Recently in Southwest Monsoon Category

This started as a pretty simple, 20 mile local chase that wound up overperforming. The day featured northwest flow with storms firing on the higher terrain and moving along the Mogollon Rim which is oriented northwest to southeast. I headed east of Flagstaff on I-40 and drove down a dirt road to a vantage point less than a mile south of Twin Arrows. I was trying to catch the collision between a cell building south of Flagstaff with a fresh outflow boundary to its southeast. Sometimes these dish out some pretty structure before everything fills in. I figured I’d try some Lightning Trigger shots while I was at it.

The growing cell was a thing of beauty by monsoon pop-up standards, with a solid updraft fist punching a big ripple into a doughy anvil.

— 12:36PM / 1936Z —

As that cell approached the outflow boundary of the dying storm downstream, it sprouted up a choppy arcus cloud, but that was about it. Not quite what I was hoping for, but there was still plenty of afternoon left and I thought maybe something closer and further north would light up.

— 12:44PM / 1944Z —

It wasn’t long before another cell went up near where the previous one had started, and from then on, it seemed Anderson Mesa was going to be the tracks for a steady train of storms cruising southeast. By then, another Arizona chaser, John Sirlin, had situated himself about a mile and a half further south and was watching from a good hilltop vantage.

Storm chaser, John Sirlin, parked at the next hilltop

Over the next hour, I noticed that storms were picking up laminar striations in their bases and had a couple eye-catching silhouettes taunting me from 11 miles away.

— 1:19PM / 2019Z SSW of Twin Arrows —

— 2:00PM / 2100Z SSW of Twin Arrows —

— 2:01PM / 2101Z SSW of Twin Arrows —

— 2:10PM / 2110Z SW of Twin Arrows —

As that last funnel looking thing materialized, another storm had taken root northwest of it and was growing stronger. It was being led by a lowered, shelfy base while the trailing core looked cupped and hollowed out. I was noticing thin rain shafts on this and previous storms that kept catching my eye, but I wrote them off.

— Earlier pair of rain shafts 12:47PM / 1947Z S of Twin Arrows —

This new storm started to develop broad anti-cyclonic rotation on its north side but eventually picked up a tighter cyclonic couplet and a decent wall cloud on the opposite/south side of the core. And that core was gradually hiding the action. I wish I had been out on Lake Mary Road watching this, but road options require a huge commitment. Investing in a 35 mile drive through mostly trees to get to a probably-not-long-to-live storm with an unobstructed view 11 miles away is a tough call to make.

— 2:35PM / 2135Z lightning strike and developing wall cloud —

About the time rain popped up overhead and chased me into my car, I got a message from John asking “Did you get it?” Cold chill time. What did I miss? The pic he sent afterward showed a close up view of one of those ‘rain shafts’ stretching out at a 30 degree angle from the storm. I was time lapsing the cell at that time, and figured I should have caught the feature I wrote off. We finished watching a couple more cells develop and chatting with another chaser that had set up in the area, Nick Pease.

— 3:18PM / 2218Z severe-warned storm —

— 4:10PM / 2310Z last cell over Anderson Mesa —

Getting home and processing the shots, sure enough, that thin feature dangled cloud to ground, getting pulled along with the anticylonic rotation for about 6 minutes. In addition to John’s shot, I posted the time lapse and a line-of-sight map for the Flagstaff NWS office to review. Their assessment aligned with John’s earlier heads-up and the SPC storm report was updated to plot it as a landspout tornado.

— 2:26PM / 2126Z landspout about 12 miles SW of Twin Arrows —

Line of site points and map markup

Definitely not the hit-you-over-the-head variety that we saw in Colorado a few months ago, but it was pretty rewarding to finally document one in Arizona.

11 August

Nocturnal storms moving in from the southwest sent me up to Sunset Crater National Monument for a try at some shots. CGs were very reluctant as the storms weakened on approach. I still wound up with some rim lighting on the cloud base as a consolation.

Nocturnal lightning display at Sunset Crater National Monument - 0908Z

21 August

No storm chasing going on here, just spontaneous German Shepherds in the sky.

Convection or dog with a stick from east Flagstaff - 0152Z

26 August

Another day of southwest flow had me out at the Winona/I-40 exit shooting some time lapse photography. As a strong storm set up over Flagstaff. This one picked up a weak (~14 mph radial velocity), pulsey velocity couplet through 4 slices for about 20 minutes. Not enough to qualify as even a minimal mesocyclone. Structure, as far as Flagstaff storms go, was pretty nice and it covered the San Francisco Peaks in a white cap of hail. I drove further east to Buffalo Range Road and got a look at a pretty nice shelf moving in. It was interesting to watch the time lapse on that as a northbound gust front interacted with it and sent a cool whirl along the shelf.

