Wx Information

Question 1

State the general characteristics in regard to the flow of air around high and low pressure systems in the Northern Hemisphere

Answer 1

Low pressure - inward , upward , and counter clockwise.

High pressure - outward, downward, and clockwise.

Question 2

If your route of flight takes you towards a low pressure system , in general , what kind of weather can you expect? What if you were flying towards a high pressure system?

Answer 2

A low pressure system is characterized by rising air, which is conducive to cloudiness, precipitation and bad weather. A high pressure system is an area of descending air which tends to favor dissipation of cloudiness and good weather.

Question 3

Describe the different types of fronts

Answer 3

Cold front- occurs when a mass of cold , dense, and stable air advances and replaces a body of warmer air .

Occluded front- occurs when a fast moving cold front catches up with a slow moving warm front. Two Types: cold front occlusion and warm front occlusion.

Warm front-The boundary area formed when a warm air mass contacts and flows over a colder air mass

Stationary Front- when the forces of two air masses are relatively equal , the boundary or front that separates them remains stationary and influences the local weather for days. The weather is typically a mixture of both warm and cold fronts.

Question 4

What are the general characteristics of the weather a pilot would encounter when operating near a cold front ? A warm front?

Answer 4

A cold front-

As the front passes , expected weather can include - towering cumulus or cumulonimbus , heavy rain accompanied by lightning, thunder and or hail , tornadoes possible , during passage poor visibility , winds variable and gusting. Temperature /dew point and barometric pressure drop rapidly.

A Warm Front

As the front passes , expected weather can include stratiform clouds, drizzle , low ceilings and poor visibility , variable winds, rise in temperature.

Question 5

What is a trough?

Answer 5

A Trough I also coalled a trough line, is an elongated area of relatively low atmospheric pressure. At the surface when air converges into a low, it cannot go outward against the pressure gradient , Nor can it go downward into the ground it must go upwards. Therefore a low or trough is an area of rising air . Rising air is conducive to cloudiness and precipitation , hence the general association of low pressure and bad weather.

Question 6

What is a ridge?

Answer 6

A ridge ( also called a ridge line). Is an elongated area of relatively high atmospheric pressure . Air moving out of a high or ridge depletes the quantity of air. Therefore , these areas of descending air. Descending air favors dissipation of cloudiness, hence the association of high pressure and good weather.

Question 7

What are the standard temperature and pressure values for sea level?

Answer 7

59* F or 15 *C and 29.92” Hg or 1013.2 milibars

Question 8

What are isobars?

Answer 8

An isobar is a. Line on a weather chart which connnects areas of equal area or constant barometric pressure.

Question 9

If the isobars are relatively close together on a surface weather chart or a constant pressure chart , what information will this provide?

Answer 9

The spacing of the isobars on these charts defines how steep r shallow a pressure gradient is. When isobars are spaced very close together , a steep pressure gradient exists which indicates higher wind speeds. A shallow pressure gradient ( isobars not close together ) usually means wind speeds will be less.

Question 10

Why do surface winds generally flow across the isobars at an angle ?

Answer 10

Surface friction

Question 11

At what rate does atmospheric pressure decrease with an increase in altitude?

Answer 11

1” Hg per 1,000 feet.

Question 12

Wat does dew point mean ?

Answer 12

Dew point is the temperature to which a sample air must be cooled to attain the state of saturation.

Question 13

When temperature and dew point are close together ( within 5* ) what type of weather is likely?

Answer 13

Visible moisture in the form of clouds, dew , or fog . Also , these are ideal conditions for carburetor icing.

Question 14

What factor primarily determines the type and vertical extent of clouds.

Answer 14

The stability of the atmosphere.

Question 15

Explain the difference between a stable atmosphere and an unstable atomosphere . Why is the stability of the atmosphere important?

