Weather Information

N-ational weather service
F-light service
F-oreflight or Garmin
1-800wx.brief
A-viationweather.gov
P-IREPS
C-WAs
A-irmets
S-igmets
C-onvective sigmets

- determines weather or not the air will rise and cause a storm or sink and create clear skies
- always depends on the day and saturated adiabatic lapse rate

- increases 2 degrees per 1000ft
- STD temp is 15 degrees celsius

1 - Standard
2- Abbreviated
3- Outlook
4- Inflight

low pressure: moves inward, upward , and counter clockwise
high pressure: outward, downward, and clockwise

rising air = Cloudiness, precipitation, bad weather

descending air = good weather few clouds

- cold front
- warm front
- occluded front
- Stationary front

when cold dense and stable air advances and replaces warmer air

when warm air mass flows over a cold airmass

when a fast moving Cold front Catches up to a slow moving warm front

When two relatively equal Air massess remains stationary and influences the local weather for a few days. Tends to be a mixture of both warm and cold air masses.

- towering cumulonimbus Clouds
- heavy rain
_ lightning
- thunder
- tornadoes
- poor visibility
- winds variable and gusting
- drop in temperature /dew point and barometric pressure

- stratiform clouds
- drizzle
- low Ceilings
- poor visibility
- variable winds
- rise in temperature

depends on the amount of moisture avaliable

an area of rising air
- often associated with Cloudiness and precipitation as well as low pressure and bad weather

area of high atmospheric pressure and descending air
- associated with dissipation of clouds, and good weather

15° C and 29.92 Hg

Requested when you are planning a flight and have not yet recieved a previous breifing or have not recieved preliminary information through mass dissemination of media

Request this whe you need information to supplement mass disseminated data, update a previous briefing, or when you need only one or two items

request whenever you proposed time of departure is 6 or more hours from the time of the briefing, for planning purposes only

request when needed to update a preflight briefing

connects areas of equal or constant pressure
- if they are close together, means they have high wind speeds and if they are far apart, means low wind speeds

The Corolis force

surface friction

1hg per 1000 feet

the temperature to which a sample of air must be cooled to attain the state of saturation

the stability of the atmosphere

- small vertical movements create larger turbulent airflow
- also creates convective activity
- cumuliform or comulonimbus clouds
- precipitation tends to be showery
- visibility for some reason is very good

- makes vertical movement difficult
- creates stratiform clouds
- low turbulance
- has steady drizzle / precipitation
- visibility tends to be fair or poor

visible moisture and below freezing temperatures at the point moisture strikes the aircraft

- structural
- induction
- instrument icing

- clear
- rime
- mixed ice

- forms after impact with surface
- liquid portion flows over aircraft surface and gradually freezes into a sheet of ice

- forms when drops are small like in stratiform clouds or in light drizzle
- liquid portion freezes rapidly before the drop has time to spread out

- descend or climb to a warmer altitude preferably staying below a cloud base or remaining above cloud tops or turning to a new course

- high moisture content
- unstable lapse rate (air)
- upward boost action (air)

1: Cumulus Stage
- updrafts cause raindrops to get bigger
2: Mature Stage
- rain at earths surface falls through or has lightening and rolling clouds besides updrafts
3: Dissipating Stage
- downdrafts and rain begin to dissipate

- the opposite of what normally happens with temperaturing
- so the higher you go the warmer it gets and the lower you go the colder it becomes

"Fog Usually Stays Present After Rain."
U-pslope fog
S-team Fog
P-recipitation Fog
A-dvection Fog
R-adiation Fog

Forms when the ground cools the air to the dew point on calm clear nights

Forms when warm humid air rolls over a cold surface usually along coastel areas during the winter
- also may occur with winds, cloudy skies, over a wide geographic area, and at any time of the day or night

- forms as a result of moist, stable air being cooled adiabatically as it moves up the slopping terrain. Is often dense and extends up to high altitudes

A sudden rate of change of wind velocity in any direction that can occur at any point in the atmosphere
- tends to last for 15 minutes
- can bump you up or push you down 6,000'

- wind sear with low temperature inversion
- wind shear in a frontal zone or thunderstorm
- CAT at high levels associated with a jet stream or strong circulation

"Hazardous In-Fight Weather Advisory Service."
- depicted on sectional charts with the letter H
- broadcasted on all frequencies except emergency frequencies
- is a combination of all weather services like sigmets, airmets, and PIREPS

- hourly observation of conditions observed at the airport
- there are two types: the regular METAR and the SPECI
Regular METAR
- transmits information every hour
SPECI
- special metar that changes based on how frequenltly weather conditions change, or how often they can report aircraft mishaps

"Terminal Aerodrome Forecasts."

Concise statemet of meterological conditons significant to the aircraft for a specified period of time within 5 sm of the center of the airports runway complex aka terminal.

Sigmets, airmets, CWAS, etc

- SIGMET
- AIRMET
- CWAS
- CIG

- implies severe or greater TB, icing, or llws
- if there are sfc winds greater than 50kts
- hail at the surface greater than or equal to 3/4 inches in diameter
- tornadoes
- embedded TS
- a line of TS
- TS producing greater than or equal to heavy precipitation that affects 40% or more of an area at least of 3,000 ft sq miles

- issued valid for 4hrs and can be valid for 6hrs if the report involves tropical cyclones and volcanic ash
Covers
- severe icing not associated with TS
- severe or extreme TB or CAT not associated with TS
- widespread dust storms or sandstorms lowering surface visibilities to below 3 miles
- volcanic ash

- issued every 6hrs
- includes outlook for certain weather conditions about IFR conditions, TB, Strong winds, icing, and freezing levels
- here are 3 types of AIRMETS: Sierra, Tango, Zulu

- describes IFR conditions and or extensive mountain obstructions

- describes moderate tb, sustained winds of 30kts or more, and or non convectional low level wind shear

- describes moderate icing and provides freezing level heights

- surface analysis charts
- weather depiction charts
- short range surface prognostic chart
- significant weather prognostic chart
- convection outlook chart
- constant pressure analysis chart

Displays.....
- low pressure areas
- position of high, lows, ridges, troughs, fronts, drylines, outflow boundaries, sea breeze fronts, convergence lines
- is also produced 8 times daily

- contains a plot of weather conditions at METAR stations as well as VFR, MVFR, IFR

ceiling less than 500 feet and or visibility less than 1 mile

Ceiling 500 to less than 1000' and or visibility 1 to less than 3 miles

ceiling 1000-3000' and or visibility 3-5 miles

Ceiling greater than 3000' and visibility greater than 5 miles includes clear sky