ORH_wxman

Does the coop still use a non-ASOS thermometer. I'd hope it does.

Maybe...but both can still be true. It's not a either/or with these things. The break in ORH graph just looks really really weird and extremely unlikely to be explaned by a gradual warming trend. Maybe ORH had different pre-ASOS instrumentation than CON? Not sure how to look that up...but that could be another explanation.

Blue Hill has an ASOS....but I know they keep alternate records. I just don't know if they are easily available online.

CON didn't pull 30s in the 1980s either despite several big "low dew" years on the graph comparable to the 1970s. I wonder if subtle development in the area made them unable to radiate like they could even 10 years earlier. Rad sites are annoyingly fickle which is why a well-mixed site like ORH popped out to me. I also noticed CON had zero hours of sub-40 dews in 1993 and 1994 while ORH had logged a lot of hours (esp 1994) before going basically silent in 1995-onward.

1920s weren't nearly as dry as the 1930s? The '30s were pretty exceptional on both extremes...it had exceptionally cold temps and also exceptionally hot temps. The CONUS acted closer to a desert than at any other point.

Yes I know....dry = colder mins.

A place that is well-mixed and not prone to other factors like radiational cooling (esp with UHI development) such as ORH airport makes me a bit suspicious when I see such a clean break like that. It's not claiming that the ASOS is the only source of the trend...of course it isn't. From a pure mathematical standpoint, we're going to see higher dews as we warm....every full degree C rise produces 7% more water vapor. But in addition to the underlying trend, it's always fascinating to me to find where else certain statistical oddities may come from. That ORH graph is very unlikely to happen by pure chance....though unlikely doesn't mean impossible. In a warming world, we'd still expect cold Julys like 2000 and 2001 to have some sort of resemblance to early 1990s and 1980s cool Julys.

1930s were dry....dust bowl era....epic drought in middle of country so not really conductive to high dew airmasses. There's probably another anthropogenic trend in dewpoints that is unrelated to GHG warming....midwest/plains agriculture. We have far more corn acreage now than we did in the middle 20th century and it's a lot more productive and efficient. This will make airmases coming out of the plains more moist than previous years.

Interesting that ORH has a clean step break around the time ASOS went in (1995). Could just be coincidence but one wonders if there was some difference in instrumentation.

Well the area right along the Arctic Ocean isn't part of the region that has been bucking the trend. Maybe that's why? That's the area where permafrost is probably the deepest too. Its been more across the boreal forest region over the interior of Siberia. We also have to take into account the media too...we're probably more likely to hear of records in the media versus "flat trend in temperatures across the taiga!!"...doesn't quite have the same ring to it.

I've seen this phenomenon on the seasonal scale (winter comes to mind where our trend is flat the past 20+ years), but running the numbers on an annual basis doesn't really stick out. We're warming in SNE here around 0.2C per decade going back to the 1990s which isnt that different than the global trend. The largest area that seems to buck the global trend these days is Siberia which has large areas that haven't seen any warming at all in the past 20-30 years...largely driven by colder autumns and winters.

If it fits his narrative of how the climate should be, then it makes sense.

'07 and '08 were actually warmer than normal in ORH. Esp '08...'07 was near normal. But '09 was the 5th coldest summer at the airport site going back to 1948...including the coldest June/July couplet on record edging out 1982. Weve only had 2 below normal summers since then...2014 and 2017 and both were not by much.

On extent or area? I think 2007 both extent and area are very good chances to be surpassed by 2019...2016 has a good chance on extent but not as good for area. Prob like a 50/50 chance or less to pass 2016 area.

I agree with the low chance of beating 2012 at this point. I wanted to see a pretty good sized lead heading into late July/early August. I might go higher than 3% on extent but not by a lot. Maybe 10-20%. For area I probably wouldn't go higher though as we slightly trail 2012 in area.

It's the wave lengths and also strength of the polar jet in winter. The temp gradients increase dramatically in winter so if you end up on a certain side of the PJ for an anomalously long period, then your departure is going to be huge. In summer, everything is more diffuse with weaker temp gradients so it's hard to rack up massive anomalous airmass residence time.

I don't think they are. A day like yesterday will mask the issue because you're probably maxing out the heat a bit inland (see hot Saturday, etc). Again, we're talking a couple degrees here so it's harder to notice on big downslope day.

You'd expect just inland and west of them to be a little hotter on that type of setup. So you don't end up noticing the drift as much on that type of synoptic setup.

He sudden shifts/decays that happen over like a couple months are the ones that are probably real problems. The ones that are very gradual are probably more due to additional meso stations coming online. The sudden step-changes (no decay at all...just a total straight cliff) are probably due to a siting change like either moving the ASOS station on site or a huge project like paving a new runway like we saw at SEA. Or maybe some rocks around the ASOS site, lol.

Yeah I could see it doing that on some. I don't believe that is the reason for the BOS drift though IMHO. That one was way more noticeable when it happened because it was running a lot different than other ASOS stations in uniform conditions like snow events...so we weren't even comparing it to Davis stations.

I haven't seen any run obviously cold in a while on MADIS. I think AFN did way back in the day for a time but it was corrected pretty quickly. I recall them being like consistently 4F colder than ORH one winter which is way too high given very similar elevation. Ive always found the issues are much easier to find in the winter versus the summer. The summer has a lot of additional outside factors that winter doesn't have which can muck up temps.

BDL didn't really have a big MADIS jump anyway recently. BOS I definitely think is warm...sudden move late last year that also fits the anecdotal evidence that all of us posted out during the winter. BDL is probably a legit tarmac fart...like scooter said. It's real but probably a degree or two warmer than most in the CT valley...but we know they can bake on west wind. It's why we started the jokes about BDL tarmac in the first place.

Meh. 85 at 1. Prob not happening.

If ORH can go NW a bit more in the wind, 90 is possible still. It will be hard if they stay SW.

Yeah and again, nobody outside of this wx nerd community would notice...at all. Most people hear balls cold and don't care if it's 3F with a little wind vs -2F with less wind. But on here, we might say "oh that was kind of a bust, we missed the record because we couldn't decouple enough" or something like that. Im the scheme of things, it didn't matter. The idea was right, but a small detail changed the actual temperature outcome by a few degrees even though the sensible wx wasn't very different.