WEATHER INFORMATION · The upper two panels show forecast significant weather, which may include...

RAM Private Pilot ACS - Areas of Operation: Task C 2016-2017 Page

WEATHER INFORMATION

ACS – AREAS OF OPERATION: TASK C

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How do you prepare for a flight? PAVE: Pilot, Aircraft Environment and External Pressures.

PILOT

A pilot must continually make decisions about competency, condition of health, mental

and emotional state, level of fatigue, and many other variables.

AIRCRAFT

A pilot frequently bases decisions on evaluation of the airplane, such as performance,

equipment, or airworthiness. This task will concentrate on the aircraft (ASEL – Airplane

Single Engine Land).

ENVIRONMENT

The environment encompasses many elements that are not pilot or airplane related,

including such factors as weather, air traffic control (ATC), navigational aids, terrain,

takeoff and landing areas and surrounding obstacles. Weather is one element that can

change drastically over time and distance.

EXTERNAL PRESSURES

The pilot must evaluate the three previous areas to decide on the desirability of under-

taking or continuing the flight as planned. It is worth asking why the flight is being made,

how critical it is to maintain the schedule, and if the trip is worth the risks.

P – Pilot for the Private Pilot:

Start with I’M SAFE: Illness, medication, stress, alcohol (.04), fatigue (acute and chronic) and

eating/emotional factors. If any of these factors apply, you should not fly. As a private pilot, you

are required to carry your pilot’s certificate, medical and a government ID. As a private pilot,

you are allowed to carry passengers (not for hire) – 61.113, fly when visibility is less than 3

miles (SVFR – Special VFR) and can fly without visual reference to the surface. Special

requirements for the Private Pilot are: Must be a Private Pilot to take off and land within (KSFO)

Class B Airspace (AIM 3-2-3) and can fly at night. Must maintain currency to carry passengers:

1.) 3 touch-n-go’s during the day and 3 full stop landings at night every 90 days – 61.57. 2.)

Complete a BFR (Flight Review) (minimum 1 hour of ground and 1 hour of flight – every 24

calendar months – 61.56. 3.) Have a First Class (valid for 6 months), Second Class (valid for 12

months) or Third Class (valid for 2 years if over 40 years old or 5 years if under 40 years old)

medical certificate to be pilot in command.


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A – Aircraft for the Private Pilot:

Remember A R O W. Airworthiness Certificate (Has the aircraft had an Annual, 100 hour,

Progressive - 91.409, Pitot Static/Transponder check (24 months - 91.411, 91.413), Aircraft has

the required equipment – 91.205 if NOT Special Flight Permit 21.197 & 21.199, ELT check -

91.207 and all AD’s have been complied - 91.403 39.3, Registration (Every Three Years) – 47.41,

Operating Limits (Section 2 of POH, Pilot’s Operating Handbook) – 91.9 and Weight and Balance

(Section 6 of POH). Fuel requirements for all flights (30 minutes Day, 45 minutes Night) -

91.151. The required takeoff and landing distances, runway lengths and weather forecasts -

91.103. Avionics familiarity, density altitude and a current sectional information.

V – Environment for the Private Pilot:

Think of the Airport and weather conditions: Crosswind, Takeoff and Landing distances, Ceiling

conditions, visibility and your personal minimums. Plan on the weather for your Departure, En-

route and Destination. For example: Current Metar, TAF and FA (Area Forecast), surface

analysis chart, radar summary chart, winds and temperature aloft, significant weather

prognostic chart, convective outlook chart, Airmets and Sigmets, PIREPs, wind shear reports,

icing and freezing levels and AWOS, ASOS and ATIS reports for the route and destination. The

pilot wants to make a competent “go/no-go” decision based on available weather information.

Reference Weather Information – Task C in RAM Study Guide.

E – External Pressures for the Private Pilot:

Think about “Get there Itis.” The determination to reach a destination, combined with

hazardous weather, claims the lives of dozens of pilots and their passengers yearly. Think about

the hazardous attitudes: Anti-authority, Impulsivity, Invulnerability, Macho and Resignation to

see if they may apply to this flight. Allowance for delays and diversions, alternative plans and

personal equipment. After you use the PAVE checklist (step 1), use the CARE checklist

(Consequences, Alternatives, Reality and External pressures) (step 2) and determine the level

and severity of the risk. (Step 3) perform the TEAM checklist. Transfer Risk, Eliminate Risk,

Accept Risk and Mitigate Risk.


