Term
| Name the two forms of liquid precipitation: |
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Definition
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Term
| Define “freezing precipitation.” |
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Definition
| Liquid precipitation that falls and freezes upon impact with objects on the ground or in flight. |
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Term
| Transparent or translucent particles of ice that is round or irregular in shape. They usually rebound when striking hard ground and make a sound on impact: |
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Definition
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Term
| Very small, white, opaque grains of ice, which usually fall in small quantities, mostly from stratus clouds, and never as showers: |
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Definition
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Term
| Ice crystals that appear mostly branched in the form of six-pointed stars: |
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Definition
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Term
| Falls from strong convective clouds and occasionally freeze together, falling in irregular lumps: |
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Definition
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Term
| Unbranched and in the form of needles, columns, or plates: |
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Definition
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Term
| Form exclusively in convective clouds and, under the right conditions, serve as the nuclei for hail development: |
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Definition
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Term
| What are the three categories of precipitation? |
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Definition
(1) Continuous.
(2) Intermittent.
(3) Showery. |
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Term
| What category of precipitation is usually associated with stratiform cloud types? |
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Definition
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Term
| What category of precipitation stops and starts at least once within the hour preceding the observation: |
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Definition
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Term
| What category of precipitation do swelling cumulus and cumulonimbus clouds produce? |
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Definition
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Term
| What precipitation category changes intensity rapidly or begins and ends abruptly? |
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Definition
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Term
| Individual raindrops aren’t identifiable: |
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Definition
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Term
| Snow is falling. There are no obstructions to vision present. The prevailing visibility is ¼ mile: |
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Definition
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Term
| Ice pellets are falling and there are no obstructions to vision. The prevailing visibility is 5 miles: |
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Definition
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Term
| Rain is falling. Scattered drops don’t completely wet an exposed surface. |
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Definition
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Term
| Drizzle is falling and there are no obstructions to vision present. The prevailing visibility is 1 mile. |
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Definition
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Term
| What is the capacity of the FMQ-19’s rain gauge before tipping? |
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Definition
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Term
| Describe the process of measuring frozen precipitation: |
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Definition
Remove the collector-funnel unit and measuring tube. Pour a measured amount of water into the overflow
can to melt the solid precipitation, pour the melted liquid into the measuring tube, measure the total amount of liquid, and subtract the amount of warm water used. |
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Term
| What’s the term for a whirling vortex which doesn’t reach the ground? |
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Definition
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Term
| What’s the term for a whirling vortex which descends to the surface over water? |
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Definition
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Term
| What’s the term for a whirling vortex which touches the ground? |
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Definition
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Term
| What criteria must be met for tornadic activity to be classified as occurring “at the station?” |
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Definition
| The phenomenon must be visible from the observation site. |
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Term
| When can a thunderstorm be included in an observation even if thunder isn’t heard? |
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Definition
When hail is falling or lightning is observed in the immediate vicinity of your station and the local noise
level prevents you from hearing the thunder. |
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Term
| When does a thunderstorm end? |
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Definition
| 15 minutes after the last occurrence of thunder, hail, or lightning. |
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Term
| List the five hydrometeors: |
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Definition
(1) Fog.
(2) Blowing snow.
(3) Freezing fog.
(4) Blowing spray.
(5) Mist. |
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Term
| List the five lithometeors: |
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Definition
(1) Dust.
(2) Sand.
(3) Haze.
(4) Smoke.
(5) Volcanic ash. |
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Term
| Classify the specific hydrometeor or lithometeor described in the following statement: Small water droplets suspended in the air, visibility ¼ statute mile |
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Definition
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Term
| Classify the specific hydrometeor or lithometeor described in the following statement: Reported only at sea stations near large bodies of water. |
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Definition
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Term
| Classify the specific hydrometeor or lithometeor described in the following statement: Finely divided earthly matter uniformly distributed in the atmosphere. |
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Definition
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Term
| Classify the specific hydrometeor or lithometeor described in the following statement: Loose sand blown by the wind and restricting visibility to 4,800 meters. |
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Definition
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Term
| Classify the specific hydrometeor or lithometeor described in the following statement: A uniform veil that subdues natural colors. |
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Definition
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Term
| Classify the specific hydrometeor or lithometeor described in the following statement: The disk of the sun appears very red at sunrise and the visibility is 8,000 meters due to a suspension of particles in the air. |
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Definition
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Term
| What pressure concept is the basis for determining other pressure values? |
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Definition
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Term
| Which one of the three main pressure concepts is the reference for all other pressure values? |
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Definition
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Term
| Which pressure concept is a calculated sea-level pressure in inches of mercury? |
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Definition
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Term
| What does temperature measure? |
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Definition
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Term
| What indicates the temperature to which a given parcel of air must be cooled with constant water vapor content and pressure to reach saturation? |
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Definition
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Term
| What’s the wet bulb depression? |
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Definition
| Difference between wet and dry bulb temperatures. |
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Term
| Relative humidity is the ratio expressed as a percentage of what factors? |
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Definition
| Actual vapor pressure of the air to the saturation vapor pressure. |
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Term
| How do you convert magnetic north wind directions to true north? |
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Definition
| Add easterly variations to the magnetic direction and subtract westerly variations from the magnetic direction. |
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Term
| Over what period of time is wind direction determined? How is it read? |
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Definition
| A 2-minute period (10 minutes overseas). It’s read to the nearest 10°. |
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Term
| Over what period of time is windspeed determined? How is it read? |
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Definition
| A 2-minute period (10 minutes overseas) and is read to the nearest knot. |
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Term
| When wind instruments aren’t available, what’s one way to estimate the windspeed? |
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Definition
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Term
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Definition
A sudden intermittent increase in windspeed with at least a 10-knot variation between peaks and lulls
within the past 10 minutes. |
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Term
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Definition
| A sudden increase of windspeed of at least 16 knots with a sustained average of 22 knots or more maintained for at least 1 minute before the speed diminishes. |
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Term
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Definition
| A change in wind direction of 45° or more that takes place in less than 15 minutes. |
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Term
| What constitutes a variable wind direction? |
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Definition
| A condition in which the wind direction is fluctuating by 60° or more during the observation. |
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