LithiaWx Posted December 1, 2011 Share Posted December 1, 2011 Wouldn't it be more precise for the NWS to use tenth's of a degree instead of rounding? How do they round? .5 and above gets rounded up? .4 and below goes down? They have the ability so I guess I just can't fathom why they would not be more precise. Link to comment Share on other sites More sharing options...
isohume Posted December 1, 2011 Share Posted December 1, 2011 Wouldn't it be more precise for the NWS to use tenth's of a degree instead of rounding? How do they round? .5 and above gets rounded up? .4 and below goes down? They have the ability so I guess I just can't fathom why they would not be more precise. We do. The ASOS network reports to the nearest 1/10 of a degree C and that is what is used for the official daily and end of the month climate. For mean temps...the nearest 1/100 is rounded up if it's a 5 or above. METARs show the tenths of a degree with the T group. KGSP 011353Z 00000KT 10SM CLR 03/M02 A3031 RMK AO2 SLP269 T00281017 This T group is indicating a temp of 2.8 C and a Td of -1.7 C. The first digit is 0 or 1, which indicates positive or negative respectively. For the METAR, it rounds up if the 1/10 digit is 5 or greater. Link to comment Share on other sites More sharing options...
Chinook Posted December 1, 2011 Share Posted December 1, 2011 We do. The ASOS network reports to the nearest 1/10 of a degree C and that is what is used for the official daily and end of the month climate. For mean temps...the nearest 1/100 is rounded up if it's a 5 or above. METARs show the tenths of a degree with the T group. KGSP 011353Z 00000KT 10SM CLR 03/M02 A3031 RMK AO2 SLP269 T00281017 This T group is indicating a temp of 2.8 C and a Td of -1.7 C. The first digit is 0 or 1, which indicates positive or negative respectively. For the METAR, it rounds up if the 1/10 digit is 5 or greater. The thing at the end of the METAR with the "T" in front of it always indicates a whole number of degrees F (even though it expresses this in degrees C), if it is in the United States. In Canadian METARs, I don't believe I have seen this type of thing in the remarks section. Link to comment Share on other sites More sharing options...
isohume Posted December 1, 2011 Share Posted December 1, 2011 The thing at the end of the METAR with the "T" in front of it always indicates a whole number of degrees F (even though it expresses this in degrees C), if it is in the United States. In Canadian METARs, I don't believe I have seen this type of thing in the remarks section. Yeah, ASOS converts temperature to C for standardized WMO METAR reporting purposes. I'm not sure what Canadian METARs report, only the NWS ones. Link to comment Share on other sites More sharing options...
LithiaWx Posted December 1, 2011 Author Share Posted December 1, 2011 I guess what I really meant was why are record temperatures reported as rounded degrees in Fahrenheit? Also for example this page. http://www.nws.noaa.gov/data/obhistory/KMGE.html Link to comment Share on other sites More sharing options...
isohume Posted December 1, 2011 Share Posted December 1, 2011 I guess what I really meant was why are record temperatures reported as rounded degrees in Fahrenheit? Also for example this page. http://www.nws.noaa....story/KMGE.html That's for ease of use for the general public. Yo don't want a bunch of decimal points everywhere. If we did it for temp we'd end up doing it for all the variables. Link to comment Share on other sites More sharing options...
LithiaWx Posted December 1, 2011 Author Share Posted December 1, 2011 That's for ease of use for the general public. Yo don't want a bunch of decimal points everywhere. If we did it for temp we'd end up doing it for all the variables. ok thanks for taking the time to answer my question. So basically you guys do measure in tenth's and hundredth's of degrees but it's just not reported to the public as prominently as it could be for simplicity's sake? Link to comment Share on other sites More sharing options...
isohume Posted December 1, 2011 Share Posted December 1, 2011 ok thanks for taking the time to answer my question. So basically you guys do measure in tenth's and hundredth's of degrees but it's just not reported to the public as prominently as it could be for simplicity's sake? Yeah...but after looking at that website again I noticed slp and vsby are reported to the nearest 1/10 and 1/100 respectively. Ha...who knows why the site is set up like that then? Good question. Link to comment Share on other sites More sharing options...
famartin Posted December 6, 2011 Share Posted December 6, 2011 ok thanks for taking the time to answer my question. So basically you guys do measure in tenth's and hundredth's of degrees but it's just not reported to the public as prominently as it could be for simplicity's sake? Depends on the sensor. ASOS reports in whole degrees Fahrenheit. It probably could do tenths but has not been programmed to do so. Some AWOS sites now report to the nearest tenth celsius, using the T group that ASOS uses to report whole degrees Fahrenheit. Its not very common, though. The NWS cooperative electronic temperature system (MMTS) reports to the nearest tenth, but we don't report it with that much accuracy. Given various errors that I've seen in all of those three system's as far as temperatures go, its probably good we don't bother to report to the nearest tenth. So, at least to me, I think the accuracy of the instruments precludes us from reporting in tenths. Link to comment Share on other sites More sharing options...
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