Topic: Marked temperature variations over relatively short distances

[hofpwx]

Temperature anomalies are used in many climate studies, so location-specific temperature bias due to the microclimate is eliminated.

[Central Maine Weather]

Temperature anomalies are used in many climate studies, so location-specific temperature bias due to the microclimate is eliminated.

Why do forecasts always resemble this warm biased data for this area then, if location-specific temperature bias due to the microclimate is eliminated as you say? And if the temperature data from the biased station due to this microclimate effect is eliminated, where does the data come from if that is the only ASOS station in the area.

These other stations I show on these map screenshots I’ve been sharing are CWOP stations (mine included). Does data from CWOP stations get fed into climate studies/trends? I would imagine not since these stations haven’t necessarily been “approved” by NWS/NOAA as trustworthy for providing long term accurate data.

[Central Maine Weather]

As I’ve mentioned before I’m by no means a professional in this area, just an avid weather enthusiast who loves numbers and data accuracy! I’m here to hear others input and greater expertise on the matter! I always love to see everyone’s willingness to share their experiences and knowledge on this forum! 

[hofpwx]

Temperature anomalies are used in many climate studies, so location-specific temperature bias due to the microclimate is eliminated.

Why do forecasts always resemble this warm biased data for this area then, if location-specific temperature bias due to the microclimate is eliminated as you say? And if the temperature data from the biased station due to this microclimate effect is eliminated, where does the data come from if that is the only ASOS station in the area.

I mentioned climate studies, not forecasts.
I also said "temperature bias [...] is eliminated", not that the temperature data aren't used.
For data, there's also the USCRN stations in the area.

[Central Maine Weather]

I mentioned climate studies, not forecasts.
I also said "temperature bias [...] is eliminated", not that the temperature data aren't used.
For data, there's also the USCRN stations in the area.

And in this thread I've been talking about forecasts from the beginning and I also mentioned zone hardiness which I know relates to climate, but didn't mention climate studies. I feel like this more so has to do with independent long-term studies on microclimates and temperature anomalies due to geographic sensor siting, which is a phenomenon I am definitely fully aware

In respect to the 'Temperature bias is eliminated" vs "used" statement, how is the bias eliminated then? My discussion in this thread has about the fact that it does not seem to be being eliminated. Who eliminates it? Computer models I presume? How do they know they need to eliminate it, or when/when not to eliminate it? If this is true, why not just ignore the data altogether then (i.e. not use the data as I said)? If temperature bias from a station needs to be eliminated, what is the point of using data from that station? How does one know what to "eliminate" the bias to? In my opinion that would be like us assuming we need to incorporate a set +/- adjustment on what our weather stations sensors show (as an example) without having an actual calibrated reading to align it with.

You mentioned the use of USCRN stations in a past response, but like I said in my response to that, there are only a couple USCRN stations in Maine, and none of those are even remotely close to my area. One is 205 miles to my Northeast in Limestone, ME and the other is 73 miles to my Northeast in Old Town, ME. Am I missing any? These seem to be the only 2 USCRN stations that I can find in Maine, and if this is the case, data from those stations is completely useless in respect to my area and really this entire Central Maine (Kennebec County) area as a whole.

[hofpwx]

I mentioned climate studies, not forecasts.
I also said "temperature bias [...] is eliminated", not that the temperature data aren't used.
For data, there's also the USCRN stations in the area.

And in this thread I've been talking about forecasts from the beginning and I also mentioned zone hardiness which I know relates to climate, but didn't mention climate studies. I feel like this more so has to do with independent long-term studies on microclimates and temperature anomalies due to geographic sensor siting, which is a phenomenon I am definitely fully aware

surfacestations.org?

In respect to the 'Temperature bias is eliminated" vs "used" statement, how is the bias eliminated then? My discussion in this thread has about the fact that it does not seem to be being eliminated. Who eliminates it? Computer models I presume? How do they know they need to eliminate it, or when/when not to eliminate it? If this is true, why not just ignore the data altogether then (i.e. not use the data as I said)? If temperature bias from a station needs to be eliminated, what is the point of using data from that station? How does one know what to "eliminate" the bias to? In my opinion that would be like us assuming we need to incorporate a set +/- adjustment on what our weather stations sensors show (as an example) without having an actual calibrated reading to align it with.

