First of all, METAR as an abbreviation is vague at best. Different sources will tell you this comes from METeorological Aerodrome Report, Meteorological Terminal Aviation Routine Weather Report, Meteorological Terminal Air Report, or Meteorological Airfield Report. Let’s stick with aviation routine weather report and get straight into the decrypting.

Here’s an example of a routine METAR report for a station location:

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Each METAR contains specific information in sequential order. Let’s go through each bit of the standard formatted coding.

1. METARs begin with the type of report (shown in red).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR]

You will see two types of METAR reports. The routine METAR report, transmitted at a regular time interval, or the aviation selected SPECI, a special report that can be given at any time to update the METAR for rapidly changing weather conditions, aircraft mishaps, or other critical information.

2. Next is the station identifier. A four-letter code as established by the International Civil Aviation Organization (ICAO).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

In the 48 contiguous states, a unique three-letter identifier is preceded by the letter “K.” For example, Gregg County Airport in Longview, Texas, is identified by the letters “KGGG,” with K as the country designation and GGG as the airport identifier. In other regions of the world, including Alaska and Hawaii, the first two letters of the four-letter ICAO identifier indicate the region, country, or state. Alaska identifiers always begin with the letters “PA,” and Hawaii identifiers always begin with the letters “PH.” Station identifiers can be found on various websites, such as the Aviation Weather Center or  NOAA’s METAR Observation Station Identifiers.

3. The third grouping is the date and time of the report. Depicted in a six-digit group (161753Z). The first two digits are the date. The last four digits are the time of the METAR/SPECI, which is always given in coordinated universal time (UTC). A “Z” is appended to the end of the time to denote the time is given in Zulu time (UTC) as opposed to local time. This METAR was issued on the 16th at 1753 Zulu.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

4. The modifier denotes whether the METAR/SPECI came from an automated source or if the report was corrected.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

If the notation “AUTO” is listed in the METAR/SPECI, the report came from an automated source. It also lists “AO1” (for no precipitation discriminator) or “AO2” (with precipitation discriminator) in the “Remarks” section to indicate the type of precipitation sensors employed at the automated station. When the modifier “COR” is used, it identifies a corrected report sent out to replace an earlier report that contained an error. If this example had been corrected, the word AUTO would be replaced with COR.

5. The wind is reported with five digits (14021) unless the speed is greater than 99 knots, in which case the wind is reported with six digits. The first three digits indicate the direction the true wind is blowing from in tens of degrees. If the wind is variable, it is reported as “VRB.” The last two digits indicate the speed of the wind in knots (KT) unless the wind is greater than 99 knots, in which case it is indicated by three digits. If the winds are gusting, the letter “G” follows the wind speed. After the letter “G,” the peak gust recorded is provided (G26KT). If the wind direction varies more than 60° and the wind speed is greater than six knots, a separate group of numbers, separated by a “V,” will indicate the extremes of the wind directions.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Without gusts, this METAR would include only 14021KT.

6. The prevailing visibility is reported in statute miles as denoted by the letters “SM.” It is reported in both miles and fractions of miles (¾ SM).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

The runway visual range (RVR) may be reported following the prevailing visibility. RVR is the distance a pilot can see down the runway in a moving aircraft. When RVR is reported, it is shown with an R, then the runway number followed by a slash (/), then the visual range in feet. For example, when the RVR is reported as R17L/1400FT, it translates to a visual range of 1,400 feet on runway 17 left.

7. Now we get to the weather. It can be broken down into two different categories: the qualifiers (+TSRA) and the weather phenomenon (BR).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

First, the qualifiers of intensity, proximity, and the descriptor of the weather are given. The intensity may be light (–), moderate ( ), or heavy (+). Proximity only depicts weather phenomena that are in the airport vicinity. The notation “VC” indicates a specific weather phenomenon is in the vicinity of 5–10 miles from the airport. Descriptors are used to describe certain types of precipitation and obscurations. Weather phenomena may be reported as being precipitation, obscurations, or other phenomena, such as squalls or funnel clouds. Descriptions of weather phenomena, when they begin or end, and hailstone size are also listed in the “Remarks” sections of the report. The coding for qualifier and weather phenomena are shown in this chart. The weather groups are constructed by considering columns 1–5 in this table sequence: intensity, followed by descriptor, followed by weather phenomena.