Answer 15

The stability of the atmosphere depends on its ability to resist vertical motion. A stable atmosphere makes vertical movement difficult and small vertical disturbances dampen out and disappear . In an unstable atmosphere, small vertical air movements tend to become larger, resulting in turbulent airflow and convective activity. Instability can lead to significant turbulence, extensive vertical clouds and , severe weather.

Question 16

List the effects of stable and unstable air on clouds turbulence , precipitation and visibility . ??

Answer 16

Stable : clouds =stratiform , turbulence = smooth , precipitation= steady , Visiblity= fair to poor.

Unstable : Clouds=cumuliform, Turbulence=rough , precipitation= showery, Visibility = good .

Question 17

When significant precipitation is occurring at the surface, how thick can you expect the clouds to be ?

Answer 17

Significant precipitation usually requires clouds to be at least 4,000 feet thick. The heavier the precipitation , the thicker the clouds are likely to be .

Question 18

During your preflight planning what type of meteorological information should you be aware of with respect to icing?

Answer 18

A. Location of front- a fronts location, type, speed, and direction of movement .

B. Cloud layers- The location of cloud bases and tops, which is valuable when determining if you will be able to climb above icing layers or descend beneath those layers into warmer air, reference PIREPS and areas forecasts.

C. Freezing levels - important when determining how to avoid icing and how to exit icing conditions if accidentally encountered.

D. Air temperature and pressure - icing tends to be found in low pressure areas and at or around freezing.

Question 19

What is the definition of the term freezing level and how can you determine where that level is?

Answer 19

the freezing level is the lowest altitude in the atmosphere over a given location at which the air temperature reaches 0*C. It is possible to have multiple freezing layers when a temperature inversion occurs above the defined freezing level. A pilot can use current icing products and forecasts icing products as well as the freezing level graphics chart to determine the approximate freezing level. Other potential sources of icing information are : GFAs , PIREP, Airmets, SIGMETS, surface Analysis charts, low- level significant weather charts, and winds and temperatures aloft (for air temperature at altitude) .

Question 20

What conditions are necessary for structural icing to occur?

Answer 20

Visible moisture and below freezing temperatures at the point moisture strikes the aircraft .

Question 21

What are two main categories of aircraft icing ?

Answer 21

Aircraft icing in flight is usually classified as being either structural icing or induction icing. Structural icing refers to ice that forms on aircraft surfaces and components, and induction icing refers to ice that forms in the engine induction system.

Question 22

Name the 3 types of structural icing that may occur in flight?

Answer 22

1. Clear ice-Forms after initial impact when the remaining liquid portion of the drop flows out over the aircraft surface, gradually freezing as a smooth sheet of sold ice.

2.Rime ice- forms when drops are small , such as those in stratified clouds or light drizzle. The liquid portion remaining after initial impact freezes rapidly before the drop has time to spread out over aircraft surface.

3. Mixed ice - Forms when drops vary in size or when liquid drops are intermingled with snow or ice particles. The ice particles become imbedded in clear ice, building a very rough accumulation.

Question 23

What action is recommended if you inadvertently encounter icing conditions?

Answer 23

The first course of action should be to leave the area of visible moisture . This might mean descending to an altitude below the cloud bases , climbing to an attitude above the cloud tops , or turning to a different course.

Question 24

Is frost considered to be hazardous to flight? Why?

Answer 24

Yes, because while frost does not change the basic aerodynamic shape of the wing, the roughness of its surface spoils the smooth flow of air, thus causing a slowing of airflow. This slowing of the air causes early airflow separation, resulting in a loss of lift . Even a small amount of frost on airfoils may prevent an aircraft from becoming airborne at normal takeoff speed. It is also possible that once airborne , an aircraft could have insufficient margin of airspeed above stall so that moderate gusts or turning flight could produce incipient or complete stalling.

Question 25

What factors must be present for a thunderstorm to form?

Answer 25

1. Sufficient water vapor 2. An unstable lapse rate 3. An initial upward boost (lifting ) to start the storm process in motion.

