Wednesday, 30 May 2012

Final chase day - May 29th

Today went out with a bang - lots of them!

We started the day in Lawton and headed to El Reno for lunch. We then headed to near Watonga and saw a storm develop to the north. After a while we headed towards it and basically stuck with it as it became a supercell and then moved slowly south-east towards Oklahoma City. It showed some pretty nice structure at times, but was packing 3-5 inch diameter hail, so we remained out of the core.

We got down to Piedmont and decided, as another cell was moving up from the south-west, with golf ball sized hail, that we'd take shelter underneath a petrol station awning.

The storm from the south-west passed just to our south-east, throwing a powerful gust front across us with some pretty nasty winds. As this bashed into the northern cell the updraught area took on an even more interesting looking appearance. I wondered whether this interaction might briefly strengthen the low-level rotation - it did. Tornado sirens suddenly wailed, and a narrow funnel could be seen to the west, only a couple of miles away. These few minutes were pretty intense!

Some hail started falling but nothing more than marble size. I have always entertained dreams of being under shelter as giant hail came down but it wasn't to be - probably for the best for other people nearby!

However, parts of northern Oklahoma City got pounded and we heard reports on TV of numerous cars with most windows being bashed out.

I had remarked to Helen earlier that with a NW-SE storm motion perhaps echoes of a very nasty hailstorm a couple of years ago, which moved into OKC, would be realised - how prophetic!

Anyway, we let the storms pass over and finally headed to our hotel in western Oklahoma City for our final night - flight home is tomorrow.

Supercell near Loyal, Oklahoma


Dave Lewison and Scott McPartland

East of Loyal - dust mainly kicked up by other cars. Wall cloud viewed from west.

Ian 'Windy' Miller

Supercell low-level mesocyclone just south of Okarche, Oklahoma


Supercell mesocyclone just after outflow from another storm to south slammed in, at Surrey Hills, near Piedmont, Oklahoma


Same - brief tornado developed within this circulation although very tricky to see from our location. No pics but funnel can just be seen on video.

Tuesday, 29 May 2012

Lunch in El Reno

Just stopped for lunch at Subway in El Reno. Warm front is to our north and north-west - perhaps a double-type structure as evidenced on radar.

I think we might head a bit further north or north-west but we might not have to go far. Initial storms should develop across NW and  N Cent Oklahoma on the warm front, and perhaps in W Oklahoma on the dryline. Storm motion south be SE or S today so anything which develops will head this way. After initial supercell development, such a motion with relatively weak low-level flow is likely to mean an upscale growth into a SE'wards moving MCS or two. This could yield a nice shelf cloud if they conglomerate enough.

Oklahoma - May 28th - skinny supercell

Today started sunny in Salina, Kansas. We knew we had to blast south to get storms but the last few days of chasing and driving, and not getting to bed until at least 1.30am most nights meant it was tough to get up. However, we left before 11am and hit the road southbound.

We stopped for lunch in northern Oklahoma, at a Subway we'd stopped at back in 2008 - back then we we heading north at the start of the trip, 2 days before a tornadofest started up.

Anyway, back to today - we continued south, through Oklahoma City and onto I-44 towards Lawton. We'd picked Wichita Falls as a place to head towards as various models had suggested a complex of storms would move towards there later on in the day - we knew we wouldn't get the early discrete stuff in Texas.

However, we caught up with the cold front not far from Chickasha, Oklahoma, and a cell exploded into life, west of Lindsay. We decided that as this was close-by and exhibiting very strong upward motion in the tower, we'd take a look. As we got around to the south side of it, just south of Lindsay, we were greeted by the sight of a developing supercell updraught, beginning to rotate strongly, with a powerful core developing. A hail roar could be heard aloft, and it wasn't long before a few stray stones started pinging down. We had to get east, which involved a short jaunt back north to Lindsay, and then east towards Maysville. A few 1 to 1.25 inch stones came down amongst the marbles. We dropped south of Maysville and caught sight of the updraught again. We watched an it continued to rotate strongly, but started to take on more of a low precipitation supercell look about it. It then went about decaying in the textbook LP fashion, revealing more and more of the skinny updraught - it was stunning to see a rotating column about 8-10 miles high, but only a couple of miles wide.

