p. 277
Cold Front: cold air behind front (often to NW) abrupt cooling as it passes Warm Front:warm air behind front (often to S) more gradual warming Stationary front: divides airmasses, but little forward motion Occluded front: cold front “catches up” to warm front warm sector now only found aloft less temperature contrast
Vertical displacement along a cold front
COLD FRONT Infrared Imagery Radar Imagery
Profile of a warm front
Occlusion sequence p. 291
Stationary Front POLAR FRONT POLAR AIRMASS SUBTROPICAL AIRMASS
Maturity
Lifting processes and cloud cover
Occlusion
Convergence and divergence along a Rossby wave
If lows and highs aloft and at the surface are above one another, the systems will weaken !
Divergence aloft promotes the surface low Convergence aloft promotes the surface high Surface divergence Surface convergence
Longwaves
MIGRATE THROUGH THE LONGWAVE TROUGHS
1 2 3 Differential temperature advection intensifies the wave Condensation may release even more heat energy for the storm Less upper level divergence No temp advection
Relative vorticity
Vorticity through a Rossby wave
Values of absolute vorticity on a hypothetical 500 mb map
Temperature variations in the lower atmosphere lead to variations in upper-level pressure
Example of a midlatitude cyclone April 15
April 16
April 18
Flow patterns and large-scale weather – Zonal height patterns “zonal flow”
Meridional flow pattern
Typical winter midlatitude cyclone paths
A. cyclogenesis B. occlusion C. maturity D. senescence What is the term for this early stage in the life cycle of a midlatitude cyclone?
A. cyclogenesis B. occlusion C. maturity D. senescence What is the term for this early stage in the life cycle of a midlatitude cyclone?
A. cyclogenesis B. occlusion C. maturity D. senescence What is the term for this stage in the life cycle of a midlatitude cyclone?
A. cyclogenesis B. occlusion C. maturity D. senescence What is the term for this stage in the life cycle of a midlatitude cyclone?
A. A B. B C. C D. D In which area would overrunning occur? A C B D
A. A B. B C. C D. D In which area would overrunning occur? A C B D
A. A B. B C. C D. D Which location would have the lowest pressure? A C B D
A. A B. B C. C D. D Which location would have the lowest pressure? A C B D
A. 1 B. 2 C. 3 D. 4 Which area would have the greatest positive relative vorticity? [insert figure 10-4]
A. 1 B. 2 C. 3 D. 4 Which area would have the greatest positive relative vorticity? [insert figure 10-4]
A. 1 B. 2 C. 3 D. 4 Which area would have the least relative vorticity?
A. 1 B. 2 C. 3 D. 4 Which area would have the least relative vorticity?
A. uplift over a surface low B. sinking air C. chaotic flow D. anticyclones To what might divergence along the jet stream contribute? [insert figure 10-7]
A. uplift over a surface low B. sinking air C. chaotic flow D. anticyclones To what might divergence along the jet stream contribute?
A. a barotrophic atmosphere B. divergence aloft C. convergence aloft D. negative relative vorticity What would cause this surface low to strengthen? [insert figure 10-11b]
A. a barotrophic atmosphere B. divergence aloft C. convergence aloft D. negative relative vorticity What would cause this surface low to strengthen?
A. A B. B C. C D. D Where is the “dry conveyor belt” in the diagram? B A D C
A. A B. B C. C D. D Where is the “dry conveyor belt” in the diagram? B A D C
A. baroclinic B. zonal C. meridional D. mythical Which term best describes the upper air flow in the diagram?
A. baroclinic B. zonal C. meridional D. mythical Which term best describes the upper air flow in the diagram?
A. baroclinic B. zonal C. meridional D. mythical Which term best describes the upper air flow in the diagram? [insert figure 10-15b]
A. baroclinic B. zonal C. meridional D. mythical Which term best describes the upper air flow in the diagram? insert figure a]