GaWx

 The March ‘26 is easily headed to a record high for March (back to 1950). The current record is +1.85 (1989).

 Based on actual dailies March 1-22 and GEFS progs for March 23-31, I believe that the range of possibilities is +2.4 to +3.4. Remember to multiply the dailies by 2 to estimate the monthlies. The highest of any month is Nov of 1992’s +2.63. That is likely to be exceeded  (75% chance as of now).

Monthly NAO:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

3 hours ago, MJO812 said:

Timber just in time for April

Thanks, Anthony.

 I hope they really timber! But the “timber” of the AO and NAO means are still just to neutral. The means were timbering to actual negatives starting around now that were shown 8 days ago per the images below vs today’s bringing them down to just neutral and not til early April: they’re verifying now WAY more + than those timbering progs to negative. Thus they get an easy F grade:

I just realized Chris Martz is a meteorologist, which you must know. I had assumed he wasn’t. Now I’m more surprised he made those errors about 1879! A pro met doing that? Shouldn’t he have known better?
 

 He’s not an AGW denier, however, per the following link. Instead he seems to be in the category of non-alarmist AGW believer. His beef doesn’t seem to be with AGW, itself, but instead it seems to be with AGW alarmists.

@donsutherland1is my assessment correct in your opinion?

 Quoted from link below: do you think he’s being sincere here? Is it possible he’s possibly making a fact based case?

The magnitude of warming and the rate at which it occurs make all the difference in

whether global warming is cause for alarm that requires economic decarbonization

and/or large-scale interventions like SRM, or is largely unimportant in terms of

environment and public health.

Just how much warming will occur is dependent on “equilibrium climate sensitivity”

(ECS), which is the amount of warming that results from doubling atmospheric CO2

levels plus any feedbacks that amplify or dampen the slight increase in temperature

caused directly by CO2 and other greenhouse gases (GHGs).

• If ECS is ≥3°C, then the climate system is highly sensitive to GHGs, and climate

warming is therefore a concern.

• If ECS is <3°C, then the climate system is largely insensitive to GHGs, and

warming impacts are exaggerated. This seems to be the likely case given that

we have not seen increases in most types of extreme events, climate models

overestimate warming (U.S. DOE CWG, 2025)[30] and the state of human welfare

has never been better than it is today by nearly every measurable metric.

https://oversight.house.gov/wp-content/uploads/2025/09/Martz-Written-Testimony.pdf

10 minutes ago, donsutherland1 said:

No. He blocked me when I corrected him in the past for misrepresenting data and provided links to the actual data. I did post the correct MWR data on Twitter/X in a thread in which he's copied.

 So, would he have seen your corrections regarding the current heatwave? If so, does that mean he no longer could be ignorant of the facts about it? Could he instead be outrightly lying and intentionally trying to deceive?

31 minutes ago, donsutherland1 said:

Yes. that's correct regarding San Diego and Los Angeles. That's why I referred to it as a "localized heat event in southern California." Some heat came eastward into a portion of Arizona (Yuma's 100° reading), but this wasn't the kind of widespread heatwave like the ongoing on. It was nowhere near as intense as the ongoing one.

Unfortunately, the maps have a a nine-hour gap between observations and there isn't a larger set of observations. I suspect that the offshore winds winds seen north of Los Angeles at the 4:35 am PDT observation sank south after that observation. The wind then turned onshore shortly before the 1:35 pm PDT observation, as the temperature was still 97° in the Los Angeles area. 

 

 Thank you, Don. I corrected my mentions of SE winds to the correct SW winds.

 I agree with you on all of this.
 

 Have you by chance replied to Chris Martz? I can’t tell because I’m not a registered X user.
 In case you haven’t seen these followup tweets, here are two he did:

and he then posted this saying his posting of “facts” “makes people angry”: 

2 hours ago, donsutherland1 said:

As was the case last year when Phoenix reached an August monthly record high of 118°, an ignorant handful are attempting to dismiss the magnitude of the ongoing unprecedented March heatwave. In this case, the effort is to transform what was very likely a localized heat event in southern California due to possible offshore winds into an epic regionwide heat event that surpassed the ongoing heat event that has toppled March and April records in many locations in the West.

The above post also applies projection, accusing the news media, of not doing "much digging." In fact, the post demonstrates dismal research skills. 

The question concerns whether Phoenix ever reached 112° in March during 1879. That heatwave was likely referenced, because Phoenix's daily records go back to August 1895. Thus, the underlying assumption was that one could not credibly question the claim. 

That's not true.  Several approaches apply.

1) Is there any credible data for Phoenix from March 1879?

Yes. Monthly Weather Review published monthly maximum and minimum temperatures for select locations. Below is the Monthly Weather Review report for March 1879.

