Pittsburgh, Pa Summer 2024 Thread.

[TimB]

90/50 at that. Rare combo in these parts.

[TheClimateChanger]

1 hour ago, TimB said:

90/50 at that. Rare combo in these parts.

92/51, as of 4 pm. One thing you had pointed out, all of the 90+ readings this year have been 91F or better.  Historically, a disproportionate number of 90+ days have topped out at exactly 90F. It makes a pretty substantial difference if you rank years by days with a high temperature greater than 90F [i.e., 91F or higher]. By that metric, only 9 years in the threaded record had more days strictly above 90F. And only 3 years since 1894 (1988, 20; 1966, 18; and 1952, 17). 2012, 1933 and 1901 also had 15 such days by July 28.

[Ahoff]

Was in Florida all last week.  See we are picking up where we left off, lol.

[TimB]

3 hours ago, TheClimateChanger said:

92/51, as of 4 pm. One thing you had pointed out, all of the 90+ readings this year have been 91F or better.  Historically, a disproportionate number of 90+ days have topped out at exactly 90F. It makes a pretty substantial difference if you rank years by days with a high temperature greater than 90F [i.e., 91F or higher]. By that metric, only 9 years in the threaded record had more days strictly above 90F. And only 3 years since 1894 (1988, 20; 1966, 18; and 1952, 17). 2012, 1933 and 1901 also had 15 such days by July 28.

Statistically it would make sense that there are a lot more days that reach exactly 90 vs. 91 vs. 92, etc., and that the further the departure from normal, the fewer days will top out at that exact temperature. So it’s disproportionate in a way that the mathematical explanation makes sense.

[TheClimateChanger]

Surprisingly made it up to 91F at Butler Regional (BTP) today [a typically cooler part of the metro area], where there's been significantly more sun and the lower dewpoints held off. Only 85 at KPIT, with some scattered showers starting to move into the region.

[north pgh]

Picked up 1.36 inches of rain so far today. Much needed.

[TheClimateChanger]

4 hours ago, north pgh said:

Picked up 1.36 inches of rain so far today. Much needed.

Only about half that in my backyard, but over 3/4” since yesterday afternoon. It’s been a nice rain coming in several brief spurts so no significant flooding issues.

[TheClimateChanger]

12 hours ago, TheClimateChanger said:

Only about half that in my backyard, but over 3/4” since yesterday afternoon. It’s been a nice rain coming in several brief spurts so no significant flooding issues.

Ended up with a bit over an inch of much needed rainfall IMBY yesterday. Monthly tally around 2.5".

Also, decent odds at another 90F day today at PIT, but the recent rains may present a difficulty. Could struggle to exceed 89F with the wetter grounds - maybe our first day to wind up exactly at 90F in 2024?

[TheClimateChanger]

Heaviest rains were from northeast Beaver into southern Butler County, per radar estimates, with as much as 2.5-4 inches over the past two days. Lightest rainfall was in southern Beaver down into Washington County, with less than 0.5 inches. That screw zone just missed the airport area.

[TheClimateChanger]

On 7/1/2024 at 12:40 PM, TimB said:

Here’s 1976-2023:

 

40s in July occurred 9 out of 12 years from 1977-1988 and 14 out of 34 years from 1977-2010, so about once every 2-3 years over that timespan. It’s now been 14 years since we’ve gotten into the 40s in July and I wouldn’t be surprised if none of us see that again in our lifetime.

I'm gonna say no. If you look at data from the 1980s and 1990s, outside of the heat island, it routinely dropped into the 50s on the majority of July nights in western Pennsylvania. Now you get a handful of days in the 50s. There's a lot of gaslighting about this from some, blaming it all on UHI. But if you look at the actual data, you'll see the UHI has always existed. Its just now rural areas have lows comparably to the old UHI lows, and the UHI areas have seen similar increases.

This is July 1988, widely regarded at the time as the hottest summer month since the Dust Bowl. Yes, most areas [besides the Laurel Mountain Ski Lodge] had maximum monthly temperatures in the upper 90s / low 100s but look at the low temperatures. Most areas outside of the UHI were in the 50s. Most locations outside the UHI had absolute minima in the 30s that month, including a low of freezing at Burgettstown on the 2nd.

