I'm guessing atm. pressure and cloud cover ... or a combination of both -
but I'm not even sure about that, since clear days can be humid and humidity
doesn't seem to a constant function of atm. pressure.

Sorry, what I was trying to say was 'what affects closeness' or comfort
factor - since even on low humidity days, it can be very close/clammy.

"Scumball" wrote in message
...
I'm guessing atm. pressure and cloud cover ... or a combination of both -
but I'm not even sure about that, since clear days can be humid and
humidity
doesn't seem to a constant function of atm. pressure.

Hi Scumball,

The time of day affects humidity. It usually runs high in the morning,
then usually lowers in the afternoon as drier air aloft is mixed down
to the surface from daytime heating, then it increases overnight as
the mixing process shuts down. Wind direction can also affect
humidity. If you have a warm body of water upstream it will normally
help to increase the humidity in your area. On the other hand if you
have a mountain chain upstream, it will help to lower the humidity in
you area as the sinking air warms and increases evaporation.

hope this helps
smerby
www.accuweather.com

"Scumball" wrote in message ...
I'm guessing atm. pressure and cloud cover ... or a combination of both -
but I'm not even sure about that, since clear days can be humid and humidity
doesn't seem to a constant function of atm. pressure.

On the subject of humidity, that's the one topic in this area (SE Virginia)
that is totally misunderstood. Often the TV weather folks talk about how
high the humidity will be today. They do this without explaining that when
you have high temps, the air can hold more moisture, therefore the wetness
is much more evident. 100% is 100%, yet in Jan, you don't notice it as much
for the air can't hold as much moisture. To have them explain themselves,
the TV guys say it's too hard to explain to the general public. Sounds
pretty simple to me.


Jim Becker

Virginia Beach Backyard Weather
http://www.vabeachweather.com


"Scumball" wrote in message
...
I'm guessing atm. pressure and cloud cover ... or a combination of both -
but I'm not even sure about that, since clear days can be humid and
humidity
doesn't seem to a constant function of atm. pressure.