The Application of Diabatic Heating in -Vectors for the Study of a North American Cyclone Event

Figure 5

-vector diagnostics from the NAM model run initialized at 1200 UTC 24 December 2009 and valid at 0000 UTC 25 December 2009 (12-hour solutions), including (a) standard 500-hPa (hPa m⁻¹ s⁻¹), (b) the diabatic form of the 500-hPa (hPa m⁻¹ s⁻¹), (c) the divergence of the standard 500-hPa, (every 20 × 10⁻¹⁵ hPa m⁻² s⁻¹; values <0 are dashed; values of 0 or greater are solid), (d) the divergence of the diabatic form of the 500-hPa, (every 20 × 10⁻¹⁵ hPa m⁻¹ s⁻¹; values <0 are dashed; values of 0 or greater are solid), (e) the difference in divergence between the standard and diabatic forms of the 500-hPa (every 10 × 10⁻¹⁵ hPa m⁻¹ s⁻¹; values <0 are dashed; values of 0 or greater are solid), and (f) the Laplacian of pressure vertical motion, (every 20 × 10⁻¹⁵ hPa m⁻¹ s⁻¹; values <0 are dashed; values of 0 or greater are solid). Frames (c) and (d) also feature the 6-hour precipitation (shaded at 2, 4, 10, and 20 mm), accumulated in the model in the ensuing 6-hour period, ending at 0600 UTC 25 December 2009.

(a)

(b)

(c)

(d)

(e)

(f)