GaWx

 On July 4th, the DMI mean Arctic temp finally reached and exceeded 0C with it at +.01C. That sets a new record latest 1st above freezing as it replaces the old record latest of June 20th, which had been set in 2013.

23 hours ago, GaWx said:

As of July 2nd per the DMI data, the mean Arctic temperature based on 80N+ has still not quite reached freezing although it was only barely below it yesterday. Going back to 1958, the latest day it first hit freezing before 2026 was way back on June 20th (2013)!

Daily Mean Arctic temp. in degrees Kelvin:  freezing is at 273.15 (July 2nd was 0.1C below freezing):

0260618 169 272.561676
20260619 170 272.634399
20260620 171 272.647522
20260621 172 272.469360
20260622 173 272.153870
20260623 174 271.679565
20260624 175 271.918213
20260625 176 272.421326
20260626 177 272.655334
20260627 178 272.803802
20260628 179 272.680786
20260629 180 272.732056
20260630 181 272.903717
20260701 182 272.963715
20260702 183 273.045624

https://download.dmi.dk/pub/plus80N_temperatureindex/meanT2026_running.txt

July 3rd cooled back very slightly. So, the DMI 80N+ mean Arctic temp still hasn’t reached 0C! The old record latest was 6/20/2013.

At 1:40 told me that she was in one of the worst popup thunderstorms she’s ever experienced while driving with high winds, very heavy rain, and small hail in Buckhead near Roswell Rd! Temps suddenly plunged from a sunny 90s to 72 on her car therm! It ended about as fast as it started.

29 minutes ago, michsnowfreak said:

Most expansive heatwave in history? Lmao. I guess the 1930s-50s just removed themselves from history. Not to mention 1988, 1995, 2012, etc

Very intense? Absolutely! One of the most expansive? No way! That along with trying to connect the developing super-Nino with summer heat made his post bad to me.

 But then Chris Martz had a terrible reply, himself, when he downplayed the U.S. and European heatwaves by saying “It’s called ‘summer’”. Also, he criticized Jeff’s use of the term “heat dome” for the heatwaves even though it has been used frequently in the pro-met community for decades!

 So, both of them, who are looking at this from opposing standpoints more or less, looked bad here imho.

CFS 10 day mean relative prog is at a new record high prog for its Nov peak in 3.4:

SON/OND peak +3.2 vs +3.1 earlier vs +2.5 record (1982):

N peak +3.4 vs +3.3 earlier vs +2.7 record (1982):

As of 10AM, Philly is 4F warmer than 24 hours ago (94 vs 90)!

As of July 2nd per the DMI data, the mean Arctic temperature based on 80N+ has still not quite reached freezing although it was only barely below it yesterday. Going back to 1958, the latest day it first hit freezing before 2026 was way back on June 20th (2013)!

Daily Mean Arctic temp. in degrees Kelvin:  freezing is at 273.15 (July 2nd was 0.1C below freezing):

0260618 169 272.561676
20260619 170 272.634399
20260620 171 272.647522
20260621 172 272.469360
20260622 173 272.153870
20260623 174 271.679565
20260624 175 271.918213
20260625 176 272.421326
20260626 177 272.655334
20260627 178 272.803802
20260628 179 272.680786
20260629 180 272.732056
20260630 181 272.903717
20260701 182 272.963715
20260702 183 273.045624

https://download.dmi.dk/pub/plus80N_temperatureindex/meanT2026_running.txt

2 minutes ago, hooralph said:

i thought I saw KNYC tied the record high low at 84, but the hourly obs say 84.9. Did we tie or break it?

Per this, the lowest at NYC as of 8AM today was 84:

https://forecast.weather.gov/data/obhistory/KNYC.html

 At C Park, the lowest so far today is 84. IF that were to hold up through 11:59PM, it would tie the all time highest low there on record! 

18 minutes ago, NorthHillsWx said:

I stand corrected. 104+ anywhere up there is insane 

 Indeed! I’m not at all trying to minimize the heatwave in the NYC area. There has been some talk about Central Park running a couple of degrees cooler for highs than in the past due to increased foliage (showing the cooling power of foliage). Even so, 100F with increased foliage is obviously still very intense. Also, C Park had a low of only a ridiculous 82 yesterday!

 At C Park, the lowest so far today is 84. IF that were to hold up through 11:59PM, it would tie the all time highest low there, which goes way back to 1869! 

2 hours ago, NorthHillsWx said:

NYC hit 104 yesterday at both LGA and Central Park 

 Whereas La Guardia did hit 104 and Newark hit 105, the official Central Park high actually was “only” 100.

28 minutes ago, olafminesaw said:

Round 2 in 10 days?

 Once again the GFS (6Z) is way too hot in the extended. Even if H5 reaches the near record high upper 590s as it has, highs on July 14-15th will not reach anywhere near as hot as this shows even with the drought:

6Z GFS July 14th highs: for example 112 at SAV is loltastic as that’s compared to the 105 all-time hottest on record there back 155 years!

6Z GFS July 15th highs: also not going to happen

17 minutes ago, bluewave said:

This is the first time that a number of stations in the East approached their all-time warmest temperature with a developing super El Niño. 
 

