TheClimateChanger

Looking at all Septembers from 1999-2022, AGC has averaged 0.5F warmer than PIT, so it's a little unusual for PIT to be warmer by 0.1F, but certainly not unprecedented. PIT was also warmer than AGC in 2004, 2009, 2013, 2017 and 2018 in the month of September. Definitely not running 2-4 degrees too warm. If anything, it was unusual AGC was running 1-1.5F warmer for awhile, so I suspect PIT's sensor was actually running 0.5-1F too low for a while, so even a slight warm bias feels exaggerated. PIT: AGC:

Maybe slightly, but these single point in time comparisons are not particularly helpful in making that determination. Just like the claim that: "KPIT seems to be running 2-4 degrees warmer than Allegheny County for weeks now?" In fact, this month, the mean difference between the two sites this month has only been 0.1F:

Chamber of commerce weather in Pittsburgh. Here is the point-click forecast centered on the official observation site at Pittsburgh International Airport:

Incredible turnaround from recent years. Again looking only at airport data, you can see the top 20 years are dominated by recent years (2018, 2019, 2022, 2017, 2021, with 2020 not far behind). Two other years from the 21st century also appear (#1, 2004; and 2009).

Just goes to show how difficult it is to have a drought in this state. Looking at airport data only for the Pittsburgh area (AGC: 1935-1952; PIT: 1953-2023), this is the 20th driest year [out of 89 years]. Only three years so far in the 21st century have been drier to date (2009, 2016 and 2002), and, of those three, just one significantly drier (2002). It is also the sixth warmest (of the past 89 years): You would think with those statistics, it would at least be "abnormally dry."

I feel like these radar estimates usually come in high, especially over long periods. Pittsburgh Airport has had 24.83" and nowhere in western Pennsylvania is shown below 25 inches. Around the airport, it shows 30-35" with an area of 25-30" just east of there over the city and river valleys. Morgantown is at 26.12", but everywhere in Monongalia County is shown in 30-35" except a small area of 25-30" well west of there and 35-40" in the ridges. It's been a fairly dry year in most of western Pennsylvania too, especially compared to recent years. No drought, but it certainly hasn't been wet.

Since August 3rd, only 7 days have been below normal at Pittsburgh, and only 2 have been more than 3 degrees cooler than normal: August 16 (-1); August 18 (-6); August 19 (-7); August 23 (-2); August 30 (-3); August 31 (-2); and September 1 (-2).

Was reading up on the Mississippi levels last year, and came across this gem from the New Orleans media published in December. The Mississippi River is low, but nowhere near its record | Environment | nola.com Do they realize the Mississippi River is a tidal reach at New Orleans? The levels are maintained by the tides. And sea levels have risen considerably since 1872. It's not at all comparing apples to apples. Here is the past several days worth of river levels at NOLA, which illustrates the tidal component. Levels dropped below 2' overnight, approaching the 1.6' from last year. These values cannot be compared to 19th century values, as sea level rises would prevent those numbers from being possible (except perhaps if drought were to be accompanied by a period of extreme northerly winds and/or a tsunami wave that would pull the water out to sea).

More climate mayhem. The mighty Mississippi is drying up for a second consecutive year. Current gage level on the Mississippi River down to -9.9 feet. This is already third lowest on record, behind 10/21/2022 (-10.81') and 7/10/1988 (-10.70'), but is forecast to continue falling to -10.6 feet by Wednesday. Next week, the river level is supposed to continue below -10 feet, so we could see the lowest flow on record at Memphis in two consecutive autumns. The long-range forecast favors drier than normal conditions across almost the entire basin in the 6-10 day and 8-14 day periods.

Impressive. The gage at Memphis is down to -9.9 feet. This appears to be the third lowest level on record beind 10/21/2022 (-10.81') and 7/10/1988 (-10.7'). It's forecast to drop to -10.6' by Wednesday, before recovering somewhat, but maintaining -9 to -10 feet, before dropping back below -10 feet early next week. The long-range forecast calls for dry weather over much of the basin, so we could make a run at lowest level on record later this month.

Big shocker there. Plan B is to block out the sun. Opinion: We're very far off course in meeting global climate goals. Get ready for Plan B (yahoo.com)nb

NOAA's NCEI has released the August 2023 and Summer 2023 rankings for the contiguous U.S. It was the 9th warmest August, and 15th warmest summer nationally. In Pennsylvania, it was a rather pedestrian 58th warmest summer on record, with a mean temperature of 68.5F, just 0.2F above the 20th century mean. In Chester County, NOAA's official ranking says that it was the 47th warmest summer on record countywide with a mean temperature of 72.5F, 1.0F above the 20th century mean.

Digging a little deeper into the contiguous U.S. data, Louisiana had its hottest summer on record. Texas and Florida both had their 2nd hottest summers on record. The hottest summer on record in Texas was 2011 and the hottest summer on record in Florida was 1998. New Mexico had its third hottest summer on record, behind only 2011 and 2020. Only 5 states were cooler than the 20th century mean (Indiana, Ohio, Kentucky, West Virginia and Tennessee).