The notation +TSRA BR is “heavy thunderstorms and rain with mist.” Another example, “heavy rain showers” is coded as +SHRA.

8. Next we have the sky condition. This is always reported in the sequence: amount, height, and type or indefinite ceiling/height (vertical visibility).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

The heights of the cloud bases are reported with a three-digit number in hundreds of feet AGL. Clouds above 12,000 feet are not detected or reported by an automated station. The types of clouds, specifically towering cumulus (TCU) or cumulonimbus (CB) clouds, are reported with their height. The amount of cloud coverage and obscuring phenomena is described using fractions, then reported based on the amount of sky coverage in eighths of the sky from horizon to horizon.

Less than 1/8 is abbreviated as Sky Clear, Clear, or Few; 1/8–2/8 as Few; 3/8–4/8, Scattered; 5/8–7/8, Broken; and 8/8, Overcast. For aviation purposes, the ceiling is the lowest broken or overcast layer, or vertical visibility into an obscuration.

9. The air temperature and dew point are always given in degrees Celsius (C).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Temperatures below 0 °C are preceded by the letter “M” to indicate minus.

10. The altimeter setting is reported as inches of mercury (inHg) in a four-digit number group.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

It is always preceded by the letter “A.” Rising or falling pressure may also be denoted in the “Remarks” sections as “PRESRR” (rising) or “PRESFR” (falling).

11. Lastly, we have the remarks section, which always begins with the letters “RMK.”

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Comments may or may not appear in this section of the METAR. The information contained in this section may include wind data, variable visibility, beginning and ending times of phenomenon, pressure information, and various other information deemed necessary. An example of a remark regarding weather phenomenon that does not fit in any other category would be: OCNL LTGICCG. This translates as occasional lightning in the clouds and from cloud to ground. Automated stations also use the remarks section to indicate the equipment needs maintenance.

Our sample METAR would be read as follows:

Routine METAR for Gregg County Airport for the 16th day of the month at 1753 zulu from an automated source. Winds are 140 at 21 knots gusting to 26 knots. Visibility is ¾ statute mile. Thunderstorms with heavy rain and mist. Ceiling is broken at 800 feet, overcast at 1,200 feet with cumulonimbus clouds. Temperature 18 °C and dew point 17 °C. Barometric pressure is 29.70 inHg and falling rapidly.

A few more examples:

To find more examples and learn even more about weather events that can affect flying, check out the Aviation Weather Handbook, available at asa2fly.com.

The post METAR Deciphered first appeared on Learn To Fly.

The FAA has issued a Change 1 to Advisory Circular AC 00-45H effective January 8^th 2018. AC 00-45, more commonly referred as Aviation Weather Services, is the go-to resource for U.S. aviation weather products and services. This document is organized using the FAA’s three distinct types of aviation weather information: observations, analyses, and forecasts. This is a vital resource and should be a part of any aviators library.

Here are some of the highlights on what you need to know regarding Change 1:

