beavis1729

Another interesting component of this arctic outbreak is the dry air over the southwest. Las Vegas was 59/-15 this afternoon with very dry NE winds, RH 4%. The record dry streak continues in Las Vegas. 189 days and counting since the last measurable rainfall on 4/20/2020.

Hopefully we get an airmass like that in our area in the heart of winter, like the 1995-96 La Niña. The infamous -60 in Tower, MN...and -40s in parts of IA.

High temp today in Sidney NE was 14. Normal high is 61; departure -47. High temp today in Laramie WY was 6. Normal high is 52; departure -46. High temp today in Denver CO was 16. Normal high is 61; departure -45. High temp today in Dalhart TX was 24. Normal high is 68; departure of -44. High temp today in Cheyenne WY was 14. Normal high is 55; departure -41.

This same airmass has led to an Ice Storm Warning for OKC...in October: URGENT - WINTER WEATHER MESSAGE National Weather Service Norman OK 828 AM CDT Mon Oct 26 2020 ...Periods of Freezing Rain and Sleet Expected This Morning Through Early Wednesday... OKZ007-008-012-013-016>020-022>027-033>038-TXZ083>085-262200- /O.UPG.KOUN.WW.Y.0009.000000T0000Z-201027T0000Z/ /O.NEW.KOUN.IS.W.0001.201026T1328Z-201028T1800Z/ /O.UPG.KOUN.WS.A.0004.201027T0000Z-201028T1200Z/ Grant-Kay-Garfield-Noble-Custer-Blaine-Kingfisher-Logan-Payne- Washita-Caddo-Canadian-Oklahoma-Lincoln-Grady-Harmon-Greer-Kiowa- Jackson-Tillman-Comanche-Hardeman-Foard-Wilbarger- Including the cities of Medford, Pond Creek, Lamont, Wakita, Ponca City, Blackwell, Enid, Perry, Weatherford, Clinton, Watonga, Geary, Okeene, Kingfisher, Hennessey, Okarche, Guthrie, Stillwater, Cordell, Burns Flat, Sentinel, Anadarko, Hinton, Yukon, Concho, El Reno, Mustang, Oklahoma City, Chandler, Stroud, Prague, Meeker, Davenport, Wellston, Chickasha, Tuttle, Hollis, Mangum, Granite, Hobart, Snyder, Altus, Frederick, Lawton, Quanah, Crowell, and Vernon 828 AM CDT Mon Oct 26 2020 ...ICE STORM WARNING IN EFFECT UNTIL 1 PM CDT WEDNESDAY... * WHAT...Periods of significant icing through at least Wednesday morning. Ice accumulations up to one-half inch will be common, with some locations possibly receiving upwards of one inch. There will also be accumulations of sleet. * WHERE...Central, northern, and southwest Oklahoma and western and northern Texas. * WHEN...Until 1 PM CDT Wednesday. * IMPACTS...Expect power outages and widespread tree damage due to the ice. Travel could become very dangerous.

Some shockingly cold temps for October are occurring, or will soon occur, in MT/WY/CO/NE. Laramie, WY may drop to -16, which would be the coldest temp on record so early in the season (October record low is -18 on 10/30/1993). Most impressive relative to climo may be Billings, MT. Tomorrow morning, it may hit 4...which would shatter the record low of 18 set in 1997. Monday morning may hit -2; the record low is 22 set in 1970. Breaking a daily record by 24 degrees...not bad. Records in Billings go back to 1934. There has only been one sub-zero October day in Billings in recorded history (-7 on 10/30/1991).

Interesting data for MSN...hard to believe the -37 on 1/30/1951. Their 2nd coldest temp on record is "only" -30 on 1/15/1963. A few days have come close in the (somewhat) modern era...such as -29 on 2/3/1996; -28 on 1/16/1979 & 2/1/1985; -27 on 1/20/1994; -26 on 1/31/2019. This makes the -29 on 3/1/1962 even more impressive.

Yeah, I thought about the -25 and -27. The one thing that 12/24/1983 had going for it was that it's nearly the shortest day of the year. But I agree a case could be made for it being #1 on the list. EDIT: I made a couple updates to the ORD list.

