Chapter 7

(Refer to figure 14) The wind and temperature at 12,000 feet MSL as reported by a pilot are

080 deg at 21 knots and -7 degrees C - (The ambient temperature and wind velocity appear in the part of the PIREP that indicates "/TA M7/WV 08021/". All temperatures aloft are given in degrees Celsius, and the "M" indicates temperatures below zero. Wind speed is reported in knots.)

(Refer to Figure 12.) What are the wind conditions at Wink, Texas (KINK)

110 degrees at 12 knots, peak gusts 18 knots - (The wind entry for KINK is "11012G18kT," meaning the wind direction is 110 degrees, and the velocity is 12 knots, with peak gusts of 18 knots.)

(Refer to figure 15.) In the TAF from KOKC, the "FM (FROM) Group" is forecast for the hours from 1600Z to 2200Z with the wind from

180 DEGREES AT 10 KNOTS (The TAF code "FM," followed by the time, indicates a rapid change in the forecast conditions starting at that time. 18010KT indicates wind from 180 degrees at 10 knots. "BECMG 2224" means that the next change will happen gradually from 2200 to 2400Z)

(Refer to Figure 12.) The wind direction and velocity at KJFK is from

180 deg TRUE AT 4 KNOTS - (tHE WIND ENTRY FOR KJFK is "18004kt," meaning the wind is from 180 degrees at four knots. Winds on an aviation routine weather report are referenced to true north.)

(Refer to Figure 15.) What is the valid period for the TAF for KMEM?

1800Z to 1800Z - (Terminal Area Forecasts TAFs are usually valid for a 24-hour period and are schedule four times a day (000z, 0600z, 1200z and 1800z) The six-digit issuance date-time group is followed by the valid date-time group. Therefore, "121720Z121818" indicates that the KNEM TAF was issued on the 12th at 1720 zulu.this report is valid from 1800 Zulu on the 12th until 1800 Zulu on the 13th)

To obtain a Flight Service briefing over the internet, go to

1800wxbrief.com and sign up using your pilot credentials. (The site for official flight service briefings is 1800wxbrief.com. This website is for pilots only and you must sign up before you can use this site. You can also obtain official NWS briefings at AviationWeather.gov, but that is website is not offered by Flight Service, and FSS.gov is not a valid website.)

(Refer to figure 17.) What wind is forecast for STL at 9,000 feet?

230 degrees at 39 knots (In the Winds and Temperatures Aloft Forecast, directions are relative to true north and rounded to the nearest 10 degrees. The wind information for STL at 12,000 feet is 2339-04. The first two digits represent the wind direction, 230 degrees true. The next two digits are the speed, 39 knots. The temperature is -4 degrees C.)

(Refer to Figure 17.) What wind is forecast for STL at 9,000 feet?

230 degrees true at 32 knots (In the winds and temperatures aloft forecast, directions are relative to true north and rounded to the nearest 10 degrees. The wind information for STL at 9,000 feet is 2332+02. The first two digits represent the wind direction in relation to true north, 230 degrees. The next two digits are the speed, which in this case is 32 knots. The temperature is +2 degrees C.)

(Refer to Figure 15.) Between 1000Z and 1200Z, the visibility at KMEM is forecast to be?

3 STATUTE MILES (During a specified time perio, when changes in the weather conditions are forecast, a change group is appended to the forecast. In this TAF, "BCMG 1012" indicates that a change in the weather will occur between 1000Z and 1200Z. The "3sm" indicates that the visibility is forecast to become 3 statute miles.)

(Refer to figure 14.) If the terrain elevation is 1,295 feet MAL, what is the height above ground level of the base of the ceiling?

505 feet AGL (The ceiling is the lowest cloud layer reported as broken, overcast, or obscured. In this PIREP, the lowest layer is 1,800 feet broken MSL. To find the AGL height, subtract the fround elevation e.g. 1,899 - 1,296 = 505 feet AGL)

(refer to figure 14.) The base and tops of the overcast layer reported by a pilot are

7,300 feet MSL AND 8,900 FEET MAS - (In the pilot report PIREP, which is identified by the letters UA, sky cover is designated by the letters SK, followed by the base and top of each cloud layer. The overcast layer is shown as OVC072-TOP 089, Which means the base is 7,200 feet and the tops are 8,900 feet. Altitudes are MSL unless otherwise noted.)