• DUATS II no longer requires an airman medical to access the system (duats.com).
• A new section was added to Chapter 3, Terminal Doppler Weather Radar (TDWR). The TDWR network is a Doppler weather radar system operated by the FAA, which is used primarily for the detection of hazardous windshear conditions, precipitation, and winds aloft on and near major airports situated in climates with great exposure to thunderstorms in the United States. To review this information refer to Section 3.4.
• A new sub-section was added to Chapter 3, POES. POES stands for the Polar Orbiting Environment Satellites, although more recently the U.S. polar satellite program has been rechristened the Joint Polar Satellite System (JPSS). Polar satellites are not stationary. They track along various orbits around the poles. Typically, they are somewhere between 124 and 1,240 mi above the Earth’s surface. The satellites scan the Earth in swaths as they pass by on their tracks. To review this information refer to Section 3.5.3.
• Note in chapter 5 section 6 that Collaborative Convective Forecast Planning (CCFP) is now Convective Forecast (TCF). The figures and language throughout this section have been updated to reflect this updated weather product. To review this information refer to Section 5.6.3.
• A new section was added to Chapter 5, Graphical Forecasts for Aviation (GFA). The GFAs are a set of Web-based displays which are expected to provide the necessary aviation weather information to give users a complete picture of the weather that may impact flights in the CONUS. These displays are updated continuously and provide forecasts, observational data, and warnings of weather phenomena that can be viewed from 14 hours in the past to 15 hours in the future. This product covers the surface up to FL420 (or 42,000 ft MSL). Wind, icing, and turbulence forecasts are available in 3,000-ft increments from the surface up to 18,000 ft MSL, and in 6,000-ft increments from 18,000 ft MSL to FL420. Turbulence forecasts are also broken into low (below 18,000 ft MSL) and high (above 18,000 ft MSL) graphics. A maximum icing graphic and maximum wind velocity graphic (regardless of altitude) are also available. The graphic below is an example of an aviation forecast for clouds. To review this information refer to Section 5.9.
• A new section was added to Chapter 5, Localized Aviation Model Output Statistics (MOS) Program (LAMP). The LAMP weather product is a statistical model program that provides specific point forecast guidance on sensible weather elements (perceivable elements such as temperature, wind, sky cover, etc.). LAMP weather product forecasts are provided in both graphical and coded text format, and are currently generated for more than 1,500 locations. The LAMP weather product is entirely automated and may not be as accurate as a forecast generated with human involvement. However, information from the LAMP weather product can be used in combination with Terminal Aerodrome Forecasts (TAF), and other weather reporting and forecasting products and tools, to provide additional information and enhance situational awareness regarding a particular location. To review this information refer to Section 5.10.  
• Hawaii was added to Section 5.11.1 as an area of issuance for an Area Forecast (FA). You will find new figures and detailed information regarding the Hawaii Area Forecast. To review this information refer to Section 5.11.1.
• A new sub-section was added to Chapter 5, Low-Level Wind Shear Alert System (LLWAS). The LLWAS system was originally developed by the FAA in the 1970s to detect large-scale wind shifts (sea breeze fronts, gust fronts, and cold and warm fronts). It was developed by the FAA in response to an accident at JFK Airport in New York. The aircraft (Eastern 66) landed during a wind shift caused by interacting sea breeze and thunderstorm outflows. To review this information refer to Section 5.13.2.10.

ASA will have an Change 1 update available shortly to go along with all printed copies of the Aviation Weather Handbook (ASA-AC00-45H). The update will be posted on the Textbooks Update page at www.asa2fly.com.

The post CFI Brief: Aviation Weather Services (AC 00-45H) – UPDATE first appeared on Learn To Fly.

Here is an example of a routine METAR report for a station location.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

This METAR reports contains the following typical information in sequential order which is the standard formatted coding for all METAR reports.

1. Type of report. There are two types of METAR reports. The first is the routine METAR report that is transmitted on a regular time interval. The second is the aviation selected SPECI. This is a special report that can be given at any time to update the METAR for rapidly changing weather conditions, aircraft mishaps, or other critical information.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR]

2. Station identifier. A four-letter code as established by the International Civil Aviation Organization (ICAO). In the 48 contiguous states, a unique three-letter identifier is preceded by the letter “K.” For example, Gregg County Airport in Longview, Texas, is identified by the letters “KGGG,” K being the country designation and GGG being the airport identifier. In other regions of the world, including Alaska and Hawaii, the first two letters of the four-letter ICAO identifier indicate the region, country, or state. Alaska identifiers always begin with the letters “PA” and Hawaii identifiers always begin with the letters “PH.” Station identifiers can be found by searching various websites such as DUATS and NOAA’s Aviation Weather Aviation Digital Data Services (ADDS).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

3. Date and time of report. Depicted in a six-digit group (161753Z). The first two digits are the date. The last four digits are the time of the METAR/SPECI, which is always given in coordinated universal time (UTC). A “Z” is appended to the end of the time to denote the time is given in Zulu time (UTC) as opposed to local time. This METAR was issued on the 16th at 1753 Zulu.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

