Weather

Question 1

What is a METAR?

Answer 1

Gives weather at mission control site.

Question 2

KDCA 291552Z 10016G21KT 5SM BR OVC012 21/20 A3015 RMK AO2 RAE06 SLP208 P0000 T02110200

Answer 2

1: Airport
2: Taken at date (29) and time (1552) in zulu.
3: Winds from 100 (NE) at 16 knots, with gusts up to 21 knots.
4: 5SM is 5 statute miles of visibility.
5: BR is mist.
6: Overcast at 1200 feet
7: Temperature 21/dewpoint 20.
8: Altimeter set at 3015.

Question 3

What is a TAF?

Answer 3

TAF is Terminal Aerodrome Forecast. Is more in-depth than a METAR. Issued

Question 4

KDCA 291432Z 2915/3012 10017G22KT 4SM -RA BR OVC010
FM291800 08013G20KT 3SM SHRA OVC008
FM300300 07015KT 5SM -SHRA OVC008

Answer 4

1: Airport: KDCA, Washington National
2: Time/Date the TAF was issued. In this case it was issued on the 29th, at 14:32 zulu time.
3: Time that the TAF covers. In this case, 29th, from 1500Z to the 30th, at 12:00 zulu. Thus it is a 22 hour forecast.
4: Followed by the initial forecast. In this case wind from 100 at 17 knots with gusts up to 22 knots.
5: 4 statute miles of visibility.
6: -RA is light rain and BR is fog.
7: Overcast at 1000 ft.
8: FM designates some quick weather event. In this case, from 29th at 1800 Z, the wind shifts, is coming from 080 (coming from the north east) at 13 knots, gusts up to 20 knots.
9: SHRA Showers, rain. Overcast at 800 feet.

Question 5

What are the three types of weather briefings?

Answer 5

1. Standard weather briefing
2. Abbreviated weather briefing
3. Outlook

Question 6

What are three characteristics of stable air?

Answer 6

Stratiform clouds. Stratus, thin, low-lying clouds, not vertical development.
⁃ Stable is fair to poor visibility. Foggy, burns off…stable morning even if visibility is poor.
⁃ Continuous precipitation. Steady, very consistent.

Question 7

What are three characteristics of unstable air?

Answer 7

Unstable Air
Cumulous clouds, heating from below. Extensive vertical development.
Good visibility, summer time. Florida, Texas, afternoon thunderstorms.
Showery precipitation: Afternoon thunderstorm.

Question 8

What is surface friction?

Answer 8

Local turbulence caused by obstacles. Surface Friction
⁃ Wind and currents can affect small UAS performance during all phases of flight. Be vigilant, low altitudes, and near natural.
⁃ All about how wind interacts with what is around. Be aware WHERE its coming from, how it works around. If in a valley, will travel faster.
⁃ Surface friction, from trees… can create that. Eddies. Updrafts. Then downdrafts.
⁃ When in open field, trees can create low level turbulence.
⁃ May consume battery power. Winds performance on battery power, where the wind is coming from.

Question 9

How many types of fog are there?

Answer 9

Occurs when temperature/dew point are close. Three types. Radiation fog, Advection fog, Upslope Fog.

Question 10

Radiation fog

Answer 10

Heat radiates from surface at night. Prefers no wind. Straight up and stay there.

Question 11

Advection Fog

Answer 11

Warm air, flows over cooler surface. Like Golden Gate bridge in the morning. Requires a bit of wind. Enough to move the air over surface.

Question 12

Upslope Fog

Answer 12

Moist air, aloft where temp and dew point, moisture becomes visible.

Question 13

Low clouds

Answer 13

6500 and below, stratus, flat, thin, stable air, Cumulus can be low. Become Cumuli Nimbus, Nimbostratus and Cumulonimbus

Question 14

Middle Clouds

Answer 14

⁃ Altocumulus

⁃ Altostratus

Question 15

High Clouds

Answer 15

⁃ Cirrus
⁃ Extensive Vertical development
⁃ Towering Cumulonimbus

Question 16

Standing Lenticular Cloud

Answer 16

Form over mountains. NASTY turbulence. Almond shape. Lenticular Cloud, associated with TERRIBLE WEATHER.