Observations of Supercooled Liquid Water in Wintertime Alpine Storms in South Eastern Australia

• We quantified SLW quantities over an orographic environment using a microwave radiometer.
• We observed high frequencies of SLW occurrence from a radiometer and MODIS.
• We decomposed SLW occurrence by dominant synoptic type.
• Concurrent liquid water quantities from the radiometer and MODIS were contrasted.

A ground based microwave profiling radiometer has been operational in the Snowy Mountains in south eastern Australia and was used to build a limited three year data set of supercooled liquid water (SLW). Satellite observations (MODIS) of cloud-top thermodynamic phase suggest that SLW commonly occurs over the Snowy Mountains during the winter months and at much higher rates compared to other mountain ranges such as the Sierra Nevada. The radiometer was able to confirm the high frequency of occurrence of SLW at 53% of the time (April-September) and the observations were consistent with MODIS. Path integrated liquid water amounts observed from the radiometer were compared to those from MODIS, although the radiometer tended to observe significantly more liquid water than MODIS. SLW was documented and assigned to synoptic types with 43.0% of total SLW attributed to “cutoff lows" (equatorward of 45°S) and 42.2% were assigned to “embedded lows".