4. Modifier. Denotes that the METAR/SPECI came from an automated source or that the report was corrected. If the notation “AUTO” is listed in the METAR/SPECI, the report came from an automated source. It also lists “AO1” (for no precipitation discriminator) or “AO2” (with precipitation discriminator) in the “Remarks” section to indicate the type of precipitation sensors employed at the automated station. When the modifier “COR” is used, it identifies a corrected report sent out to replace an earlier report that contained an error. If this was the case for this example the word AUTO would be replaced with COR.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

5. Wind. Reported with five digits (14021KT) unless the speed is greater than 99 knots, in which case the wind is reported with six digits. The first three digits indicate the direction the true wind is blowing from in tens of degrees. If the wind is variable, it is reported as “VRB.” The last two digits indicate the speed of the wind in knots unless the wind is greater than 99 knots, in which case it is indicated by three digits. If the winds are gusting, the letter “G” follows the wind speed (G26KT). After the letter “G,” the peak gust recorded is provided. If the wind direction varies more than 60° and the wind speed is greater than six knots, a separate group of numbers, separated by a “V,” will indicate the extremes of the wind directions.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

6. Visibility. The prevailing visibility (¾ SM) is reported in statute miles as denoted by the letters “SM.” It is reported in both miles and fractions of miles. At times, runway visual range (RVR) is reported following the prevailing visibility. RVR is the distance a pilot can see down the runway in a moving aircraft. When RVR is reported, it is shown with an R, then the runway number followed by a slant, then the visual range in feet. For example, when the RVR is reported as R17L/1400FT, it translates to a visual range of 1,400 feet on runway 17 left.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

7. Weather. Can be broken down into two different categories: qualifiers and weather phenomenon (+TSRA BR). First, the qualifiers of intensity, proximity, and the descriptor of the weather are given. The intensity may be light (–), moderate ( ), or heavy (+). Proximity only depicts weather phenomena that are in the airport vicinity. The notation “VC” indicates a specific weather phenomenon is in the vicinity of five to ten miles from the airport. Descriptors are used to describe certain types of precipitation and obscurations. Weather phenomena may be reported as being precipitation, obscurations, and other phenomena, such as squalls or funnel clouds. Descriptions of weather phenomena as they begin or end and hailstone size are also listed in the “Remarks” sections of the report. The coding for qualifier and weather phenomena are shown here in this chart. The weather groups are constructed by considering columns 1–5 in this table sequence: intensity, followed by descriptor, followed by weather phenomena. As an example “heavy rain showers” is coded as +SHRA.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

8. Sky condition. Always reported in the sequence of amount, height, and type or indefinite ceiling/height (vertical visibility) (BKN008 OVC012CB, VV003). The heights of the cloud bases are reported with a three-digit number in hundreds of feet AGL. Clouds above 12,000 feet are not detected or reported by an automated station. The types of clouds, specifically towering cumulus (TCU) or cumulonimbus (CB) clouds, are reported with their height. Contractions are used to describe the amount of cloud coverage and obscuring phenomena. The amount of sky coverage is reported in eighths of the sky from horizon to horizon as shown in this table. Less than 1/8 is abbreviated as Sky Clear, Clear, or Few. 1/8 – 2/8 Few. 3/8 – 4/8 Scattered. 5/8 – 7/8 Broken. 8/8 Overcast. For aviation purposes, the ceiling is the lowest broken or overcast layer, or vertical visibility into an obscuration.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

9. Temperature and dew point. The air temperature and dew point are always given in degrees Celsius (C) or (18/17). Temperatures below 0 °C are preceded by the letter “M” to indicate minus. 10.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

10. Altimeter setting. Reported as inches of mercury (“Hg) in a four-digit number group (A2970). It is always preceded by the letter “A.” Rising or falling pressure may also be denoted in the “Remarks” sections as “PRESRR” or “PRESFR,” respectively.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

