All Snow or Snow with Sleet Category


Principal forecast issues

o        Insufficient melting layer – a maximum temperature in the melting layer <1 C supports a forecast of snow. Evaluate soundings.

o        Increased precipitation rates can erode the small melting layer. The appearance of a near freezing isothermal segment in the soundings signals cooling from melting. Evaluate soundings.

o       Significant thermal advection can erode or increase the small melting layer. Evaluate trends in the partial thickness values for significant thermal advection.

o       If the inland low associated with a Miller “B” or “A/B” cyclogenesis pattern occludes, then warm advection ahead of the inland low will end and likely lead to the erosion of the small melting layer

o       Small melting layer – Snow/sleet mix is favored if the max temperature in the melting layer is > 1 C and < 3 C. Evaluate soundings.


Vertical temperature profiles associated with the snow/sleet predominant p-type category


Tentative Findings