Moisture from bodies of water or existing precipitation is essential to raise the dew point temperature and saturate the boundary layer.
Convective Available Potential Energy (CAPE): Snow squalls are convective events, and CAPE is a significant discriminator between squalls and other snow events. Higher CAPE values indicate a greater potential for deep vertical growth.
Time of occurrence: Because they are convective, snow squalls most often happen during daylight hours, with 69% of events occurring between 1300 and 2300 UTC.
Radar parameters
Reflectivity: Snow squalls typically show reflectivity values greater than 30 dBZ.
Radial velocity: Maximum radial velocities in excess of 30 knots are another indicator.
Atmospheric parameters
Isallobaric effects: Strong surface isallobaric (pressure rise/fall) couplets, combined with steep near-surface lapse rates, contribute to the conditions that produce a squall.
0–2 km layer: The stability of the 0–2 km AGL layer is a factor in snow squall development.