When the term "light and variable" is used in a winds aloft forecast, the coded group and wind speed is

9900 AND LESS THAN 5 KNOTS - (The direction is shown as 99, indicating that the direction is variable. When the second two digits are listed as 00, the speed is less than 5 knots)

To get the complete weather briefing for the planned flight, the pilot should request

A STANDARD BRIEFING (A standard briefing is the most compete type of weather briefing.)

SIGMETs are issued as a warning of weather conditions hazardous to which aircraft?

ALL AIRCRAFT (SIGMETs are issued for weather potentially hazardous to all aircraft. An AIRMET advises of weather that is of operational interest to all with limited capabilities, such as light single-engine airplanes)

AIRMETs are advisories of significant weather phenomena but of lower intensities than SIGMETs and are intended for dissemination to

ALL PILOTS - (An AIRMET advises of weather that is of operational interest to all aircraft, but may be hazardous to aircraft with limited capabilities, such as light single-engine airplanes.)

Which type of weather briefing should a pilot request to supplement mass disseminated data?

AN ABBREVIATED BRIEFING (An abbreviated briefing is appropriate for supplementing non-official weather data, or for updating the information from a previous briefing)

To update a previous weather briefing, a pilot should request

AN ABBREVIATED BRIEFING (An abbreviated briefing is appropriate for supplementing non-official weather data, or for updating the information from a previous briefing.)

A weather briefing that is provided when the information requested is 6 or more hours in advance of the proposed departure time is

AN OUTLOOK BRIEFING (An outlook briefing is appropriate for flights with proposed departure times that are at least six hours in the future)

When requesting weather information for the following morning, a pilot should request

AN OUTLOOK BRIEFING (Assuming your flight is six or more hours away, you would request an outlook briefing)

Low-level significant weather (SIGWX) charts provide depictions of forecast

AVIATION WEATHER HAZARDS SUCH AS MFVR AND IFR CONDITIONS, TURBULENCE, AND FREEZING LEVELS. (Low-level significant weather SIGWX charts cover altitudes up to flight level 240. They forecast aviation weather hazards to be used as guidance for pre-flight briefings, including flying categories MFVR, IFR, turbulence, and freezing levels. They provide a snapshot of weather expected at the valid time, 12 or 24 hours after chart issuance. Surface pressure systems, fronts, and areas of probable precipitation are depicted on the surface prog chart, not the low-level SIGWX chart.)

(Refer to Figure 15.) the only cloud type forecast in TAF reports is

CUMULONIMBUS - (If cumulionimbus clouds are expected at the airport, the contraction "CB" in a TAF is appended to the height of the cloud layer to indicate the base of the cumulonimbus cloud.)

How are low-level significant weather (sigwx) prognostic charts best used by a pilot?

FOR DETERMINING AREAS TO AVOID FREEZING LEVELS AND TURBULENCE (Low-level SIGWX charts depict weather flying categories, turbulence, and freezing levels. In-flight icing is not depicted on the low-level SIGWX chart.)

(Refer to Figure 15.) During the time period from 0600Z to 0800Z, what visibility is forecast for KOKC?

GREATER THAN SIX STATUTE MILES - (This TAF section reads, "BECMG 0608 21015kt p6sm sct040 =." These abbreviations mean that between 0600-0800Z, the wind will become 210 deg at 15 knots, visibility is forecast to be more than (not possibly) 6 statute miles, and clouds will become scattered at 4,000 feet.)