Eventually it went completely and some new cells were moving up from the SW. As these reportedly contained hail to tennis ball size we decided not to get into them. The main storm was a left mover from a previous storm split - the updraught was on the northern side of the storm with the precip core to its south.

This then moved away and we headed just north of Maysville to see another supercell in the distance to the WNW - a decent wall cloud was under it for a short time but it started to fall apart. Some intense CGs were coming down, and I managed to capture one on still camera, purely because it had multiple return strokes.

We've stopped in Lawton, Oklahoma, for the night - one more chase day to go.

Supercell getting going near Lindsay, OK. Me explaining to camera what's going on - no response from camera.

South of Maysville - nice core.

Storm starts to loose it.

Updraught starts to fly apart, but still rotating strongly.


Giant, rotating cylinder with decreasing precip.


Almost gone.

Mammatus under anvil of next storms.

Lucky capture CG lightning splitting Sun.

Sunset in Maysville.

Monday, 28 May 2012

Heading south

Morning! We'll be leaving Salina shortly to head south to southern Oklahoma or northern Texas - a few supercells may develop before transitioning into a larger-scale system. I doubt we'll get there in time for the initial supercells but may be able to intercept a squall line. If not, we need to be down that way anyway for both another risk tomorrow, and then DFW airport on Wednesday.

Various storms in Kansas - May 27th

We started today in Hays, KS, and spent the morning working out that we didn't really need to move far. We spent until mid-afternoon either in the Subway or McD's carparks, chatting to Will at times.

We decided to start heading a little north, and before long, cell started firing along the dryline, just to our west. Cue a sudden explosion of convection, which, when tied with an upper flow not far from parallel with the initiating boundary, tended to become severe for a while and then turn a bit more mushy. Even so, it was a very pleasant way to spend the afternoon, with thunder growling around, convective skies in every direction, and open Kansas countryside.

We noted a stronger cell heading towards us, near Stockton. We decided to intercept but very quickly, some 1.5 inch hail chunks started falling. Cue an amusing scene where I was trying to grab one and bring it in, and then getting Helen to measure it, whilst getting a picture, and trying to turn the car around!

We then dropped south onto a very picturesque low-precipitation supercell north of Hays, which we stopped to photograph. Another cell was to the south, so we dropped south to I-70 at Hays, and then east to Russell. We got a nice view as the cell recycled and a new LP supercell developed. It was almost dark by then but some shots were taken.

We then headed east, stopping to get some more pics as the storm moved away.

We then headed to Salina for the night. Tomorrow, I think we'll be starting early and heading down into Oklahoma. The risk is moving south, which is useful as we need to be back in DFW by Wednesday.

Hastily measured hail - it was 1.5 inches, even if it looks less!

Panorama of LP supercell north of Hays (centre and left), and another one to the south (right).

Mammatus from the southern storm over Hays

Original LP storm, viewed to the north, from Hays.

Supercell after dark near Russell.

LP supercell moving away to the north-east, near Wilson.


Sunday, 27 May 2012

Still in Hays

It's like we just rewound 24 hours - sitting in the Subway carpark waiting for storms. However, the risk is higher today. Latest guidance still shows a surface low forming close to or west of here, with backing surface flow by early evening, as well as a strengthening low-level jet. Thus, although hail remains the prime severe threat, I think tornadoes are possible this evening across north-central Kansas.

Sunday thoughts

Only 3 chase days left to go now, and it looks like each will bring the potential for severe weather, so at least there is plenty to keep us occupied as we start to draw the trip to a close. However, let's not think about leaving yet as there are still 3 days to go!

Today, a cold front will move from the NW into central Nebraska and Kansas, as a powerful upper trough works in from the west. Strong southerly flow ahead of this is transporting reasonable moisture northwards although still not as high as one might expect at this time of year. Even so, with favourable kinematics and thermodynamics in place, another round of severe thunderstorms is expected. The main threat today, given strong instability and wind shear, is very large hail, perhaps 4 inches. Thus, today is not a day to get overtaken by the core, or have to approach the mesocyclone from the north or west!

