@Chulemangule
Hello,
If San Juan that you are referring to is the one in the map - there are many in Argentina- the minimum temperatures predicted there by the weather models are slightly higher compared to reported temperature the weather station at the airport (dotted curves vs color shaded curve).
C05CBA9C-B367-40DA-8015-880B74FEB4B5.jpeg
This is probably due to the temperature inversion as shown by the forecast sounding. Weather models can’t calculate precisely the temperature at 2m ground level, because the inversion does not depends directly on the airmass temperature but to nocturnal radiation with clear sky.
E0264FC9-CEEE-43B7-BB94-F0D4CA934E25.jpeg