Late Spring Heat in Arizona

[azskyman]

To no one's surprise, it is now HOT in Arizona. I topped out at 108 on the 27th.

My rule of thumb (which doesn't hold up much when the monsoon humidity arrives) is that temps below 104 are tolerable. My body takes notice when we pass that mark.

I noticed the temps on Tuesday.

Good news is that the pool temp is now 85+. I'll be swimming this weekend.

[therock1811]

I bet you will steve. I may be swimming before thw week is out.

[Aslkahuna]

the early SUMMER heat is even worse. Fortunately, once the monsoon begins, Sierra Vista sees a sharp drop in temperature from highs in the high 90's to 100F or so to highs in the mid to upper 80's on average. We have the unusual circumatance of seeing our hottest weather of the year in late June/early July vs mid to late July in the rest of the Country.

Steve

[Rainband]

OMG 108..that is too hot for me..try and stay cool!!!!

[Arizwx]

Wait until June. 117+ in TUC is the threshold and 122 in PHX..I know.I was there not so long ago.
Look at 1989...the record books.That may be as I mentioned some weeks ago..what we may be seeing this year.If so..we are in deep trouble for Urban Fires and H2O shorts.
DJ

BTW..the backdoor/ridge set is pumping heat in from all directions now.Dews were pushing 46F last eve..it was 101F at 21:00 hrs last eve with a hot sse wind to 34.
Lo here was 89F.Hottttttttttt.
14:30 PDT Current:102F/DP 44F/ese 26/light dust/sun

[Rainband]

Wait until June. 117+ in TUC is the threshold and 122 in PHX..I know.I was there not so long ago.
Look at 1989...the record books.That may be as I mentioned some weeks ago..what we may be seeing this year.If so..we are in deep trouble for Urban Fires and H2O shorts.
DJ

Hope you got the AC cranked when that happens stay cool ArizXW..

[Aslkahuna]

we have seen hotter periods of short duration, 1989 remains the hottest year of record in AZ if I recall correctly both the earliest and latest 100F reading in Tucson were set then as was the record number of days with 100+. In looking at my records, I see that the 1989 monsoon started late and was a bit drier than normal but not horrendously so and was fairly violent-at least here in SV where I had a thunderstorm gust to 78mph at the house as a funnel cloud passed overhead and we had blowing dust. I was thinking more of 1994 as an analog for this year's monsoon or perhaps 95 or 98 but 1989 could do as well. We also had a very significant Tropical Cyclone hit in SE AZ in October 1989 (Raymond).

Steve

[Arizwx]

we have seen hotter periods of short duration, 1989 remains the hottest year of record in AZ if I recall correctly both the earliest and latest 100F reading in Tucson were set then as was the record number of days with 100+. In looking at my records, I see that the 1989 monsoon started late and was a bit drier than normal but not horrendously so and was fairly violent-at least here in SV where I had a thunderstorm gust to 78mph at the house as a funnel cloud passed overhead and we had blowing dust. I was thinking more of 1994 as an analog for this year's monsoon or perhaps 95 or 98 but 1989 could do as well. We also had a very significant Tropical Cyclone hit in SE AZ in October 1989 (Raymond).

Steve

1989 Brought CJ,Myself and Family the Oct 'World Series' Loma Prieta 7.1MM Richter Quake..as I was working in a 30story HiRise in Oakland.
I went home early that afternoon..about 4:20 to see the Game and BB Q.
I was on the Lower deck of the Cypress Structure(I-880) heading out of Oakland to the BART SF Express Pickup in Orinda to get CJ from her 44th Floor at "101 California Tower" in the SF Financial Dist across SF BAY.
BART ran extra 78mph express trains tha day to the East Bay/Oakland... 200ft UNDER SF BAY.
Picked up the then 2 kids at daycare in Walnut Creek and headed home.
The rest is history.The Cypress Structure by 5:10 PM had totally collapsed.
1989 also brought our Carolina Friends the wrath of someone named ...
"Hugo".
Quite the year..'89

[weatherlover427]

Yep, that is true DJ. I lived in southern CA during that time and remember seeing the quake happen on live TV.

[azskyman]

111 at the house today.

I have noticed, too, that the hottest days are generally before the monsoon season (for the same reasons we rarely hit 100 back in Illinois). I've seen 117 thus far since 1997, but I can tell you that today's 111 was a bit of a push.

Is it the elevation in Tucson that is the bigger factor in those few degrees difference, or is it more a factor of a few points on the humidity scale?

[Aslkahuna]

higher in elevation than Phoenix. The humidity is usually not a factor since the air is bone dry during the high heat. On the day that TUS hit 117F SV hit 108F though our East Range meso site and Benson were in the 112F range. That extreme heat is a prerequisite most years for the monsoon to occur and all places (Asia, Africa, Australia, North America) that experience a Summer monsoon have that heat burst ahead of it. The reason is quite simple, the ST ridge line and Upper High has to move north of the monsoon region before the monsoon can set in and as it does so the subsidence and compression results in some mighty hot temperatures. It takes an unusual pattern such as we had in 1988 and 2000 for the monsoon to set in without that heat burst and then the monsoon usually has some unusual features to it.

Steve

[David]

Atleast you have little to no humidity!

[Arizwx]

Atleast you have little to no humidity!

YET.
When the 'Soons hit..Dews of 60F-70F and temps of 112F+ combine,the Humidity levels are so intense that Miami visitors feel downright uncomfortable.Plus,many here have 'Dual Cooling Systems'.The infamous
'Swamp Coolers'(Evaporative Type) are utterly useless after the Rh % breeches 33. Then the main 'Heat Pump'HVAC units are on 'HyperThrottle'
at 70F inside with 110 outside.The Heat Pumps..Heat OUT if the highest point of the house,then mixes in A/C cooled and dried air.Puts quite a strain on the 'Train'.

[Aslkahuna]

about humidity and high heat values. Using AZ's example of 112F and a dewpoint of 70F (a dewpoint value that can hardly be considered "dry") my moisture calculation program gives a Relative Humidity of 25% which doesn't sound all that high to someone back east where the same dewpoint with a temperature of 90F yields a higher RH. However, the Heat Index values with such a combination are going to be out of sight and generally well above the values that cause so much complaining and grief elsewhere in the US. Many times, Phoenix will come in with the highest Heat Index in the Country and this fact will be glossed over as though people here don't suffer in the heat too (this fact is one reason why AZ does not observe DST since people don't even want to think about the Sun setting an hour later by the Clock). What AZ didn't mention is that the dewpoints in AZ can surge to values near or even over 80F at times during the monsoon. In 2000, our monsoon started very early and I was attending the Parent's Orientation for incoming students at the UofA and I was amused at the Easterners who were having trouble coping with our rather juicy "Dry" Heat-in fact, they opened the first session with a "Welcome to Arizona's Monsoon".

Steve