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MtnMagic
08-22-2006, 09:59 AM
One of the 6 rules to forecasting excellent visibility that is stated in Brent Scudder's White Mountain Viewing Guide is: 6.)When a barometer (set for sea level) exceeds 30.20 inches at one or more of the following locations: Burlington, VT; Syracuse or Buffalo NY.

I've two questions. When a barometer reads 30.20" at sea level, what is the corresponding reading at the observatory?

Are there several locations for weather instruments at different elevations?

kiloalpha
08-24-2006, 01:56 AM
One of the 6 rules to forecasting excellent visibility that is stated in Brent Scudder's White Mountain Viewing Guide is: 6.)When a barometer (set for sea level) exceeds 30.20 inches at one or more of the following locations: Burlington, VT; Syracuse or Buffalo NY.

I've two questions. When a barometer reads 30.20" at sea level, what is the corresponding reading at the observatory?

Are there several locations for weather instruments at different elevations?
A rough rule of thumb is that pressure, as measured in inches of mercury, drops an inch for each 1000 feet of elevation gained. (This is actually not a linear function because of lessening air density with elevation gain.)
Using the approximation, the pressure at the summit of Mount Washington (6288 feet) would be about 24 inches when the sea level pressure is 30.2 inches.
I don't understand your question about instrument location.

MtnMagic
08-24-2006, 06:30 AM
Are other group's weather instruments located at different elevations? To clarify, the Mount Washington's Observatory has weather instuments at 6266', although the summit is 6288'. Are there separate weather gathering organizations that have instruments to collect weather data at a lower elevation?

Nin
08-24-2006, 08:53 AM
Are other group's weather instruments located at different elevations? To clarify, the Mount Washington's Observatory has weather instuments at 6266', although the summit is 6288'. Are there separate weather gathering organizations that have instruments to collect weather data at a lower elevation?
Not that I am allowed below the summit, but we do have instruments down the mountain as part of the Auto Road Vertical Temperature Profile (ARVTP) (http://www.mountwashington.org/weather/arvtp/). During Winter, AMC also collects data (http://www.mountwashington.org/goto/http://www.outdoors.org/recreation/tripplanner/go/backcountry-weather.cfm) from the hutmasters.

MtnMagic
08-24-2006, 11:41 PM
Nothing like the coolest cat on the rock pile to give one the most accurate answer! Thank you for the accuracy. Wishing all the best to those spending each evening on the rock pile!