Question 26

What are the three stages of a thunderstorm?

Answer 26

1. Cumulus stage- updrafts cause raindrops to increase in size. 2. Mature stage- Rain at earths surface , it falls through or immediately beside the updrafts; lightning; perhaps roll clouds. 3. Dissipating stage- Downdrafts and rain begin to dissipate.

Question 27

What is a temperature inversion?

Answer 27

An inversion is an increase in temperature with height- a reversal of the normal decrease with height. An inversion aloft permits warm rain to fall through cold air below. Temperature in the cold air can be critical to icing. A ground based inversion favors poor visibility by trapping fog, smoke, and other restrictions into low levels of the atmosphere. The air is stable, with little or no turbulence.

Question 28

How does fog form?

Answer 28

Fog forms when the temperature and dew point of the air become identical (or nearly so ). This may occur through cooling of the air to a little beyond its dew point( producing radiation fog, advection fog, or upslope fog) or by adding moisture and thereby elevating the dew point ( producing frontal fog or steam fog).

Question 29

Name 5 types of Fog ?

Answer 29

1. Radiation Fog 2. Advection fog 3. Upslope fog. 4. Frontal fog or precipitation-induced fog. 5. Steam fog

Question 30

What causes radiation fog to form?

Answer 30

The ground cools the adjacent air to the dew point on calm, clear nights.

Question 31

What is advection fog , and where is it most likely to form?

Answer 31

Advection fog results from the transport of warm humid air over a cold surface. A pilot can expect advection fog to form primarily along coastal areas during the winter. Unlike radiation fog I am occurs with winds , cloudy skies over a wide geographic area and at any time of the day or night.

Question 32

What is upslope fog?

Answer 32

Upslope fog forms as a result of moist , stable air being cooled adiabatically as it moves up sloping terrain. Once the upslope wind ceases, the fog dissipates. Upslope fog is often quite dense and extends to high altitudes.

Question 33

Define the term wind shear, and state the areas in which it is likely to occur?

Answer 33

Wind shear is defined as the rate of change of wind velocity (direction and/ or speed) per unit distance, conventionally expressed as vertical or horizontal wind shear. It may occur at any level in the atmosphere but three areas are of special concern: A. Wind shear with a low level temperature inversion. B. Wind shear in a frontal zone or thunderstorm . C. Clear air turbulence (CAT) at high levels associated with a jet stream or strong circulation.

Question 34

Why is wind shear an operational concern to pilots?

Answer 34

Wind shear is an operational concern because unexpected changes in wind speed and direction can be potentially very hazardous to aircraft operations at low altitudes on approach to and departing from airports.

Question 35

What types of weather information will you examine to determine if wind shear conditions might affect your flight?

Answer 35

A. Terminal forecasts- any mention of low level wind shear (LLWS) or the possibility of severe thunderstorms , heavy rain showers, hail, and wind gusts suggest the potential for LLWS and microburst. B. METARS - inspect for any indication of thunderstorms, rain showers, or blowing dust. Additional signs such as warming trends, gusty winds, cumulonimbus clouds, etc. should be noted. C. Severe Weather Watch Reports. SIGMETS and convective SIGMETS- severe convective weather is a prime source for wind shear and microbursts. D. LLWAS ( low level wind shear alert system) reports- installed at 110 airports in the U.S. ; designed to detect wind shifts between outlying stations and reference centerfield station. E. PIREPS- reports of sudden airspeed changes on departure or approach and landing corridors provide a real time indication of the presence of wind shear.

Question 36

What is the primary means of obtaining a weather briefing?

Answer 36

A flight Service Station (FSS) is the primary source of preflight weather information. Weather briefings are available via 1800 WX BRIEF and 1800wxbrief.com

Question 37

What are two examples of other sources of weather information ?

