wrote:
Robert Gammon wrote:


... ALL the cities mentioned here have very high humidities at night
in particular.

Exactly what does that mean, and is it true, and how is it relevant?

We're discussing ABSOLUTE vs relative humidity.


You might enjoy learning the difference.


All we can really calibrate to is RELATIVE as it is what WE feel, not
what the intruments are telling us.


Whaddya mean "WE," Kemosabe?

Nick


The rest of us, everyone except Nick

see
http://apollo.lsc.vsc.edu/classes/me...nd_parcel.html

This says that absolute humidity is NOT a good moisture variable even
though the amount of moisture is constant as a given volume of air
rises This is a useful tool only to calculate how much water is in the
air at any given time and as that water rises towards the stratosphere,
how likely are clouds to form and rain to fall.

http://members.tripod.com/running4fun/run/humidity.html

This page is written by a Meteorologist. He gives a good explanation of
the problem and points out that RH without Dew Point temp is half a loaf.

For instance, right now in Houston
Temp 73F
RH is 87%
Dew Point is 69F

Right now in Villanova
Temp 59F
RH 88%
Dew Point is 56F

I do not imagine that you want to introduce this moisture laden air into
your apartment/home if you can help it. Doesn't matter whether we talk
Deep South or Pennsylvania. And in no case, do you want 90+F air in any
significant quantity coming inside to increase your A/C bill.


The Meteorologist points out that the highest dew point ever recorded in
his location was 88F right after a thunderstorm. Other than that, on
very humid days, the dew point only gets to the low 80s there
(Cincinatti) although Gulf War vets do know 90/90 days as the Red Sea
heats to above 90 F and with air temps in Kuwait rising to 110 or higher
lots of water is in the air. 90% RH with air temps above 90F is a very
very real situation for that location.