frontal weather

FRONTAL WEATHER

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ELO 1:Action: The student will identify the Action: The student will identify the

characteristics common to all characteristics common to all fronts.fronts.

Condition: Given pertinent Condition: Given pertinent information about frontsinformation about fronts

Standard: IAW FM 1-230 para 10-1, Standard: IAW FM 1-230 para 10-1, 10-210-2

FRONT - BOUNDARY BETWEEN AIR MASSES OF DIFFERENT DENSITY

COLD WARM

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mT

Frontal weather is caused by the lifting of warm moist air by colder more dense

air.ALL FRONTS HAVE

A TEMPERATURE INVERSION

FRONTAL DISCONTINUITIES

• TEMPERATURE • DEWPOINT• PRESSURE “FALL THEN RISE”• WIND SHIFT : APPROX 90° DRIFT CORRECTION TO THE RIGHT

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ELO 2:Action: The student will identify the Action: The student will identify the

general characteristics of a cold general characteristics of a cold front.front.

Condition: Given pertinent Condition: Given pertinent information about cold frontsinformation about cold fronts

Standard: IAW FM 1-230 para 10-3Standard: IAW FM 1-230 para 10-3

CHARACTERISTICS OF A COLD FRONT

• Slope• Clouds• Width of weather band• Winds• Direction of movement• Speed• Symbol

a. Average Slope – 1:80

25 kts

Steep Slope 1:50

25 kts

Shallow Slope 1:100

a. Slope -1:80b. Cumuliform cloudsc. 50 mile wide band of coverage d. Winds NW behind front, SW aheade. Moves southeastf. 25 knots average speed

25 kts

Possible hail, destructive winds, and tornadoes

Squall Line

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Property of Lear Siegler

SQUALL LINE

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Squall Line

Squall Line

ELO 3:Action: The student will identify the Action: The student will identify the

general characteristics of a warm general characteristics of a warm fronts.fronts.

Condition: Given pertinent Condition: Given pertinent information about warm frontsinformation about warm fronts

Standard: IAW FM 1-230 para 10-4Standard: IAW FM 1-230 para 10-4

CHARACTERISTICS OF A WARM FRONT

• Slope• Clouds• Width of weather band• Winds• Direction of movement• Speed• Symbol

a. Slope - 1:200b. Stratiform clouds predominatec. 400-600 mile band of coveraged. Wind SW behind, SE ahead of the fronte. Moves Northeastf. 15kts avg speed

STNS

ASCS

Stratus

nimbo-

a. Slope - 1:200b. Stratiform clouds predominatec. 400-600 mile band of coveraged. Wind SW behind, SE ahead of the fronte. Moves Northeastf. 15kts avg speed

15 kts

Cold Air Moving Southward

Receding Cold Air Receding Cold Air

ELO 4:Action: The student will identify the Action: The student will identify the

general characteristics of a general characteristics of a stationary front. stationary front.

Condition: Given pertinent Condition: Given pertinent information about stationary frontsinformation about stationary fronts

Standard: IAW FM 1-230 para 10-6Standard: IAW FM 1-230 para 10-6

CHARACTERISTICS OF A STATIONARY FRONT

• Slope – 1:200• Clouds - Stratiform• Width of weather band – 400 to 600 miles• Winds – 180o wind shift• Symbol

Stationary Front

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CHARACTERISTICS OF A STATIONARY FRONT

• Slope – 1:200• Clouds - Stratiform• Width of weather band – 400 to 600 miles• Winds – 180o wind shift• Symbol

• Direction of movement – unpredictable• Speed – 0 to 5 knots

Stationary Front

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ELO 5:Action: The student will identify the Action: The student will identify the

characteristics of an open wave.characteristics of an open wave.Condition: Given pertinent Condition: Given pertinent

information about open wavesinformation about open wavesStandard: IAW FM 1-230 para 10-7Standard: IAW FM 1-230 para 10-7

OPEN WAVE

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Open Wave

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Property of Lear Siegler

Property of Lear Siegler

Property of Lear Siegler

Open Wave

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Open Wave

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Open Wave

ELO 6:Action: The student will identify Action: The student will identify

characteristics of an occluded characteristics of an occluded front. front.

Condition: Given pertinent Condition: Given pertinent information about occluded frontsinformation about occluded fronts

Standard: IAW FM 1-230 para 10-5Standard: IAW FM 1-230 para 10-5

Occlusion in Action…Occlusion in Action…

Occlusion in Action…

15 kts25 kts

5oCCold Front Warm Front

10oC

Open Wave

Trailing EdgeLeading Edge

25 kts 15 kts

5oC 10oC

Cold Occlusion

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Cold Occlusion

5o C10 o C

Warm Air

15 kts25 kts

10oCCold Front Warm Front

5oC

Open Wave

Trailing EdgeLeading Edge

25 kts 15 kts

Warm Occlusion

10oC 5oC

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Warm Occlusion

5 o C

10o C

Occlusions have the most violent weather of all fronts.

Cold front occlusion – most severe weather above occlusion

Cold Occlusion

Warm front occlusion – most severe weather ahead of occlusion

ELO 7:Action: The student will identify the Action: The student will identify the

proper flight procedures to use proper flight procedures to use when dealing with frontal weather when dealing with frontal weather while conducting flight operations.while conducting flight operations.

Condition: Given pertinent Condition: Given pertinent information about frontal weather information about frontal weather conditionsconditions

Standard: IAW FM 1-230 para 10-3, Standard: IAW FM 1-230 para 10-3, 10-4, and 10-5 10-4, and 10-5

FRONTAL FLIGHT PROCEDURES

•Cold fronts and squall lines

•Warm fronts

•Stationary fronts

•Open wave

•Occluded fronts - WARNING !!!

ELO 8:Action: The student will identify the Action: The student will identify the

indications of frontal passage.indications of frontal passage.Condition: Given pertinent Condition: Given pertinent

information about frontsinformation about frontsStandard: IAW FM 1-230 para 10-2Standard: IAW FM 1-230 para 10-2

FRONTAL PASSAGE

•On the ground – wind shift and temperature change

•In flight – OAT gauge – best indication

•Drift correction to the right

ROY G. BIV

FM 1-230 Referencesfor today

• Frontal Weather Chapter 10

FM 1-230 Referencesfor tomorrow…

• Mountain Waves 6-9 (d)• Turbulence Chapter 11• Thunderstorms Chapter 12• Icing Chapter 14• Fog Chapter 15

The endThe end

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WARM FRONT0 100 200 300 400 500 MILES

Property of Lear Siegler