# What is a "bar"?

Quesion:

Can you explain in "redneck" terms what a "bar" is in relation to a hurricane?

Pressure is reported in several types of units . . . most commonly we use "inches of Mercury (in. Hg)" on air, but weather scientists tend to use units called millibars (mb) .

1 bar = 1000 millibars (mb) = about 14.5 pounds per square inch, or roughly the downward pressure of the atmosphere at sea-level.

Interestingly, that means that every square inch of your shoulders, and the top of your head, are holding up 14.5 pounds of air . . .  so you are actually holding up something like a few hundred pounds of air when you are standing, sitting, walking . . . so why don't you just collapse on the ground from all that weight?

Because the pressure INSIDE our bodies is roughly the same, pushing outward.  So the pressure is balanced between your innards and the outside air.

For inches-of-Mercurry to millibars . . . 30.00 in. Hg is roughly equal to 1000 millibars.
The actual conversion is: 29.92 in. Hg = 1013.25 mb  . . .  both numbers represent standard sea-level pressure.

You may also see the "big league" weathernerds refer to hectopascals, which is the same as millibars.

Confused yet?

Now .. to properly answer your question:  in redneck terms, I understand that a "bar" is a place you go to buy a 16-ounce "hurricane."

Jay Grymes
Chief Meteorologist
WAFB Storm Team