Term
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Definition
a distinctive HOMOGENOUS body of air that has taken the TEMPERATURE and AIR MOISTURE characteristics of the source region.
--covers a large area of 1000 miles or + |
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Term
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Definition
| it is the region where AIR MASSES ORIGINATE. **In order for a huge air mass of air to develop UNIFORM CHARACTERISTICS, source region should be generally FLAT with LIGHT SURFACE WINDS and HIGH PRESSURE. |
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Term
| AIR MASSES that affect the U.S. |
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Definition
-Continental Arctic (cA)
-Continental Polar (cP)
-Continental Tropical (cT)
-Maritime Polar (mP)
-Maritime Tropical (mT)
**CONTINENTAL = OVER LAND
**MARITIME = OVER WATER |
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Term
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Definition
SOURCE REGION = ICE-COVERED regions of NORTH CANADA and ALASKA
*VERY COLD
*VERY DRY
*STABLE AIR |
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Term
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Definition
SOURCE REGION = COLD regions of NORTH CANADA and ALASKA
*DRY
*COLD
*STABLE AIR |
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Term
| Continental Tropical (cT) |
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Definition
SOURCE REGION = MEXICO in SUMMER only
*HOT
*DRY
*STABLE AIR ALOFT/UNSTABLE SURFACE AIR |
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Term
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Definition
SOURCE REGION = over PACIFIC OCEAN and ATLANTIC OCEAN of HIGH LATITUDES
*COOL
*MOIST/HUMID
*UNSTABLE AIR |
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Term
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Definition
SOURCE REGION = tropical oceans (ATLANTIC, PACIFIC and GULF OF MEXICO)
*WARM
*MOIST
*USUALLY UNSTABLE AIR |
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Term
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Definition
| It is the BOUNDARY SEPARATING 2 AIR MASSES that are differing in TEMP, MOISTURE and DENSITY. |
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Term
| What are the 4 TYPES of fronts? |
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Definition
1. Warm front
2. Cold Front
3. Occluded Front
4. Stationary Front |
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Term
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Definition
Forms when a WARM AIR MASS ADVANCES and REPLACES a COLD AIR MASS.
- the warm air glides over the retreating cold air creating a GENTLE SLOPE (overrunning)
-OVERRUNNING leads to formation of cloud types along the gentle slope (NIMBOSTRATUS)
-warm fronts move SLOWLY and do NOT CREATE SEVERE WEATHER. |
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Term
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Definition
Forms when a COLD AIR MASS ADVANCES and REPLACES a WARM AIR MASS.
- warm air lifted STEEPLY = STEEP SLOPE
- these STEEP SLOPES create CUMULONIMBUS CLOUDS = severe weather and hours of rain where front meets surface.
- cold fronts move FASTER and may produce LIGHTNING, TORNADOES, or HAIL. |
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Term
| What is an OCCLUDED FRONT? (2 TYPES) |
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Definition
Forms when a COLD FRONT completely OVERTAKES a WARM FRONT
**2 TYPES**
1. COLD TYPE: front that forms when air BEHIND the cold front is COLDER than underlying warm front it is overtaking.
2. WARM TYPE: front that forms when AIR BEHIND the cold front is WARMER than the air underlying warm front it is overtaking. |
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Term
| What is a STATIONARY FRONT? |
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Definition
Forms when a front is (NEARLY) STATIONARY, with winds blowing ALMOST PARALLEL and from OPPOSITE DIRECTIONS of EACH SIDE of front.
**The weather along the front is clear to partly cloudy with colder air on each side. NO PRECIPITATION. |
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