Heh, you are right about that...when you look at the loop of 11/18 the day before, you can see SNE is kind of straddling the 0C 850 isothemr with little gradient on the sfc plot....so yeah prob that upper 40s to near 50F type calm day that conceals what is merely 18 hours away to the west.
http://www.meteo.psu.edu/fxg1/NARR/1986/us1118.php