11. Remarks—the remarks section always begins with the letters “RMK.” Comments may or may not appear in this section of the METAR. The information contained in this section may include wind data, variable visibility, beginning and ending times of particular phenomenon, pressure information, and various other information deemed necessary. An example of a remark regarding weather phenomenon that does not fit in any other category would be: OCNL LTGICCG. This translates as occasional lightning in the clouds and from cloud to ground. Automated stations also use the remarks section to indicate the equipment needs maintenance.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Putting it all together you would read this sample METAR as follows:

Routine METAR for Gregg County Airport for the 16th day of the month at 1753 zulu automated source. Winds are 140 at 21 knots gusting to 26 knots. Visibility is ¾ statute mile. Thunderstorms with heavy rain and mist. Ceiling is broken at 800 feet, overcast at 1,200 feet with cumulonimbus clouds. Temperature 18 °C and dew point 17 °C. Barometric pressure is 29.70″Hg and falling rapidly.

The post CFI Brief: Deciphering the METAR first appeared on Learn To Fly.

The GFA at the Aviation Weather Center (AWC) website is an interactive display providing continuously updated observed and forecast weather information over the continental United States (CONUS). It is intended to give users a complete picture of weather critical to aviation safety. The GFA display shows user-selected weather categories, each containing multiple fields of interest at altitudes from the surface up to FL480. Depending on the field of interest chosen, weather information is available from -6 in the past (observed) to +15 hours in the future (forecast).

The GFA is not considered a weather product but an aggregate of several existing weather products. The information and data from the various weather products are overlaid on a high-resolution basemap of the United States: www.aviationweather.gov/gfa. The user selects flight levels and current time period for either observed or forecast weather information. Mouse-clicking or hovering over the map provides additional information in textual format, such as current METAR or TAF for a selected airport. The GFA replaces the textual area forecast (FA) for the CONUS and Hawaii with a more modern digital solution for obtaining weather information. The Aviation Surface Forecast and Aviation Cloud Forecast graphics are snapshot images derived from a subset of the aviation weather forecasts.

The Aviation Surface Forecast displays surface visibility with overlays of wind and gusts, predominant precipitation type (i.e., rain, snow, mix, ice, or thunderstorm) coincident with any cloud and predominant weather type (i.e., haze, fog, smoke, blowing dust/sand). The graphical AIRMETs (Airmen’s Meteorological Information) for instrument flight rules (IFR) and strong surface wind are overlaid. See FAA Figure 260. Forecast surface visibility is contoured for Low IFR (0 – 1 statute miles), IFR (1 – 3 statute miles), and Marginal VFR (MVFR; 3 – 5 statute miles) conditions. Visibilities in excess of 5 statute miles are not shown. Winds are depicted with a standard wind barb, in red when indicating gusts (see the figure below).

Below are some sample questions for what you could expect to see on an FAA knowledge test in the near future using those aforementioned GFA figures.

1. (Refer to Figure 261.) The precipitation type forecast to occur over southern ND (area C) is
A—Freezing rain.
B—Freezing drizzle.
C—Moderate snow.

2. (Refer to Figure 266.) Precipitation throughout Washington and Oregon is predominantly
A—Light rain and rain showers.
B—Heavy rain showers.
C—Freezing rain.
3.(Refer to Figure 269.) The cloud coverage around area B on the Aviation Cloud Forecast is forecast to be
A—Bases at 6,000 feet, tops at 7,000.
B—BRKN tops at 7,000 feet.
C—OVC at 7,000 feet.

Answers and explanations

The post CFI Brief: New GFA Supplement Figures first appeared on Learn To Fly.

The Low-Level Significant Weather Prognostic Chart (FL240 and below) portrays forecast weather hazards that may influence flight planning, including those areas or activities of most significant turbulence and icing. It is a two-panel display representing a 12-hour forecast interval (left) and 24-hour forecast interval (right). Turbulence intensities are identified by standard symbols as shown in the figure below. The vertical extent of turbulence layers is depicted by top and base heights separated by a slant and shown in hundreds of feet MSL (180/100 = 18,000’ MSL to 10,000’ MSL). Freezing levels above the surface will correspond with a given altitude in hundreds of feet MSL (080 = 8,000’ MSL). Low-level SIGWX charts are issued four times daily, and valid time, date, and chart type are depicted in the lower left corner of each panel.

