Weather Information Flashcards
What are the various ways that you can check the weather while flying enroute?
ATC, HIWAS, FSS, listen to the weather frequencies of nearby airports.
What kind of weather would legally require us to be on an IFR flight plan in order to take off today out of KIWA?
Anything below VFR T/O mins, i.e. below either 3sm OR 1000ft ceiling when departing from a controlled airport.
What kind of weather would legally require us to be on an IFR flight plan in order to take off today out of KCGZ?
Vis below 1sm OR if you can’t maintain clear of clouds.
Show METARs with various weather and ask, could we take off VFR if this were the weather at our departure airport, or would we need to be on an IFR flight plan?
Look for METARS
With whom can you file a PIREP?
ATC or a FSS.
Interpret this PIREP: KCMH UA /OV APE 230010/TM 1516/FL085/TP BE20/SK
BKN065/WX FV03SM HZ FU/TA 20/TB LGT/IC MDT MXD 040-050/RM LLWS –15 KT SFC-030 DURGC RY 22 CMH
KCMH UA /OV APE 230010/TM 1516/FL085/TP BE20/SK
BKN065/WX FV03SM HZ FU/TA 20/TB LGT/IC MDT MXD 040-050/RM LLWS –15 KT SFC-030 DURGC RY 22 CMH
What would “UUA” (instead of UA) on a PIREP signify?
Urgent.
What ingredients are necessary for a thunderstorm to form?
Lifting force
Unstable Lapse Rate
Visible Moisture
Are all three ingredients for a storm always required?
Yes
Is it VISIBLE moisture or just any moisture in the air, like water vapor, that is required for thunderstorm formation?
Doesn’t have to be visible.
What charts can you use to determine the presence each ingredient?
Plenty of options
here. One viable answer: For moisture look at the temp/dew point spread; for instability look at the temperature lapse rate on the winds aloft; for a lifting action look at the surface analysis and/or prog chart for low pressure systems, frontal activity, etc.
What is meant by “unstable air?”
Air that, when it’s pushed up, keeps rising. Conversely, stable air resists upward movement.
What are some examples of weather phenomena that can cause a lifting action?
Orographic effects (wind moving across mountains and valleys), frictional effects (low pressure systems), frontal lifting, buoyancy (uneven heating of surface).
What weather is associated with a thunderstorm?
Flash flooding, lightning, hurricanes, tornadoes
If you accidentally fly into a thunderstorm what airspeed will you fly?
Penetration speed
If you’re stuck in one would you try to maintain a level altitude or level attitude?
Attitude
What are the stages of a thunderstorm? What characterizes each stage?
Cumulus stage: 3-5 mi height, lifting action begins, 3000 fpm
Mature: 5-10 mi height, precipitation from cloud base, updraft 6000 fpm, downdraft 2500 fpm hazards most severe
Dissipating: 5-7 mi high, strong downdrafts, cell is dying out
By how many miles are you supposed to circumvent a thunderstorm
20 nm, hail can approach at 20 nm is why
What does the METAR symbol -TSRA mean?
No it does not mean light thunderstorm, there’s no such thing. It means LIGHT RAIN associated with a thunderstorm
As you turn final at your destination airport, you notice virga just above the runway. Your indicated airspeed starts increasing despite that fact that you’re not adding power or descending any more rapidly. What do you think is going on here? What additional sign might you see at the surface? What are you going to do? How strong can the downdrafts get? How long would you expect this microburst to last? What sort of weather activity needs to exist for a microburst to form ?
Microburst Blowing ring of dust Add full power and start climbing, go around 6000 fpm 45 kts (90kt shear) 15 mins Convective
Pretend that the weather at your destination airport at your ETA is this: 071653Z 03004KT 10SMOVC04007/02A3029RMKAO2SLP260T00670017. YouintendtofileIFRand this airport has multiple approaches. Would you make a go or no go decision? Why or why not?
No go due to icing. With a normal lapse rate the temp at 4000ft would be -1 degrees, and the ceiling is overcast at that altitude.
Show me with these charts and weather information how exactly you determined that we won’t be at risk of flying into icing conditions?
This will involve using the charts to both show where the clouds/visible moisture will be during every phase of the flight, as well as to determine the freezing level throughout the route. There are many ways to effectively do this. Some options: as the TAF range extends only 5sm from the airport, and seeing as only larger airports have TAFs, determining cloud coverage beyond the range of these airports involves using the area forecast. The graphical area forecast (GFA) tool on aviationweather.gov allows you to plot your flight path, then it shows the cloud coverage along the entire route at various selected times. To determine precise freezing levels along your route involves using the winds aloft; be sure to use the stations along the entire route, not just departure and destination airport stations. More options include using graphical icing forecasts, PIREPs, freezing level charts, etc. Using the “show flight path” feature is always extremely helpful, as it allows you to prove the location of this weather relative to your exact route.
What kind of weather conditions need to exist for structural icing to form?
Temperatures around freezing and visible moisture.
What are the different types of ice and what characterizes each?
Rime
Clear
Mixed
