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.

Looking like some very comfortable dews in the 50s today for the District.

Nice graphic. This depicts exactly what I had said months ago. I know it's not all of the stations, but you've picked a pretty representative 5-site sample, and demonstrated how every station could have a defined warming trend within a certain time frame but the average of all available stations can show a fake cooling trend if warmer stations are replaced over time by cooler ones [or even if simply more "cooler" stations are added to the station mix over time].

And it looks like dewpoints did in fact drop into the 40s and 50s, at least in the places I looked at. Good work by the HRRR!

Looks like the models did pretty well. Lots of triple digits. I saw a cousin was in Birmingham and posted a picture of his car thermometer reading 110!

Very solid numbers statewide, with many locations in the midst of their warmest June in many decades. Harrisburg [3rd warmest to date, warmest since 1943] Williamsport [6th warmest to date, warmest since 1943] Hagerstown, Maryland [just over the border] [3rd warmest to date] Bradford [shorter POR - 1958] [warmest to date] Dubois [shorter POR - 1963] [2nd warmest to date, behind 1967] Scranton/Wilkes-Barre Area [5th warmest, warmest since 1967]

I guess it depends on the level of rarity you wish to achieve. There have been 13 of those at MDT since 2000 - or a little more frequent than once every other year. 5 days of 90+ would be a little more than once every year. But either is better than the traditional 3 days of 90+.

There's a fine line between rare and climatologically impossible.

IMO, the 3-day threshold is more appropriate for places like Pittsburgh, Cleveland, Detroit, Buffalo, Albany, Boston, etc. Not sure why it became the standard in Harrisburg.

The 3-day definition was never intended for very hot climates like Harrisburg. Pittsburgh has had 26 stretches of 3 or more 90F readings in a row since 2000 - an average of about once per year. When people think of a heat wave, they think of a period of heat that is expected to occur about once a year more or less. Harrisburg, on the other hand, has had 75 stretches of 3 or more 90F readings since 2000 - an average of about 3 per year. To get it to that once per year sweet spot, you should be using 5+ days of 90F or more. There have been 28 of those, or just a little more than once per year.

Nobody uses that definition, nor should they. You realize there are only 6 overnight lows of 80F+ in Harrisburg weather history? None on back-to-back nights.

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.

Thanks for the update.

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.

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.

80 degrees already.

000SXUS71 KPBZ 222127RERDUJRECORD EVENT REPORTNATIONAL WEATHER SERVICE PITTSBURGH PA0525 PM EDT SAT JUN 22 2024...RECORD HIGH TEMPERATURE SET AT DUBOIS PA...A RECORD HIGH TEMPERATURE OF 92 DEGREES WAS SET AT DUBOIS PA TODAY.THIS BREAKS THE OLD RECORD OF 91 DEGREES SET IN 2022. THIS ALSO TIES THE ALL-TIME TEMPERATURE RECORD FOR JUNE.$$MILCAREK

Wow! Generational heat in Chester!

000SXUS71 KCTP 212125RERIPTRECORD EVENT REPORTNATIONAL WEATHER SERVICE STATE COLLEGE PA0523 PM EDT FRI JUN 21 2024...RECORD HIGH TEMPERATURE SET AT WILLIAMSPORT PA...A RECORD HIGH TEMPERATURE OF 98 DEGREES WAS SET AT WILLIAMSPORT PATODAY. THIS BREAKS THE OLD RECORD OF 97 DEGREES SET IN 1923.

That 57 near East Berlin (Brrr-Lin) looking mighty nice right about now.

Dewpoint has dropped back into the comfortable 50s.

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.