Now, in the month of July, we get gaslit about how it's 44F at a 4,000' elevation frost hollow at New Canaan, WV, and how that's oh so impressive. What a joke.

[TheClimateChanger]

More shenanigans. Erie, PA... in 1988, the normal July temperature was considered to be 69.1F. Today, it's 72.7F, an absurd 3.6F (2C) warmer. Which is a massive change for a low variability summer month over 3 decades. Literally, a normal July in Erie today would have been considered a very hot July just 35 years ago. Let that sink in.

A normal August at Erie is now 2.4F warmer than a normal July was just a little over 30 years ago, and a normal June less than 1F cooler. The normal low temperature for July is now just a handful of degrees cooler than the normal mean temperature just a little over 30 years ago. And most recent Julys have had mean low temperatures just 2-3F cooler than the normal mean of 1990. Absolutely bonkers.

Sorry for the rants.

[TimB]

45 minutes ago, TheClimateChanger said:

I'm gonna say no. If you look at data from the 1980s and 1990s, outside of the heat island, it routinely dropped into the 50s on the majority of July nights in western Pennsylvania. Now you get a handful of days in the 50s. There's a lot of gaslighting about this from some, blaming it all on UHI. But if you look at the actual data, you'll see the UHI has always existed. Its just now rural areas have lows comparably to the old UHI lows, and the UHI areas have seen similar increases.

This is July 1988, widely regarded at the time as the hottest summer month since the Dust Bowl. Yes, most areas [besides the Laurel Mountain Ski Lodge] had maximum monthly temperatures in the upper 90s / low 100s but look at the low temperatures. Most areas outside of the UHI were in the 50s. Most locations outside the UHI had absolute minima in the 30s that month, including a low of freezing at Burgettstown on the 2nd.

Now, in the month of July, we get gaslit about how it's 44F at a 4,000' elevation frost hollow at New Canaan, WV, and how that's oh so impressive. What a joke.

Hmm, a 17 degree difference between Burgettstown and Pittsburgh International, about a 12 mile distance?

[TheClimateChanger]

1 minute ago, TimB said:

Hmm, a 17 degree difference between Burgettstown and Pittsburgh International, about a 12 mile distance?

Hey, I don't lie when I say the thermometer at PIT was garbage then. Almost like the "urban heat island" became smaller over time.

[TheClimateChanger]

Just compare the PIT mean to the divisional average in 1988. 76.9F versus a divisional average of 73.7F (+3.2F).

In 1998, a very typical July around western Pennsylvania. You'll see it was still in the 50s in most places. But PIT was only 0.4F warmer than the divisional average.

In the interest of full disclosure, you'll see it's started to widen again in recent years. July 2022, for instance, saw a mean of 74.2F at PIT versus a divisional average of 72.9F (+1.3F). But that probably reflects a growing UHI effect in the area.

[TheClimateChanger]

10 minutes ago, TheClimateChanger said:

Just compare the PIT mean to the divisional average in 1988. 76.9F versus a divisional average of 73.7F (+3.2F).

In 1998, a very typical July around western Pennsylvania. You'll see it was still in the 50s in most places. But PIT was only 0.4F warmer than the divisional average.

In the interest of full disclosure, you'll see it's started to widen again in recent years. July 2022, for instance, saw a mean of 74.2F at PIT versus a divisional average of 72.9F (+1.3F). But that probably reflects a growing UHI effect in the area.

As far as the allegation of manipulation to this data made by a certain poster or posters (not here). I find little evidence of any sort of systematic cooling of the past and warming of the present, which is the allegation frequently made. Admittedly, they are slightly different, but not in a way suggesting some sort of manipulation. In fact, if you look at NCDC, you'll see the divisional averages for July 1988, 1998 and 2022 for the Southwest Plateau division of Pennsylvania are all somewhat lower from what was reported in the monthly climate review publication. Now given as 73.4F (-0.3F), 69.7F (-1.1F), and 72.0F (-0.9F), respectively.