Answer 37

A. Weather and aeronautical information available from numerous private industry sources. B. Flight Information Services (FIS-B via ADS-B in) C. Aviation Weather Cameras (available throughout Alaska)

Question 38

You’re planning a cross country flight. Does the Weather data provided by commercial and /or third party vendors satisfy the preflight action required by 14 CFR 91.103 ?

Answer 38

Pilots and operators should be aware that weather services provided by entities other than FAA , NWS, or their contractors may not meet FAA/ NWS quality control standards. All operators and pilots contemplating using such services should request and / or review an appropriate description of services and provider disclosure. Pilots and operators should be cautious when using unfamiliar products or products not supported by FAA/ NWS technical specifications. When in doubt, consult with an FAA flight service specialist.

Question 39

What types of weather briefings are available from an AFSS/ FSS briefer ?

Answer 39

Standard Briefing- request when you are planning a flight and you have not received a previous briefing or have not received a preliminary information through mass dissemination media. Abreviated briefing- Request when you need information to supplement mass disseminated data, update a previous briefing, or when you need only one or two items. Outlook briefing- request whenever your proposed time of departure is six or more hours from the time of the briefing, for planning purposes only. Inflight briefing- Request when needed to update a preflight briefing. Exam tip : some pilots prefer to print out their weather briefing and then highlight all the pertinent METARS, TAFS, Notams, etc, applicable to the departure, en route, destination, and alternate segments of their planned flight. When the examiner begins asking about the weather for the flight , you will be well prepared to demonstrate your knowledge.

Question 40

What pertinent information sold a weather briefing include ?

Answer 40

A. Adverse Conditions B. VFR Flight Not Recommended C. synopsis D. Current Conditions. E. Enroute Forecast F. Destination Forecast G. Winds Aloft H. Notices to airmen (notams) i. ATC delay. J. Pilots may obtain the following from FSS briefer upon request: information on special use airspace (SUA) and (IFR, VFR, VR, and SR training routes). warning areas, and ATC assigned airspace(ATCAA) , a review of the printed Notm publication approximate density altitude data, information on air traffic services and rules; customs / immigration procedures, ADIZ rules, search and rescue, runway friction measurement value NOTAMs, GPS RAIM availability , and other assistance as required.

Question 41

Describe the flight information service- Broadcast (FIS-B)

Answer 41

FIS-B is ground based broadcast service provided through the ADS-B Universal Access Transceiver(UAT) network. The service provides users with a 978 MHz data link capability when operating within range and line of sight of a transmitting ground station. FIS-B enables users of properly equipped aircraft to receive and display a suite of broadcast weather and aeronautical information products.

Question 42

Can onboard datalink weather (FIS-B) be useful in navigating an aircraft safely around an area of thunderstorms?

Answer 42

Weather data linked from a ground weather surveillance radar system is not real time information, it displays recent rather than current conditions. This data is typically updated every 5 minutes, but can be as much as 15 minutes old by the time it displays in the cockpit. Therefore, FIS aviation weather products are not appropriate for tactical avoidance of severe weather such as negotiating a path through a weather hazard are.

Question 43

While en route , how can a pilot obtain updated weather information ?

Answer 43

A. FSS on 122.2 and appropriate RCO ( Remote communication outlet) frequencies. B. ATIS / ASOS/AWOS broadcasts along your route of flight. C. Listen to ARTCC broadcasts-AWWs, Convective SIGMETs, SIGMETs, AIRMET, Urgent PIREPS, or CWA alerts are broadcast once on all frequencies , except emergency. D. Datalink weather-cockpit display of FIS-B information . E. ATC ( workload permitting) . Exam tip : Be prepared to demonstrate how you would obtain inflight weather advisories and updates, and how you would communicate with a FSS while en route.

Question 44

What is a METAR and what are the two types?

Answer 44

A METAR is an hourly surface observation of conditions observed at an airport . There are to types of METAR reports-a routine METAR report that is transmitted ever hour and an aviation selected special weather report (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.

