- Diurnally averaged MAE data in Fig. 6 do provide some evidence to support this thought. The MAE at these levels indicates that the WRF PXACM does have a slightly lower error around 700 m from night through the midmorning (0400–1500 UTC), and a slightly larger MAE than the WRF Noah YSU around 2000 m during the day (1700–2300 UTC). There is little systematic difference between the WRF PXACM and WRF Noah YSU at the 1300-m level.