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Radar Summary Chart

Based on Precipitation (Echo Return)

Lt. Green – Weak Precipitation, no turbulence

Yellow – Moderate precipitation and moderate turbulence

Red – Heavy Precipitation and severe turbulence


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Weather Depiction Chart

Shows where it’s IFR, MVFR, and VFR Conditions

IFR – Ceiling less than 1000’, visibility less than 3sm MVFR – Ceiling 1000’ – 3000’, visibility 3 -5sm

VFR – Ceiling greater than 3000’, vis greater than 5sm


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Significant Weather Prognostic Charts

A four-panel chart that includes 12– and 24–hour forecasts for significant weather

and surface weather. Charts are issued four times a day at 0000Z, 0600Z, 1200Z,

and 1800Z. The valid time for the chart is printed on the lower left corner.

The upper two panels show forecast significant weather, which may include non-

convective turbulence, freezing levels, and IFR or MVFR weather.

The lower two panels show the forecast surface weather and depicts the forecast

locations and characteristics of pressure systems, fronts, and precipitation.


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Surface Analysis Chart

Shows Fronts, Pressure Systems and Isobars

For planning flights, based on the fronts and winds/Temps

Trough is an elongated low pressure

Ridge is an elongated high pressure

The surface analysis chart is a computer-generated chart, with frontal analysis by Forecasters, transmitted every 3 hours covering the contiguous 48 states and

adjacent areas.


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Surface Analysis Chart Extended


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STABILITY OF AIR MASSES:

Stable Air Unstable Air Stratiform Clouds & Fog Cumuliform Clouds Steady Precipitation Showery Precipitation Smooth Air Rough Air (Turbulence) Fair to Poor Visibility Good Visibility Haze and Smoke Blowing Obstructions Rime Icing Probability Clear Icing Probability Typical Warm Front Typical Cold Front


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FRONTS:

There are four types of fronts, which are named according to the temperature of the advancing air relative to the temperature of the air it is replacing: • Warm • Cold • Stationary • Occluded


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CLOUDS:

Clouds: Low, Middle and High Clouds are visible indicators and are often indicative of future weather. For clouds to form, there must be adequate water vapor and condensation nuclei, as well as a method by which the air can be cooled. When the air cools and reaches its saturation point, the invisible water vapor changes into a visible state. Through the processes of deposition (also referred to as sublimation) and condensation, moisture condenses or sublimates onto miniscule particles of matter like dust, salt, and smoke known as condensation nuclei. The nuclei are important because they provide a means for the moisture to change from one state to another. Cloud type is determined by its height, shape, and behavior. They are classified according to the height of their bases as low, middle, or high clouds, as well as clouds with vertical development. Low clouds are those that form near the Earth’s surface and extend up to 6,500 feet AGL. They are made primarily of water droplets, but can include super cooled water droplets that induce hazardous aircraft icing. Typical low clouds are stratus, stratocumulus, and nimbostratus. Fog is also classified as a type of low cloud formation. Clouds in this family create low ceilings, hamper visibility, and can change rapidly. Because of this, they influence flight planning and can make visual flight rules (VFR) flight impossible. Middle clouds form around 6,500 feet AGL and extend up to 20,000 feet AGL. They are composed of water, ice crystals, and super cooled water droplets. Typical middle-level clouds include altostratus and altocumulus. These types of clouds may be encountered on cross-country flights at higher altitudes. Altostratus clouds can produce turbulence and may contain moderate icing.


