GaWx

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!!

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

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?

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?

I think it was a D.

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

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+

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.