[TheClimateChanger]

Has reached at least 87F at PIT today, so far. Still looks like it will be a close one right on the cusp of 89/90.

It is pushing/reaching 90 in the western parts of the county warning area (HLG, PHD & ZZV) where there was less rainfall in recent days.

[TimB]

1 hour ago, TheClimateChanger said:

Has reached at least 87F at PIT today, so far. Still looks like it will be a close one right on the cusp of 89/90.

It is pushing/reaching 90 in the western parts of the county warning area (HLG, PHD & ZZV) where there was less rainfall in recent days.

6 straight 5-min obs of 90 and it’s not even 3:00. I don’t see how we fall short if we haven’t gotten there already.

[TheClimateChanger]

13 minutes ago, TimB said:

6 straight 5-min obs of 90 and it’s not even 3:00. I don’t see how we fall short if we haven’t gotten there already.

Yup, 90F as of the 2:51 pm observation.

[TheClimateChanger]

3 minutes ago, TheClimateChanger said:

Yup, 90F as of the 2:51 pm observation.

16th on the year. 19th most in the threaded record for the YTD [i.e. through July], but most of the higher years were from the 19th century when the thermometer at Pittsburgh was doing "special" things. Tied with 1931 for ninth highest since 1901. Continues to trail only 1988, 1966 & 2012 at the airport site. One higher than 1999 & 1991.

[TimB]

43 minutes ago, TheClimateChanger said:

Yup, 90F as of the 2:51 pm observation.

And another 91. Dewpoints really dropped.

[PghPirates27]

Ended up on Tuesday with 2.66 inches IMBY just NE of Evans city. 

[TheClimateChanger]

7 hours ago, PghPirates27 said:

Ended up on Tuesday with 2.66 inches IMBY just NE of Evans city. 

Nice. Your area looked like one of the jackpots on radar. The CoCoRAHS site in Saxonburg had 2.96 inches, I think.

[TimB]

17 hours ago, TheClimateChanger said:

16th on the year. 19th most in the threaded record for the YTD [i.e. through July], but most of the higher years were from the 19th century when the thermometer at Pittsburgh was doing "special" things. Tied with 1931 for ninth highest since 1901. Continues to trail only 1988, 1966 & 2012 at the airport site. One higher than 1999 & 1991.

If you ascribe to the theory that 91F is no more arbitrary than 90F (which is indisputably true), then we’re actually ahead of 2012 for 91F days through 7/31 and only trailing 1988 and 1966.

Further, 14 of those 16 days have reached 92F. Since 92F is also no more arbitrary than 90F, we’re behind only 1988 for 92F days through the end of July.

(at Pittsburgh international)

[TheClimateChanger]

Looks like CPC is on board with a cooler period next week, so today might be the last opportunity for a 90F for awhile, although Sunday and Monday might be close but right now look like mid to upper 80s. We're sort of on the edge of the cooler than normal area, so it might not be super cool but 90+ weather certainly looks unlikely during that stretch.

[jwilson]

Certainly clashes with their hot August prediction.  Would have to mean the latter half of the month is much warmer.

[TimB]

I think there’s a lot to be resolved, as we’re trapped between cooler air with an eastern Canadian trough and the warm airmass already in place. Models and ensembles have already moved away from any extended period of cooler weather, but it seems it might be possible a front could dive down later next week and give us a few days near to slightly below normal. But I don’t see the 8-14 day period being below normal on the whole and in fact the CPC has already reversed course on that with today’s outlooks.

[TheClimateChanger]

Looks like another 91F high today.

[TimB]

I don’t think we can hit just 90 anymore.

[TimB]

A swath of 1.5” to 2” rainfall amounts this morning in the N/W half of the county with near zero in the S/E half.

[TheClimateChanger]

So far, the rain today has stayed just to my north, other than maybe a few sprinkles. Been hearing thunder for about an hour.

Not far outside of our area, Akron-Canton Airport had 4.07" of rain in 1 hour and 25 minutes, between 10:20 and 11:50 am. So these storms are very capable of torrential downpours and flash flooding.