Weather Hazards Flashcards
Four conditions necessary for the formation of fog
small temperature/dewpoint spread
condensation nuclei
light surface wind
warm air above cooling land surface
What are the dissipation factors of fog?
Heating
Strong wind
Greenhouse effect/overcast sky
What type of cooling factors causes radiation fog to form?
Radiation cooling
Describe the formation and typical location of precipitation induced fog?
created as rain falls through a frontal inversion and saturates the cooler air below. It is typically found ahead of a warm front or behind a cold front
The 2400L forecast report (TAF) for your destination airport predicts the sky CLR, wind at 4 knots, temp of 17 degrees, and a dew point of 15 degrees. You will arrive just after midnight. What METAR weather coding would you expect to encounter?
FG
Assuming same conditions exist, except the forecast wind for 2400L was stronger–12-15kts. No water near by. What kind of weather would you expect and why?
Clear skies. Strong wind would tend to prevent or dissipate any fog.
Your DEC mission is taking you to Tyndall along Florida Coast. The ground is cold. Warm, moist air is flowing inland (3-9 kts) from Gulf of Mexico. You would expect_____ fog to form, possibly covering a (large/small) area.
Advection
large area
Moist, stable air is being forced up an incline, expanding and cooling as it is lifted. What type of fog?
upslope fog
Fog has formed during the late evening hours. Before sunrise, a thick overcast layer of clouds moves in over the fog. What effect will this have on the dissipation of this fog?
OVC cloud layer slows dissipation of fog
What type of icing is described as small supercooled water droplets in temperatures -8 to -10 degrees and stratus clouds?
Rime ice
Clear icing will typically occur in cumulus clouds where supercooled water droplets are (larger/smaller) than those in stratiform clouds.
larger
What intensity of icing would require immediate diversion from the affected altitudes?
severe
Where is common frontal location to find freezing rain (during the winter weather months)?
warm front
In addition to being a hazard to vision by covering windshields, ice can cause a loss of vital airspeed readings by covering the______
pitot tube
Factors needed for thunderstorm to form
Unstable air
small temperature/dewpoint spread
lifting action
What type of frontal thunderstorm would match the definition “a severe line of thunderstorms that form ahead of a fast moving cold front?”
squall line front
Summertime thunderstorm, forms everyday for the past week around 3 pm. What type is forming?
Air mass thunderstorm
The windward side of the mountain range has vertical clouds developing into a thunderstorm. What type of thunderstorm is forming?
Orographic
3 stages of a thunderstorm in order
Cumulus
mature
dissipating
Most severe weather would occur in which stage of a thunderstorm?
Mature
How do you know the cumulus stage has ended and the mature stage has begun?
precipitation and down drafts are descending from the cloud
Updrafts are only found in the ____ stage of the development of a thunderstorm?
cumulus
The category of turbulence on the OWS Turbulence chart is set for what category of aircraft?
Cat II
A microburst occurring in the heavy rain shaft of a thunderstorm would be classified as a (wet/dry) microburst.
wet
A microburst with virga from under vertical clouds would be classified as a (wet/dry) microburst.
dry
Best conditions for dry microburst at KOZR
CU clouds; 14:00 CST, July
High DA means what type of aircraft performance…
performance will be worse because a DA of 2031’ at KOZR indicates less air density
How does relative humidity affect aircraft performance?
Low RH indicates a small percentage of moisture in the air, fewer clouds, and better aircraft performance.