With today's data release, NOAA's NCEI has confirmed this to be the 15th warmest summer on record nationally, with a nationwide mean temperature of 73.01F - placing slightly ahead of 1933 and just a hair behind 2007. As noted, only three summers of the 20th century were warmer (1934, 1936 & 1988). National Time Series | Climate at a Glance | National Centers for Environmental Information (NCEI) (noaa.gov)

August was the 9th warmest on record nationwide, with meteorological summer coming in 15th place. While the final ranking is not terribly impressive, it's important to note that only three summers of the 20th century were warmer than this summer nationally (1934, 1936 & 1988).

For more context, the HO-83 artificially inflated daytime maxima by up to 2C in the southwest US on sunny days with light winds (the kind of days characteristic of a place like Tuscon). 2C is huge... it's possible with current instrumentation, there may have only been 4-6 days of 110F+ in those summers. So this is incredibly impressive to be blowing away these old records like this. The HO-83 Hygro- thermometer « Climate AuditThe HO-83 Hygro- thermometer « Climate Audit Inside the HO83 Hygrothermometer « Climate Audit Note: I don't normally link to Climate Audit, but they had some excellent information on this bias in 2007/2008, with a number of links to scientific papers exploring the issue. Their angle was the recent warming was biased by this issue, but obviously time has shown this to be nonsense as it has continued to warm even with improved instrumentation. Of course, as they noted, these ASOS sites are only about 5% of the USHCN sites, so it was a negligible issue to begin with. With that said, it does give reason to be a bit skeptical of some of the extreme heat records set in that era, and there were a number of them.

@donsutherland1 Wow, and the earlier records are likely illegitimate. See 1991 New York Times article on the erroneous temperature readings from the faulty HO-83 hygrothermometer in Tuscon during that era: In Tucson, It's Not the Heat, It's the Thermometers - The New York Times (nytimes.com) This would be like someone not only breaking the baseball steroid-era home run records, but knocking 100 out of the park.

Can you imagine if CXY was still the official observation site like it was in 1961? Looks like CXY is averaging 80.3F so far this month. Wow.

There's no way that's set back anywhere near four times the height of those trees.

Not only that, but you have to question the "statistical tests" he did to confirm the compatibility of his numbers with those of Coatesville and earlier sites in the county. Difference between these numbers for JJA and those for PHL in recent decades: 1982: PHL was 73.0, or 3.2 warmer 1985: PHL was 72.8, or 3.0 warmer 1986: PHL was 75.3, or 3.8 warmer 1992: PHL was 73.9, or 4.9 warmer 1997: PHL was 74.1, or 3.6 warmer 2000: PHL was 73.5, or 3.1 warmer 2004: PHL was 74.4, or 4.0 warmer 2009: PHL was 75.1, or 5.1 warmer 2014: PHL was 75.7, or 6.0 warmer 2023: PHL was 75.8, or 5.5 warmer In the years shown from 1982 to 2004, PHL averaged 3.7F warmer than the co-op site. In the three years since (2009, 2014, 2023), PHL has averaged 5.5F warmer than his figures for East Nantmeal. The only year somewhat comparable difference is 1992, when PHL averaged 4.9F warmer than the co-op site. I suspect that is related to the warm-biased HO-83 hygrothermometer that was in use at first order sites at the time. Since he's started adding his observations to create an "official" time series, the difference between the sites has jumped nearly 2.0F. Obviously, there was no massive increase in UHI in a single year. This would not pass any legitimate statistical scrutiny. If you use the real numbers, the trend is largely the same in recent decades.

Very hit or miss. Nothing in my neighborhood this evening.

Also, when I look at the most recent 14 years (2010-2023), I find a significant warming trend in daily maximum temperatures at Omaha - particularly in June. This is preferable for analysis, since this is the timeframe when the global warming signal just started overwhelming everything else. Compared to 1961-1990, the June maximum over the last 14 years is 2.7F warmer; the July maximum is 0.8F warmer; and the August maximum is 1.3F warmer. Looking at your data for 1991-2020, which shows minimal warming, I would say a linear trend is not a good approximation. This is a hockey stick pattern, with little warming over decades followed by rapid heating in the past 15 years.

The map posted by Brian Brettschneider is mean temperature, not average maximum. Both Des Moines and Omaha have very closely aligned trends and have warmed around 2F in the summertime just over the past couple of decades. The map shows little to no trend in that region. Given the trends match almost exactly, it would appear to be a regionwide warming and not something specific to either site. These are first-order stations that have been in the same location for decades, in two quiet cities that haven't experienced any population growth or significant increase in urbanization since the late 20th century, ruling out the possibility of urban heating effects. Maybe there's no trend if you are taking temperature in the middle of a cornfield, but that's not how the temperature is supposed to be recorded. Could be impacts from shading or improper exposure, similar to New York City's Central Park, which shows smaller warming trends than surrounding areas?

The alleged cool zone doesn't withstand scrutiny. It's warming rapidly in those areas in the summertime at official, first order NWS observation sites.

Des Moines, IA Relative to 1961-1990, the last 14 years at Des Moines have averaged 2.8F warmer in June, 1.2F warmer in July, and 1.7F warmer in August [+2.9, +1.6, +1.7, respectively, compared to 1951-1980].