The risk area is large, as you would expect from a frontal boundary. The tornado risk is low overall but one location which might be able to produce is extreme south central Nebraska into north central Kansas, where a surface low pressure area is progged to develop by early evening by several models, close to the cold front/dryline intersection. Cloud bases will be high during the afternoon due to the large temperature/dewpoint spreads, but cooling during the early evening, along with the increase of the low-level jet may be enough to get a couple of tornadoes going. Also, storms will modify the environment by producing cooler outflow, and sometimes other storms can ingest some of this air and have lower cloud bases.

As we're starting in Hays, and need to be in Oklahoma tomorrow for a severe threat there, we don't want to be heading way north. I don't think we'll have to go too far north, though, given my thoughts above.

A Norton - Smith Centre - Russell - WaKeeney square would be a good starting point, so until further analysis of both observational and short-range model data is possible, there's no reason to stray too far from Hays.

Hays - that's it

Today we managed to do close to 70 miles, just to move about 100 yards from the Sleep Inn in Hays to the Best Western in Hays.

We did this via heading to the north of town, where I attempted to get a tan; then to Subway for lunch, and then McD's for coffee. During this time, Helen watched the entire Eurovision Song Contest over the web.

We were intending to head to Nebraska at some point during the day ready to chase tomorrow, but as time went on, the prospect of driving 180 miles for no apparent reason seemed less enticing. This is because there is also a risk of severe storms around here tomorrow too.

Also, a cell popped up about 100 miles to the SSW, near Dodge City, and became severe. We decided to book into the Best Western, and then headed west to Ellis, to watch the cell come in. It was motoring along at about 50mph now, so it arrived as we did. Not much rain, but quite a lot of wind. A semi in front of us almost went onto just one set of side wheels, and we were concerned it might blow over - luckily it didn't but the driver must have been unnerved, as he turned off at the next junction, and stopped on the side.

We went up a side road and stopped to measure the wind. I measured 46.6 knots at arm height, which is not bad - 80mph winds had been observed further south but I guess it had lost some intensity.

We then headed north for a bit after it, but it was moving away quickly, and dying out. We headed back to Hays. We saw Will Owen and Jacci Ingham - they had gone to look at the storm too.

I went for a swim, or rather, sitting in the hot tub listening to screaming American kids jumping around in the pool. After a while they went to so I could get a little swim in, and cool off a shade as the hot tub was hot!

Dinner in Applebee's (no surprise!). A line of storms has developed to the west and is throwing out a nice gust front. Storms seem to be developing behind this gust front as the low-level jet rides up and over it, and pumps moisture into the updraughts. They might make it here.

The radar image below shows the storms, and also the gust front (the long green sausage). Hays is at the top, about 2/3rds from the left.

Saturday, 26 May 2012

Good morning!

Hello! After yesterday's incredible chase we woke up reasonably late this morning - I didn't go to bed until after 2am and even then was still quite pumped up about the chase.

Today's best tornado targets are probably Wyoming, in an upslope flow regime, and along a warm front in northern Nebraska. Wyoming is probably too far, and the sandhills of northern Nebraska, whilst very picturesque, are not great chase territory, given very few roads.

There is a chance of isolated supercells developing along a rather diffuse dryline through central Kansas today too. Given that's where we are, I think we'll probably see if we can find one around here. Model guidance suggests at least a chance of development, and convection-allowing models show one or two cells developing through the peak heating of this afternoon. If these develop, they are likely to be rather high-based, as dewpoint depressions will be rather large. However, there could still be something quite nice to be had!

Thus once we check out we'll assess the latest data, and also consider where we need to be tomorrow and make a final call on where to head to.

Tornadoes in Kansas! May 25th summary

The day started drizzly and humid in Salina, Kansas. The SPC had issued a slight risk of severe thunderstorms, with a 5% risk to our west. Morning analysis and model guidance suggested the Great Bend - Hays - Russell triangle would likely be a good starting point, so we headed to Great Bend for lunch.

We spent a while at Subway - managed to Skype my Dad and Mum whilst there. We also met Scott McPartland, Dave Lewison, and the remainder of their chase team - it was great to chat. Stu Robinson also joined us so it was great to catch up with him too.

