In article ,
Jon O'Rourke writes:
"comp.john" wrote in message
...

How does 850mb temp correspond with surface temp at this time of year?
is -5 @ 850mb 0C at the surface?
-- comp.john

It's not really the best guide for surface temperatures as the boundary
layer conditions at this time of year can heavily modify a direct
adiabatic translation. However, to give you some idea, when 850mb
temperatures were around -4 around a week ago daytime surface
temperatures were in the +4 to +6 ballpark.

And the long-term mean 850mb for this time of year is about -1, as shown
by the white line on the GFS ensemble temperatures. The mean maximum
surface temperature at this time of year would be about 8, again
indicating a difference between the 850mb level and the surface of about
8 degrees on average.
--
John Hall "[It was] so steep that at intervals the street broke into steps,
like a person breaking into giggles or hiccups, and then resumed
its sober climb, until it had another fit of steps."
Ursula K Le Guin "The Beginning Place"