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Atmosphere Comparison
Posted: May 15 2009 8:25 pm
by Jim
The endless chatter of weather.
Re: Atmosphere Comparison
Posted: May 27 2025 6:44 am
by RedRoxx44
Slightly excited about Sunday forecast; 40% chance thunderstorms near the border. Of course that could change 100 plus times by then.
Re: Atmosphere Comparison
Posted: May 27 2025 2:59 pm
by chumley
@RedRoxx44 Let's hope that Hurricane Alvin waters the chipmunks! Tropical moisture aside, the cutoff low is unusual for this time of year and I expect that the lack of available historical data will make it difficult for the computers to make any kind of accurate models. It's nice to not be under a stationary 120-degree high for a month straight though.
Re: Atmosphere Comparison
Posted: May 30 2025 3:34 pm
by DixieFlyer
Going back to the late 1800's, I saw where Phoenix has only had measurable rain one time on June 1st. That might change this Sunday.
Re: Atmosphere Comparison
Posted: May 30 2025 4:28 pm
by LosDosSloFolks
Re: Atmosphere Comparison
Posted: Jun 01 2025 7:05 am
by RedRoxx44
So far about 30 min of off and on light rain, and a fair amount of thunder with the gray quilt of clouds. Getting Heep packed up.
Re: Atmosphere Comparison
Posted: Jun 02 2025 8:43 am
by tibber
steady rain from 3:15PM and then a couple blaster rain storms this AM around 3:15AM and ? (I didn't look at my watch). I was stunned to wake up to an INCH of rain. OMG!

I thot I was back on the Big Island, ha!
(north Phx)
Re: Atmosphere Comparison
Posted: Jun 02 2025 9:43 am
by LosDosSloFolks
@tibber
1.14" of much needed rainfall up here in Cave Creek accompanied by deafening lightning strikes that were uncomfortably close to the house.
Re: Atmosphere Comparison
Posted: Jun 02 2025 9:51 am
by chumley
@tibber A nice low drizzle most of the day resulted in a quarter inch or less across most of the valley. It was really nice though.
Then that complex moved through overnight that blasted Suprise to New River and the northeast valley with as much as 2+ inches. The Agua Fria and New River both flashed. Down south some of the sky islands got much-needed relief, but Flagstaff, the rim, and White Mtns ended up with barely anything at all.
Still, any June day with high humidity, clouds, and cool temperatures is one day less of fire-danger furnace conditions, so it's still beneficial statewide.
A windows-open afternoon in June in the valley was a rare treat.
Re: Atmosphere Comparison
Posted: Jun 04 2025 10:24 am
by chumley
I find occasional amusement in rainfall totals in the desert southwest as a percentage of normal. When normal is under 10 inches annually and one storm can drop a quarter of that total in a local area in an hour, statistics that indicate an area is suffering from less than half the normal total (or more than twice the normal total) can sometimes be a bit misleading, or at least benefit from additional context.
Currently four days into the month of June, PHX is running at over 20 times (2000%) of normal rainfall for the entire month (with 26 more days to go)! Reaching such totals is not difficult when normal is .02".
Does this explosion of moisture have a meaningful impact? Every little bit helps, I guess. And it certainly produces a little bit of relief for wildfire risk in the near term. But expanded to a larger time frame, PHX is still below normal for rainfall in both the water year (October-September) 1.47"/4.81" (just 31% of normal) and the calendar year 1.47"/2.92" (50% of normal). But it's .45" of rain that hadn't fallen as of last week, so there's that.
But being at 30% or 50% of normal can be made up in a single thunderstorm.
The current map for June looks great. But percentages of tiny numbers can be wildly misleading.
*note the image below is current as of 6/1. When updated to include 6/2-6/5, much of the tan color across central and eastern Arizona should also shift to green.
Re: Atmosphere Comparison
Posted: Jun 04 2025 11:04 am
by Grimey
It's the desert. Referencing "normals" is a fool's errand.
Re: Atmosphere Comparison
Posted: Jun 13 2025 11:28 am
by chumley
Summer is over!
Yesterday was the earliest sunrise here in the valley, and today is the first day where sunrise begins getting later.
There's still 16 days of sunset getting later before that too begins to move toward its winter minimums.
Relief is coming!
Re: Atmosphere Comparison
Posted: Jun 13 2025 12:13 pm
by trekkin_gecko
@chumley
Just getting started
Re: Atmosphere Comparison
Posted: Jun 14 2025 7:56 am
by RedRoxx44
Looking at the recent Weather Channel for the 10 day interesting Tucson is going to be close to Phoenix for current projected highs.
Re: Atmosphere Comparison
Posted: Jun 15 2025 6:30 am
by azbackpackr
Today is the first day of monsoon season, ever since the Weather Circus decided (back in 2008, if I'm not mistaken) to have an official "first day" instead of using one of two time-honored traditions: Dewpoint of 55 degrees for 3 days in a row, OR the historic "San Juan's Day" of June 24th.
Here in beautiful downtown Eagar, (yes, I do live in the "downtown" area) it got up to a sizzling 91 degrees yesterday, with a dewpoint of 4 degrees! Sheesh! FOUR degrees!
Re: Atmosphere Comparison
Posted: Jun 15 2025 7:18 am
by Jim
https://www.cpc.ncep.noaa.gov/products/ ... cp.new.gif
Give it a week, you might start to see moisture roll in to SE AZ.
Re: Atmosphere Comparison
Posted: Jun 15 2025 11:51 am
by azbackpackr
@Jim
Looks lovely. Hoping for it!
Re: Atmosphere Comparison
Posted: Jun 15 2025 9:33 pm
by chumley
azbackpackr wrote:Dewpoint of 55 degrees for 3 days in a row
Under this rule, the monsoon began on June 1 this year as there were 4 consecutive days with an average dewpoint over 55 at PHX! (Also, under the old rules, it was only 55 for PHX. Tucson had a trigger dew point of 54)

.
Re: Atmosphere Comparison
Posted: Jun 16 2025 4:35 am
by azbackpackr
@chumley
Well, that could confuse things.
Here in Round Valley it used to often start on the 4th of July, during the parade. Everyone would cheer.
Re: Atmosphere Comparison
Posted: Jun 16 2025 6:22 am
by Mountain_Rat
azbackpackr wrote: it used to often start on the 4th of July
Same in Tucson. Always messing with the fireworks. More recently, if it doesn't rain on the 4th, they want to cancel due to fire risk. Can't win.
Re: Atmosphere Comparison
Posted: Jun 16 2025 12:28 pm
by Alston_Neal
Monsoon starts when water comes out of my AC evap line. Research cost: $0, Accuracy: 100%