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Altocumulus clouds, which usually form when altostratus clouds are breaking apart, also may contain light turbulence and icing. High clouds form above 20,000 feet AGL and usually form only in stable air. They are made up of ice crystals and pose no real threat of turbulence or aircraft icing. Typical high level clouds are cirrus, cirrostratus, and cirrocumulus. Dew and Frost On cool, calm nights, the temperature of the ground and objects on the surface can cause temperatures of the surrounding air to drop below the dew point. When this occurs, the moisture in the air condenses and deposits itself on the ground, buildings, and other objects like cars and aircraft. This moisture is known as dew and sometimes can be seen on grass in the morning. If the temperature is below freezing, the moisture is deposited in the form of frost. While dew poses no threat to an aircraft, frost poses a definite flight safety hazard. Frost disrupts the flow of air over the wing and can drastically reduce the production of lift. It also increases drag, which, when combined with lowered lift production, can adversely affect the ability to take off. An aircraft must be thoroughly cleaned and free of frost prior to beginning a flight. Fog: Radiation Fog, Advection Fog (SFO), Upslope Fog, Steam Fog and Ice Fog Fog is a cloud that begins within 50 feet of the surface. It typically occurs when the temperature of air near the ground is cooled to the air’s dew point. At this point, water vapor in the air condenses and becomes visible in the form of fog. Fog is classified according to the manner in which it forms and is dependent upon the current temperature and the amount of water vapor in the air. On clear nights, with relatively little to no wind present, radiation fog may develop. Usually, it forms in low-lying areas like mountain valleys. This type of fog occurs when the ground cools rapidly due to terrestrial radiation, and the surrounding air temperature reaches its dew point. As the sun rises and the temperature increases, radiation fog lifts and eventually burns off. Any increase in wind also speeds the dissipation of radiation fog. If radiation fog is less than 20 feet thick, it is known as ground fog. When a layer of warm, moist air moves over a cold surface, advection fog is likely to occur. Unlike radiation fog, wind is required to form advection fog. Winds of up to 15 knots allow the fog to form and intensify; above a speed of 15 knots, the fog usually lifts and forms low stratus clouds. Advection fog is common in coastal areas where sea breezes can blow the air over cooler landmasses. Upslope fog occurs when moist, stable air is forced up sloping land features like a mountain range. This type of fog also requires wind for formation and continued existence. Upslope and advection fog, unlike radiation fog, may not burn off with the morning sun, but instead can persist for days. They can also extend to greater heights than radiation fog. Steam fog, or sea smoke, forms when cold, dry air moves over warm water. As the water evaporates, it rises and resembles smoke. This type of fog is common over bodies of water during the coldest times of the year. Low-level turbulence and icing are commonly associated with steam fog. Ice fog occurs in cold weather when the temperature is much below freezing and water vapor forms directly into ice crystals. Conditions favorable for its formation are the same as for radiation fog except for cold temperature, usually –25 °F or colder. It occurs mostly in the arctic regions, but is not unknown in middle latitudes during the cold season.


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Area Forecast (FA)

An area forecast (FA) is a forecast of Visual Flight Rules (VFR) clouds and weather conditions over an area as large as the size of several states. The area forecast together with the AIRMET Sierra bulletin are used to determine forecast en-route weather and to interpolate conditions at airports which do not have a terminal forecast (TAF) issued. FAs are issued 3 times a day from Kansas City for each of 6 areas in the contiguous 48 states. The FA consists of a:

12 hour forecast plus a 6 hour outlook. All times are Coordinated Universal Time (UTC). All distances except visibility are in nautical miles. Visibility is in statute miles.

Synopsis section which is a brief summary of the location and movement of fronts, pressure system, and circulation patterns for an 18 hour period.

VFR clouds and weather section which is a 12 hour forecast, in broad terms, of clouds and weather significant to flight operations plus a 6 hour categorical outlook. This section is usually several paragraphs. AIRMET Sierra supplies information regarding Instrument Flight Rule (IFR) conditions. The breakdown may be by states, by well-known geographical areas, or in reference to location and movement of a pressure system or front. A categorical outlook, identified by OTLK, is included for each area breakdown.


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TAF (Terminal Aerodrome Forecast)

Valid for 24hrs, issued 4 times daily, within 5nm of airport

Gives you an Outlook of weather for the Day

For planning on an alternate and type of conditions on your arrival.

