I do not know what flights you are interested, but loads for the 27th are high. I do not see how the fares will get any cheaper right now. Simply, the planes are filling up! For example, on the 27th:
NW 1429 ATL-MSP P9 F9 Y9 B9 M2 H0 Q0 V0 L0 T0 K0
NW 1763 MSP-YVR P9 F9 Y9 B9 M2 H0 Q0 V0 L0 T0 K0