Sheared convection east of Flagstaff looking north from Winona/I-40 exit - 2002Z

Storm building over Flagstaff looking west from Winona/I-40 exit - 2010Z

2019Z

Shelf cloud looking west from Buffalo Range Road/I-40 exit - 2103Z

Hail on the San Francisco Peaks from Hwy 180 west of Flagstaff - 0035Z

2 September

One more southwest flow day back out at Twin Arrows to watch for the occasional shelf or lowering near Merrill Crater. As convection filled in southward, a building gust front loaded up with meshing gears of vorticity to wrap up the time lapse.

Convection and lowering north of Twin Arrows/I-40 exit - 1833Z

No landspouts, just galaxy cores overhead - 1958Z

Passing convection and gust front looking northeast from Twin Arrows/I-40 exit - 1904Z

1911Z

A few days in early August gave me opportunities to intercept monsoon thunderstorms along the Mogollon Rim Convergence Zone during southwest flow. The 5th, 6th and 10th of the month served up some nice ones. I’m not getting too detailed with these, or else I’ll never get around to posting the pics.

5 August

Around noon, I followed a strong cell east out of Flagstaff as it drifted along north of I-40. I managed some time lapses south of the Twin Arrows/I-40 exit as it was draping a shaggy shelf cloud around its core. I paced it further east to Buffalo Range Road where it ran into a boundary being laid down by another line of north-south convection to the east. The interaction worked some beautiful structure into the updraft of the original cell before it merged, mushed and gusted out. I tried for some more convection further north on the AZ-87 toward Dilkon. Nothing strong materialized, but the landscape was stunning against the tattered sky.

Flaring shelf cloud north of Twin Arrows - 1924Z

1924Z

1925Z

Debris clouds east of Twin Arrows - 1937Z

Northbound convection looking east from Buffalo Range Road & I-40 - 1954Z

Eastbound convection looking north from Buffalo Range Road & I-40 - 1954Z

1955Z

Gust fronts beginning to merge - 1958Z

1959Z

2000Z

Enhanced structure as interaction strengthens eastbound cell - 2011Z

2013Z

Disorganized convection southeast of Dilkon - 2113Z

2114Z

2122Z

2123Z

2123Z

2132Z

6 August

Another noon chase, and another cell drifting east out of Flagstaff. This one was over Doney Park with a severe warning when I first got on it. The warning soon dropped off and I ran some more time lapse ops on the structure at Twin Arrows again. Later that evening while visiting friends, a pair of cells popped up north of the San Francisco Peaks. The sun was setting and casting a mellow light on the anvil and updrafts as lightning moved around their innards. A few bolts snuck a peek outside the clouds, but I only caught a couple while shooting the time lapse sequence.

Severe-warned storm over Doney Park as seen from Winona & I-40 - 1903Z

Looking north from Twin Arrows & I-40 - 1936Z

1936Z

Twilight storms north of the San Francisco Peaks from Doney Park - 0239Z

0253Z

10 August

Some tropical storm moisture and a Pacific low overlapped a bit over northern Arizona, and I headed east once again for a look. My first view was from east Flagstaff of a cell to the southwest over Kachina Village. Although the base was strung out, it was still decent by Arizona standards as it played at displaying some tail cloud characteristics. After that dissipated, I got east on I-40 and hung out at Homolovi State Park for a while, grabbing time lapse as a new cell got going southwest of Winslow. This one sported some more beautiful structure as the orange landscape reflected up onto the base of the storm. Bryan Snider and his wife Monika showed up and we shot some time lapses together as the storm grew a lowering and grumbled at us. We got ahead of it as the rain moved in and watched from Hibbard Road as it withered and sheared away. Later that night, another round of convection slowly moved up from Verde Valley and gave an opportunity for some nighttime lightning photography at Sunset Crater National Monument. Not a lot of nearby CG activity as the storms weakened by this point, but still some good under-cloud illumination against the cinder hills and ponderosas.

Cell over Kachina Village as seen looking southwest from east Flagstaff - 2010Z

2014Z

Lowering on a new cell over Winslow as seen from Homolovi State Park - 2302Z

2302Z

2303Z

2307Z

2316Z

Sheared convection looking west from Hibbard Road & I-40 - 2331Z

2336Z

2337Z

Monsoon storms got an early start on July 2nd. The night before, the HRRR model was trending toward an MCS rolling out of southern Nevada and into Flagstaff by around 6 AM. I set my alarm for 5 and sure enough she was right on schedule just west of town. I quickly threw myself and everything else in the car and headed out on east Route 66 to watch it plow through town. I love watching Arizona storm clouds when they’re in high-speed mode.

Storms towering over Flagstaff as seen from east Route 66 - 1226Z

Gust front making its way out of town - 1230Z

A nice eddy sculpts the gust front as it rushes by the south side of Mt. Elden - 1231Z

Since it looked like it might stay interesting, I headed east to Twin Arrows—and was reminded how much I disliked the view from that exit. So I headed a bit further east to the Buffalo Range Road exit—no real foreground elements to speak of, but at least it wan’t fences, power lines and dumpsters. As the gust front moved in, a northern stretch of it lunged out and sculpted an amazing, terraced shelf.

Beautifully sculpted shelf cloud between Twin Arrows and Two Guns - 1302Z

I jumped further east to Two Guns and composed some shots of the ghost town structures with the heavy morning sky. I’ve snagged a few photo ops with the stone structures in the area, but this was my first time working with the buildings on the east side.

Moody sunrise over Two Guns - 1313Z

Insane graffiti and advancing storms at Two Guns - 1317Z

After that, I raced ahead to Holbrook and then southeast on Hwy 180. The line of storms was messier at this point but still had some moments of shelfy goodness to offer.

Fangy, embedded shelf cloud southeast of Holbrook - 1451Z

Tantalizing scud photographed on the move, southeast of Holbrook - 1458Z

As that line weakened and moved off to the east, I had a look at the models again. Indications were that the morning cirrus shield would move on, the atmosphere would recover, and more storms would fire, despite subsidence in the wake of the morning MCS. So I headed back west and decided to explore Homolovi State Park for a little bit while convection slowly got going again.

Receding convection and windmill on Hwy 180, southeast of Holbrook - 1612Z

A Loggerhead Shrike keeping an eye on parking spaces at the entrance to Homolovi State Park

Pottery shards gathered on stone platforms at the Homolovi II Archeological Site

Cumulus bubbling south of Homolovi State Park - 1957Z

Convection strengthening over the San Francisco Volcanic Field - 2016Z

Collared Lizard showing off its colors at Homolovi State Park

Storms continued firing west of Leupp while tracking along and north of I-40, so I headed over to Rt 99 northwest of Winslow, then the Meteor Crater Road exit, and then back to Rt 99 south of Winslow. Storms were not as sculpted as they were that morning, but still enjoyable viewing on desolate roads.

Convection south of Leupp from Rt 99 - 2147Z

Lightning strike from north of Meteor Crater Road - 2246Z

Transient structure at the I-40/Rt 99 offramp - 2306Z

Storms forming along an intersection of outflow boundaries south of Winslow on Rt 99 - 2348Z

A hangnail of vorticity and a sunbeam along Rt 99 - 0007Z

I wrapped it up with a time lapse near Clear Creek as distant storms pulsed along a southward moving outflow boundary.

Convection and anvils along a receding outflow boundary from near Clear Creek - 0048Z

A short sequence of time lapses from the day.

I had a nice local storm chase today. I headed west, past Wiliams, to catch storms as they started firing and hopefully ride them east with some road network testing along the way.

A little after noon, I took an exit at Welch Road a few miles east of Ash Fork to get some shots as convection was developing to the west. Somebody had kindly donated* a sofa. It was facing the wrong way, but I was not tempted by its mysterious comforts.

Furniture spotting on Welch Road east of Ash Fork - 1950Z

A couple other angles as it dared me to take a load off.

As cells blew eastward, I cruised up to Williams and took Rt. 64 north to see what would pop up next on the outflow. I stopped a bit south of Valle to watch a transient lowering, as one does when trying to randomly spot landspouts. While I was there, another chaser, Jonathan Triggs, from Grand Canyon Village stopped to say hi before making his way toward Flagstaff. Convection at this point was pretty laid back, wimpy and grungy as I circled back southeast on Hwy 180.

A momentarily interesting updraft east of Valle - 2031Z

Tendrils of rain that kept reflexively catching the corner of my eye - 2052Z

Made a stop at Red Mountain for a quick look around—I need to hike this cinder cone some day - 2119Z

Although I’d been hoping for a chance of a developing cell drawing up some vorticity as the gust front passed the San Francisco Peaks, it seemed pretty unlikely at this point. So I decided to run an audit of one of the forest service roads, north of the Peaks in the no-man’s-land between Hwy 180 and 89.