The High-Level Significant Weather Prognostic Chart (FL250 to FL630) outlines areas of forecast turbulence and cumulonimbus clouds, shows the expected height of the tropopause, and predicts jet stream location and velocity. The chart depicts clouds and turbulence as shown in the figure below.

Cumulonimbus cloud (CB) areas are enclosed by a red scalloped line. The height of the tropopause is shown in hundreds of feet MSL and enclosed in a rectangular box; centers of high (H) and low (L) heights are enclosed in polygons. Areas of turbulence are enclosed in yellow dashed lines and labeled with the appropriate severity symbol and top and base altitudes. A jet stream axis containing a wind speed of 80 knots or greater is identified by a bold green line and directional arrowhead. A standard wind symbol is placed on the jet stream to identify velocity and an associated flight level is placed adjacent to it. An omission of a base altitude (XXX) identifies that the weather phenomena exceeds the lower limit of the high-level SIGWX prog chart (FL250).

1. (Refer to Figure 18.) The right panel of the significant weather prognostic chart provides a forecast of selected aviation weather hazards up to FL240 until what time?
A—March 18th at 0600.
B—March 17th at 1800.
C—March 18th at 1800.

2. (Refer to Figure 19.) The next issuance of the 12-hour significant weather prognostic chart will become valid at
A—0000Z.
B—1200Z.
C—1800Z.

3. (Refer to Figure 20.) What is the height of the tropopause over the northwest United States?
A—45,000 feet MSL.
B—45,000 meters.
C—450,000 feet MSL.

Answers posted in the comments section. 

The post CFI Brief: Significant Weather (SIGWX) Forecast Charts first appeared on Learn To Fly.

If you’ve never used www.1800wxbrief.com, the first step is to  register for an account, it’s a free and simple process. Lockheed Martin, who manages the site, provides several how-to videos in an effort to simplify the process even more. I will provide you with a couple of these videos to check out and provide you with a link to where you may find the remaining how to videos from Lockheed Martin.

This first video will give you a quick 3 minute overview on how to register and login to the system.

https://www.youtube.com/watch?v=_UFEwWSfOjE&index=1&list=PLJfjhkAOKxKucil-m9ZPLgT9MfM38ibrY

This next video is going to actually teach you how to obtain your first flight plan route briefing. Now maybe you’ve used the system before and have already obtained route briefings. If so, it’s not going to hurt to still take a look at this video, you may learn something new or at the very least pick up on a few new tricks of the system.

There are several additional how-to videos posted on the Lockheed Martin Flight Services YouTube Page and other useful information posted under the help menu at www.1800wx.brief.com.

Airman Certification Standards: Private Pilot Airplane and Instrument Rating Airplane eBook PDFs are now available!

Looking for more information? Check out our interview with ASA Curriculum Director and ARAC ACS WG member Jackie Spanitz. You can also read her article “Certifying Pilots: The New Airman Certification Standards” on airfactsjournal.com. AOPA also offers their take as well. Softcover copies of each edition are also now available for preorder and will begin shipping later this month.

The post CFI Brief: www.1800wxbrief.com first appeared on Learn To Fly.

Self-brief first, to get the big picture before calling or logging onto the briefing site. Your first choice when looking for weather reports and forecasts should be the Aviation Digital Data Service (ADDS) webpage. It has recently been revised and improved. The next best is http://digital.weather.gov. It is loaded with information but in a different format than the ADDS page. In some cases that ADDS page will refer you to this site.

To learn how to interpret the reports and forecasts, refer to Aviation Weather Services, FAA Advisory Circular 00-45 (or, “AWS”). Ideally, you should have a copy of the AWS in your library, but it is available for reading and download at the FAA website (www.faa.gov). The advantage of the online publication over the book is that the online version includes changes and updates; the disadvantages are that it is a huge file and it is not searchable. Still, it is the only place where you can find explanations for all of the online weather charts and graphics—and a list of abbreviations used in text products.

[Update: In December 2022, the FAA published the Aviation Weather Handbook (FAA-H-8083-28) which replaced Advisory Circulars 00-6 and 00-45.]

