate rain, mist Sky Condition SCT011 BKN028 OVC043 Scattered at 11,000 feet AGL, Ceiling broken at 2,800 feet AGL, Overcast at 4,300 feet AGL Temperature/Dewpoint 23/21 Temperature 23⁰ C (73⁰ F), dewpoint 21⁰ C (70⁰ F) Altimeter A2991 29.91 inches of mercury (1013.0 millibars, 1013.0 hectopascals) Remarks RMK Remarks section designator Automated, Manual, and Plain Language AO2 Automated station with a precipitation discriminator PK WND 13029/2000 Peak wind from 130 degrees (the southeast) at 29 knots (33 mph, 14.9 m/s) occurred at 2000 UTC
LTG DSNT ALQDS Lightning distant all quadrants Additive and Automated Maintenance Data P0020 0.20 inches of precipitation fell in the past hour Section 3: Observed Text Products Page 3-30
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
METAR KMDW 090153Z 23003KT 1/2SM R31C/4000V4500FT SN FZFG VV002 M04/M05 A3004 RMK AO2 SLP191 SNINCR 1/10 P0000 T10391050
GROUP CODED TRANSLATION Type of Report METAR Aviation Routine Weather Report Station Identifier KMDW United States Chicago (Midway), Illinois Date and Time of Report 090153Z 9th day of the month,0153 UTC Report Modifier [omitted] Either a manual or an augmented observation Wind 23003KT Wind from 230 degrees (the southwest) at 3 knots (3 mph,1.6 m/s) Visibility 1/2SM Visibility one-half statute miles (0.8 kilometers) Runway Visual Range R31C/4000V4500FT Runway 31 center visual range variable between 4,000 and 4,5000 feet Present Weather SN FZFG Snow, freezing fog Sky Condition VV002 Indefinite ceiling, vertical visibility 200 feet Temperature/Dewpoint M04/M05 Temperature -4⁰ C (25⁰ F), dewpoint -5⁰ C Altimeter A3004 Altimeter 30.04 inches of mercury (1017.4 hectopascals, 1017.4 millibars) Remarks RMK Remarks section designator Automated, Manual, and Plain Language A02 Automated station with a precipitation discriminator SLP191 Sea level pressure 1019.1 hectopascals (1019.1 millibars) SNINCR 1/10 Snow increasing rapidly, snow depth increase of 1 inch in the past hour, a total depth on the ground of 10 inches Additive and Automated Maintenance Data P0000 Less than 1/100 of an inch of precipitation fell in the past hour T10391050 Temperature -3.9⁰ C (25⁰ F), dewpoint
- 5.0⁰ C (23⁰ F) Section 3: Observed Text Products Page 3-31
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
SPECI KMEM 091826 27013G27KT 240V310 1/2SM R36L/1000VP6000FT +TSRAGR FG FEW002 BKN023 OVC032CB 18/17 A2992 RMK A02 PK WND 31031/1802 WSHFT 1759 TSB22RAB17GRB23 PRESRR FRQ LTGIC W-NW TS W-NW GR 1/2 P0005
GROUP CODED TRANSLATION Type of Report SPECI Aviation Selected Special Weather Report Station Identifier KMEM United States Memphis, Tennessee Date and Time of Report 091826Z 9th day of the month, 1826 UTC Report Modifier [omitted] Either a manual or an augmented observation Wind 27013G27KT 240V310 Wind from 270 degrees (the west) at 13 knots (15 mph, 6.7 m/s) gusting to 27 knots (31 mph, 13.9 m/s), wind variable between 240 degrees (the westsouthwest) and 310 degrees (the northwest) Visibility 1/2SM Visibility one-half statute miles (0.8 kilometers) Runway Visual Range R36L/1000VP6000FT Runway 36 left visual range variable between 1,000 and more than 6,000 feet Present Weather +TSRAGR FG Thunderstorm, heavy rain, hail, fog Sky Condition FEW002 BKN023 OVC032CB Few at 200 feet AGL, ceiling broken at 2,300 feet AGL, overcast at 3,200 feet AGL cumulonimbus Temperature/Dewpoint 18/17 Temperature 18⁰ C (64⁰ F), dewpoint 17⁰ C (63⁰ F) Altimeter A2992 29.92 inches of mercury (1013.2 millibars, 1013.2 hectopascals) Remarks RMK Remarks section designator Automated, Manual, and Plain Language AO2 Automated station with a precipitation discriminator PK WND 31031/1802 Peak wind from 310 degrees (the northwest) at 31 knots (36 mph, 15.9 m/s) occurred at 1802 or 2 minutes past the hour UTC WSHFT 1759 Wind shift occurred at 1759 UTC TSB22RAB17GRB23 Thunderstorm began at 22 minutes past the hour, rain began at 17 minutes past the hour, hail began at 23 minutes past the hour PRESRR Pressure rising rapidly FRQ LTGIC W-NW Frequent lightning in-cloud west through northwest TS W-NW Thunderstorm west through northwest GR1/2 Largest hailstone 1/2 inches in diameter Additive and Automated Maintenance Data P0005 0.05 inches of precipitation fell in the past hour Section 3: Observed Text Products Page 3-32
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
SPECI KMSN 012312Z 13021G26KT 1SM -FZRAPL BR OVC011 00/M02 A2988 RMK AO2 PK WND 14031/2255 SFC VIS 1 1/2 P0005 $