You plan to phone a weather briefing facility for preflight weather information. You should

IDENTIFY YOURSELF AS A PILOT (When requesting a preflight briefing, identify yourself as a pilot and provide type of flight - VFR or IFR; aircraft tail number or your name; aircraft type; departure airport; route of flight; destination; flight altitudes; ETD and ETE The number of occupants is provided in the flight plan and the route is given after you have initially identified yourself as a pilot)

To determine the freezing level and areas of probable icing aloft, the pilot should refer to the

INFLIGHT AVIATION WEATHER ADVISORIES - (Freezing level and icin aloft are contained in in-flight weather advisories, which include SIGMETSs, convective SIGMETs, AIRMETs, alert service weather watch bulletins (AWWs), center weather advisories (CWAs), and urgent PIREPs. These advisories are broadcast over hazardous in-flight weather advisory service HIWAS OR PROVIDED BY FLIGHT SERVICE.)

(Refer to figure 12.) Which of the reporting stations have VFR weather?

KINK, KNOL and KLAX (To answer this question, you must know that the definition of VFR is visibility of at least three statute miles and ceiling of at least 1,000 feet. KINK has 15 miles visibility with clear skies, KBOI has 30 miles visibility with a scattered layer at 15,000, and KLAX has 6 miles visibility, with scattered layers at 700 feet and 25,000 feet. Remember, a scattered layer does not constitute a ceiling.)

(Refer to figure 14.) The intensity and type of icing reported by a pilot is

LIGHT TO MODERATE RIME - (Icing intensity and type is shown in this PIREP as "/IC LGT-MDT RIME/" or light to moderate rime.)

Radar weather reports are of special interest to pilots because they indicate...

LOCATION OF PRECIPITATION ALONG WITH TYPE, INTENSITY, AND CELL MOVEMENT OF PRECIPITATION. (Radar weather reports show areas of precipitation; type, such as rain showers; intensity, such as light or heavy; and azimuth of movement.)

For aviation purposes, ceiling is defined as the height above the earth's surface of the

LOWEST BROKEN OR OVERCAST LAYER OR VERTICAL VISIBILITY INTO AN OBSCURATION. - (According to Aviation Weather Services, AC 00-45, a ceiling is defined as the lowest broken or overcast layer, or vertical visibility into an obscuration.)

You planned a route and obtained preliminary weather information to determine the feasibility of your flight. On the morning of your flight, an FAA- approved briefing consists of

OBTAINING A STANDARD BRIEFING AT 1800WXBRIEF.COM - (Obtain you FAA-approved weather briefing by telephone or online. You can fill out a preliminary flight plan and select Standard Briefing at 1800wxbrief.com or call a flight service briefer at 1-800-WX-BRIEF 1-800-992-7433. While you can obtain official weather service information by listening to recorded weather at 1-800-WX-BRIEF or online at AviationWeather.gov, these methods are not substitutes for an approved briefing, and do not include temporary flight restrictions TFRs or other essential NOTAMs)

(Refer to Figure 12.) The remarks section KMDW has RAB35 listed. The entry means

RAIN BEGAN AT 1835Z - (The remarks section of a METAR is used to report weather considered significant to aircraft operations. The contraction "RMK" precedes remarks, which include the beginning and ending times of certain weather phenomena. In this case, "RAB35" means that the rain began at 35 minutes past the hour, or 1835Z)

(Refer to figure 15) In the TAF for KMEM, what does "SHRA" stand for?

RAIN SHOWERS ARE EXPECTED - (This group of the taf, "PROB40 2202 3SM SHRA," indicates a 40-percent probability, between 2200 Zulu and 0200 Zulu, that the cisibility will be 3 statute miles with showery precipitation or rain showers SHRA. The next entry, "FM0200 35012KT OVC008" indicates, from 0200 Zulu, the wind is expected to be from 350 degrees at 12 knots.)

Which in-flight advisory would contain information on severe icing not associated with thunderstorms?

SIGMET - (A SIGMET advises of weather potentially hazardous to all aircraft, which would include severe icing. A convective SIGMET is an advisory of especially hazardous thunderstorm activity.)

(Refer to figure 12.) what are the current conditions depicted for Chicago Midway Airport (KMDW)?

