WinterWolf Posted October 31, 2023 Share Posted October 31, 2023 12 minutes ago, dendrite said: Not if you read and understand it. The error is comparing the analysis temp to the reported temp. So when the error is positive, the analysis temp is higher than the reported temp…therefore the sensor is reading cooler than expected. It wouldn’t be correct to judge a sensor’s error based on these analyses because it compares the data to stations around it. Microclimates can affect these. A place like BOS, on the coast, will see higher than usual “error” with east flow in the spring and fall because of possible significant differences between the coast and places 10 miles inland. UHIs, elevation differences, geographical differences, siting differences, etc all have an effect. What we look for are significant step changes (jumps) in the error over a short amount of time to indicate something changed with the station’s siting or instrumentation. New stations coming online can affect the analysis generated temps as well, but it doesn’t usually acount for significant shifts in the error. Thanks for the explanation. I erased my post, cuz I kind of understood it in my mind after as….if it’s a negative departure, the temp should have actually read less(thus negative). Maybe that’s still wrong, but that way it made more sense. Lol. Thank you though. 1 Link to comment Share on other sites More sharing options...
dendrite Posted October 31, 2023 Share Posted October 31, 2023 1 minute ago, WinterWolf said: Thanks for the explanation. I erased my post, cuz I kind of understood it in my mind after as….if it’s a negative departure, the temp should have actually read less(thus negative). Maybe that’s still wrong, but that way it made more sense. Lol. Thank you though. It's kind of semantics, but it isn't necessarily fair to say a site like BOS is erroneous and reads 2F too high when it could simply be the effects of the heat island compared to the burbs. You don't know if a sensor is truly erroneous unless you're testing it directly with a calibrated comparison or in a chamber. 2 Link to comment Share on other sites More sharing options...
CoastalWx Posted October 31, 2023 Share Posted October 31, 2023 4 minutes ago, dendrite said: It's kind of semantics, but it isn't necessarily fair to say a site like BOS is erroneous and reads 2F too high when it could simply be the effects of the heat island compared to the burbs. You don't know if a sensor is truly erroneous unless you're testing it directly with a calibrated comparison or in a chamber. BOS became pretty obvious with T/Td spreads of 3-4F in dense fog and ZR at 34F. 1 1 Link to comment Share on other sites More sharing options...
dendrite Posted October 31, 2023 Share Posted October 31, 2023 13 minutes ago, CoastalWx said: BOS became pretty obvious with T/Td spreads of 3-4F in dense fog and ZR at 34F. I always enjoy these step changes. 2F too warm for all of 2019 1 2 Link to comment Share on other sites More sharing options...
ORH_wxman Posted October 31, 2023 Share Posted October 31, 2023 43 minutes ago, dendrite said: I always enjoy these step changes. 2F too warm for all of 2019 And the record will never be corrected. 1 Link to comment Share on other sites More sharing options...
CoastalWx Posted October 31, 2023 Share Posted October 31, 2023 2 minutes ago, ORH_wxman said: And the record will never be corrected. I always got frustrated when I talked to people I know about this. I used to tell them look at the departures across the 1st order stations in SNE. How can one station be over 2F above the rest. The airmass doesn't magically change inside 128 lol. But people would still push back on it claiming UHI...but it doesn't work like that. Having over 2F difference in departures compared to other stations is statistically significant with this kind of data. Local micro climates aren't enough to explain it. Something was up there. Oh well. Link to comment Share on other sites More sharing options...
ORH_wxman Posted October 31, 2023 Share Posted October 31, 2023 4 minutes ago, CoastalWx said: I always got frustrated when I talked to people I know about this. I used to tell them look at the departures across the 1st order stations in SNE. How can one station be over 2F above the rest. The airmass doesn't magically change inside 128 lol. But people would still push back on it claiming UHI...but it doesn't work like that. Having over 2F difference in departures compared to other stations is statistically significant with this kind of data. Local micro climates aren't enough to explain it. Something was up there. Oh well. Yeah UHI only matters for the raw numbers...not the departure from average....unless the UHI is a very new phenomenon as to not be fully factored into the 30 year normals (something like Dulles airport between 1980s and 2000s had a lot of increased land use change)....and we know Boston isn't a situation like that. The same exact thing is going on with ORH for 3 years now....they are consistently 1.5-2F higher on the departures than the other first order sites....confirming what MADIS shows Link to comment Share on other sites More sharing options...
CoastalWx Posted October 31, 2023 Share Posted October 31, 2023 46.3 so far. Halloween of yore. 6 Link to comment Share on other sites More sharing options...
