vortex95

That's true, calling bad obs out is good, but then many "break" or "wander" again, and the cycle repeats. So it doesn't go away really for long-term average temps impact. UHI is not to be discounted. It impacts long-term temp averages significantly, and in certain cases, the short-term as well. Such as days hitting some psychologically pleasing number ending in 0 or 5 (e.g. temp 90+). UHI adds a couple of degrees to the max for many cities. and w/ time, the warm biases are getting higher. ***** Here is something I think some may find useful concerning wx data and stats,, esp. when it comes to reporting today, perceptions, and how things can be manipulated and skewed easy when details or facts are left out. This goes back to what I said about data sets and how they can be processed and interpreted in many different ways, and how the resultant stats can be made to say just about anything. You need to be skeptical and put on your critical thinking that more than ever these days, that is what I emphasizing here, not who is "right" or "wrong" or the like. ----- I would caution as to the number of records broken in any given event w/ primary wx parameters involved. I've seen posts that over 600 all-time temp records have been set w/ the current heatwave. That may be true, but there is a caveat. What stations are they using to get that number? I ask b/c the period of record (POR) for many wx stations now is very short since we have installed a *lot* in the last 30 years alone. I know this subject very well b/c I was the keeper of files for wx reporting sites across the globe when I was at WSI, and I still keep track of it all on my own time now. In last 25 years alone, over 600 AWOS sites have been installed and METARs available from the MS Valley to the West Coast. Just in TX, over 130. So you can see where I am going w/ this. When it is claimed a temp record is set at any site, you *have* to ask, "what is its POR?" Sure, we have many GHCN sites and those are proper to use, but I found in order to inflate and hype totals, sites that do not have a long climate history are included. I shouldn't have to spell it out, but can you see how easy it is to set temp records of *any* kind when POR is short? This doesn't discount the nature of current heatwave as to high-end, but you see how numbers can be "played with" to make things appear more impressive than they really are. Disregarding POR is disingenuous when you are talking climate records. This comes all around to how we report on things, and "adjust" for the max effect for hype and to promote certain narratives. Considerable exaggeration and plain lies derived from wx data exist and this practice is rife for a host of non-scientific reasons, and it is lopsided toward gloom and doom b/c of warmer overall temps to the point it has become ridiculous (i.e. everything bad that happens now is due to warmer global temps or "the Earth's day has increased by 1.33 milliseconds in the last century from climate change!"). And what I say above about POR, this is just one of many things that can be manipulated concerning wx data. POR omission is something straightforward and easy to detect, but it gets more complicated than that. Such as this: P-hacking The manipulative practice of re-analyzing or selecting data until non-significant results become statistically significant often by testing multiple variables or stopping data collection early. This technique generates false positives, misleads research findings, and undermines scientific integrity.

Thanks. The push back or snark does not bother me. I don't try to label ppl anything (e.g. usual suspects) b/c that tends to hurt the overall dialogue. I'm not here to tell ppl what to think, only present hard facts or items that some may not be aware of that can do a long way as to how one thinks about and approaches things. There are two things I focus on: 1) Past wx history (esp. recorded) - It has occurred and factual so you can't really debate its validity in a debate. And it is remarkable what is out there that you may not have know about that puts what occurs today to shame in many regards. Such provides context and perspective, and the more you look and learn, the better the picture becomes. 2) The social aspects involved w/ debate/argument - this is biggie, and is what wrecks many civil discussions/debates these days. Things like logical fallacies and cognitive biases, these are harmful to science. Human nature and all its shortcomings and nuances we all are susceptible to cloud issues to the max. Example?, recency bias - the tendency to assign more value or significance to what happens in the here and now or in recent memory vs. long ago.

Huge B&B fan!

I never questioned the overall scope of the heat out west currently. Just details are important in the sciences. Such an event allowed an exercise in presenting such details in the form of limits and caveats of how we measure and record wx data, along w/ some ancillary practical information. That is a good thing.

As CoastalWx might have said if he had this scenic view, "IT LOOKS VIOLENTLY BEAUTIFUL OUT THERE!!!" Never in 1000 years would have ever thought to pair the words "violently" and "beautiful" together!

Thank you. Not trying to score points or be dogmatic, just presenting food for thought.

Is +-2 F good enough? I would say not when you are calculating averages out to the 1/10 or 1/100 of a deg. Or when you are counting days reaching, say 90 or 100, when you have some fixed values as benchmark for a record. Recall the first 100 F at Tampa last year? And how the ASOS is sited at the turn point for taxiing jets? Here's where it gets more psychological than physical, but has real world impacts. We love numbers ending in 0 or 5, and powers of 10?, forget it! So when Tampa hit 100 F for the first time, it was treated like the second coming for news. Really? 99 vs. 100?, that's not a big deal, but we make it a make deal. As a result this skews perception about things like heat and warming more than it should. It can be put this way, if Tampa hit 99 instead of 98 this day, it would have been nothing for news. So minor things are not always so minor as to their effects.