I highlighted Phoenix and Tucson, as one can make a comparison to the current heatwave. The monthly high temperatures for Phoenix and Tucson during the current heatwave are 105° and 102° respectively, vs. the 94° and 90° in March 1879. 

2) If there were no credible data (not the case here), are there any reliable records from this period in the relevant area? 

Yes. Yuma's climate record goes back to January 1878. Yuma's monthly maximum temperature for March 1879 was 100° on March 29, 1879. Yuma's highs are typically above those of Phoenix. For example in the current heatwave, Yuma had a peak high of 109° vs. Phoenix's 105°. 

One could also construct a regression equation to estimate Phoenix's high based on Yuma's data. Since one is dealing with pre-urban Phoenix, I chose the earliest 30-year period of each site's overlapping record (March 1896-March 1935).  The regression equation was (0.908 *Yuma's Maximum) +3.152. The standard error was 3.33°. The coefficient of determination was 0.833.

So, what happens when one calculates the estimated highs for Phoenix based on the Yuma's March 3 high of 81° and its March 29 high of 100°. The end result is an expected high of 77° (76.7°) on March 3 and a high of 94° (94.0°) on March 29.  

The statistical data reveal that there was virtually no chance that Phoenix was 112° during March 1879. In fact, the statistical data matches the actual monthly high.

Major Findings:

Note: Actual data is the Monthly Weather Review monthly maximum temperatures for Phoenix and Tucson and daily data from Yuma's climate record.

What happened?

More than likely Martz was using data from a thermometer that was exposed to direct sunshine. Amateurs accept such data at face value. They have little understanding of issues that could compromise the data or little understanding about conducting research. Those with motivated reasoning embrace such data when it confirms their biases. 

Researchers ask questions concerning whether reliable data exists for the specific location, whether reliable data exists for nearby locations, etc. If reliable data is present for nearby locations, but not the specific location, they construct models based on the relationship of those nearby locations and the specific location in question. Afterward, they run those models and make estimates.

I used statistical modeling just to illustrate how such models can be quite accurate. There was actual data (Monthly Weather Review).

Overall Conclusion:

The March 2026 heatwave is the most severe heatwave Phoenix has experienced in the period where records exist (even prior to the daily period of record that begins in August 1895). There has been no remotely comparable past March heat event to the ongoing one affecting Phoenix and the Southwest.

Thanks, Don. Fantastic post!

 I’ll just add that, as I assume you realize, that LA and SD did actually both hit 99 on 3/29/1879 and that those remain their hottest on record in all of March. 

 The 100 of 3/29/1879 remained at least tied for the hottest in all of March in Yuma til it hit 102 in 2004. And the current heatwave obliterated these as you know with 109 for the hottest (3/20/2026).

 So, I agree that the tweeter is taking what was largely a localized historic heat event for S CA and making it seem as if it were in a much larger region and more historic in the SW US overall than the current one. 

Aside: Meteorology related Q: I wonder why this official map shows onshore (SW) winds in LA and a temp. of 97 at 1:35PM PST on 3/29/1879? The 97 is consistent with the 99 high, but the SW winds aren’t. Anyone know? My guess is that the winds had been offshore til just before 1:35PM and that the 99 high occurred a little before 1:35PM. If so, the temps were just starting to fall with the SW winds.

 Note that SD, also shown with SW winds then, had already fallen way down to 79 then. Thus, I’m guessing their winds shifted sooner:

https://library.oarcloud.noaa.gov/docs.lib/htdocs/rescue/dwm/1879/18790329.pdf

*Edited for correction: I meant SW winds, not SE winds. Brain fart!

 Today was the 3rd day in a row of Phoenix hitting 105, which not only obliterates another daily record but also again ties with the hottest on record in April. The day prior to the 105 string was 102. Prior to this string, the hottest on record in all of March was only 100, set on March 26th in 1988.

 More 100+ days are quite possible next week! Crazy!

On 3/19/2026 at 1:30 PM, roardog said:

I probably should have been more clear in my post. I was referencing the MJO impacting the developing Nino. The strong phase 7 and 8 in 2023 was looked at as an indication that the Nino could get very strong. This year it's in 7 and 8 again but weaker. I just thought it was interesting.

  Interesting because 2015 and 1997 had similar strong 7/8 in March to 23. OTOH, the strong to super Ninos of 1982 and 1991 didn’t while the weak 2014 did:

2014 had strong 7/8 but ended up very weak Nino:

 Some of this is due to UHI at Phoenix with them at 78 

ARIZONA HOURLY REGIONAL WEATHER ROUNDUP  
NATIONAL WEATHER SERVICE PHOENIX AZ  
400 AM MST SAT MAR 21 2026  
  
NOTE: FAIR INDICATES FEW OR NO CLOUDS BELOW 12,000 FEET WITH NO  
SIGNIFICANT WEATHER AND/OR S TO VISIBILITY.  
  
