Monday 22 May 2017

Day 9 - New Mexico

A Slight risk of severe thunderstorms was forecast for today by the SPC (Storm Prediction Center) with a 2% chance of a tornado within a 25mile radius - might sound low, but when you're constantly moving from storm to storm naturally your odds will be higher than if you sat in 1 location all day long expecting one to come to you. That said, given the low dew points it seemed unlikely to happen given the high cloud bases expected.

We headed south from Amarillo (TX) to lunch in Lubbock (TX) before moving west across the border into New Mexico (our 3rd state of the trip) and into a different timezone - Mountain Time, which is 1 hour behind Central Time, or alternatively 7 hours behind UK time rather than the 6 hours we'd become accustomed too thus far.

By this stage a few thunderstorms had developed over the higher terrain of New Mexico, but as they moved southeastwards over the high plains they were struggling to maintain intensity due to limited moisture and marginal upper support. We parked up north of Dora (NM) to watch a few of these storms attempt to become supercells but fail, but eventually things started to look more promising and a couple of severe-warned storms (1 inch hail and 60mph winds) were born and began to head in our general direction.

We headed west to refuel at Elida (NM), with the first of such storms practically overhead by this stage. We followed it south, the storm following us, but ran out of paved roads - and had no option but to drive for a good 17 miles east on dirt roads, which meant the storm caught us up and we ended up right underneath it. Some small (marble sized) hail and heavy rain made the drive a little more interesting, but the storm was weakening and essentially dissipated within 30mins or so.

Low-precipitation supercell thunderstorm over a gas station in Elida (NM)
Spying another couple of severe-warned storms to our northwest, we decided to head further west towards Caprock (NM), and chose a south road to park up and watch these 2 storms - the westernmost one had a nice looking base, and on radar at least a decent couplet. This storm became tornado warned, but given a good view of the rather high base it was clear nothing much was going to happen, and sadly it didn't produce. In fact within 45 minutes the storm had also completely disintegrated.

iPhone pano of the 2 severe warned thunderstorms approaching Caprock (NM)

Low updraft base of a low-precipitation supercell thunderstorm west of Caprock (NM)
The updraft 30 minutes later - practically disintegrated!
As the sun set we were treated to a rather nice orange-lit mammatus display from the decaying anvils, before heading to Hobbs (NM) for dinner and our hotel for the night.

Our GPS location (blue circle) in relation to the severe-warned (yellow polygon) thunderstorm to our NW, with tornado warning (red polygon)

Sunday 21 May 2017

Day 8 - Oklahoma Panhandle

The plan today was to head to Dalhart (TX) in the far northwest TX panhandle, and then reassess from there as to how things were looking. We lunched in Amarillo (TX) en-route and headed up towards Dalhart - a cluster of severe-warned thunderstorms had already formed over SE Colorado, moving slowly (10mph or so) to the ESE and so would push into the Oklahoma panhandle with time. We nudged north through Boise City (OK) and parked just north of town to watch the very turbulent skies. CG (cloud-to-ground) lightning was very frequent with this high-based thunderstorm, and it became very outflowy - in fact, the wind felt icy cold once the outflow reached our location! Nonetheless, it was cool to watch the very turbulent skies with lots of eddies.

Into The Storm - north of Boise City (OK)

The only lightning shot I managed to get - daytime lightning is quite difficult for an amateur photographer!

We headed east to near Keyes (OK) to keep ahead of the storm (where we bumped into Tony Gilbert), and here it became incredibly windy whipping up loads of dust. We followed this thunderstorm complex southwards towards Stratford (TX), but it was weakening all-the-while as it encountered a less unstable environment. The chase was called-off relatively early to head back to Amarillo (TX) for dinner and an overnight stay, to get us closer to the expected action on Monday...

Day 8 into 9 GPS tracker

Saturday 20 May 2017

Day 7 - Rest/position day in TX

The options today were either chase a messy cold front into deep south TX, knowing we would need to drive 6-7 hours back north on Sunday to be in position for Monday's storms in west Texas, or ditch the front to do the drive now and maybe catch a few high-based storms over the TX panhandle on Sunday before the main bigger risk on Monday.

We drove south for a couple of hours to try and keep up with the storms near San Antonio (TX), but after getting stuck in traffic in Austin (TX) we decided, over lunch in San Marcos (TX), to ditch this cloudy mess and head for the sunshine behind the cold front and try our luck at some high-based marginally-severe storms in the TX Panhandle Sunday. Steak in Abilene (TX) for dinner and then an overnight stay at Snyder (TX).

Looking ahead, the pattern for the 2nd and final week of this year's trip has some promise of chaseable weather - especially Monday in west Texas, Thursday in Colorado and perhaps Friday in Kansas/Oklahoma which would serve us well to make our way back to Dallas (TX) for Saturday evening's flight home. Overall the pattern is quieter than last week given a trough over the eastern US and northwesterly flow aloft, but small perturbations in the flow should offer some convective activity at least - hopes for a tornado, mind you, are pretty low given a lack of substantial Gulf of Mexico moisture.

