Pittsburgh, Pa Summer 2024 Thread.

[TheClimateChanger]

Looking solid. 

 

[TheClimateChanger]

Up to 91F at the airport. My home station is baking but I think it gets heat from the balcony rail I have it installed on.

Might still reach a respectable 92 or 93 officially today. I still think Saturday will probably wind up being the hottest day of this stretch. Should at least tag an official 3-day heat wave today through Saturday, with Sunday being a toss-up at this point. This area does seem to perform better directly ahead of the cold front, so I think if convection can hold off, we should be able to do it.

[jwilson]

I know the air temps haven't hit particularly notable highs, but it definitely feels disgusting outside.  I struggled to hit 3 miles and felt like I was dying.

This is good watermelon weather.

[Ahoff]

4 hours ago, TimB said:

90 might be in trouble again today. I do think we get there, but still a far cry from historic.

Yeah, this is run of the mill summer heat.  I won’t be buying anything the NWS hypes up anymore, lol.

[TheClimateChanger]

Sounds like Saturday is going to be a scorcher. 25th percentile NBM temperatures in the mid 90s, with H85 temperatures climbing to 22-24C. 75th-90th percentile temperatures must be pushing triple digits. Record highs are 95 for tomorrow, and 98 for Saturday (also the monthly record). Record max lows are 73F and 75F, respectively.

The upper ridge will then begin to retrograde slowly on Saturday but
still hold strong enough for one more day providing a continuation
of the dangerous heat, and perhaps the hottest day with even the NBM
25th percentile suggesting mid 90s. Ensemble 850 mb temperatures
still remain in the 22-24C range. Some records may be challenged.
Due to the compounding effects, continued heat indices at and above
100 degrees, and the WPC heat risk tool showing major to extreme
impacts, the heat headlines remain in effect through Saturday.
That said, as with the past several days, some subtle weaknesses in
the flow as the ridge axis pulls south could allow for isolated to
scattered afternoon convection to throw wrinkles in the heat, but
predictability in coverage and location is low probability at this
time range.

[Ahoff]

42 minutes ago, TheClimateChanger said:

Sounds like Saturday is going to be a scorcher. 25th percentile NBM temperatures in the mid 90s, with H85 temperatures climbing to 22-24C. 75th-90th percentile temperatures must be pushing triple digits. Record highs are 95 for tomorrow, and 98 for Saturday (also the monthly record). Record max lows are 73F and 75F, respectively.

The upper ridge will then begin to retrograde slowly on Saturday but
still hold strong enough for one more day providing a continuation
of the dangerous heat, and perhaps the hottest day with even the NBM
25th percentile suggesting mid 90s. Ensemble 850 mb temperatures
still remain in the 22-24C range. Some records may be challenged.
Due to the compounding effects, continued heat indices at and above
100 degrees, and the WPC heat risk tool showing major to extreme
impacts, the heat headlines remain in effect through Saturday.
That said, as with the past several days, some subtle weaknesses in
the flow as the ridge axis pulls south could allow for isolated to
scattered afternoon convection to throw wrinkles in the heat, but
predictability in coverage and location is low probability at this
time range.

They’ve said that for everyday this week, lol.  Believe it when I see it.

[TheClimateChanger]

Baking today. PIT ASOS popping an 88F at 10:25.

[Rd9108]

My parents were telling me this heat wave is nothing compared to 1988 when my brother was born. Had to look up the stats for myself and wow they weren't kidding.

 

[TheClimateChanger]

Record high of 90F at DuBois - likely to rise higher. That's the fifth consecutive daily record. Even for a relatively small period, very impressive. Good chance of matching or exceeding the monthly record of 92F, set on June 30, 1969, and earlier in this heat stretch (June 18, 2024). That's also 4 90+ readings on the year. For context, only 6 entire years since 1962 have seen more 90+ days, and this is only June 21! Those 6 years are: 1988, with 20; 2020 & 1966, with 8 each; 2010, with 6; and 2016 & 2011, with 5 each.

Odd how 1800' elevation is obliterating records from 1988 & 1994, but they claim it was so much hotter in Pittsburgh. Like they are going to toe to toe with the 1994 heat episode, and breaking records set during that stretch by noon every day. Seems strange to me. 

[TheClimateChanger]

Dewpoint has dropped back into the comfortable 50s.

[Ahoff]

Looks like another 94.