Too many accident reports include the words “There was no record of a weather briefing.” You definitely want to get a weather briefing, and you definitely want that briefing on record. The way to do this is to use a government-sponsored site such as DUATS (1-800-767-9989) or the Automated Flight Service Station system. Go to www.1800wxbrief.com and register. You will not only be able to get a briefing and file your flight plan, but if you have a smartphone you will be able to use EasyActivate and EasyClose: about 30 minutes before your ETD you will get a text message with a link to open the flight plan, and about 30 minutes before your ETA you will get a text with a link to close the flight plan. In either case, just tap the link to open/close your flight plan. This does not work with other providers. The Lockheed-Martin website www.1800wxbrief.com has a weather tab with a treasure trove of weather data. There is some duplication with the ADDS page, but there are also sites not covered by ADDS. You do not have to be registered in order to access the weather pages.

Of course, if you want to talk to a human being, 1-800-WXBRIEF will do the trick. Three types of briefings are available: standard, abbreviated, and outlook. If you have not collected any weather information before calling the FSS, ask for the standard briefing—then you can be sure that nothing will be left out. Ask for an abbreviated briefing if you want to update an earlier standard briefing or add to information you have already received from other sources. In this situation, tell the briefer where you got the original information so that he or she can fill in any gaps. It is possible to get an in-flight briefing, but doing so ties up the radio frequency and is not good manners.

Request an outlook briefing when your proposed departure time will be more than six hours after the briefing, then back it up with a standard briefing closer to takeoff time.

You can listen to the Hazardous Inflight Weather Advisory Service (HIWAS) on selected radio navigational aids (VORs and NDBs) for weather updates. Check your sectional chart, paper or digital, and the Chart Supplements U.S. to identify navaids that broadcast weather information—a blue circle with a reversed “H” in the upper corner for HIWAS. If you have a radio in your airplane you will always have access to up-to-date weather information from Flight Service and should not rely solely on a pre-takeoff briefing; weather changes.

The post Weather Services: Sources of Information first appeared on Learn To Fly.

I bring this personal story up because today I want to discuss 14 CFR §91.103, “Preflight action”, which reads:

“Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight.”

Basically as pilot-in-command (PIC) you cannot just hop in the plane and go. It doesn’t matter if you’ve conducted the same flight 100 times in the past; you still need to familiarize yourself with all available information for this particular flight. The regulation goes on to further break down exactly what information you must obtain:

(a) For a flight under IFR or a flight not in the vicinity of an airport, weather reports and forecasts, fuel requirements, alternatives available if the planned flight cannot be completed, and any known traffic delays of which the pilot in command has been advised by ATC;

(b) For any flight, runway lengths at airports of intended use, and the following takeoff and landing distance information:

(1) For civil aircraft for which an approved Airplane or Rotorcraft Flight Manual containing takeoff and landing distance data is required, the takeoff and landing distance data contained therein; and

(2) For civil aircraft other than those specified in paragraph (b)(1) of this section, other reliable information appropriate to the aircraft, relating to aircraft performance under expected values of airport elevation and runway slope, aircraft gross weight, and wind and temperature.

This is essentially the regulation in its entirety. To make this regulation little easier to understand let’s map it out in a more logical way.

Today I plan on conducting a flight as PIC from Bellingham Airport (BLI) in Northern Washington state to Seattle’s Boeing Field (BFI). Based solely off 14 CFR §91.103, I would need to obtain and determine the following (and from the following sources):

• Weather reports and forecasts (800-WX-BRIEF or www.1800wxbrief.com)
• Fuel requirements (POH/AFM for the aircraft I’m flying)
• Alternate airports (Sectionals, TAC, and/or Airport/Facility Directory)
• Known traffic delays (NOTAMs, TFRs, ATIS)
• Runway length at airports of intended use (Airport/Facility Directory)
• Takeoff distance (POH/AFM + weather briefing)
• Landing distance (POH/AFM + weather briefing)