After a while, word came through that development was starting towards LaCrosse/Rush Center. We all parted company and generally headed that we. We headed north after a while as we wanted to make sure we remained ahead of the developing storm, and not let it get away to our north.

We played around for a while with this storm, observing numerous outflow vortices (known as gustnadoes by many chasers). We also caught sight of a dusty tornado to our north.

After a while it became apparent that this storm was crossing the warm front and starting to look less interesting, at least to us. We paused somewhere south-west of Russell, Kansas. The next storm in the line was throwing out plenty of CGs and we watched as a wall cloud developed to our west. However, this became ragged after a while so we started to head south as a much bigger storm had developed back down towards LaCrosse (the tail-end storm). As we did so, we noticed another very flat, well-defined updraught base to our west. This began to develop a wall cloud, so we paused to watch. We repositioned and got sight of a brief tornado before it dissipated. We then watched for a while longer as the main updraught continued to move north-east. However, the previous low-level mesocyclone was not done. As it started to drift westwards, it suddenly wrapped up and generated a stunning tornado directly down the road. We got several shots which were reminiscent of some of my earliest ideas of Great Plains tornadoes might look: a line of poles down the side of the road, with the tornado in the distance.

It then roped out in an orangey sky, as the sun set.

Thunder was now booming to our south-west, so we continued to drop south to intercept the next storm, which was already producing tornadoes. We stopped to watch it for a while, about 15-18 miles to the north-east. The thunder was incredible - enormous distant explosions, which seemed to shake the very earth.

After a while we decided to drop south and then head west. As we closed in on the mesocyclone we stopped, and observed 3 tornadoes develop in reasonably quick succession. It was after dark by now.

After these had gone we headed to Hays for the night, although had to negotiate some slippery dirt roads as LaCrosse has sadly suffered damage and we couldn't go through the town. We only passed through this little place a few days ago.

Below are a few pics. Video of rope-out here -

Observing initial supercell

Initial supercell

Tornado from occluded low-level mesocyclone develops

My childhood vision of a tornado, with poles

Stunning ropeout


Almost gone

Developing cone tornado east of LaCrosse after dark

Stovepipe-type tornado east of LaCrosse after dark

Friday, 25 May 2012

Great Bend for lunch

Just had some lunch at - guess where - Subway! We're at Great Bend, Kansas, and now starting to think about where we might head from here, if anywhere. Guidance is still suggesting the cap will break to the SW of here but the warm front has already lifted north, so we might hang here a little longer to see where the various pieces of the puzzle end up. If anything can go, the veering wind profiles close to and just north of the warm front are very favourable for low-level mesocyclones and tornadoes.

Kansas slight risk

Morning! Today looks potentially interesting although a stout inversion may keep the atmosphere capped in many places. An area of low pressure across the SW of Kansas should slowly move north or north-east today, as a dryline mixes eastwards to its south, and a warm front lifts north to its north-east.

Targeting the triple point of the dry line and warm front should yield the best chance of thunderstorm development, and along and just north of this warm front, backed low-level winds should give the best chance of low-level mesocyclones and possible tornadoes.

As always, pin-pointing the exact location of these features for late afternoon via models yields somewhat different results - thus, picking a relatively central starting target point and then refining as observations come in is the plan. Guidance suggests that the Russell - Hays - Great Bend triangle may be a good starting point, so either Russell or Hays for lunch seems a good plan, and then refining from there.

There's also a chance of severe storms down the dryline into western Oklahoma - indeed, some models, such as the ECMWF, are much more bullish about storm development down there than around here. However, with a deeper boundary layer, the tornado risk would seem lower down there than close to the warm front.


We decided to head to Salina today rather than chasing the fast-moving mess which was expected across portions of the Upper Mississippi Valley - rather glad we did, although slightly annoyed that we didn't hang around in Nebraska to chase the scattered showers and odd thunderstorm which moved from the west, and somehow managed to produce a tornado!

Anyway, we got to one of our familiar hotels, the Sleep Inn, and I proceeded to head to the pool. Sadly the hot tub was out of order, so after getting a few lengths in I opened the window to let the sunshine in and proceeded to give the Speedos, and my very white body, some sunshine.