Day 7 (into Day 8) GPS tracker

Friday 19 May 2017

Day 6 - TX

A messy start to the day with several rounds of convection ongoing across many parts of the Plains - it looked like the best parameters for a tornado would be in eastern OK, but given the messy setup we decided to opt for NW TX initially given the promise of some cloud clearance and late day isolated thunderstorms. We drove south from Elk City (OK) to Vernon (TX) for lunch, with mammatus above our heads for much of the journey.
Mammatus display north of Vernon (TX)

Storms were already in evidence, with a tornado-warned specimen south of Abilene (TX), so we continued to nudge south in that general direction - but Texas is a big place! It took us several hours to get to the cluster of thunderstorms that looked promising on radar, but once we eventually arrived in the evening they looked pretty outflow-dominant. There were a couple of reports of a tornado SW of Brownwood (TX) but we couldn't see anything from our location and it was likely rain-wrapped.
Nonetheless, we witnessed some spectacular structure and the lightning became prolific deeper into the evening as we let the cluster of thunderstorms slowly follow us to our hotel in Killeen (TX) for the night. We were woken up several times overnight by thunderstorms moving through the area.

Outflow-dominant storm south of Santa Anna (TX)
Our location (blue circle) in relation to severe thunderstorm complex (yellow polygons are severe thunderstorm warnings). The cell to our northern produced a tornado SW of Brownwood apparently...

Day 6 GPS tracker

Thursday 18 May 2017

Day 5 - NW OK

The SPC (Storm Prediction Center) had issued a rare 'High risk' of severe thunderstorms for today, capable of all hazards - very large hail, damaging winds and strong tornadoes. I'm always sceptical about Moderate or High risk days because several times in the past these types of days are often associated with ample amounts of the key ingredients required that it tends to turn quite messy fairly quickly, and often ends with disappointment.

With that in mind, there were also large discrepancies amongst the model output as to how the day would evolve, with several of them simulating a large round of thunderstorms moving NNE-wards across Oklahoma into Kansas, which would potentially overturn the atmosphere and make it hard for any significant tornadoes to form with any deep convection later in the day.

In either case, we left Enid (OK) at lunchtime and headed some ways west to get closer to the dryline, which was close to the TX/OK border. Refuelling in Seiling (OK), storms were beginning to fire to our west and becoming quickly severe-warned. We nudged back to Bouse Junction (OK) to give us some options to either of these storms, then up to Waynoka (OK) to wait for the storm near Seiling to get closer - it had become tornado warned, with reports of a tornado on it.

The terrain around this part of Oklahoma is not particularly ideal, with hills around the river valleys and quite a few trees too - it made getting a good visual on the base of this approaching supercell quite hard, especially considering the very low base to the evident wall cloud. As such, we followed the storm for some time north to Alva (OK), but couldn't tell for sure if there was a tornado on the ground or not because of the wide wall cloud that was hovering just above ground level. Nonetheless, it looked very dramatic, but soon began to weaken, so we ditched this storm once we reached Alva and headed back south to chase a couple of other cells approaching from the southwest.

Wall cloud near Waynoka (OK)
These looked like they were weakening as they ran into the much cooler boundary layer air (temperature had dropped from 28C to 19C after the first round of storms) so we were going to park up and let them come over us (as they were no longer with a warning). However, they rapidly intensified as they approached us, and we had to move quickly to keep ahead of them - radar velocities suggested damaging winds of 70+mph were possible. The storm kept accelerating NE-wards and we couldn't keep ahead of it (due to road options) so we had to seek shelter in a car wash in Alva against the large hail. As we parked up, the storm became tornado warned! Numerous emergency vehicles suddenly started their sirens, and the tornado siren then followed - very eerie.

Shelf cloud of approaching storm south of Alva (OK)

Shelf cloud of approaching storm south of Alva (OK)
Our GPS location (blue circle) in relation to the tornado warning (red polygon) at Alva. Any potential tornado would be with the bowing/hook segment to our SE

Radar scans would suggest the part of the storm with the potential tornado would stay south of town so I wasn't overly concerned, but we experienced a lot of heavy rain, thunder and lightning, and a flash flood on the nearby road. Once things had died down, we headed south and spent the night in Elk City (OK) to get closer for Friday's target - the town who's southern suburbs were hit by a substantial tornado on Tuesday.

Day 5 GPS tracker

Wednesday 17 May 2017

Day 4 - Rest/position day in OK

Given the lead impulse was now moving away towards the Great Lakes with a subtle upper ridge now covering much of the southern and central Plains, a down day was expected for Day 4 before the next 2 very active days as the western US upper trough moves closer. We decided to slowly amble northwards to be in position for Day 5, stopping in Norman at the Storm Prediction Center, and then Wakita (OK) - a small town in northern Oklahoma where the film Twister was set, with a dedicated museum run by a lovely lady who was clearly still passionate about the film over 20 years on.