My first order of business is to obtain weather reports and forecasts. The regulation does not specifically state, but this should include information for arrival and departure points as well as en route. Next I need to determine fuel requirements. How much fuel is needed to get to BFI? I want to account for possible weather, known traffic delays and be sure to meet VFR day or night fuel reserve regulations. With fuel in mind, I want to determine availability of alternate airports. You always want to have a backup plan if for some reason you can no longer land at your planned destination. Just like you would for you destination airport, become familiar with any alternate airports you may choose. This leads us into runway lengths at airports of intended use. We want to gather this data for both BLI and BFI. It’s also a good idea to have this information on hand for the alternate airport(s) we have chosen. Lastly, we need to determine performance for takeoff and landing distances. This is to ensure we have selected airports that have sufficient runway lengths. Remember, performance data can change due to environmental conditions, so an airport that might have sufficient runway length one day may not the following day (think wind, density altitude, runway surface conditions, etc).

As you can see there is a lot of information you need to gather before each flight. One way to keep track of all this information is to use an ASA Flight Planner form. In addition to the actual flight plan, you have a note section to jot down performance data and a terminal information section to list runway lengths and other airport information such as communication frequencies. On the backside is where you have a dedicated section for Preflight Pilot Checklist, Weight and Balance, and the ICAO Flight Plan form.

Now, by no means am I saying this is all that needs to be accomplished prior to taking flight, this is just the minimum as outlined in 14 CFR §91.103.

So when your instructor tells you to do something, there’s usually a pretty good reason behind it.

The post CFI Brief: It’s sunny and 80°F, why do I need a weather brief? first appeared on Learn To Fly.

But first, what exactly is a GFA? In short the GFA’s main purpose is to provide a complete picture of necessary weather information impacting flight over the Continental United States. It includes a wealth of data in graphical output including observational data, forecasts, thunderstorm activity, clouds, precipitation, icing, and turbulence to name just a few. The image below is an example of the GFA output.

As a user you will have the unique ability to configure and choose exactly what you want displayed on the GFA. For example you can display icing conditions across the U.S. at specific flight levels of your choosing with the ability to overlay airports and roads and even depict terrain. There are so many things you can do and it would take too long to describe it all to you here. So I urge you to check it out for yourself! Play around with the GFA for awhile, read the product description (included as attachment below), and finally let the NWS and FAA know what you think by completing the online survey. Your information and suggestions are vital.

Graphical Forecast for Aviation (GFA)

GFA Product Description

Complete the GFA Survey Here

The post CFI Brief: NEW Experimental Aviation Weather Product first appeared on Learn To Fly.

Radar Observations
Weather observers use four types of radar to provide information about precipitation, wind, and weather systems.

1. The WSR-88D NEXRAD radar, commonly called Doppler radar, provides in-depth observations that inform surrounding communities of impending weather. Doppler radar has two operational modes: clear air and precipitation. In clear air mode, the radar is in its most sensitive operational mode because a slow antenna rotation allows the radar to sample the atmosphere longer. Images are updated about every 10 minutes in this mode. Precipitation targets provide stronger return signals therefore the radar is operated in the Precipitation mode when precipitation is present. A faster antenna rotation in this mode allows images to update at a faster rate, approximately every 4 to 6 minutes. Intensity values in both modes are measured in dBZ (decibels of Z) and depicted in color on the radar image. Intensities are correlated to intensity terminology (phraseology) for air traffic control purposes.

2. FAA terminal doppler weather radar (TDWR), installed at some major airports around the country, also aids in providing severe weather alerts and warnings to ATC. Terminal radar ensures pilots are aware of wind shear, gust fronts, and heavy precipitation, all of which are dangerous to arriving and departing aircraft.
3. The third type of radar commonly used in the detection of precipitation is the FAA airport surveillance radar. This radar is used primarily to detect aircraft, but it also detects the location and intensity of precipitation which is used to route aircraft traffic around severe weather in an airport environment.
4. Airborne radar is equipment carried by aircraft to locate weather disturbances. The airborne radars generally operate in the C or X bands (around 6 GHz or around 10 GHz, respectively) permitting both penetration of heavy precipitation, required for determining the extent of thunderstorms, and sufficient reflection from less intense precipitation.

The post Weather Services: Radar Weather Reports first appeared on Learn To Fly.