NAM 13FEB Discussion

OBS

VERF

This is the 72 hour 500mb heights forecast. Clearly, the NAM was a little bit slow with the trough over the midwest.

This is the 72 hour forecast sfc pressure. The slow trend is also evident here with the low centered over TN.

These two images show the same lag, this time in 1000-500 thickness. The top is the 12Z run current, the bottom is the run from 72 hours ago.

QG

ISEN

isentropic analysis

ENS