The home of the Storm Prediction Center in Norman (OK)

One of the Dorothys used in the film Twister, stored at the Twister museum in Wakita (OK)

The Wakita water tower that features in the film Twister

We ended the day in Enid (OK) and all enjoyed steak for dinner to celebrate our tornadoes from yesterday. 

Day 4 GPS tracker

Tuesday 16 May 2017

Day 3 - TX panhandle to W OK

We left Dumas (TX) late morning and trundled southeastwards towards Wheeler (TX), stopping at Shamrock (TX) for lunch and a refuel. A lot of chaser convergence in the area, surprising number of Brits too! Had a chat with the Netweather team and Dave Ewoldt, before lifting a little north to Wheeler (TX) once again to re-assess.

By this stage, a few storms had began to fire out west, and were rapidly intensifying on just a couple of radar scans. We dropped south to McLean (TX), and parked up just south of town to watch this supercell eventually produce a tornado to our west! After a few minutes it began to get rain-wrapped, so we followed it north and caught it during it's roping out stage just southwest of McLean. There was also some sizeable hail on the grass verges here too.

Tornado beginning to form southwest of McLean (TX)

Tornado in progress southwest of McLean (TX), beginning to have wrapping rain curtains

Large hail on the ground just south of McLean (TX)

Now the tricky and frustrating part - there were two potentially tornadic supercells to chase, both to our east and moving to the northeast at 35-40mph (i.e. away from us) so we then spent several hours playing catch up, trying to get ahead and look into the storms. The northern storm produced a large, rain-wrapped tornado near Wheeler (TX), while the southern storm went to produce a damaging tornado (again, rain-wrapped) near Elk City (OK) - we missed both of these due to the logistical issues (not that they would have been photogenic anyway), but we stopped a couple of times to watch the frequent lightning as darkness fell in the evening, before spending the night in Lawton (OK).

Tornado warning (red polygon) for the supercell thunderstorm, with our location (blue circle)

Day 3 GPS tracker

Monday 15 May 2017

Day 2 - TX panhandle

Monday began in Amarillo - and a look at various models and observations we decided to sit tight as initiation would be close to the N-S dryline over Amarillo (TX) around 4-5pm. So, to kill time we visited Cadillac Ranch, popped to the Big Texan shop to explore their souvenir merchandise and then camped out in McDonalds (where else?) whilst watching the cumulus attempt to grow and collapse multiple times over the course of a couple of hours.

Eventually things started to look more promising, so we nudged a little further east to get out of the metro area as it was now rush hour, and parked up a short distance east of Amarillo. Numerous towers were going up, but struggling to organise themselves and clearly being sheared-off by the strong mid-level winds. Eventually a few began to look a bit healthier visually and on radar, as we nudged progressively northeastwards towards Panhandle (TX) and then eventually Borger (TX).

Clear rotation from this thunderstorm near Borger (TX)

Nice base with the sun setting behind north of Borger (TX)

The supercell to our northwestof our location (blue circle)

By now, several of the storms had become severe-warned, but in a rather messy fashion - one cell directly to our west had an interesting base, while another storm well to our south continued to aim directly at us while visibly bubbling-away, eventually becoming quite outflow-dominant. We followed these storms north to Stinnett (TX),  allowing them to cross the road in front of us and eventually finding some sizeable hail on the grass verges that the storm had put down.

Large hail on the ground north of Stinnett (TX)

By now the sun was setting, so after watching the lightning from the storms as they moved farther away from us, we turned round and headed to Dumas (TX) to spend the night.

Day 2 GPS tracker

Sunday 14 May 2017

Day 1 - TX pandhandle

Having flown from Heathrow to Dallas on Sat 13th May, we began today in Irving (TX) and headed northwest to Amarillo where it's likely we could be near for several days based on how the forecast looks. The SPC had issued a Marginal risk of severe storms in the TX panhandle, nothing majorly exciting but a nice little storm would be a great way to begin this year's chase.

Our first McDonald's of the trip was Childress (TX) for lunch, before continuing to head to Claude (TX). En-route, a few isolated storms had formed on the dryline, struggling to organise themselves - we opted to drop south to intersect a few that had formed near Happy (TX) and were heading generally in our direction.

First McDonald's of this year's chase at Childress (TX)

Towers attempting to grow, but struggling initially

We saw several flashes of lightning, constant grumbling of thunder as they approached and began to line-out. Once the storms had passed east of our location they became severe-warned for hail and wind - the main threat being strong outflow winds. It went from 32C and near calm at our location, to 20C and buffeting winds picking up dust and tumbleweed in a matter of minutes.

Rainbow in a hail shaft of a marginally-severe thunderstorm
The line of storms became severe-warned (yellow polygon) as they passed to the east of our location (blue circle)

We eventually headed back to Amarillo (TX) and booked a hotel - the others then went to the Big Texan steakhouse, I made the hard decision of staying at the hotel and going to bed as I was really struggling to keep my eyes open! (as it was technically 3am in the UK at this time). Looks like a few days of active weather coming up in the general area.

Day 1 GPS Tracker