Case Description

Reason for interest: NAM struggles with cut-off low.

Towards the end of the forecast period, a strong cut-off low developed over the southwestern US. During this particular winter, the NAM had trouble with breaking down cutoff lows and progressing them eastward. In the images below, note the discrepancy between the analysis and the model regarding the strength and placement of the low.

Go to physics suite configuration data

500mb heights and vorticity analysis 1 Decemeber 2011 at 12 UTC:

NAM 500mb heights and vorticity 84-hour forecast.
Valid 1 Decemeber 2011 at 12 UTC: