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FAQ: Chasing the Southwestern Monsoon

Thanks for all the great info, and photo's. My family and I will be spending a few days mid-July driving through Arizona/New Mexico on my way back to St. Louis, and I plan on keeping my camera handy.
Can't say I'm impressed with the arbitrary June 15 season opening.

DPs are in the high 20's across far SE Az, the first place to see Monsoonal flow. :rolleyes:
I have been noticing an increasing number of thunderstorms during the past week in the Sierra Madre Range of Central and Northern Mexico...a sign that moisture is beginning to build south of the border.
But, that moisture is likely to stay down there for at least another week or two as troughs continue to dig through the west coast. Standing by!
Good cloud cover over Tucson and most of far SE Az today!
Mid level moisture is high enough for the weather service to have issued a Hazardous Weather Outlook for the area, but dry microbursts and lightning in the mountains are about all we can expect for now. As with Tornado Season in the plains, the last few weeks of waiting are the worst!

Closer.... closer....!

Well today is the first day it looks like there's some quasi-serious monsoon action in the eastern mountains of Arizona. Last year too, the first storm I had available to chase happened to also be on 6/28
It would be nice to have a repeat!

Good luck to everyone chasing Monsoon 2010! I hope everyone gets great CGs, flash floods and even a sandstorm or two in the American Southwest.

What is Monsoon

Track the Monsoon

Storm Prediction Center radar

Be sure to post your experiences!
Well today is the first day it looks like there's some quasi-serious monsoon action in the eastern mountains of Arizona. Last year too, the first storm I had available to chase happened to also be on 6/28
It would be nice to have a repeat!

I was ready to post the same thing. Good 50+ dew points at the surface and good 850 lvl saturation too. GFS has this persisting for a couple days, may until Sunday for a good portion of the south half of Arizona.

The model runs on Alex have been persistent at bringing it in to or near Arizona. I'm in the West Valley of Phoenix, so I'll have to play the waiting game.
Do you guys know of any lightning overlays for GR3 that are available for AZ/NM? I had one that worked great for the midwest, but the shapefile didn't cover the western conus.

I live in Tucson, so if the pattern continues, I should be able to get out into the desert tomorrow night after work. Any suggestions on places to head to, to try and get some strikes?


You certainly can't ask for a more beautiful state to Monsoon chase than Arizona! :D

My husband and I will be spending 2 weeks at our cabin in the Happy Jack, AZ. area in Northern Arizona (halfway between Winslow, Payson & Flagstaff) not too far from Mogollon Rim. We will be there from August 8th thru August 20th, and are hoping that the Monsoon will show itself as it has in years past.

We live in So. Cal., where we get almost NO weather to speak of so we cherish the two weeks or so a year when we can chase some in No. Az.

Would you have an idea as to what the Monsoon season has in store for up there this year?

Any advice, insight or guesses would be appreciated!



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Sandra, predicting storm activity is always a crap shoot. Supposedly, the El-Nino / La Nina transition may initially delay, but later reinforce, the establishment of the 4 corners high which largely drives the monsoonal flow.

In the short term, we're getting a good blast of moisture this weekend, with dp in the 60s. Tucson got some light sprinkles yesterday evening, and a gorgeous sunset! Unfortunately the upper air is less than ideal, limiting instability. Still, I hope for the year's first chase this weekend. (I probably shouldn't do that! Hoping = instant bust! :rolleyes: )

Here are some good data sources.


Depending on where you're planning to go, the season peak can vary by a few weeks. Check the daily temp and precip records for the location of interest at http://www.wrcc.dri.edu/summary/Climsmaz.html

Short answer - Late July into the first few weeks of August is about as good a bet as any.

Seconds ago, at 11:23am, I heard the season's first thunder! :D:D:D
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The real danger with shooting lightning in the Borderlands, which hasn't been mentioned here is...

&%@#%$ helicopters!!


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Forget the Banditos! Beware the dreaded



I enjoyed a short season opening chase this evening: A gorgeous sunset, pretty rainbow, and some distant lightning in the mountains all around.

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It was a very active weekend in Southern Arizona. I just got back from chasing solid for 3 days there, focusing heavily on Vail AZ, a small town south of the Rincon Mountains, where the storms rolled in.

I chased widespread severe weather including a cell southeast of Tucson that caused damage, frequent lightning and blowing dust, intense downpours, lightning storms every night coming over the Rincon and Catalina mountain ranges. Huge storms also erupted along Hwy 19 and drifted off into the borderlands once they were done with Green Valley, Tubac/Carmen.

Chases lasted until 2-3am both Friday and Saturday night. En route to Phoenix Sunday night, I intercepted more CG-ing all the way from the Toltec Road near Eloy north to Phoenix. I waited until sundown to drive back, gambling that the Central Deserts would go, and they did!

Friends had successes in Seligman/Ash Fork west of Flagstaff, Paradise Valley/Scottsdale, and Benson/Willcox, Marana and Oracle Junction.

There was both day and night chasing to be had, in wide open country.
Glad to see that Arizona is having a good, consistent monsoon this season. But, i'd like to ask that you Arizonans let us borrow a little of that moisture for us here in Southern California. It has been an absolutely pathetic monsoon in SoCal so far this year...1 day of convection in all of July. I was unable to chase that day (thursday, July 15th), and tried to chase the remaining moisture the day after. All I was able to come up with was this pathetic shower moving off the back side of Big Bear...

Pretty much the worst July monsoon that I can remember. Anyway, from what I read in the Phoenix forecast discussions recently, the precip water values in Arizona right now are near record levels. This morning, they had a p-wat reading of 2.38 inches. The air must be feeling pretty steamy out there right now...


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Anyway, from what I read in the Phoenix forecast discussions recently, the precip water values in Arizona right now are near record levels. This morning, they had a p-wat reading of 2.38 inches. The air must be feeling pretty steamy out there right now...

Dew points in the low to mid 70s. It reminds me of Illinois summers. Hot and sticky.

Late-night lightning has been bad despite all the moisture and rain. I'm missing some good electric convection.
It has been an absolutely pathetic monsoon in SoCal so far this year...1 day of convection in all of July.

Most of Southern Arizona, including the Tucson area, saw very little precip in the lowlands until the last couple days in July.

I was in the Tucson area July 29-Aug 1st. Lots of convection, but very little lightning. Just too damn tropical.

I was literally driving into town just as storms were developing late Thursday night (29th)...all wet with no spark. Spent the night at Organ Pipe Cactus Nat'l Monument, woke up the next morning (Fri 30th) to overcast (debris-covered) skies. Was able to get a good hike in even during the mid-Morning, and eat outside at Ajo at Midday. Noticed a strong Gulf Surge on the 30th that was 5-6K ft deep according to the Yuma VWP. Stiff SSE winds with distinct non-diurnal pressure jumps at Puerto Penasco, Yuma, and Wellton, but little increase in sfc dewpoints except at low-lying Yuma. GPS PWV didn't seem to react either -- though it was very high to begin with. Was hoping this would lead to increased CAPE and subsequent convection South and West of the I-8/I-10/I-19 corridor, but no dice. Very weak flow aloft and warming temperatures despite having a dying upper low/inverted trough over the area. Headed back towards Tucson, stopped at Three Points and briefly considered heading down to Sasabe, figuring I could drive the Arivaca road back to I-19 (an unexplored area for me) as a consolation prize should storms fall flat. Fresh towers over the Rincons and Catalinas drew me into Tucson instead.

Sort of glad they did. Watched storms develop over the southern Rincons that afternoon, and caught a brilliant sunset from Redington Pass while more storms developed over the Rincons. Again...plenty of rain, not much cloud-to-ground lightning.

Spent Friday night with family in Casa Grande. Saw very little lightning in my rear-view mirror heading out of a rain-soaked Tucson. Rain found its way into Pinal County by morning, and I was mildly amused by localized flooding and full arroyos early Saturday. Convection chances for Saturday looked bleak. MCV was centered along the border west of Tucson with clearing skies west of north of there by early afternoon... and the high elevations around Globe showed promise...but steering flow was almost NIL. Stuck around Casa G hoping I could find a reason to head back towards Sells/Ajo/Organ Pipe but reality soon caught up with me. Headed to Florence Junction and Queen Valley hoping to catch some running arroyos at sunset. Caught a nice sunset with light rain and saw Queen Creek running relatively high. Went back to Casa G, avoiding weekend camping crowds I presumed would be infesting the mountains up north.

The next few days would bring drier air to the lowlands and shift activity into the higher terrain way up north. Headed up through Salt River Canyon, and took a side trip on a dirt road which follows the river. This turned out to be the highlight of the day. The Salt was running really nicely! Some medicore storms north of Show Low teased me at sunset... but fell flat. Again, very little lightning. Drove all the way to Canyon de Chelly in a chilly rain.

Enjoyed Canyon de Chelly Monday and took a circuitous route back towards Holbrook, AZ in the afternoon, shooting some daylight lightning along the way. Figured the area between Zuni Pueblo and Grants would be a good candidate for evening storms given trends. Photographed some nice storms with a lot of CG lightning (finally!) atop the mesas west of Zuni Pueblo before sunset, and out by El Morro National Monument after sunset. Camped out at El Morro.

Tuesday looked to be another highly suppressed day, but needed to head home. Did a morning hike at El Malapais Nat'l Monument, grabbed lunch at Grants, did a midday hike at La Ventana Arch... and spent the remainder of the day winding through Cibola National Forest, through the Gila, and made it to Silver City by Sunset, home a couple hours later.

Still waiting for good lightning photo opportunities in *southern* AZ, but with my schedule, it doesn't look good. The upside was there was good sleeping weather for camping!

Sounds like you really did give our pathetic monsoon so far this year the old college try during your trip and I enjoyed reading about your experiences. The redeeming part is that you got to see some quality scenery, but like the rest of us, that isn't what you wanted to see while you were here. I've passed up a couple of trips to Cochise County thinking that something was going to develop around Casa Grande and then wound up with a big handful of empty to show.

The latest Area Forecast Discussion from NWS Tucson is starting to beat the drum for increased activity thunderstorm starting late tomorrow with Saturday being a potentially promising day for southeast Arizona.

If something doesn't start materializing pretty darned soon, I'm going to set fire to a very large pile of chicken feathers inside of a 61 Volvo and that will really stir up the monsoon gods. I "need" my lightning fix!!!
Tucson Lightning Hotspots

Hello there,

I was hoping some of you folks in Tucson would share a couple of your lightning hot spots to an out of stater? I have been down there twice this season and could not really find a place that wowed me. I am headed there this weekend as it looks like it may produce some interesting weather.

Here is the best shot from last trip in late July. Even though my best memory from that trip was being stranded for six hours in heavy rain because all the roads were washed out south of Tucson and having to watch all the lightning from inside my truck.

---Tucson Lightning

---Albuquerque Lightning

I appreciate your help and all the information provided here,
Albuquerque, NM
You guys should have come up to Flagstaff this Monsoon Season, its currently our 6th wettest. We've had 5 events now which dropped over an inch of rain at Flagstaff Airport. It's my first summer living here and I must admit, the Monsoon did not disappoint. :)
California had a pretty sad monsoon season this year (including one of the coolest summers on record). But, I was able to get into Arizona during the last week of August. I was treated to a nice show in Southwest/West Arizona on August 27th. I was able to chase a bit while I took care of some other things that I had to do. I thought I would share a few photos from that day, which included two reports of golfball sized hail! (one in the Brawley, CA area and one in Wellton, AZ). The radar signature on a few of these storms...particularly the one that formed near San Felipe in Baja, looked like something you would see in the midwest...for a short time. It just felt like one of those days early on...extremely hot and moist...that something was going to happen.

There were two storms in particular that were extremely strong. The storm that formed in Northern Baja moved north over western El Centro and into Brawley. The second storm fired near Wellton...I believe on an outflow boundary from an earlier storm...and pushed NNE into rural parts of Yuma county.

I was in Yuma for most of the day, and eventually tried to chase the Wellton storm a bit as it moved northward just east of highway 95.

Storms fire just east of Yuma in the Wellton area. They would eventually drop golfball size hail

A nice example of how unstable the atmosphere was. There were alot of narrow but tall updrafts forming.

The rock hard towers of the Wellton storm, as seen from Yuma looking east.

The anvil of the Baja storm is seen spreading NE over Yuma, with new updrafts periodically forming along a northward moving outflow boundary.

Interesting sunset as I drive north on highway 95 in persuit of the Wellton storm, which dissipated over rural Yuma county.
Those who will be chasing Monsoon, what are your target areas this year? Mine will be the Mogollon Rim country, White Mountains, Vail/Benson/Willcox, Wickenburg, Superstitions, and Prescott/Sedona. I have abandoned I-8, Gila Bend, Stanfield, Ironwood Natl Monument, and some areas of the southern borderlands due to chance of illegal immigration and drug smuggling routes. I love the terrain and lightning action in the Central Highlands like Prescott and Payson. One town down south too, Vail, also has appeal...lots of lightning plus double locomotives full speed through town :)
Gonna reconnoiter Mescal and Cascabel roads sometime in the next few weeks. Both head N. from Benson into the eastern Rincon area, birthplace of many a thunderstorm. I can't count the number of times I've seen storms billowing behind the Rincon mountains; 'hoping they drift toward town' isn't getting it done.

Marsh Station Rd., just E. of Vail, has a few good overlooks.

70% of the Chiricahua mountains are toast. :( If the NP survives the fire, I'll have to start chasing there again. It's a bit of a drive but there are plenty of potentially gorgeous landscape + lightning compositions.

I'm taking a 10 day road trip to Ca. in late July and hope to spend ~4 days shooting any lightning that cares to join me in N. Az. The N. rim has obvious potential (and offers a most welcome relief from the Aridzona heat!) The twilight view looking E. over Lake Powell from the Page area looks tempting, and lightning over nearby Horseshoe Bend is also something I'd like to catch.

Update 6-15-11 The Horseshoe 2 fire has at least partially consumed Chiricahua National Park. :(
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As of June 22, the long-term GFS is showing the 500mb high moving over the four corners region and ushering monsoon moisture east into NM, AZ, and southeastern CA. This is a long way out and long range models are subject to significant errors, but the trend is worth watching.

I'll be east of Payson June 30 - July 3. It looks like the monsoon may be kicking off in that area towards the end of my trip to the rim.