Maximum 1-Day Mean Max Temperature 
for Poughkeepsie Area, NY (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Last value also occurred in one or more previous years.
Period of record: 1931-01-01 to 2026-07-02
1	104.0	1933-08-01 through 1933-08-01
2	103.0	2026-07-02 through 2026-07-02
-	103.0	2001-08-09 through 2001-08-09
-	103.0	1995-07-16 through 1995-07-16
-	103.0	1966-07-03 through 1966-07-03
-	103.0	1936-07-10 through 1936-07-10
3	102.0	2011-07-22 through 2011-07-22
-	102.0	2010-07-06 through 2010-07-06
-	102.0	1991-07-20 through 1991-07-20
-	102.0	1991-07-19 through 1991-07-19

 

Maximum 1-Day Mean Max Temperature 
for New York-LGA Area, NY (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Last value also occurred in one or more previous years.
Period of record: 1939-10-07 to 2026-07-02
1	107.0	1966-07-03 through 1966-07-03
2	104.0	2026-07-02 through 2026-07-02
-	104.0	2011-07-22 through 2011-07-22
-	104.0	2001-08-09 through 2001-08-09
2	103.0	2010-07-06 through 2010-07-06
-	103.0	1995-07-15 through 1995-07-15
-	103.0	1948-08-26 through 1948-08-26
4	102.0	2006-08-02 through 2006-08-02
-	102.0	1953-09-02 through 1953-09-02
5	101.0	2025-06-24 through 2025-06-24

 

Maximum 1-Day Mean Max Temperature 
for Philadelphia Area, PA (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Last value also occurred in one or more previous years.
Period of record: 1873-12-04 to 2026-07-02
1	106.0	1918-08-07 through 1918-08-07
2	104.0	1966-07-03 through 1966-07-03
-	104.0	1936-07-10 through 1936-07-10
3	103.0	2026-07-02 through 2026-07-02
-	103.0	2011-07-22 through 2011-07-22
-	103.0	2010-07-07 through 2010-07-07
-	103.0	1995-07-15 through 1995-07-15
-	103.0	1966-07-04 through 1966-07-04
-	103.0	1936-07-09 through 1936-07-09
-	103.0	1930-07-21 through 1930-07-21

 

Maximum 1-Day Mean Max Temperature 
for Reading Area, PA (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Last value also occurred in one or more previous years.
Period of record: 1888-01-01 to 2026-07-02
1	106.0	2011-07-22 through 2011-07-22
2	105.0	1918-08-07 through 1918-08-07
3	104.0	1918-08-06 through 1918-08-06
4	103.0	2026-07-02 through 2026-07-02
-	103.0	2012-07-07 through 2012-07-07
-	103.0	1966-07-03 through 1966-07-03
-	103.0	1898-07-03 through 1898-07-03
5	102.0	2011-07-21 through 2011-07-21
-	102.0	2010-07-06 through 2010-07-06
-	102.0	1988-07-17 through 1988-07-17

 This jibes with my response 3 posts above yours to Jeff B.’s implied false connection of the current developing super-Nino to increased very intense heat in the E US based on his Tweet. Only the summer of 1991 was hot overall in the E US as I said, which is essentially agreed with by your lists. I’m referring to Poughkeepsie’s 102 on 7/19/1991. None of the other developing super-Ninos prior to 2026-7 are on any of your 4 lists.

3 hours ago, LakePaste25 said:

I think the sample size for pre-super Nino summers is simply too small. That rockies ridge is definitely coming from central pacific forcing. 

 I don’t agree at all with Jeff B. implying a connection of super-Nino and the current E US heatwave. The mean temp in July (and also in summer as a whole) comes out close to normal rather than hot in the E US when averaging RONI based super strong El Niños. Hardly any were hot. 1957, 65, 72, and 97 were slightly cool. 1982 and 2015 were NN. Only 1991 was hot. That’s just 1 of the 7! That’s enough for me to say that the upcoming super-El Nino in combo with GW is not the direct cause for the current E US heatwave as Jeff said. GW, by itself, obviously favors hotter heatwaves than when the Earth was cooler. But the supposed super-El Nino piece of this, itself, correlating to E US summer heat does not compute to me at all.

 I also don’t at all agree with Jeff calling this one of the most expansive U.S. heatwaves. That’s simply not true. Intense in the VA to Boston corridor? Yes. But not one of the most expansive U.S. heatwaves.

1 hour ago, so_whats_happening said:

@Rjay @GaWx

I think are the only 2 that have not submitted. Up to folks how they want to handle the late entries (quite a few by just a few hours). I’ll be back early on the 5th so I should be able to post updates, iffy connection at times so hopefully this goes through. Happy 4th everyone!

Thank you, but I don’t think I’m going to do July. I’m currently too busy to take enough time to analyze the data (forecast and historic) well.

3 hours ago, donsutherland1 said:

For the U.S., one hasn't typically seen such heat domes during summers preceding strong/super El Niño events. Such events have been far more common in Europe and Asia. However, during 2015 (Pacific Northwest) and 2023 (July-August in the Southwest/South Central) such domes appeared. Whether these recent events suggest that things are changing in the warming climate (especially more expansive marine heatwaves) remains to be seen. A sample size of two is too small to draw firm conclusions.