GROUP CODED TRANSLATION Type of Report SPECI Aviation Selected Special Weather Report Station Identifier KMSN United States Madison, Wisconsin Date and Time of Report 012312Z 1st day of the month, 2312 UTC Report Modifier [omitted] Either a manual or an augmented observation Wind 13021G26KT Wind from 130 degrees (the southeast) at 21 knots (24 mph, 10.8 m/s) gusting to 26 knots (30 mph, 13.4 m/s) Visibility 1SM Visibility one statute mile (1.6 kilometers) Runway Visual Range [omitted] Present Weather -FZRAPL BR Light freezing rain, ice pellets, mist Sky Condition OVC011 Ceiling overcast at 1,100 feet AGL Temperature/Dewpoint 00/M02 Temperature 0⁰ C (32⁰ F), dewpoint -2⁰ C (28⁰ F) Altimeter A2988 29.88 inches of mercury (1011.9 millibars, 1011.9 hectopascals) Remarks RMK Remarks section designator Automated, Manual, and Plain Language AO2 Automated station with a precipitation discriminator PK WND 14031/2255 Peak wind from 140 degrees (the southeast) at 31 knots (36 mph, 15.9 m/s) occurred at 2255 UTC SFC VIS 1 1/2 Surface visibility one and on-half statute mile Additive and Automated Maintenance Data P0005 0.05 inches of precipitation fell in the past hour $ Maintenance is needed on the system Section 3: Observed Text Products Page 3-33
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
3.2 Pilot Weather Reports (PIREP) No report is timelier than the one made from the flight deck of aircraft in flight. In fact, aircraft in flight are the only means of observing actual icing and turbulence conditions. Pilots welcome pilot weather reports (PIREPs) as well as pilot weather briefers and forecasters. Pilots should report any observation, good or bad, to assist other pilots with flight planning and preparation. If conditions were forecasted to occur but not encountered, a pilot should also report this inaccuracy. This will help the NWS verify forecast products and create more accurate products for the aviation community. Pilots should help themselves, the aviation public, and the aviation weather forecasters by providing PIREPs.
Pipe Up with a PIREP and help the aviation community operate more safely and effectively.
PIREPs are available in the internet at the Aviation Digital Data Service (ADDS) web page at:
http://adds.aviationweather.gov/pireps/
3.2.1 Format A PIREP is transmitted in a prescribed format (Figure 3-10). Required elements for all PIREPs are: message type, location, time, altitude/flight level, type aircraft, and at least one other element to describe the reported phenomena. The other elements will be omitted when no data is reported with them. All altitude references are mean sea level (MSL) unless otherwise noted.
Distance for visibility is in statute miles and all other distances are in nautical miles. Time is reported in Universal Time Coordinated (UTC).
Figure 3-10. Pilot Weather Report (PIREP) Coding Format
3.2.1.1 Message Type (UUA/UA) The two types of PIREPs are Urgent (UUA) and Routine (UA).
3.2.1.1.1 Urgent PIREPs Urgent (UUA) PIREPs contain information about:
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Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
• Tornadoes, funnel clouds, or waterspouts
• Severe or extreme turbulence (including Clear Air Turbulence)
• Severe icing
• Hail
• Low Level Wind Shear (LLWS) within 2,000 feet of the surface. LLWS PIREPS are classified as UUA if the pilot reports air speed fluctuations of 10 knots or more or if air speed fluctuations are not reported but LLWS is reported, the PIREP is classified as UUA.
• Volcanic ash clouds
• Any other weather phenomena reported which are considered by the briefer as being hazardous, or potentially hazardous, to flight operations.
3.2.1.1.2 Routine PIREPs Routine PIREPs are issued after receiving a report from a pilot that does not contain any urgent information as listed in Section 3.2.1.1.1.
3.2.1.2 Location (/OV) The Location (/OV) can be referenced either by geographical position or by route segment.
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Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
3.2.1.2.1 Location Location can be referenced to a VHF NAVAID or an airport, using either the three-letter International Air Transport Association (IATA) or four letter International Civil Aviation Organization (ICAO) identifier. If appropriate, the PIREP is encoded using the identifier, then three digits to define a radial and three digits to define the distance in nautical miles.
Examples:
/OV APE Over Appleton VOR /OV KJFK Over John F. Kennedy International Airport, New York City, NY /OV APE230010 230 degrees at 10 nautical miles from the Appleton VOR /OV KJFK107080 107 degrees at 80 nautical miles from John F. Kennedy International Airport, New York City, New York
3.2.1.2.1.1 Route Segment A PIREP can also be referenced using two or more fixes to describe a route.
Examples:
/OV KSTL-KMKC From Lambert-Saint Louis International Airport, Missouri to Charles B. Wheeler Downtown Airport, Kansas City, Missouri /OV KSTL090030-KMKC045015 From 90 degrees at 30 nautical miles from Lambert- Saint Louis International Airport, Missouri to 45 degrees at 15 nautical miles from Charles B. Wheeler Downtown Airport, Kansas City, Missouri
3.2.1.3 Time (/TM) Time (/TM) is the time that the reported phenomenon occurred or was encountered. It is coded in four digits UTC.