While we're in a boring weather period before the cold season gets underway, I thought it would be interesting to list out the temperature records at ORD that are easiest and most difficult to break. I'm only focusing on the cold & low-solar season, NDJF. Feel free to add other locations too. I may add low max and high min records later. A more detailed statistical analysis would probably look at all daily temps, to calculate the standard deviation assuming a normal distribution...then look at departures on a z-score (# of SD) basis. That way, it would account for the fact that a -20F daily departure in summer is probably equivalent to a -35F daily departure in winter...as winter temps are more variable. But a simpler way of doing this is to just see which records seem out of place relative to surrounding days and/or time of year. What I found interesting is that there doesn't really seem to be a correlation between the easiest records to break vs. how old the record is. For example, some of the easiest records to break are from the 1800s. It just seems to be a coincidence that certain days just haven't had extreme cold or heat...probably a feature of small sample size. Even with records going back to 1870, only 150 max/min observations exist for a given day at ORD. Also, the most difficult record low temps to break are mainly focused on the absolute coldest temps on records, not so much time of year. This is due to UHI worsening over time. Regardless of early-season or late-season, I think the all-time low temp of -27 on 1/20/1985 is almost impossible to break. We saw what happened on January 30-31, 2019... ORD - daily MAX temp records 10 easiest to break (1) 58 on 2/16/1921 (2) 52 on 2/2/2020 (3) 55 on 1/30/1988 (4) 56 on 1/5/1890 (5) 57 on 12/22/1957 - only December day with a record high lower than 60 (6) 61 on 12/11/1949 (7) 70 on 11/12/1949 (8) 62 on 2/28/2016 (9) 60 on 12/17/1977 (10) 60 on 12/16/1984 10 most difficult to break (1) 67 on 1/25/1950 (2) 69 on 12/28/1984 (3) 68 on 12/31/1875 (4) 70 on 2/11/1999 (5) 78 on 11/14/1971 (6) 75 on 11/19/1930 (7) 71 on 12/3/1970 (8) 65 on 1/1/1876 (9) 65 on 1/7/2008 (10) 75 on 2/27/1976 ORD - daily MIN temp records 10 easiest to break (1) -9 on 1/13/1929 - only January day with a record low higher than -10 (2) -10 on 1/27/1955 (3) 21 on 11/1/1879 (4) 19 on 11/6/1991 (5) 4 on 12/5/2005 (6) -10 on 2/7/1875 (7) -7 on 12/30/1909 (8) 14 on 11/14/1916 (9) -7 on 12/17/1951 (10) -1 on 2/26/1963 10 most difficult to break (1) -25 on 12/24/1983 (2) -27 on 1/20/1985 (3) -26 on 1/10/1982 (4) -25 on 1/16/1982 (5) -1 on 11/23/1950 (6) -2 on 11/24/1950 (7) -14 on 12/9/1876 (8) 7 on 11/12/2019 (9) 3 on 11/17/1959 (10) -23 on 1/30/2019

It always amazes me how places in northern MN radiate, even if they're not in a valley or other drainage location. All that's needed is dry air and not being in a UHI setting - imagine that. The winds were fairly light at INL last night, but by no means calm. And, obviously, no snow cover. But it still dropped from 50F at 6 PM, to 32F at 10 PM.

Gotta love wikipedia Obscuration FU Smoke (French: Fumée) https://en.wikipedia.org/wiki/METAR

A lot of obs in the Pacific NW with smoke, due to the wildfires. Air Quality warnings over almost the entire NW. Here is Spokane WA, 1 mile visibility: METAR KGEG 151953Z 00000KT 1SM R21/6000VP6000FT FU SCT001 OVC025 22/07 A3018 RMK AO2 SLP212 FU SCT001 FU OVC025 T02170072

Maybe 1995-96? Chicago had its earliest freeze on record (ORD hit 32F on 9/22/1995)...then the next day was even more impressive with a low of 29F on 9/23/1995. Or, 1993-94? September 1993 was Chicago's coldest September on record, 59.2F vs. the 1981-2010 normal of 64.6F. Could have been lingering effects of Pinatubo?

^ Very impressive for Eau Claire...a 74-year-old record broken by 6 degrees. And it looks like Rockford IL will shatter the record low max for 9/9. Record is 63 set in 1924, but it will probably only hit 59-60 today.

Not saying it’s “fake”, I just don’t like how humans are artificially warming and modifying the environment around us. And it’s not good that the suburbs keep expanding. It’s not natural. Not saying humans should strive for a prehistoric utopia, but there needs to be a balance between long-term planning for the good of the earth vs. the individual freedoms that individuals and companies have to make short-term decisions at the expense of long-term considerations. Communities over individuals.