Thanks, Don. I’ll reiterate that I was referring to only E US rather than all of the U.S. mean temps (especially in July) and that I didn’t even consider 2023 because it was only borderline moderate/strong on a RONI basis with a peak of only +1.49. So, 2015, with its heatwave in the Pacific NW (nowhere close to the E US) and 2023  not being nearly strong enough to count as super-Nino per the now official (per NOAA) RONI basis don’t even count for me against super El Niño E US heat. And even if 2023 were counted, its heat was most concentrated in the SW/SC rather than E US.

 I’ll reiterate that I thought Chris Martz looked really bad due to saying “it’s called summer” and for saying “heat dome” wasn’t the correct term. However, I also said Jeff B. was wrong for calling the current/upcoming US heatwave one of the most expansive in history. Here again is Chris’ post responding to Jeff:

 But I forgot to earlier mention this: The mean temp in July (and also in summer as a whole) comes out close to normal rather than hot in the E US when averaging RONI based super strong El Niños. See image below. Hardly any were hot. 1957, 65, 72, and 97 were slightly cool. 1982 and 2015 were NN. Only 1991 was hot. That’s just 1 of the 7! That’s enough for me to say that the upcoming super-El Nino in combo with GW is not the direct cause for the current E US heatwave as Jeff said. GW, by itself, obviously favors hotter heatwaves than when the Earth was cooler. But the supposed super-El Nino piece of this, itself, correlating to E US heat does not compute to me at all. Thus whereas I thought Chris’ post was terrible, I also think Jeff’s was pretty bad, itself. 

@donsutherland1

As bad as it will be in much of the SE, consider that the NYC forecasted low for July 4th is a very oppressive 81 F!

19 hours ago, ORH_wxman said:

As of 6/29, 2026 sea ice area is 7.09 million sq km. This is currently 5th lowest:

 

2012: -380k

2010: -280k

2019: -170k

2024: -40k

2011: +2k

2020: +4k

2025: +10k

 

Still another day or two before I run the numbers but a new record is nearly ruled out. Top 3 is definitely still on the table. 

 
Thanks. Looking forward to your update.

 Per the following source (AMSR2), the current Arctic ice area is now getting pretty low with it a bit lower than 2020 and 2016, ~0.5 million sq km lower than 2024, and ~0.4 million sq km lower than the 2013-24 mean. Do you know anything about the reliability of this source?
 

 The CFS AAM forecast at the site I follow just updated for the first time in 6 days:

Prior run there is 0Z of 6/25: strongest multi week mean I’ve ever seen/saved with it way up at a mean of +2.8 to +3.3 July 8th to end of run, which is July 29th:

 Brand new run (0Z of 7/1): still a very strong +AAM but not surprisingly no longer to the near record breaking levels of the 0Z 6/25 run as mean is ~+2.5 on July 8th instead of +2.8, mean then has a near term peak of ~+2.65 on July 12th-13th, and then it’s mainly low to mid +2s July 14-29th instead of +2.8 to +3.3:

14 minutes ago, bluewave said:

That’s the ONI scale which is only around tenth of a degree C° warmer from a 27.8 to a 27.9 average than 1981-2010.
 

 

Thanks, Chris. I believe that would make the most up to date relative ENSO anomalies ~0.6C cooler than 1981-2010 anomalies in June. Is that incorrect?

 Please post July ‘26 obs from your area as well as current wx events/obs in July for other areas. It’s going to be quite hot with some records possibly being threatened especially in NC during the first part of the month.

@buckeyefan1please pin this. Thank you.

Just now, bluewave said:

I don’t think the overall picture would change much since the 1981-2010 climo isn’t any different along the equator in the Pacific ENSO regions.

Relative ENSO region anomalies are currently ~0.5 C cooler than 1991-2020 anomalies and likely ~0.6 to 0.7C cooler than 1981-2010 anomalies.

1 hour ago, bluewave said:

While the CanSIPS hasn’t had much skill with long range ENSO 500 mb patterns and temperatures over the CONUS, it will be interesting to see if it has some clue about the SST configuration.

Notice how the much warmer the Indio-Pacific warm pool becomes following this super event than it initializes at the current time. My guess is the big baseline global temperature jump it has warms the SSTs.

There is some cooling immediately near Japan. But the warm pool gets pushed a little east.  Also notice how much warmer the Atlantic basin becomes. The extended CFS runs are doing something similar with the SSTs. 

The ENSO region would probably be the strangest look of all. Notice how skinny the developing La Niña cold tongue is by next June around the Galápagos Islands. It’s surrounded by continuing Nino-like waters just off equator. 
 

Note that this is based on very outdated 1981-2010 climo. If instead it were using relative climo, that skinny La Niña tongue wouldn’t be as skinny since it would be compared to much more up to date warmer climo taking into account avg. warming of global tropical waters from GW. For the same reason, the surrounding tropical waters’ anomalies there wouldn’t be as warm.

 My total rainfall in June was ~5.35”.