[TheClimateChanger]

 

[TheClimateChanger]

 

[RitualOfTheTrout]

On 6/21/2024 at 10:36 AM, Rd9108 said:

My parents were telling me this heat wave is nothing compared to 1988 when my brother was born. Had to look up the stats for myself and wow they weren't kidding.

 

I dont disagree this hasn't quite been "historic heat" per se, but given we are getting it in mid June vs July and August which is more typical plus the duration still makes this a rather unusual setup. If this setup reoccurs later in July or August Id bet we get upper 90s. Of course cloud cover / storm development also threw a wrench in the forecast.

Just like in winter, you dont always maximize a great pattern for a big storm I guess.

[Mailman]

I think today has been hottest day.

[Ahoff]

Looks like we're stalling a little bit.  May not officially pass 94.  It might get close.

[north pgh]

A nice little downpour just popped up over me. Nice to wet the dry grass. I’ll take it. Only lasted 5 or ten minutes. A solid .02. lol 

my temp went from 95 to 88.

[TheClimateChanger]

80 degrees already. 

[Ahoff]

3 hours ago, TheClimateChanger said:

80 degrees already. 

Shouldn’t be too much longer and it’s over, lol.

[Mailman]

 

Mesoscale Discussion 1383
   NWS Storm Prediction Center Norman OK
   1242 PM CDT Sun Jun 23 2024

   Areas affected...Portions of the Ohio River Valley into southern New
   York

   Concerning...Severe potential...Watch likely 

   Valid 231742Z - 231945Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Severe storm risk will gradually increase through the
   afternoon, with damaging winds being the primary concern. A watch
   will likely be issued for parts of the area in the next few hours.

   DISCUSSION...Ahead of a northeast/southwest-oriented cold front
   draped across the OH River Valley, a corridor of upper 60s to lower
   70s dewpoints and pockets of heating will contribute to moderate
   surface-based instability -- despite poor midlevel lapse rates
   sampled by 12Z observed soundings. As modest midlevel height falls 
   overspread the region, surface-based thunderstorms should gradually
   increase in coverage along/ahead of the cold front. 

   Storms should slowly increase in intensity as they track eastward
   and intercept the destabilizing warm/moist sector. Given ample
   deep-layer westerly flow/shear (around 35-kt effective shear)
   roughly perpendicular to the front, a mix of loosely organized
   clusters and transient supercells are expected. Steepening low-level
   lapse rates and the enhanced low/midlevel flow will favor locally
   damaging gusts as the primary concern, especially with any localized
   upscale growth. However, marginally severe hail and a tornado or two
   cannot be ruled out, especially with any sustained semi-discrete
   supercells. A watch (potentially two separate watches) will likely
   be issued for parts of the area in the next few hours.

   ..Weinman/Hart.. 06/23/2024

[TheClimateChanger]

Say what you will about the heat wave underperformance but the most recent 7 days will indeed be the hottest 7-day stretch [as measured by average mean temperature] in 29 years at Pittsburgh International Airport. Indeed, the hottest 7-day period since the ASOS has been installed.

A lot of these are duplicates, i.e. longer single hot stretches that had multiple different 7-day periods. For context, the 82.0F mean only includes 6 days. But today's high was 86, low so far 75. Estimating the low will drop to 70F by 1 am, we get 82.0 x 6 + 78 = 570 / 7 = 81.4F. Not sure how plausible it is that we had stretches on this list from 1987, 1988, 1991, 1993, 1994 and 1995 in a narrow 10-year window with a known warm biased thermometer, but I'll leave that conspiracy hat off for now. The 1948 & 1952 periods are actually from AGC, even though incorrectly included in this dataset. The only other comparable 7-day means at Pittsburgh International (not in the aforementioned 10-year period) are the 7-days ending 7/21/1980 & 9/3/1953.

[TheClimateChanger]

Using the entire threaded record (1875-2024), including the downtown city office records, and the expected value of 81.4F, this will be the hottest 7-day period ever wholly in June behind only 1994 (7-days ending 6-19, 6-20, 6-21, and 6-22). While the magnitude might have been exaggerated, and this might be an unpopular opinion, the NWS did correctly indicate that this would be the hottest stretch in June since 1994 [although it clearly did not exceed 1994, even though they distinctly indicated that was a possibility]. And they made that forecast with several days lead time.

