Weather Chapter 4

Question 1

What is flight visibility?

Answer 1

1. Flight: ability to see and identify proinent unlighted objects by day and prominent lighted objects at night

Question 2

What are PIREPs? when do we use them?

Answer 2

a voice report given to ATC while airborne for the purpose of advising other aviators of potential hazards

1. Required when:
   
   1. requested by ATC
   2. unusual or unforeseen weather conditions are encountered
   3. weather conditions on IFR approach differ from the latest observation
   4. when a missed approach is executed
   5. when wind shear is encountered on departure or arrival

Question 3

What are Surface Analysis Charts?

When do we use them?

Answer 3

Surface Analysis Charts

Display trough, pressure centers, isobars (4 millibar spacing)

Represent past

Look at the pic

identify high/low pressure fronts

Stationary front

Occluded fronts

Question 4

What are Weather Prognostic Charts?

When do we use them?

Answer 4

Prognostic charts

1. forecast conditions
2. VFR vs IFR
3. Big picture planning

Question 5

on a TAF, what do the following represent?

FM:

BECMG

TEMPO

Answer 5

1. FM: Rapid, permanent change
2. BECMG: Gradual change in predominant conditions by end time listed
   
   1. only the changed elements will be listed and will be the new forecast weather until the end of the TAF unless unless changed later by another group
   2. we only care about the second time
3. TEMPO: temporary condition
   
   1. only certain items updated
   2. expires at the end of period listed
   3. reverts ot previous line or when superseded by subsequent line

Question 6

How do we use TAFs in flight planning?

Answer 6

Terminal Aerodrome Forecast

Forcast for >24 hours of conditions

use to determine destination weather

Question 7

What are Winds-Aloft Forecasts?

when do we use them?

Answer 7

helps with selection of altitude during flight

*I wish I could tell you more about reading these…

Question 8

What is ground based weather Radar?

Answer 8

radar senses reflectivity.

anything 55 db or higher indicates hail

Question 9

Describe the use of satellite imaggery

Answer 9

shows cloud cover

Question 10

What are Severe Weather Watch messages?

Answer 10

boils down to:

DON’T FLY IN THIS

Question 11

What is vertical visibility?

Answer 11

VV is the distance seen directly upward from the ground in a total obscuration

1. Used when:
   
   1. sky is totally hidden
   2. base within 50’ of surface

*greatly affects Slant Range Visibility

**referred to as an “indefinate Ceiling”

Question 12

SIGMET

Convective:

Non-Convective

Answer 12

SIGMET

issued for 4 hours

1. Convective- thunderstorm related
   
   1. implies severe or greater turbulence, severe icing, and low level wind shear
2. Non-Convective SIGMET- not thunderstorm related
   
   1. severe icing
   2. severe or extreme turbulence
   3. dust/sand storms reducing visibility to <3 miles
   4. volcanic ash

Question 13

What is Prevailing Visibility

Answer 13

Prevailing: Greatest horizontal visibility throughout at least half of the horizon circle (visibility does not need to be contiguous)

Question 14

What is Slant range visibility?

Answer 14

slant range: distance on final approach when the runway environment is in sight

Question 15

What is Runway visual range (RVR)?

Answer 15

runway visual range (RVR) horizontal distance looking down the runway

Question 16

What type of cloud cover do we care about with ceilings?

Answer 16

Broken or overcast

Broken = 5/8-7/8 of sky covered with clouds

Overcast = 8/8 of sky with clouds

**The ceiling is the lowest broken or overcast layer

Question 17

When are PIREPS required:

Answer 17

1. requested by ATC
2. unususal or unforseen weather conditions
3. when on an IFR approach and the weather conditions are different from the latest observation
4. missed approach is executed
5. wind shear is encountered

Question 18

What type of weather is associated with a Convective SIGMET?

How often are they issued?

how long are they valid?

Answer 18

Convective SIGMET

Thunderstorm related (but not the most severe of thunderstorms), SEVERE or greater turbulence, SEVERE icing, LLWS

issued hourly at hour+55

valid up to 2 hours

Question 19

What type of weather is associated with a

Non- Convective SIGMET?

Answer 19

Non-Convective SIGMET

SEVERE icing/turbulence not related to a thunderstorm

dust/sand storms that lower visibility to <3 SM

Volcanic Ash

*issued every 4 hours

Question 20

How far apart are the isobars on a surface analysis chart?

Answer 20

4 millibar spacing

*purpose of a surface chart is to show pressure

Question 21

What is METAR?

when do we use it?

Answer 21

“current conditions”

use METAR for criteria for take off

Question 22

Given the METAR Below

what are the winds at KNPA?

Answer 22

Winds are the third set of numbers

270/06