Question 45

Describe the basic elements of a METAR

Answer 45

A METAR report contains the following elements in order as presented: A. Type of reports- the METAR, and the SPECI (Aviation special weather report) B. ICAO station identifier- 4 letter station indentifiers , in the conterminous US , the 3 letter identifier is prefixed with K C. Date and time of report- a 6 digit / time group appended with Z (UTC). First two digits are the date , then two for the hour and two for the minutes. D. Modifier (as required) - if used the modifier AUTO identifies the report as an automated weather report with no human intervention. If AUTO is shown in the body of the report, AOI or AO2 will be encoded in the remarks section to indicate the type of precipitation sensor used at the station. E. Wind- 5 digit group (6 digits if speed is over 99 knots) first three digits =wind direction , in tens of degrees referenced with to true north. Directions less than 100 degrees are proceeded with a zero, next two digits are the average speed in knots, measured or estimated (or , if over 99 knots, the next three digits). F. Visibility - surface visibility in statue miles , space , fractions of statute miles ( as needed) and the letters SM. G. Runway visual range RVR , as required H. Weather phenomena-broken into two categories: qualifiers, and weather phenomena. I. Sky conditions- amount/height/type (as required) or indefinite ceiling/height ( vertical visiblity). Heights are recorded in feet AGL. J. Temperature/dew point group-2 digit format in whole degree Celsius, separated by a solidus(/). Temperature below zero are prefixed with M. k. Altimeter- 4 digit format representing tens, units, tenths, and hundredths of inches of mercury prefixed A . The decimal point is not reported or stated. L. Remarks (RMK)- as required operational significant weather phenomena , location of phenomena, beginning and ending times, direction of movement. Ex METAR KLAX 14065IZ AUTO 000000KT 1SM R35L/4500V6000ft -RA BR BK030 10/10 A2990 RMK A02

Question 46

Describe Several types of weather observing programs available

Answer 46

A. Manual observations- with only a few exceptions , these reports are from airport locations staffed by FAA personnel who manually observe, perform calculations , and enter their observations into the communication system. B. AWOS- Automated Weather Observation System ; consists of various sensors, a processor , a computer generated voice subsystem, and a transmitter to broadcast local , minute-by-minute weather data directly to the pilot . Observations will I include the prefix AUTO in data. C. ASOS/AWOS- automated surface observing system /automated weather observing system AWOS ; the primary US surface weather observing system. Both systems prove continuous minute by minute observations that generate METARS and other aviation weather information. Transmitted over a discrete VHF radio frequency or the voice portion of a local NAVAID , and receivable to a maximum of 25 NM from the station and a maximum altitude of 10,000 feet AGL . Observations made without human intervention will include the modifier AUTO in the report data. A maintenance indicator is coded when an automated system detects that maintenance is needed on the system. D. AWOS broadcasts- computer generated voice is used to automate the broadcast of minute weather observations.

Question 47

What are PIREPS (UA) and where they usually found?

Answer 47

A pilot report provides valuable information reguarding the conditions as they actually exist in the air, which cannot be the conditions as they actually exist in the air , which cannot be gathered from any other source. Pilots can confirm the heights of bases and tops of clouds, locations of wind shear and turbulence and the location of inflight icing. There are two types of PIREPS: routine or UA and urgent or UUA . PIREPS should be given to the ground facility with which communications are established (ie. FSS ARTCC or terminal ATC) . Altitude are MSL, Visibilities SM, and distances in NM. PIREPS are available from an FSS and on the internet via the ADDS web page at: aviationweather.gov/airep.