I got about three miles in, before the likelihood of getting stuck and busting my car in the rocky, cratered road became too great. I stopped and found a spot to hike up a hill to get some shots of a pretty decent cell popping up north of the Peaks by that time. Lots of terrain mostly blocked the view as it continued eastward and joined a strong line of storms that moved off onto the Navajo and Hopi Reservations.

Looking east at a cell developing north of the San Francisco Peaks - 2159Z

Some wildflowers in the area starting to like the recent rain - 2203Z

Rain core getting established - 2207Z

After shooting a few angles, I made my way back down toward Hwy 180 and did a bit of Coconino Cow Spotting before calling it a day.

Gate guardians

Bossy momma

*dumped

Storms of 2015

2015 went down as another year without a tornado. However, awesome weather was still in abundance, and I got to enjoy some exhilarating storms with at least one gorgeous, white funnel that stared us down between Burlington, Colorado and Kanorado, Kansas.

This year I put a lot more effort into tracking down mesocyclone potential in Arizona and wound up with some beauties. Three of them were solid, daylight examples of Arizona supercells, with deep rotation lasting over an hour. A couple more nocturnal supercells hid their structure behind terrain and darkness while other daylight examples of rotating storms were more transient and weak—but still fascinating during their brief, messy lives.

This is a video and time lapse compilation some of the amazing storms I chased and photographed across the high plains and Arizona in 2015.

Storms of 2015

Music:
Beautiful Shapes by Louis Romanos Quartet
Forgotten Shore by Dhruva Aliman
beatpick.com

Arizona Storm Chase - 9 August 2015

After noting a great supercell near Winslow, I opted to head toward Twin Arrows to see if some developing convection would take off there. It was good for a lot of heavy rain, but hardly any lightning and it didn't manage to organize.
 


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While I was toying with that mess, another storm north of Flagstaff crossed the threshold to the Colorado River Valley, west of Wupatki and went supercellular.
 


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As I pondered my situation and whether I could race to that storm in time before it drifted into the extremely hard to navigate spaces west of Hwy 89, it picked up a tornado warning. So I dropped the slop I was on—to at least give it a try. By the time I had visibility on Hwy 89, it had the merest remnants of an elevated base.
 


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On the chance it might cycle up on some new convection to the south, I took a pretty decent forest service road along the cinder cones north of Sunset Crater. What did pop up didn't develop rotation but still managed to make for some nice storms and lightning.

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Arizona Storm Chase - 8 August 2015

More storms showing up with couplets this day, but I didn't manage to intercept them during prime structure. The landscape made up for a lot of those issues. These shots are from Hwy 89 north of Flagstaff along the Mogollon Rim/Colorado River Valley margin.

A scud bomb merging into the updraft between Sunset Crater and Wupatki National Monuments.
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More disorganized convection playing with sunbeams north of the San Francisco Peaks.
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Benign convection percolating as the atmosphere begins to stabilize.
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Sunset Crater is trying to peek between the trees on the right.
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Convection has turned to mush almost everywhere, leaving a great sunset aftermath—just northwest of Sunset Crater National Monument, looking toward the San Francisco Peaks.

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The Mogollon Rim Convergence Zone worked its magic the past 3 days with southwest flow leading to some especially favorable shear along the Colorado River Valley.

On my way north to meet the best shear parameters—which I thought would be best near Page and the Arizona Strip, I encountered some heavy convection and a nice roll cloud and gust front north of Cameron on Hwy 89.
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I figured this one would probably stabilize the air mass pretty solidly, so after following it a bit, getting photos, looking for lightning and doing some roadside nowcasting, I started making my way towards Page. A couple hours later I found myself at The Gap to pick up a replacement 9-volt battery for the lightning trigger. Radar showed a couple strong storms lighting up to my south—where I thought things had already been played. So I raced back south and started catching sight of a very healthy looking anvil peeeking over the plateau to my west. Once I cleared the horizon-blocking hills, I got to meet a beautiful Arizona supercell drifting toward me from the west.

This is the first time I've caught Kelvin-Helmholtz waves along the elevated base of a supercell—and it was an hour from home. This view faces northwest as the cell moves over the edge of the Painted Desert.
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Another view as the storm starts to pass to the north
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I followed it through Tuba City and further east where it was trying to hand off to a new base before slowly withering.
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I just finished editing and uploading video to the September 27, 2014 chase report.

Arizona Storm Chase and Supercells - September 27, 2014 from Jeremy Perez on Vimeo.

Video account and time lapse sequences from the chase.