MTEOR 411/511 WEEK 6 SUPPORTING MATERIAL

Week 6 - Quasigeostrophic Theory - QG Height Tendency Equation

One of the most powerful and heavily used approximations in operational meteorology is QG Theory. If one assumes the atmosphere is hydrostatic and mostly geostrophic (but allowing for some divergence effects), it can be shown that differential vorticity advection and horizontal temperature advection have a direct impact on vertical motion and height tendencies. Just remember, these approximations apply to large scales. The output of modern high-resolution forecast models may not be well-suited to applying QG Theory.

Estimate how height values will change in the next 12 hours by using your 700 mb map and a 500 mb map. Note that cold advection (warm) at 700 mb and positive (negative) vorticity advection at 500 mb should result in falling (rising) 500 mb heights.

• Current 700 mb Heights, Temperatures and winds
• Current 500 mb Heights, Temperatures and winds