The use of temperature anomalies eliminates microclimate biases. To create anomalies, compute the 30 year monthly mean normals for the given site. Subtract that baseline from each monthly mean of the observed data.
Doing so for multiple stations is even better. Anomalies correlate very well over distance.

You mentioned the use of USCRN stations in a past response, but like I said in my response to that, there are only a couple USCRN stations in Maine, and none of those are even remotely close to my area. One is 205 miles to my Northeast in Limestone, ME and the other is 73 miles to my Northeast in Old Town, ME. Am I missing any? These seem to be the only 2 USCRN stations that I can find in Maine, and if this is the case, data from those stations is completely useless in respect to my area and really this entire Central Maine (Kennebec County) area as a whole.

As I've noted, the USCRN can be used as a baseline and to assist in quantifying microclimate and other biases for a given station.

[Central Maine Weather]

I mentioned climate studies, not forecasts.
I also said "temperature bias [...] is eliminated", not that the temperature data aren't used.
For data, there's also the USCRN stations in the area.

And in this thread I've been talking about forecasts from the beginning and I also mentioned zone hardiness which I know relates to climate, but didn't mention climate studies. I feel like this more so has to do with independent long-term studies on microclimates and temperature anomalies due to geographic sensor siting, which is a phenomenon I am definitely fully aware

surfacestations.org?

In respect to the 'Temperature bias is eliminated" vs "used" statement, how is the bias eliminated then? My discussion in this thread has about the fact that it does not seem to be being eliminated. Who eliminates it? Computer models I presume? How do they know they need to eliminate it, or when/when not to eliminate it? If this is true, why not just ignore the data altogether then (i.e. not use the data as I said)? If temperature bias from a station needs to be eliminated, what is the point of using data from that station? How does one know what to "eliminate" the bias to? In my opinion that would be like us assuming we need to incorporate a set +/- adjustment on what our weather stations sensors show (as an example) without having an actual calibrated reading to align it with.

The use of temperature anomalies eliminates microclimate biases. To create anomalies, compute the 30 year monthly mean normals for the given site. Subtract that baseline from each monthly mean of the observed data.
Doing so for multiple stations is even better. Anomalies correlate very well over distance.

You mentioned the use of USCRN stations in a past response, but like I said in my response to that, there are only a couple USCRN stations in Maine, and none of those are even remotely close to my area. One is 205 miles to my Northeast in Limestone, ME and the other is 73 miles to my Northeast in Old Town, ME. Am I missing any? These seem to be the only 2 USCRN stations that I can find in Maine, and if this is the case, data from those stations is completely useless in respect to my area and really this entire Central Maine (Kennebec County) area as a whole.

As I've noted, the USCRN can be used as a baseline and to assist in quantifying microclimate and other biases for a given station.

Thanks for the info.

[Mattk]

The problem with bias related to temperature is certainly not a scientific thing even though those that condone the idea typically have biases of their own that has never been fully supported outside the reasons for their introducing biases in the first place.   

[Central Maine Weather]

The problem with bias related to temperature is certainly not a scientific thing even though those that condone the idea typically have biases of their own that has never been fully supported outside the reasons for their introducing biases in the first place.   

That’s a lot of biases! 

[Marco551]

Yes cold air really can "drain" into lower areas.This is called temperature inversion or cold air drainage.At night, with clear skies and no wind, the air near the ground cools rapidly.The denser colder air then flows downhill into valleys creating those colder "pockets" you noticed.Ive seen the same thing around here thermometers in valleys often show several degrees lower than on nearby ridges.It’s fascinating how microclimates can impact temperature readings like that!

[hofpwx]

The problem with bias related to temperature is certainly not a scientific thing even though those that condone the idea typically have biases of their own that has never been fully supported outside the reasons for their introducing biases in the first place.

A watch that's 5 minutes slow can still tell you when an hour has passed.

[ValentineWeather]

Probably the best place to watch cold air drainage is Peter Sinks, in Utah. Difference from rim temperature and a bowl down below. Yesterday the rim low was 9 above and sink temperature 16 below. I've seen the spread a lot more, though.
 On Feb. 1, 1985, the temperature at Peter Sinks location plummeted to -69.3°F

https://climate.usu.edu/PeterSinks/index.php

[Clarkey]

Although not to do with the majority of responses ...
I've been caught before looking at a map of various station types and networks and wondering why my data was so different ... then it clicked, I update every 5 mins, most other non-CWOP networks update every hour ... values can be vastly different in an hour