AZZ001>003-036-211200-  
NORTHWEST ARIZONA  
    
CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  
BULLHEAD CITY  CLEAR     72  27  18 CALM      29.83S TC  22             
KINGMAN        CLEAR     63  21  20 CALM      30.02F TC  17             
  
  
AZZ004>008-015-016-018-211200-  
NORTH CENTRAL ARIZONA  
    
CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  
GRAND CANYON   CLEAR     29  17  61 CALM      30.26F TC  -2             
WILLIAMS       CLEAR     39  18  41 S12       30.26F WCI  32 TC   4     
PRESCOTT       CLEAR     51  21  30 S7        30.15F TC  11             
FLAGSTAFF      CLEAR     36  19  50 CALM      30.28F TC   2             
PAYSON         CLEAR     57  21  24 N3        30.16F TC  14             
PAGE           CLEAR     57  18  21 CALM      30.08F TC  14             
  
  
AZZ009>014-017-211200-  
NORTHEAST ARIZONA  
    
CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  
WINSLOW        CLEAR     43  12  28 E6        30.16F TC   6             
SAINT JOHNS    CLEAR     46   7  20 S3        30.20F TC   8             
WINDOW ROCK    CLEAR     32   9  38 CALM      30.28F TC   0             
SHOW LOW       CLEAR     43   7  22 SE6       30.26S TC   6             
  
  
AZZ540-542>544-546-548-211200-  
GREATER PHOENIX AREA  
    
CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  
PHOENIX        CLEAR     78  33  19 E13       29.84F TC  26             
BUCKEYE        CLEAR     66  16  14 N5        29.85F TC  19             
LUKE AFB       CLEAR     70  26  19 N6        29.83F TC  21             
DEER VALLEY    CLEAR     71  25  17 NE3       29.87F TC  22             
SCOTTSDALE     CLEAR     68  40  35 CALM      29.87F TC  20             
MESA-FALCON    CLEAR     75  25  15 N3        29.86F TC  24             
MESA-GATEWAY   CLEAR     67  26  20 E8        29.89S TC  20             
CHANDLER       CLEAR     67  34  29 CALM      29.87S TC  20             
  
  
AZZ539-553-211200-  
SOUTHWEST MARICOPA COUNTY AND PINAL COUNTY  
    
CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  
CASA GRANDE    CLEAR     64  19  17 CALM      29.89F TC  18             
GILA BEND      CLEAR     73  19  13 CALM      29.83F TC  23             
  
  
AZZ503-504-507>509-211200-  
SOUTHEAST ARIZONA  
    
CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  
TUCSON         CLEAR     64  20  18 SE7       29.98F TC  18             
DAVIS-MONTHAN  CLEAR     64  17  16 E5        29.98F TC  18             
NOGALES        CLEAR     61  20  20 CALM      30.07F TC  16             
SIERRA VISTA   CLEAR     70  13  11 W10       30.12F TC  21             
DOUGLAS        CLEAR     55  22  27 CALM      30.08F TC  13             
SAFFORD        CLEAR     58  17  20 E8        30.00S TC  14             
  
  
AZZ532-211200-  
SOUTHWEST ARIZONA  
    
CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  
YUMA           CLEAR     73  35  25 S5        29.78F TC  23             
  

-Phoenix has set new (or tied) daily records highs 28 times during the last 365 days. 

-94 of the 366 days have record highs there set in 2023-6 due mainly to CC but with UHI also being a factor although UHI is normally more of a factor for warm lows.

-There are a mere 3 record lows set since 1980!

Yuma’s hottest on record in March prior to 2026 was 102. Yesterday was 106 and today was 109!! The earliest 109+ prior to today was May 2nd (1947) when it hit 111!!

2 hours ago, donsutherland1 said:

Today was the most brutal day during the ongoing epic heatwave in the West. A new U.S. national temperature record for March was set at four locations.

 The new hottest in CA in March as shown above is 112. That’s only 1 short of the April hottest!

4 hours ago, donsutherland1 said:

Although the flash analysis isn't peer reviewed, it is derived from a peer-reviewed methodology, which provides credibility. These studies provide value, as they provide an alternative to pure statistical research. The corroboration between the modeling and statistics enhances the quality of their findings. Further, studies concerning prior extreme heat outbreaks in the Southwest have all found a strong link to climate change.

As for March 2026, March 2026 is poised to become Phoenix's first March to break outside the 99% confidence interval based on 30-year climate data.

 

Don and others,

 For obvious reasons I’m having trouble with what’s bolded from this article:

"The area of the U.S. being hit by extreme weather in the past five years has doubled from 20 years ago, according to the National Oceanic and Atmospheric Administration's Climate Extremes Index, which includes various types of wild weather, such as heat and cold waves, downpours and drought."

———

 This is unclear. Are they implying that cold waves have increased since 20 years ago due to CC?