TAF KSTS 261121Z 261212 VRB03KT P6SM BKN200 BECMG 1314 22005KT FEW025

METAR (Aviation Routine Weather Report)

Issued hourly, is a surface aviation weather observation

Current conditions based on ATIS, AWOS and ASOS

METAR KSTS 261451Z 30008KT 10SM SCT120 26/22 A3012

Winds and Temp Aloft (FD)

Find Freezing Conditions (+5C to -20C) + Vis Moisture

Airmet Tango - Turbulence or wind shear

Best Cruise Altitude (Tailwind/Headwind)

No winds below 3000’, use Metar

Temp Inversions


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Airmets (WA)

For Light G.A. Aircraft Conditions: Light to Moderate

Valid for a 6 hr period Contains: SIERRA, TANGO and ZULU

SIERRA - IFR Conditions TANGO - Turbulence

ZULU - Icing Conditions

Sigmets (WS)

For All Aircraft (Large and Small) Conditions: Moderate to Severe

Valid for a 4 hr period Moderate to Severe Icing and Turbulence

Convective Sigmets (WST)

Conditions: Severe to Extreme

Valid for a 2 hr period Hail Greater than ¾”

Line of Thunderstorms Embedded Thunderstorms Wind Greater than 50 kts Severe Icing Conditions


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Convective Outlook Chart

Convective Outlook (sometimes called AC) – Is a 48 hour outlook of thunderstorms. It is a forecast containing the area(s) of expected thunderstorm occurrence and expected severity over the contiguous United States, issued several times daily.

http://en.mimi.hu/meteorology/forecast.html#maintitle

http://en.mimi.hu/meteorology/thunderstorm.html#maintitle


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Thunderstorms:

Cumulonimbus clouds contain large amounts of moisture and unstable air, and usually produce hazardous weather phenomena, such as lightning, hail, tornadoes, gusty winds, and wind shear. These extensive vertical clouds can be obscured by other cloud formations and are not always visible from the ground or while in flight. When this happens, these clouds are said to be embedded, hence the term, embedded thunderstorms. For example, if an aircraft enters a thunderstorm, the aircraft could experience updrafts and downdrafts that exceed 3,000 fpm. In addition, thunderstorms can produce large hailstones, damaging lightning, tornadoes, and large quantities of water, all of which are potentially hazardous to aircraft. A thunderstorm makes its way through three distinct stages before dissipating. It begins with the cumulus stage, in which lifting action of the air begins. If sufficient moisture and instability are present, the clouds continue to increase in vertical height. Continuous, strong updrafts prohibit moisture from falling. The updraft region grows larger than the individual thermals feeding the storm. Within approximately 15 minutes, the thunderstorm reaches the mature stage, which is the most violent time period of the thunderstorm’s life cycle. At this point, drops of moisture, whether rain or ice, are too heavy for the cloud to support and begin falling in the form of rain or hail. This creates a downward motion of the air. Warm, rising air; cool, precipitation-induced descending air; and violent turbulence all exist within and near the cloud. Below the cloud, the down-rushing air increases surface winds and decreases the temperature. Once the vertical motion near the top of the cloud slows down, the top of the cloud spreads out and takes on an anvil-like shape. At this point, the storm enters the dissipating stage. This is when the downdrafts spread out and replace the updrafts needed to sustain the storm.


