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treant985
03-24-2007, 01:06 AM
Does anyone have the saved hourly METAR data from the cold snap at the beginning of March? I'm interested in what was the coldest wind chill recorded during that time....but obviously I can't just take the lowest temp and the strongest gust of the day since they probably didn't happen at the same time.

I remember reading that the wind chill was almost -100F at one point, but I can't seem to find the hourly data for more than the past 5 days anywhere online.

Bill O
03-24-2007, 05:46 AM
www.wunderground.com

They have years of metar data. Go to that site and type in kmwn. Then scroll down to where you can change the date with a pull down menu. You're gonna have to play around.

Or try this:

http://www.wunderground.com/history/airport/KMWN/2007/3/24/DailyHistory.html?req_city=NA&req_state=NA&req_statename=NA

treant985
03-24-2007, 10:57 AM
www.wunderground.com

They have years of metar data. Go to that site and type in kmwn. Then scroll down to where you can change the date with a pull down menu. You're gonna have to play around.

Or try this:

http://www.wunderground.com/history/airport/KMWN/2007/3/24/DailyHistory.html?req_city=NA&req_state=NA&req_statename=NA

Thanks for the link. I went through March 6 and 7 and put all the temps and wind speeds into a spreadsheet to calculate the wind chills. Looks like the lowest was the reading at 1251pm. It was -34.6F with sustained winds of 102.4 and a gust of 111.6. So the sustained wind chill was -91.8 (and -93.2 using the top gust).

Is there anyway to get that website to give the hourly data for a long period of time? I put in a stretch of a few years, and it just reduces all the day's hourly reports into one single line for each day.

treant985
03-24-2007, 06:32 PM
I went through some of the colder temps from the past few years, trying to find the lowest wind chill recorded at MWO. Here's the coldest I found:

Jan 16, 2004 (156am reading)
-43.6 F temperature
87.5 MPH sustained winds

Wind chill: -102.6 F

I tried finding the coldest wind chill recorded anywhere (outside Antarctica) but of course those data aren't easy to find; add in that the wind chill formula changed a few years back, and it makes older readings suspicious. The coldest I found record of was:

Kugaaruk (formerly Pelly Bay), Nunavut, Canada
Jan 13, 1975
-60 F temperature
35 MPH sustained winds

Wind chill: -110 F


So, it's not beyond the realm of possibility that Mt. Washington may have the coldest wind chill on record anywhere in the USA, especially if Alaska is left out. At the coldest temp recorded in the US (-80 in Prospect Creek, AK), even a wind of only 5 MPH would result in a wind chill colder than the -102.6 that MWO recorded. Unfortunately wind speeds are hard to find for a lot of stations.

Brad
03-26-2007, 05:57 AM
Another source of data would be the Conditions image archive at http://public.fotki.com/mwo

treant985
03-28-2007, 12:14 AM
Just for fun, I tried to find the coldest wind chill ever reliably recorded. Here's what I found, using data from the Vostok station in Antarctica:

using peak wind--
lowest definite windchill: -192.1F (8/24/2005; max temp that day was -99F and the max wind was 113mph, so that meant -192.1F had to have been experienced at some point that day)

lowest possible windchill: -202.9F (8/24/2005; min temp that day was -106 and the max wind was 113mph, so, if those two coincided, the wind chill would've been -202.9F)


using mean wind for the entire day--
lowest definite sustained windchill: -164.0F (7/3/2004; max temp was -92F and the mean wind was 55mph, so the sustained wind chill had to be less than or equal to -164.0F for the entire day)

lowest possible sustained windchill: -174.0F (7/3/2004; min temp was -99F and the mean wind was 55mph, so, if the min temp was recorded when there was an average wind, the windchill would've been -174.0F)

I only found data for 6/20/2004-2/28/2007, so I'm sure these have probably all been beaten at some point or another in Antarctica.