A monitoring device includes a cavity assembly with a plurality of cavities. Openings of the plurality of cavities are distributed about a flow-facing surface of the cavity assembly. A gas pressure sensor is disposed within each of the cavities, and is configured to measure an absolute pressure of a gas flow which flows past the monitoring device. Gas pressure measurements from the pressure sensors may be used to determine a flow speed and a flow direction of the gas flow. More specifically, a mapping may be used to map the logarithm of the difference between the maximum and minimum pressures to a flow speed. Further, a lookup table may be used to map a pattern of pressure measurements to a flow direction.