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Knowledge of thunderstorms and the hazards associated with them is critical to the safety of flight. Hazards - Weather can pose serious hazards to flight and a thunderstorm packs just about every weather hazard known to aviation into one vicious bundle. These hazards occur individually or in combinations and most can be found in a squall line. Squall Line A squall line is a narrow band of active thunderstorms. Often it develops on or ahead of a cold front in moist, unstable air, but it may develop in unstable air far removed from any front. Tornadoes The most violent thunderstorms draw air into their cloud bases with great vigor. If the incoming air has any initial rotating motion, it often forms an extremely concentrated vortex from the surface well into the cloud. Meteorologists have estimated that wind in such a vortex can exceed 200 knots with pressure inside the vortex quite low. Tornadoes occur with both isolated and squall line thunderstorms. Turbulence Strongest turbulence within the cloud occurs with shear between updrafts and downdrafts. Outside the cloud, shear turbulence has been encountered several thousand feet above and 20 miles laterally from a severe storm. A low-level turbulent area is the shear zone associated with the gust front. Often, a “roll cloud” on the leading edge of a storm marks the top of eddies in this shear and it signifies an extremely turbulent zone. Gust fronts often move far ahead (up to 15 miles) of associated precipitation. Icing Updrafts in a thunderstorm support abundant liquid water with relatively large droplet sizes. When carried above the freezing level, the water becomes super cooled. When temperature in the upward current cools to about –15 °C, much of the remaining water vapor sublimates as ice crystals. Hail Hail competes with turbulence as the greatest thunderstorm hazard to aircraft. Super cooled drops above the freezing level begin to freeze. Once a drop has frozen, other drops latch on and freeze to it, so the hailstone grows—sometimes into a huge ice ball. Large hail occurs with severe thunderstorms with strong updrafts that have built to great heights. Eventually, the hailstones fall, possibly some distance from the storm core. Hail may be encountered in clear air several miles from thunderstorm clouds. Ceiling and Visibility Generally, visibility is near zero within a thunderstorm cloud. Ceiling and visibility also may be restricted in precipitation and dust between the cloud base and the ground. The restrictions create the same problem as all ceiling and visibility restrictions; but the hazards are multiplied when associated with the other thunderstorm hazards of turbulence, hail, and lightning. Effect on Altimeters Pressure usually falls rapidly with the approach of a thunderstorm, rises sharply with the onset of the first gust and arrival of the cold downdraft and heavy rain showers, and then falls back to


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normal as the storm moves on. This cycle of pressure change may occur in 15 minutes. If the pilot does not receive a corrected altimeter setting, the altimeter may be more than 100 feet in error. Lightning A lightning strike can puncture the skin of an aircraft and damage communications and electronic navigational equipment. Although lightning has been suspected of igniting fuel vapors and causing an explosion, serious accidents due to lightning strikes are rare. Nearby lightning can blind the pilot, rendering him or her momentarily unable to navigate either by instrument or by visual reference. Nearby lightning can also induce permanent errors in the magnetic compass. Engine Water Ingestion Turbine engines have a limit on the amount of water they can ingest. Updrafts are present in many thunderstorms, particularly those in the developing stages. Severe thunderstorms may contain areas of high water concentration which could result in flameout and/or structural failure of one or more engines.


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Pilot Reports (PIREP’S) (UA)

(UUA) means Urgent

Given on FSS or Flight Following Freq.

Contains: Altitude, Vis, Turbulence, Bases, Tops, Icing, and any condition that is useful for pilots.

Great for actual conditions that pilots are flying

ATIS (Automated Terminal Info. Service)

Use Below 3000’ AGL

Contains: Wind, Vis, Sky Condition, Temp/Dew, Altimeter, Remarks: Landing Runway and What Approach is in Use.

AWOS (Automated weather Observation System)

AWOS 1 - Wind, Vis and Altimeter

AWOS 2 - 1 and Sky Condition and Temp/Dew

AWOS 3 - 1 and 2 plus Density Alt.

ASOS (Automated Surface Observation System)

Better than AWOS

Gives you everything

Wind, Vis, Sky, Temp/Dew, Altimeter and Runway Information.


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Icing and Freezing Level Information

In aviation, icing conditions are those atmospheric conditions that can lead to the formation of water ice on the surfaces of an aircraft, or within the engine as carburetor icing.

Types of Icing:

Clear ice is often clear and smooth. Supercooled water droplets, or freezing rain, strike a surface but do not freeze instantly. Forming mostly along an airfoil's stagnation point, it generally conforms to the shape of the airfoil.

Rime ice is rough and opaque, formed by supercooled drops rapidly freezing on impact. Often "horns" or protrusions are formed and project into the airflow.

Mixed ice is a combination of clear and rime ice. Frost ice is the result of water freezing on unprotected surfaces. Often

forming behind deicing boots or heated leading edges, it was a factor in the crash of American Eagle Flight 4184.