Actually, from the above graphic, you can see the 7-day period ending yesterday already on this list with a mean 80.6F, which alone makes it the highest in the month of June behind only the 4 dates from 1994, and one week each in 1888 and 1952 [and tied with the week ending 6/30/1933 & 6/24/1884]. As noted, the 7-day period ending today should be even higher and likely finish around 81.4F.

[jwilson]

It will be interesting to see if the heat comes back, perhaps even worse, in July or August.  The high temp outlooks in the near future seem to have shifted to the southeast, and there's no more sudden onset of the heatwave.  There's some signs in the further long range (10 days), but I don't trust those at this lead time.

[TheClimateChanger]

9 hours ago, jwilson said:

It will be interesting to see if the heat comes back, perhaps even worse, in July or August.  The high temp outlooks in the near future seem to have shifted to the southeast, and there's no more sudden onset of the heatwave.  There's some signs in the further long range (10 days), but I don't trust those at this lead time.

Well, Mark Margavage says unlikely, but I'm not too convinced by the logic employed to reach that conclusion. 

I did a little more analysis, looking at years with similar or warmer Junes over the past 100 years or so [excluding any 19th century records]. Specifically, I looked at 1919, 1925, 1934 (downtown city office), 1943 (AGC), and 1967 & 1994 (PIT). You could make the case for 1988 - it had 8 90+ days in June - but it was characteristically different than the other years. In fact, it was decidedly cooler than the present normal for June and nearly 4F cooler than this year on a to-date basis. So despite the periods of extreme heat, it wasn't a particularly warm month overall. Obviously, 1988 would somewhat buck the trends presented and instead look like a more extreme version of 1934 that carried straight through August.

Overall, the historical data following very warm Junes would, in fact, suggest the worst is probably over. 1919 & 1934 both saw one impressive heat wave in July. There were four days of 90+ in a row from 7/2/1919 to 7/5/1919, and 7 of 8 in 1934 from the 19th to 26th. That was regarded as one of the worst heat waves ever for much of the country with widespread 100s, but downtown Pittsburgh topped off at 98 on the 24th, and in classic fashion, had an 89 right in the middle disrupt what could have been an 8-day heat wave.

Overall, July looked fairly typical other than 1934. The city office means and maximum temperatures from that era are no doubt elevated relative to what would be observed at the airport locations. August was decidedly cooler than modern normals, with no extreme heat in any of the months. In fact, only 4 days of 90+ spread across the 6 years [and only 1 day that actually exceeded the 90 degree mark].

In any event, historically, very warm Junes in Pittsburgh have not served as a prelude to a non-stop blazing inferno the rest of the summer. In fact, the majority of years, temperatures were relatively moderate, with at most one more stretch of extreme heat seen.

 

[Ahoff]

5 hours ago, TheClimateChanger said:

Well, Mark Margavage says unlikely, but I'm not too convinced by the logic employed to reach that conclusion. 

 

Yeah, that's a pretty stupid reasoning.  July and August are warmer months than June on average, that kind of heat can happen again during those two months.

 

Anyway, CPC thinks the 1st week of July could be toasty.

[TheClimateChanger]

Rest Of Today

Partly sunny late this morning, then mostly cloudy with scattered thunderstorms this afternoon. Some thunderstorms may be severe with damaging winds, small hail, heavy rainfall, and tornadoes. Highs in the mid 80s. Southwest winds 10 to 15 mph. Chance of precipitation 50 percent.

Tonight

Considerable cloudiness. Thunderstorms and showers likely in the evening, then a slight chance of showers and thunderstorms after midnight. Patchy fog. Some thunderstorms may produce damaging winds, small hail, heavy rainfall, and tornadoes in the evening. Humid with lows in the lower 60s. Northwest winds 10 to 15 mph, becoming west around 5 mph after midnight. Chance of rain 70 percent.

[TheClimateChanger]

Rare to see them trot out the "t" word, especially with SPC not even giving us a 2% chance.

[Mailman]

5 minutes ago, TheClimateChanger said:

Rare to see them trot out the "t" word, especially with SPC not even giving us a 2% chance.

Think they're covering their butts now from May.

[TheClimateChanger]

It could be SPC that’s asleep at the wheel.

 

[KPITSnow]

Surprised we have a severe thunderstorm watch. Would imagine will be tough for much to develop with this cloud cover.