Editing Freezing rain (section)

== Observations ==
[[File:Radar-bright-band.png|thumb|left|upright=1.5|Echoes at {{convert|1.5|km|m mi ft|abbr=on}} altitude at the top with strong contamination from the [[Weather radar#Bright band|bright band]] (yellows). The vertical cut at the bottom show that this strong return is only above ground (Source: [[Environment Canada]]).]]
Surface observations by staffed or automatic stations are the only direct confirmation of freezing rain. One can never ''see'' directly freezing rain, rain, or snow on any type of [[weather radar]], whether [[Doppler effect|Doppler]] or conventional. It is possible, however, to estimate the area covered by freezing rain with [[radar]] indirectly.<ref name="Doviak">{{cite book|last1=Doviak|first1=R. J.|author-link1=Richard Doviak|first2=D. S. |last2=Zrnic|author-link2=Dusan S. Zrnic|title=Doppler Radar and Weather Observations|year=1993|publisher=Academic Press|location=San Diego CA|edition=2nd|isbn=978-0-12-221420-2 }}</ref><ref name=AMS-BB>{{cite web|url=https://glossary.ametsoc.org/wiki/Bright_band |title=Bright band|publisher=[[American Meteorological Society]] |work=Glossary of Meteorology |access-date=2022-02-21}}</ref>

The intensity of the radar echoes ([[reflectivity]]) is proportional to the form (water or ice) of the [[precipitation (meteorology)|precipitation]] and its diameter. In fact, rain has much stronger reflective power than snow, but its diameter is much smaller. So, the reflectivity of rain coming from melted snow is only slightly higher. In the layer where the snow is melting, however, the wet flakes still have a large [[diameter]] and are coated with water, so the radar returns are much stronger.<ref name="Doviak"/><ref name=AMS-BB/>

The presence of this [[Weather radar#Bright band|brightband]] indicates the presence of a warm layer above ground where snow can melt. This could be producing rain on the ground or the possibility of freezing rain if the temperature is below freezing. The accompanying image shows how such an [[Artifact (observational)|artifact]] can be located with a cross-section through radar data.<ref name="Doviak"/><ref name=AMS-BB/> The height and slope of the brightband will give clues to the extent of the region where melting is occurring. Then, it is possible to associate this clue with surface observations and numerical prediction models to produce output such as the ones seen on television weather programs, where radar echoes are shown distinctly as rain, mixed, and snow precipitations.