Freezing Level Charts

Conditions for ice to form: +5C to -20C and visible moisture.

https://en.wikipedia.org/wiki/Aviation

https://en.wikipedia.org/wiki/Atmospheric_icing

https://en.wikipedia.org/wiki/Atmospheric_icing

https://en.wikipedia.org/wiki/Carburetor_icing

https://en.wikipedia.org/wiki/Freezing_rain

https://en.wikipedia.org/wiki/Freezing_rain

https://en.wikipedia.org/wiki/Airfoil

https://en.wikipedia.org/wiki/Stagnation_point

https://en.wikipedia.org/wiki/American_Eagle_Flight_4184


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NOTAMS (Notice to Airmen)

Notam Types: Runway, Aerodrome, Obstruction, Navigation, Communication, Airspace, Taxiway, Ramp/Apron, Unverified

Aeronautic Information, Other and Notams without Keywords.

Notam (FDC): - Regulatory in nature, after 14 days notam 2 Bluebook, Natural Disasters and Accident Sites.

CLOUD TYPES

Stratus: Rime Icing, Heavy Precip and low Visibility

Cumulus: Clear Icing, Light Precip, and Good Visibility

PENATRATE A THUNDERSTORM

Reduce to @ or Below VA

Fly Straight ahead, do not turn (Increase Load Factor)

Attempt to hold Altitude

Reduce Electrical Load

WINDSHEAR REPORTS

Wind shear is the generic term for wind differences over an operationally short distance (in relation to flight) which encompass meteorological phenomena

including gust fronts, microbursts, vertical shear, and derechos.

https://en.wikipedia.org/wiki/Wind_shear

https://en.wikipedia.org/wiki/Gust_front

https://en.wikipedia.org/wiki/Microburst

https://en.wikipedia.org/wiki/Derecho


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Wind shear is a sudden, drastic change in wind speed and/or direction over a very small area.

Wind shear can subject an aircraft to violent updrafts and downdrafts, as well as abrupt changes to the horizontal movement of the aircraft. While wind shear can occur at any altitude, low-level wind shear is especially hazardous due to the proximity of an aircraft to the ground. Directional wind changes of 180° and speed changes of 50 knots or more are associated with low-level wind shear. Low-level wind shear is commonly associated with passing frontal systems, thunderstorms, and temperature inversions with strong upper level winds (greater than 25 knots).


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Personal Minimums:


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GO, NO-GO DECISION

1. Departure: Metar: Current Conditions TAF: Time of Departure Conditions

2. En-Route: Metar: Current conditions at midway point TAF: Conditions at ETE

3. Destination: Metar: Current Conditions TAF: Conditions at ETE

4. Radar Summary Chart: Is there any precip for the route! 5. Visible Satellite: Overall view of the route and cloud cover! 6. Surface Analysis Chart: Where are the Fronts/Pressure systems! 7. Winds & Temp Aloft: Most favorable Altitudes (HW/TW)

Look for turbulence, wind shear Check temps (+5 to -20C)

8. Notice to Airmen (NOTAMS): Check entire route

9. Airmets for route: Sierra, Tango, and Zulu 10. Pilot Reports for route: are there any 11. Sigmets for route: are there any 12. Convective Sigmets for route: Thunderstorm forecast!

13. TFR’s (Temporary Flight Restrictions) for the route

14. Destinations with an AWOS or ASOS have phone numbers listed in

the Flight Guide. Call prior to departure for current conditions.


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Aviation Weather Checklist Departure ________: METAR ____________________________________________________ TAF _______________________________________________________ En-Route _________: METAR ____________________________________________________ TAF _______________________________________________________ Destination _______: METAR ____________________________________________________ TAF _______________________________________________________ Go No Go Radar for Route Go No Go Satellite for Route Go No Go Surface Analysis for Route Go No Go Winds Aloft for Route Go No Go Notam’s (Notice to Airmen) Go No Go Airmet Sierra Go No Go Airmet Tango Go No Go Airmet Zulu Go No Go Pilot Reports (Sierra, Tango, and Zulu) Go No Go Sigmets Go No Go Convective Sigmets Go No Go TFR’s (Temporary Flight Restrictions)

Weather Web-site: Adds.Aviationweather.noaa.gov TFR’s Website: TFR.faa.gov

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