As much as we're talking about Denver, it has been and will be even crazier in Laramie WY. High of 91F yesterday after it was in the 40s during the AM with haze/smoke from wildfires, then winds gusted out of the NW and it hit 90/3 at an hourly ob, RH 3%. Laramie is around 7,200 feet elevation. Expecting 4-8" of snow Mon-Tues, with a low near 0F on Tuesday night.

The 2-day temp drop at DEN later this weekend could be around 63 degrees, from 91F On Labor Day to the upper 20s at some point on Tuesday. So, probably won’t make the top 10, but very impressive for September, and early in the month at that. It hit 101F today, a new all-time September record high. There have been 10 occurrences of a 66+ degree 2-day temp drop at DEN, but none have occurred in September. They were all Oct-Feb. Largest 2-day temp drop on record is 76 degrees, from 58F on 12/13/2008 to -18F on 12/14/2008.

Earliest first measurable snow: 9/3/1961 (4.2”) Average first measurable snow: 10/18 Warmest temp on the day before a measurable snow: 92F on 9/12/1993

Darker red color right by ORD.

61-day streak of consecutive 100+ days ended today in Las Vegas. 2nd longest streak on record.

Good to know the sensor is fine, but all that other stuff is troubling. People outside of the scientific community probably don’t care...but it’s not good to disturb the site around a sensor over time. Shouldn’t the powers that be have considered this before moving the sensor to its current location? One could argue that this biased temps upward just enough to land the hottest summer on record for Chicago. There will always be an asterisk. A similar thing probably happened when ORD only hit -21 on 1/31/2019, when many other sites in N IL were -25 to -30 or even colder. It just bothers me when science gets compromised like this. The lack of attention to detail is unfortunate.

Ha, I agree and you beat me to it. Consistency of 85+ high temps plus warm (but not record-breaking) overnight lows due to UHI = record warm summer. Never thought Chicago would see a record warm summer with only 3 days of 96+ highs. UHI played a huge role. One would expect overnight lows to be a bit cooler due to the general dry soils in the area throughout JJA, all else being equal. But that didn't happen. Also, only 8 (!) of the 92 days this summer at ORD were below normal. 5 in June, 0 in July, 3 in August. I still think there's something up with ORD's sensor, location, etc...as the temps at ORD this summer seemed to be materially higher than PWK, which isn't very far away (and isn't really much closer to the lake) as the crow flies. At a minimum, it illustrates the scientific "peril" of having wx obs taken at airports. Besides the UHI due to the abundance of concrete at airports, it doesn't help when ORD does construction on runways and has to re-locate the sensor. It tarnishes the historical record. Good stats Chicago Storm.

DFW hit 105 today, with a max HI of 115.

RFD is even drier this August, only 0.52".

Yep, understood. Of course there is no "one size fits all" rule, and it depends on the season and the antecedent conditions on a given day. But, anecdotally, I'd suggest the average UHI impact is a bit greater than what you noted. This morning, RFD (72F) was 2F warmer than "baseline"...namely FEP, a very small nearby rural town that dropped to 70F. Overall, from what I've seen over the years, RFD will check in at 1-2F warmer than nearby rural areas. Probably 2-3F higher at night (especially in winter), and 0.5-2F higher during the day. Just estimates, of course...but significantly greater than 1/3 of a degree F. Another example - the MSP metro area (3.5 million population) has a huge UHI problem...amplified further in the winter when the rural vs. urban differences in radiational cooling become apparent. I've seen many winter mornings were it will be -10F to -15F in areas outside (and even south of) the metro area, but MSP will be much warmer, around 0F. And, sometimes, it can come down to the very microscale detail of the exact location of the ob site. You always hear about the joke of DCA (one of the Washington DC airports), where the thermometer is right on the tarmac and right by the river. DCA also records much lower snowfall totals due to this. Same idea with BDL - Bridgeport CT. I know airports have historically been a convenient place to record wx obs, but it's probably not the most representative when jet exhaust and concrete can be even more intense than a "regular" urban area. Not meaning to argue about this, of course...just a good discussion. Back to the heat wave - looks like ORD hit 94/70/100 today. While I'm on a roll with pet peeves, it's still shocking to me how there have been no heat advisories in the Chicago metro area all week, when we've had 5 (?) consecutive 90+ days...especially noting that it's late August and can be considered "out of season" heat. I would even suggest there should've been heat advisories if this were June/July...but especially for late August. A heat index of 95+ is pretty miserable, especially with full sun, the cumulative effects day after day, and little nighttime relief in the metro/urban core (heck, ORD had a low of 78 this AM...and it was probably similar in Chicago proper with 2.8 million people). But I digress...