SKY 700 FEET OVERCAST, VISIBILITY 1 - 1/2 SM, RAIN - (Cloud heights or the vertical visibility into an obscuration is reported with three digits in hundreds of feet. Visibility is reported in statute miles SM. In this case, the METAR from KMDW indicates that Midway's visibility is 1-1/2 miles and the sky is overcast at 700 feet. "RA" indicates precipitation in the form of rain.)

Which type of weather briefing should a pilot request, when departing within the hour, if no preliminary weather information has been received?

STANDARD BRIEFING (A standard briefing is the most compete type of weather briefing, and assumes you do not have a detailed comprehensive weather picture for your flight.)

Short-range surface prognostic (prog) charts provide depictions of forecast

SURFACE PRESSURE SYSTEMS, FRONTS, AND PRECIPITATION (The short-range surface prognostic prog chart provides depictions of surface pressure systems, fronts and precipitation. It is available in five forecast periods: 12, 18, 24, 48 and 60 hours. Each chart depicts a snapshot of weather elements expected at the specified valid time. MVFR and IFR conditions, and areas of probable turbulence, are shown on SIGWX, not surface prog, charts. Icing is not specifically forecast on either SIGWX or surface prog charts.)

When telephoning a weather briefing facility for preflight weather information, pilots should state

THE AIRCRAFT IDENTIFICATION OR THE PILOT'S NAME. (You should give your name or the aircraft tail number, and other information, to the weather briefer.)

What is indicated when a CONVECTIVE SIGMET forecasts thunderstorm?

THUNDERSTORMS OBSCURED BY MASSIVE CLOUD LAYERS; (Convective SIGMETs are issued for thunderstorms very strong, not moderate covering 40 percent or more not 30 percent of an area at least 3,000 sq. miles. They also are issued for embedded thunderstorms; those obscured by massive cloud layers. All convective SIGMETs imply severe or greater turbulence, not moderate turbulence)

What information is contained in a CONVECTIVE SIGMET?

TORNADOES, EMBEDDED THUNDERSTORMS, AND HAIL 3/4 INCH OR GREATER IN DIAMETER (Convective SIGMETs are issued for any of the following phenomena: tornadoes, lines of thunderstorms covering 40 percent or more of the area at least 3,000 sq miles, and hail of 3/4 inch or greater in diameter.)

What values are used for Winds Aloft Forecasts?

TRUE DIRECTION AND KNOTS (All forecast and ASOS/AWOS - reported winds are given in true direction, and speed is always in knots. The only time wind direction is given in magnetic is when it is provided by the tower or ATIS)

What considerations apply when using a cockpit display of radar data obtained from FIS-B?

The radar echoes that are depicted on the cockpit display can sometimes be more than 20 minutes old. (FIS-B is an example of a data-link weather service you can receive if an airplane has ADS-B capability and the proper receiver. The main concern when using a FIS-B in-cockpit radar display in that the data can be up to 20 minutes older than the age shown on the display and significant changes can occur over that time.)

(Refer to figure 15.) What is the forecast wind for KMEM from 1600Z until the end of the forecast?

VARIABLE IN DIRECTION AT 6 KNOTS - (This part of the TAF reads, "FM1600 VRB06KT P6SM SKC = "From 1600Z until the end of forecast, the wind is variable in direction at 6 knots, with visibility greater than 6 miles.)

When speaking to a flight service weather briefer, you should state

WHETHER THE FLIGHT IS VFR OF IFR (It is important that the briefer knows whether a pilot intends to fly VFR or IFR, so that the information can help the pilot make a component go/no-go decision.)

(refer to figure 14.) the intensity of the turbulence reported at a specific altitude is

light from 5,500 feet to 7,200 feet (in this PIREP, turbulence is reported as "TB LGT 055-072/", meaning light turbulence between 5,500 and 7,200 feet MSL)

(Refer to Figure 15.) in the TAF from KOKC, the clear sky becomes

overcast at 2,000 feet during the forecast period between 2200Z and 2400Z