These are great questions. No. they are not all wrong, but when we are talking avg temps out to the tenth or hundredth of deg in long-term climate, what is a minor error for a daily temp, becomes major monthly and longer. It's not a big deal daily if a sensor runs 0.5 F too warm, but that shows up once you get to monthly, and that 0.5 F become more significant as you avg over longer and longer periods. There are a couple of hard facts that indicate warm bias. 1) Urbanization and the location of climate sites is a significant issue and growing larger w/ time. Many climate sites are located in and near urban areas, and this means warmer locally/mesoscale practically by default. But only about 2% of the world is urbanized, so how can this be an good representation of avg global temp when so many climate sites are located near and in this 2%? 2) Even w/o urbanization, having infrastructure nearby (like at airports) can and do bias warmer b/c so much of our infrastructure gives off or retains heat. Things like paved areas, concrete/metal structures, solar panels, jet exhaust, AC units, etc. they are all extra heat sources. How many artificial cold sources are there overall comparatively? Not much. 3) Digital thermometers have largely replaced glass thermometers, and record a continuous record of temps. They more sensitive to passing artificial external heat sources. So instantaneous spikes are recorded more. If one does avg temp, say hourly, to get value for a day, this error is washed out, but that's not done a lot. Absolute max and min for a day are used to get an avg temp. Yes, sensor calibration can run cold, but this seems largely masked by items 1 and 2 above, I mean, how often do we see or notice, "that sensor is running cold."? I don't know about studies comparing mesonet to ASOS/AWOS, but look at siting of most mesonet sites, they are more remote and placed better. That means less artificial heat contamination. Another items to consider for records, we have far more wx stations now, and they increase all the time. So certain wx records, such a state's highest temp or max 24 hr precip, as two examples, are more likely to be detected and go into the record. This gives the perception that things are more intense or worse, when technology has merely allowed us to see better what has always been there or can happen due to more data recording points. How our observation network changes and the technology associated w/ it over time are factors, just another caveat about comparing wx/climate over long periods of time. This doesn't discount warming trends overall, both from natural variability and added CO2., but it is not wrong to be skeptical and ask questions about methods and networks as to how we record and process wx data. And there are many ways to do this w/ data, all have their pluses and minuses, and can be manipulated to produce desired results. Not necessarily wrong, but calculated in a way that isn't what it seems, or have practical/noticeable/meaningful effects, such as being statistically significant. I recommended this book: https://en.wikipedia.org/wiki/How_to_Lie_with_Statistics

ASOS not so good here (see news clip below). And the statement it is considered ok as long as it is +- 2 F from actual temp? So given 2 F whole deg error, how is it proper accuracy calculating a monthly mean temp out to a tenth of a degree? You are over an order of magnitude off given the overall temp sensor's accuracy and not following significant digit rules. Also, ASOS first and foremost job is to aviation, so temp takes a back seat. A documented case, not unique, is Reno NV touted as the fastest warming city in the U.S. Not true, b/c the ASOS placement has been checked as too warm from adjacent infrastructure. The NWS wanted to move it to a better location at the airport, but the FAA said no. EWR had a big problem several years ago that existed for some time. It would always come in around 2 F warmer every month compared to NYC/LGA/JFK/BDR/ISP. Not sure if it still exists, but this is a first-order climate and GHCN site. And AWOS?, they make up the bulk of the hourly observations we see at airports now, and they have worse issues that ASOS. They are notorious bad for dew points, esp. when high. So it is more than just the sensor accuracy/calibration themselves, ASOS/AWOS primary purpose is not meant for climate records. Is this not of significant concern? This data is used for make many, many decisions, big and small. Site that are good? Mesonet sites, like the one OK has had for over 30 years. Those are sited properly and are geared for climate data.

Understood. Standard deviations is one of a number of ways to gauge measure an event. Also, not all significant standard deviations, regardless of what wx parameter you chose, result in the same sensible wx or societal impact. Such as anomalously high 500 mb heights. That works for the heat in the Desert SW currently, but many times do not b/c first, we do not live at 500 mb, and second, what goes on at the near and the sfc is what matters. You can have record high 500 mb heights, but nothing special as to deviations for sfc temp b/c the strength and position of the sfc high relative to your location.

Not bad for daytime accumulation in late March!

I said this about flawed premise: And the concept of "wins the debate" is a flawed premise. What matters in science are facts and the truth. It does not care about who "wins" or "loses." I was not talking about the definitions from the norm or anomalies. I was talking about the idea of "win" or "lose" and that concept bring brought into a scientific discussion. So your reply is a non-sequitur.

That is correct. I never it is wasn't a record breaking air mass. Local contamination from infrastructure is common even in sparely populated areas. Parking lots, vehicle traffic, solar panel arrays, AC units, etc. all contribute. And the digital thermometers have a warm bias compared to glass thermometers b/c they record instantaneous temp and react quickly to any changes in the air. ASOS use 5-min avg temp to mitigate this, but sensors and equipment out there are far from standardized, never mind not all ideally located (look the areal view of the official temp sensor in Death Valley, parking lots and solar arrays all around). So it's not just UHI that skew temp records. It's all too easy to get caught up in it all when big wx events occur. I get that. It is our passion for wx that drives it. However, we should not let that cloud our judgement when talking about caveats and shortcomings that just happen to "deflate" that excitement or how impressive it is. Taking everything as face value and acting there is nothing to question or analyze is not a good scientific position.

UHI does impact daytime highs (Baltimore/Inner Harbor is perhaps the most egregious example). Also, local airport infrastructure and sensor placement impact highs, regardless of UHI.