After a relaxing hour or so in the pool and sunbathing I headed back to the room, and we went out to Applebee's (surprise surprise!) for dinner.

On Friday there's a small chance of a severe storm here in Kansas as a dryline starts to come in from the south-west and a slow-moving frontal boundary is across the north of the state. It looks like things might crank up towards Sunday, but we're just enjoying the holiday a day at a time.

Time for bed now - it's still 21C outside at 1230am!

Thursday, 24 May 2012

Day 10 - May 23rd - severe thunderstorms

We started the day in Hays, Kansas. With a cold front moving in from the north-west and a modestly moist southerly flow ahead of it, we decided to head north-east into SE Nebraska. The initial target location was between Geneva and York. We had lunch in Geneva, enjoying the 34-35C heat and strong southerly winds. We had decided that if we were going to get as far as York, the east and then north option was more favourable, to keep ahead of the cold front.

We hung around there until around 4.50pm, having Skype'd my brother, Rich, and his partner, Ann, from the car.

We then headed north to Fairmont and then east past Exeter and Friend. By now, storms had developed further to the north along the cold front, but as is often the case in such situations, the activity started to build south-south-westwards along the front. We noted some towering cumulus to our west and paused to observe this. It was rapidly developing, with a very flat, firm, base - indicative of a stout updraught. We then headed north towards Seward -  by now, it had now become a thunderstorm. It had rapidly organised amongst the strong shear and started to exhibit supercellular characteristics. However, the RFD was already surging out of the storm and it quickly became apparent this would be an outflow dominant storm, as was expected. The storm had overtaken us a bit now so we had to continue north and then east towards Wahoo before we caught sight of the updraught again. The storm had become tornado warned, but I have seen no reports of a tornado. From the look of the updraught area at the times we saw it, the outflow-dominance was quite pronounced. We ran into some quite large hail, and paused to measure it...1.5 inches, which we reported via Spotternetwork - it was in the NWS obs within 5 mins, so a good dissemination there.

We saw plenty of dust whirls along the outflow but once to the NW of Omaha, we let the storm go, as we didn't think it was going to do much more.

We then dropped south ahead of the next cell, which was looking quite strong on radar. We stopped to the north of Gretna and spent a good hour or more watching the storm spit out some stunning CGs. I used Helen's Olympus bridge camera to try some 15 second exposures - I got the settings reasonably well adjusted after a while, and caught the following images. The last one has been cropped for more dramatic effect but the others are 'as is'.

Tomorrow sees the SVR risk shift into Wisconsin and environs - models are suggestive of some quite active/severe thunderstorms as the cold front moves east, and low-level wind profiles are suggestive of tornadoes. However, it also looks like with a fast moving cold front moving across, early discrete development may quite quickly transition into a fast moving squall line with a damaging wind threat, perhaps widespread. I'm not really sure the 450-500 mile drive is worth it! I'm sure a number of chasers will, and I wish them all the best, and look forward to seeing imagery of tornadoes that we've missed - however, I'm not sure we can justify the drive.

Wednesday, 23 May 2012


Just stopped for lunch in Geneva, Nebraska. Cumulus are now covering the sky although as expected, high based. Cold front is moving in from the north-west, with some kind of pre-frontal wind shift evident too. Latest short-range convection-allowing model guidance still tries to break out thunderstorms close to here by 1800 local time, although it's a little touch a go. With such a stout cap, being close to the front is probably necessary, but the same front will likely undercut cells rather early on in development. However, we'll see - stranger things have happened!

North of Salina

Just paused at a rest area north of Salina - ob from Kestrel, at stretched arm height: 34.4C over 16.5C dewpoint. Southerly, 23.4 knots, gusting 36.6 knots!

Nebraska today

Hello! Just finished looking at the available observational and model data for today and I think we'll initially head towards York, Nebraska. A cold front will move in from the north-west through today but should become somewhat more slow-moving as it approaches SE Nebraska. A modestly moist airmass ahead will yield CAPE values to around 1500-2000 J/Kg by mid-late afternoon, and most models break out precip along and behind the front. A few cells may manage to develop just ahead of the front too. Large hail and winds will be the main threats, but an isolated tornado or two is possible, especially with more discrete development early on. The whole lot should transition into a line this evening, with further thunderstorms likely north of the front tonight.