Example:
/TM 1315 1315 UTC
3.2.1.4 Altitude/Flight Level (/FL) The Altitude/Flight Level (/FL) is the altitude in hundreds of feet MSL where the phenomenon was first encountered. If not known, UNKN is entered. If the aircraft was climbing or descending, the appropriate contraction (DURC or DURD) is entered in the remarks (/RM). If the condition was encountered within a layer, the altitude range is entered within the appropriate element that describes the condition.
Examples:
/FL085 8,500 feet MSL /FL310 Flight Level 310 /FLUNKN /RM DURC Flight Level unknown, remarks, during climb
3.2.1.5 Aircraft Type (/TP) Aircraft Type (/TP) is entered. If not known, UNKN is entered. Icing and turbulence reports always include aircraft type.
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Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010) Examples:
/TP BE20 Super King Air 200 /TP SR22 Cirrus 22 /TP P28R Piper Arrow /TP UNKN Type unknown
3.2.1.6 Sky Condition (/SK) Sky Condition (/SK) group is used to report height of cloud bases, tops, and cloud cover. The height of the base of a layer of clouds is coded in hundreds of feet MSL. The top of a layer is entered in hundreds of feet MSL preceded by the word -TOP. If reported as clear above the highest cloud layer, SKC is coded following the reported level.
Examples:
/BKN040-TOP065 Base of broken layer 4,000 feet MSL, top 6,500 feet MSL /SK OVC100-TOP110/ SKC Base of an overcast layer 10,000 feet MSL, top 11,000 feet MSL, clear above /SK OVC015-TOP035/OVC230 Base of an overcast layer 1,500 feet MSL, top 3,500 feet MSL, base of an overcast layer 23,000 feet MSL /SK OVC-TOP085 Overcast layer, top 8,500 feet MSL
Cloud cover amount ranges are entered with a hyphen separating the amounts; i.e., BKN-OVC.
Examples:
/SK SCT-BKN050-TOP100 Base of a scattered to broken layer 5,000 feet MSL, top 10,000 feet MSL /SK BKN-OVCUNKN-TOP060/BKN120-TOP150/ SKC Base of a broken to overcast layer unknown, top 6,000 feet MSL, base of a broken layer 12,000 feet MSL, top 15,000 feet MSL, clear above
Unknown heights are indicated by the contraction UNKN.
Example:
/SK OVC065-TOPUNKN Base of an overcast layer 6,500 feet MSL, top unknown If a pilot indicates he/she is in the clouds, IMC is entered.
Example:
/SK OVC065-TOPUNKN /RM IMC Base of an overcast layer 6,500 feet MSL, top unknown, remark, in the clouds
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Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010) When more than one layer is reported, layers are separated by a solidus (/).
3.2.1.7 Flight Visibility and Weather (/WX) Weather conditions encountered by the pilot are reported as follows:
Flight visibility, when reported, is entered first in the /WX field. It is coded as FV followed by a two-digit visibility value rounded down, if necessary, to the nearest whole statute mile and appended with SM (FV03SM). If visibility is reported as unrestricted, FV99SM is entered.
Flight weather types are entered using one or more of the standard surface weather reporting symbols contained in Table 3-7.
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Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
Table 3-7. PIREP Weather Type and Symbols Type METAR Code Drifting / Blowing Snow DRSN/BLSN Drifting Dust DRDU Drifting Sand DRSA Drizzle/Freezing Drizzle DZ/FZDZ Dust / Blowing Dust DU/BLDU Duststorm DS Fog (visibility less than 5/8SM) FG Freezing Fog FZFG Freezing Rain FZRA Funnel Cloud FC Hail (Approximately ¼-inch diameter or more) GR Hail Shower SHGR Haze HZ Ice Crystals IC Ice Pellets/Showers PL/SHPL Mist (visibility great than or equal to 5/8SM) BR Patchy Fog BCFG Patchy Fog on part of airport PRFG Rain/Showers RA/SHRA Sand/Blowing Sand SA/BLSA Sandstorms SS Shallow Fog MIFG Small Hail/Snow Pellet Showers SHGS Small Hail/Snow Pellets GS Smoke FU Snow Grains SG Snow / Showers SN/SHSN Spray PY Squalls SQ Thunderstorm TS Tornado/Waterspout +FC Unknown Precipitation UP Volcanic Ash VA Well developed Dust/Sand Whirls PO
Intensity modifiers for precipitation (- for light, no qualifier for moderate, and + for heavy) indicates precipitation type, except ice crystals and hail, including those associated with a thunderstorm and those of a showery nature.
Intensity modifiers for obscurations are ascribed as moderate or heavy (+) for dust and sandstorms only. No intensity modifiers are used for blowing dust, blowing sand, or blowing snow.
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