Monday 20 May 2013

2013 Chase Day 13 - Moore (OK) and Paul's Valley (OK) to Ardmore (OK)

Even though we started the day in the middle of the SPC's MDT area, I knew we had to be much further southwest for storm initiation (ideally west of Oklahoma City once more) for the best tornadic potential. Multi-model consensus suggested a fairly early initiation time of 2-3pm, so I chose Chickasha (OK) as our starting position and we subsequently drove from our hotel in Tulsa (OK) down the I-44 Turner Turnpike towards Okalhoma City, then south on I-35 through Moore (OK) and into Norman (OK) where we stopped for some lunch (about 1pm). I remember commenting on how nice a day it was, with the extensive morning stratus now breaking with some chinks of blue sky appearing. It's amazing how quickly things can change...

I began to worry that Chickasha (OK) may be too far west and was half-tempted to wait in Norman (OK), but knew at the same time that given the largely urban and populated area it wouldn't be ideal chasing territory, so we nudged a little further south to Purcell (OK). We only waited about 15 mins before cells were already firing on radar and visibly as a row of anvils to our west, so drove south on 74 to Maysville (OK), paused to check the latest situation, and then west on 19 to Lindsay (OK). We could see new updrafts going up to our north and managed to capture a photograph of them (below).
Updraft towers of the Newcastle/Moore (OK) supercell, prior to turning tornadic
We pulled over on the side of the road just west of Lindsay (OK) to view the developing mesocyclone, albeit very high based, on this storm that we were aiming for. The storm was still moving northeast, so we drove north on 76 to follow it, passing Mike Bettes and Dr Greg Forbes of The Weather Channel fame. However, it quickly became clear that the new supercell over Newcastle (OK) and one near Marlow (OK) were the main players, and this one we were chasing was dying very quickly. We had to make a decision - head north after the Newcastle cell, or south towards the Marlow one.

I chose not to go any further north after the Newcastle (OK) supercell, even though it was only 20-25 miles away, because I knew it would pass over a heavily urbanised/populated area of Moore (OK), which would not be ideal for chasing, especially with rush hour approaching in an hour or so. Instead we headed back south and east on 39, 59, 122, 24 and 74 back through Maysville (OK) towards Elmore City (OK). En-route we could hear on the radio that a tornado had touched down near Newcastle (OK) and was heading straight for Moore (OK), and we knew this didn't sound good. At the same time, the Marlow cell became tornado-warned also, although no reports of an actual funnel at this stage. We went through some rain between Maysville and Elmore City, then headed west on 29 into the rain-free inflow.

Stepping outside the car (amongst many other chasers and law enforcement on the same road) it felt very warm, humid and very windy with strong southeasterlies. We could see the ragged wall cloud through a gap in the trees to our northwest, and kept a close eye on it as it continued to try and become better organised. Suddenly the winds turned westerly and it felt cooler, so we jumped back in the car and drove east, back through Elmore City, before stopping the other side to observe. Still no significant development was occurring from the base of this storm, just a very threatening-looking cloud base. All the while we were hearing of the devastation being caused in Moore at exactly the same time from the EF-5 tornado, and this had already begun to affect our mood.
Nice green tinge - hail anyone?
Once again warm inflow winds turned to cool outflow, while it was also apparent a new cell was approaching from Duncan (to the southwest of the original cell) with a new meso and wall cloud to our west. This eventually became the dominant feature as we continued to nudge-stop further east on 29 towards the I-35 intersection. The wall cloud was starting to look better and more promising for tornadic development as it neared I-35, and we dived north on 77 to Paul's Valley (OK). The coverage of the Moore tornado on the radio suddenly changed (briefly) to the storm we were chasing, with the residents of Paul's Valley being told to get into their shelters. Unfortunately there were just too many trees and very few opportunities for us to park on 77, so we had to head back south towards Wynnewood, along with many other chasers.
The closest this supercell came to producing a tornado, between Elmore City (OK) and Paul's Valley (OK)
It appears the cell was really ramping up, and by the sounds of chasers on the News9 live radio coverage it sounded like it could drop a tornado at any minute - but it didn't. The storm itself continued to head ENE towards Stratford (OK), while we had to take a rather long route round due to the poor road network locally, via the 29 east then 177 north. Radio coverage turned back to the Moore event which was (thankfully) coming to an end by this stage, but new details of casualties and damage were forever being added through the following hours, and our moods kept changing more to sadness than excitement. This wasn't fun, and part of me just wanted to stop chasing for the day and head to a hotel.

What we hadn't kept an eye on was the developments further south - other initially discrete supercells had merged into a massive MCS/line, and had effectively developed to the south and east of the cell we were chasing, cutting off it's inflow and causing it to rapidly weaken. We gave up on this storm, and after having a quick look at the forecast for tomorrow we decided to drive towards Paris (TX) to spend the night, enabling us to be in a good enough position for tomorrow's activity in parts of northern Texas.

However, this looked easier than it actually was. Firstly, we had to navigate around this cell we had been chasing to avoid it's remaining hail core - this involved driving north on 177 to the Canadian River, then dropping back southeast on 3 towards Ada. Then we had to somehow core this MCS line to get on the other side; we had two attempts, the first attempt down 377 until we went into very heavy rain and hail, where we decided to turn around and go back towards Ada. The second attempt took us down 3 until we reached Tupelo (OK) where we once again went into some hail and heavy rain. This wasn't working, so we parked the car underneath a petrol station canopy and waited 30-45mins for the rain and hail to gradually ease off to our east. There was no physical way we could get through this line of storms (with rotation and large hail in places), the western edge was all the way back to Wichita Falls in Texas, miles away!

Plan B lead us towards Ardmore (OK) which gave us a fast route south ready for the next day on the I-35. Thus, once the hail had passed we headed back north to Ada on 3, then southwest on 1 (including the very strange Chickasaw Turnpike), 7 and 77, and then the I-35 to Ardmore (OK). While unpacking the car a rogue couple of thunderstorms with small hail passed over the area, so we temporarily put the car under the hotel awning until it eased! We went to bed still feeling very sad and shocked at the tragedies of the Moore tornado, with continued coverage on radio and The Weather Channel.

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