Sunflower State - and a painful ankle

Hello! Today was a positioning day. We drove from Amarillo to Hays, Kansas. This is about 350 miles, give or take - more give I think! This was in anticipation of severe thunderstorms tomorrow across portions of south Nebraska, and possibly N Central Kansas. A strong capping inversion has overspread the Plains, and low-level moisture remains meagre by late May standards. Even so, an approaching upper system, strong low-level heating, and persistent convergence along a cold frontal boundary should initiate at least isolated convection. The magnitude of the shear suggests supercells will be possible, and with very steep mid-level lapse rates, some very large hail may develop, along with strong winds. A tornado is possible, but like recent days, it will be down to very local storm-scale processes if one can occur. Of course, most tornadoes probably develop from storm-scale processes, but on some days the wider environment can also be very conducive to tornadic development - tomorrow is likely not one of these.

As for today, though - nothing of much note occurred other than enjoying the Plains scenery, which is generally quite verdant at the moment given some recent rain.

Early in the drive, as we were getting out of Amarillo we stopped for petrol. I cleaned the windscreen and the Go Pro captured this. What was most annoying, and painful, was the fact there in front of the car, a dip several inches deep in the tarmac was present. I didn't see this, and put the whole of my not unsubstantial weight onto my left foot, which was on the edge of this dip, and rolled over on my ankle - ouch! The image below shows the immediate facial aftermath - I'm quite surprised I didn't beat the entire front of the car and windscreen in with the windscreen scraper thing, but I'm on holiday, so I'm fairly chilled out!

Tuesday, 22 May 2012


Morning! We're heading north today in anticipation of a slight risk of severe thunderstorms tomorrow across portions of Nebraska. The capping inversion may hold but if it goes, supercells will develop, and with good directional shear, there is at least the chance of a tornado.

We're heading to Hays - 4 years to the day since we stayed there with Matt Dobson and James Brennan, during a period where we saw several tornadoes!

Great storms and some structure too!

This morning we woke to find the SPC had placed a slight risk across west Texas and eastern New Mexico. We had thought something might fire but circumstances had got a little better through the night - for example, some elevated storms had left something of a boundary, and also put a little more moisture into the air.

We headed to Clovis for lunch and noted storms firing to the west and north-west, over the higher ground of New Mexico. Guidance and past experience suggested that these would eventually coalesce into a line of south-eastwards moving storms with wind/hail, but initially the development was more isolated.

We headed west and then north to Tucumcari, where we saw a great high-based storm with copious amounts of CG lightning, and some wind/hail too. We headed east and got ahead of the developing line of storms to see some nice outflow features. We then had to continue east to get away from the core.

An isolated storm had been going for some time to the north of Adrian, Texas, and was now moving slowly southwards. This direction placed the storm in a favourable inflow regime to become a supercell, and it duly did. We approached this southwards moving supercell from the west, a reasonable direction in these circumstances. The structure was pretty stunning, as the Go Pro images below show. A tornado was reported by chasers at about the time of these pics, and we noticed an interesting feature as we drove, and the pics seem to also show it - this *may* be the tornado, but we can't be sure.

As we got closer to the storm, it became apparent that the RFD was full of reasonably large hail (1 inch or so), driven on by a strong wind. We decided to wait for the main core to cross I-40 before continuing eastwards. Not more than a couple of miles to the east the road suddenly was covered in 2-3 inches of hail, and the rapid cooling of the moist air above by the ice generated copious amounts of blowing hail fog. Needless to say the driving conditions were pretty appalling and we pulled off at Adrian to await the melting of the hail and clearing of the fog. The fog continued to blow past for a good 15-20 mins, and the temp dropped to about 6-7C!

Eventually we headed to Amarillo, where we've checked in for the night. We met Paul Sherman and the Netweather chase crew at Applebee's, and swapped storm stories - they were in a better position to see the brief tornado.

All in all a great chase day on a marginal set-up!

Supercell - *possible* view of the tornado to left of road.


Closer view of supercell


Lightning and me!

Hail covering road and hail fog

Hail at petrol station in Adrian

Hail covering ground at Adrian