Angus Posted October 31, 2023 Share Posted October 31, 2023 I was thinking of this departure recently when out riding one morning on the minuteman bike trail while crossing route 128 not far from Hanscom. It was probably 645am so traffic had been heavy for a while and as I crossed the bridge, I noticed a significant increase in temperature - it was a cloudy day so the sun's impact was insignificant IMO. Has there been any studies done about how exhaust from jet engines could raise the air temperature? I know this issue at Logan has driven everyone crazy since it was noticed. The weather station should be in the Boston Common or something. 1 1 Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted October 31, 2023 Share Posted October 31, 2023 Out on the water I would imagine any negligible affect from jet exhaust is countered by winds off the water etc. But I hope they would account for exhaust Link to comment Share on other sites More sharing options...
powderfreak Posted October 31, 2023 Share Posted October 31, 2023 Cold day to end October. First high in the 30s and currently 33F. Went from shorts to needing hat and gloves outside. 4 Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted October 31, 2023 Share Posted October 31, 2023 36F here attm. Got down to 29 this morning I guess. Mid 20s incoming. 2 Link to comment Share on other sites More sharing options...
powderfreak Posted October 31, 2023 Share Posted October 31, 2023 Finally feels like legit winter. 28/23 at 6:30pm. METAR KMVL 312230Z AUTO 00000KT 10SM CLR M02/M05 A3007 1 Link to comment Share on other sites More sharing options...
512high Posted October 31, 2023 Share Posted October 31, 2023 Maybe I'm alone on this, but 41F not so many kids trick or treating (neighborhood getting old), but nice crisp air. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted October 31, 2023 Author Share Posted October 31, 2023 Fish doing the “ I am going to flex and make my arm look big for the picture , but make it seem like I’m really not flexing” . I mean lol https://x.com/ericfisher/status/1719477752426885270?s=46&t=dhcbvkjmRcyBVQtDxJ3lRg 2 1 Link to comment Share on other sites More sharing options...
kdxken Posted October 31, 2023 Share Posted October 31, 2023 29 minutes ago, powderfreak said: Finally feels like legit winter. 28/23 at 6:30pm. METAR KMVL 312230Z AUTO 00000KT 10SM CLR M02/M05 A3007 Beauty down here. Perfect day for roping trees. 80 ft first shot. 5 Link to comment Share on other sites More sharing options...
mreaves Posted October 31, 2023 Share Posted October 31, 2023 1 hour ago, powderfreak said: Cold day to end October. First high in the 30s and currently 33F. Went from shorts to needing hat and gloves outside. With bright sunshine too. I ran up to the golf course and was able to get 5 holes in. Car thermo read 30° on the way out. It wasn’t that bad. There was no wind and I had hand warmers in my pocket. Currently 28.2° 2 Link to comment Share on other sites More sharing options...
CoastalWx Posted October 31, 2023 Share Posted October 31, 2023 38 here. Finally feels cold. 2 1 Link to comment Share on other sites More sharing options...
DavisStraight Posted October 31, 2023 Share Posted October 31, 2023 I'm still at 44, need the first frost to dump the leaves on my Japanese Maple. Link to comment Share on other sites More sharing options...
TauntonBlizzard2013 Posted October 31, 2023 Share Posted October 31, 2023 32 already. Yore Link to comment Share on other sites More sharing options...
WxWatcher007 Posted November 1, 2023 Share Posted November 1, 2023 Still hovering at 44 Link to comment Share on other sites More sharing options...
dryslot Posted November 1, 2023 Share Posted November 1, 2023 Looks like the coldest night so far this fall on tap tonight, 34.7/27°F. 1 Link to comment Share on other sites More sharing options...
CoastalWx Posted November 1, 2023 Share Posted November 1, 2023 36.5 but clouds coming in. Link to comment Share on other sites More sharing options...
dendrite Posted November 1, 2023 Share Posted November 1, 2023 Been stuck at 36° for 3 hours. Link to comment Share on other sites More sharing options...
metagraphica Posted November 1, 2023 Share Posted November 1, 2023 39/34 but almost completely clouded over. Probably have to wait until Thursday AM for first frost. Link to comment Share on other sites More sharing options...
alex Posted November 1, 2023 Share Posted November 1, 2023 Down to 23 already. Some nice scenery driving around and the resorts making snow felt festive lol 7 Link to comment Share on other sites More sharing options...
rimetree Posted November 1, 2023 Share Posted November 1, 2023 First frost this morning at 33.5F. Had to scramble to find the scrapers for the car. This month was almost identical to Oct. 2021 temp wise with a 55F average. Finished at 3.78" of precip. Be nice to see some flakes this week. 37/34 Link to comment Share on other sites More sharing options...
weathafella Posted November 1, 2023 Share Posted November 1, 2023 Had the most number of trick or treaters in years. Still plenty of candy left for next year if I can avoid consuming it. Old school chilly Halloween. 1 Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted November 1, 2023 Share Posted November 1, 2023 2.44" on the month. Link to comment Share on other sites More sharing options...
DavisStraight Posted November 1, 2023 Share Posted November 1, 2023 Down to 39, not sure if I get down to freezing. Link to comment Share on other sites More sharing options...
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