Question 48

What are terminal aerodrome forecasts (TAFs)

Answer 48

A terminal aerodrome forecast (TAF) is a concise statement of the expected meteorological conditions significant to aviation for a specified time period within 5 statute miles (SM) of the center of the airports runway complex (terminal). The TAFs use the same weather codes found in METAR weather reports, in the following format: A. Type of reports- a routine forecast (TAF) , an amended forecast (TAF AMD) , or a corrected forecast (TAF COR) . B. ICAO station identifier - 4 letter station identifiers. C. Date and time of origin- the date/time of forecast follows the terminals location identifier. It contains the day of the month in two digits and time in four digits in which the forecast is completed and ready for transmission, with a Z appended to denote UTC. Ex 061737Z- the TAF was issued on the 6th day of the month at 1737 UTC. D. Valid period date and time - The first two digits are the day of the month for the start of the TAF followed by two digits indicating the starting hour (UTC). The next two digits indicate the day of the month for the end of the TAF , and the last two digits are the ending hour (UTC) of the valid period . Scheduled 24- and 30 hour TAFs are issued four (4) times per day at 0000, 0600,1200,1800 Z. Ex= A 00Z TAF issued on the 9th of the month and valid for 24 hours would have a valid period of 0900/0924. E. Forecasts-wind, visibility , significant and vicinity weather, cloud and vertical obscuration, non convective low level wind shear, forecast change indicators (FM, TEMPO and PROB)

Question 49

Define aviation area forecast (FA)

Answer 49

FAs are issued for the Gulf of Mexico , the Caribbean Sea, and alaska. An FA is an abbreviated plane language forecast concerning the occurrence or expected occurrence of specified enroute weather phenomena. The FA (in conjunction with AIRMETs, SEIGMETS , CWAs , etc) is used to determine forecast enroute weather over a specified georgraphy region. FAs cover an 18-24 hour period, depending on the region, and are issued three to four times daily, depending on the region, and are updated as needed.

Question 50

Describe the graphical forecasts for aviation (GFA)

Answer 50

The GFA is a set of web-based graphics that provide observation forecasts and warnings that can be viewed from 14 hours in the past 15 hours in the future. The GFA covers the continental United States (census) from the surface up to FL480. Wind icing and turbulence forecasts are available in 3,000-foot increments from the surface up to 30,000 feet MSL , and in 6,000-foot increments from 30,000 feet MSL to 48,000 feet MSL. Turbulence forecasts are also broken into LO (below FL180 )and HI (at or above 18,000 feet MSL) graphics. A maximum icing graphic and maximum wind velocity graphic (regardless of altitude ) are so available. The GFA interactive web tool can be viewed at aviationweather.gov/gfa.

Question 51

What type of aviation forecasts are available when selecting the “forecast” tab of the GFA? (AIM 7-1-4)

Answer 51

The “forecasts” tab will provide gridded displays of various weather parameters as well as NWS textual weather observations forecasts, and warnings out to 15 hours. Icing, turbulence, and wind gridded products are three dimensional . Other gridded products are two dimensional and may represent a “composite” of a three-dimensional weather phenomenon or a surface weather variable such as horizontal visibility. Selecting the “ forecasts” tab will provide the following forecasts: A. TAF- terminal aerodrome forecast. B. CIG/VIS- Ceilinand visibility C. Clouds D. PCPN/WX - precipitation and weather E.TS-thunderstorms. F. Winds. G. Turb-Turbulence. H. Ice

Question 52

Describe some of weather products available when selecting the “obs/warn” tab of the GFA.

Answer 52

Selecting the “obs/warn” tab provides an option to display weather data for the current time and the previous 14 hours (rounded to the nearest hour.) Selecting the “obs/warn” tab will provide the following observations / warnings: A. METAR B. PCPN/WX-PRECIPTIATION and weather C. CIG/Vis-Ceiling and visiblity D. PIREP-pilot reports. E. RAD/SAT- Radar and Satellite.

Question 53

What are the four types of inflight aviation weather advisories ?

Answer 53

Inflight aviation weather advisories are forecasts to advise encounter aircraft of the development of potentially hazardous weather in four types: SIGMET (WS) , the convective SIGMET (WST) , the AIRMET (WA; text or graphical product and the center weather advisory (CWA). All heights are referenced MSL, except in the case of ceilings (CIG) which indicate AGL.