Fwiw this article was just released:

https://www.yahoo.com/news/articles/early-southwest-heat-latest-parade-070743575.html

 Note this paragraph:

“Climate scientists at World Weather Attribution did a flash analysis — which is not peer-reviewed yet — of whether climate change was a factor in this Southwest heat wave. They compared this week's expected temperatures to what's been observed in the area in March since 1900 and computer models of a world with climate change. They found that ‘events as warm as in March 2026 would have been virtually impossible without human-induced climate change.’”

 Any opinions about this article?

I read this today from a pro-met. @donsutherland1and others, I’m curious about your thoughts about this:

“Many of the radiation absorption bands for CO2 OVERLAP with H2O. H2O is 95% of the planet's greenhouse gas effect(we would be a frozen wasteland without the BENEFICIAL greenhouse effect).  Turns out that in areas with higher dew points, those overlapping absorption bands ARE ALREADY SATURATED by H2O!! In those cases and in those bands, it doesn't matter how much CO2 that you add. When they are already absorbing 100% of the long wave, heat radiation of what they are capable of because of water vapor/H2O, adding CO2 in those bands will have near 0 impact.

Now the kicker. Cold places lack water vapor in the dry air so CO2 will be impacting bands that are NOT saturated from H2O absorbing. We can see that on the graph above. However, DESERTS also lack water vapor, so they too are seeing a greater impact from CO2 than the rest of the planet at the same latitude. Even DESERTS located in already hot places, like Phoenix.

Turns out that DESERTS are warming at a similar, elevated rated to the Arctic.”

Opinions?

2 minutes ago, WolfStock1 said:

50 states x 12 months = 600 records for "highest temperature for state X during month Y".

To be honest - breaking one of those every now and then seems like not so much of a big deal, and would be expected regardless of whether the planet is warming or not.

Point being - perhaps showing trendlines of more broad data would be a lot more meaningful and poignant that touting a given broken single-state record for a given month.   As it is these posts with their desert graphics, and the obvious troll phrasing, seem very... tabloidish (or perhaps clickbait-ish being the modern equivalent), especially on a forum that thrives on deep data analysis.

 

Good point although the good possibility of Phoenix approaching if not reaching 105, the hottest on record in April, during some point within the next 3 days is amazing. But Don, myself, and others realize that their rapid growth’s caused increasing UHI has also been a notable factor.

 Speaking of UHI though, isn’t that more of a factor for warm lows than hot highs? 

16 minutes ago, Stormchaserchuck1 said:

I would give the CPC a "C" grade

I think it was a D.

I had another great walk this evening with upper 40s, light winds, and dewpoints in the middle 30s.

3 hours ago, MJO812 said:

The final countdown 

 Anthony, today’s NAO forecast is consistent with yesterday’s (bad/+):

Yesterday’s GEFS:

Today’s GEFS:

 Could an earlier than avg final strat warming be coming next week? This suggests some chance. Opinions? @snowman19

Gainesville, FL (aka Hogtown) got down to 30! Impressive radiation like usual.

KTLH 30

KSAV 31 (official SAV station, the airport)

KSVN 34 (very likely more representative of my low)

Today’s MJO forecasts still are all in phases 7 and 8, the coldest in Baltimore (as rep. city) in March on average following La Niña winters:

@EastonSN+

1 hour ago, roardog said:

There’s a lot of things that make a very strong Nino look likely but I can’t shake the fact that it’s only been 3 years since we’ve had one and the PDO is still negative. March isn’t over yet but right now the 30 day SOI is still extremely positive. As Chuck showed, the very strong Ninos never have an extremely positive March SOI. I guess we’ll see. 

And the Euro, one of the warmest currently, does have a warm bias plus RONI is ~0.5 lower right now. In addition, Eric’s bold calls shouldn’t be mistaken for him necessarily being likely to be right as he’s had his share of busts.

 Today’s MJO forecasts are suggesting it may back up into phase 7 in a portion of the rest of this month but otherwise be in phase 8. Those two phases have averaged the two coldest March post winter La Niña phases in Baltimore, which tells me it will be rather difficult for warmth to win out overall the rest of this month despite some of the days being warm in between cold periods:

GEFS:

EPS:

3 hours ago, suzook said:

28 degrees at 5:30 am, will probably drop another degree or 2 before sunrise. This blows. A forecast high of 48 with wind chills in the low 30's this afternoon. We usually have outdoor activities for st Pat's day downtown. I'll stay home. I already see black on the tips of just bloomed perennials. Wondering how much damage there will be to plants and such that bloomed already. 

 From summery low 90s in some areas just a few days ago back to winter now! It was down to 32 all of the way down to parts of N FL including Cross City, Crestview, and Pensacola! KSAV was 34. Look out tonight for areas that radiate decently to have even colder lows. Some of these areas have freeze warnings for tonight.