Question 54

Describe the winds and temperature aloft forecasts (FB)

Answer 54

Winds and temperature aloft forecasts are computer prepared forecasts of wind direction, wind speed , and temperature at specified times , altitudes, and locations . They are produced 4 times daily for specified locations in the continental United States , Hawaii , Alaska and coastal waters , and the western Pacific Ocean amendments are not issued to the forecasts. Wind forecasts are not issued for altitudes within 1,500 feet of a location elevation. Some of the (FB) A). Product header includes date and time observation collected forecast valid date and time , and the time period during which the forecast is to be used B)altitudes up to 15,000 feet referenced to MSL , altitudes at or above 18,000 feet are reference to flight levels (FL) C). Temperature indicated in degrees Celsius (2 digits) for the levels from 6,000 through 24,000 ft. Above 24,000 feet, minus sign is omitted since temperature are always negative at those altitudes . Temperature forecasts are not issued for altitudes within 2,500 feet of a locations elevation. Forecasts for intermediate levels are determined interpolation. D). Wind direction indicated in tens of degrees(2 digits) with reference to true north and wind speed is given in knots 2 digits. Light and variable wind or wind speeds of less than 5 knots are expressed by 9900. Forecast wind speeds of 100 through 199 knots are indicated by subtracting 100 from the speed and adding 50 to the coded direction .for example , a forecast 250 degrees ,145 knots, is encoded as 7545 . forecast wind speeds of 200 nots or greater are indicated as a forecast speed of 199 knots. For example 7799 is decoded as 270 degrees at 199 knots or greater . * The AWC website provides a graphical depiction of the FB wind and temperature forecasts as well as a text version at AVIATIONWEATE.GOVE /WINDTEMP.

Question 55

What valuable information can be determined from winds and temperatures aloft forecasts (FB)

Answer 55

Most favorable altitude - based on winds and direction of the flights Areas of possible icing - by noticing air temperatures of +2*C to -20*C Temperature Inversions. Turbulence- by observing abrupt changes in wind direction and speed at different altitudes.

Question 56

What are center weather advisories

Answer 56

A center weather advisory (CWA) is an aviation warning for use by aircrews to anticipate and avoid adverse weather conditions in the en route and terminal environments. The CWA is not a flight planning product, , instead it reflects current conditions expected at the time of issuance and / or is a short range forecast for conditions expected to begin within 2 hours of issuance. CWA’s are valid for a max of 2 hours. If conditions are expected to continue beyond the 2 hour valid period , a statement will be included in the CWA

Question 57

Give some examples of the various weather charts you will used during preflight planning ?

Answer 57

A. Surface analysis chart B. Weather depiction chart- being phased out in favor of the ceiling and visibility analysis (CVA). C. Short-range surface prognostic chart . D. Significant weather prognostic chart. E. Convective outlook chart. F. Constant pressure analysis- chart - being phased out in favor of upper air constant pressure level forecasts. G. Freezing level graphics.

Question 58

What is a surface analysis chart?

Answer 58

Surface analysis charts are analyzed charts of surface weather observations. The chart depicts the distribution of several items including sea level pressure, the positions of highs, lows, ridges, troughs, the location and character of fronts, and the various boundaries such as dry lines, outflow boundaries, sea breeze fronts , and convergence lines. The chart is produced eight times daily.

Question 59

Describe a ceiling and visibility analysis (CVA)

Answer 59

A CVA is a real time analysis (updated every 5 minutes) of current ceiling and visibility conditions across the continental United States . It is intended to aid situational awareness with a quick glance visualization of current ceiling and visibility conditions across an area or along a route of flight. The CVA provides a viewer-selectable representation of ceiling height (AGL) , surface visibility in statute miles (SM). And flight category designation. The overview provided by a CVA should be followed by further examination of METARs , TAFs, AIRMETs , GFAs, FAs, and other weather information.