WKU Storm Chase 2016 – Day 12

Posted on May 26, 2016 by
Today's route map. An interactive version is available below

Today’s route map. An interactive version is available below

Models indicated this morning that a much deeper surface low would coalesce by the afternoon as a shortwave ejected northeastward along an upper-level trough. This low would be the deepest and most organized of the trip, and as a result the most well-defined warm front of the trip would be in play. These warm fronts are important because, like weaker outflow boundaries, they provide an axis along which low-level winds back and improve the overall shear profile. This warm front would provide a more focused area for rotating supercell and tornado development. Since the surface low was expected in southwest Kansas by the afternoon,  the warm front was expected to drape along the Nebraska-Kansas border, and our target was north central Kansas. We decided to move to Salina for another look at data and make futher decisions about our target.

11 AM CST mesoanalyses and radar analysis combined with surface observations indicated clear mositure wrapping from the south counterclockwise around the low through north central Kansas. The axis of this moisture wrapping was centered on Ellsworth, KS. The 11:30 SPC convective outlook update upgraded central Kansas to a moderate risk with a 15% chance of tornadoes and a 10% chance of EF-2 TO EF-5 tornadoes. Satellite and radar observations indicated boundary interaction near Russel, KS. We targeted that city and moved to wait for initiation.

12:30 PM CST initiation in southwest Kansas outside of our target area quickly became messy and numerous due to a very weak cap over the region. This brought concerns for our target area, as early convection could stabilize the atmosphere enough that later convection could struggle to initiatie. We became uncertain about the severity of the day, which turned out to be warranted.

We decided to intercept a storm just north of Jetmore that had initated to the southwest of the target region. We chose this storm because the larger storms to the south were entering a cloudy environment that convection had already been present in. The Jetmore cell was entering a clear area, and was closer to the boundary so better shear was present. The storm ended up fizzling, but the larger storms to the south were moving north into a boundary, so we moved ahead of them to attempt an intercept, even thought the storms were non-rotational. Road conditions quickly deteriorated, and we were left with no clear escape route. The storm’s shelf cloud overtook us (Figure 1), and we got deluged on.

Figure 1: A shelf cloud overtakes the van in Otis, KS

Figure 1: A shelf cloud overtakes the van in Otis, KS

After the storm weakened, we stopped in Hoisington, KS to decide what to do. It seemed that the incredibly messy convection and low shear were causing this day to become unchaseable, and we nearly called a scrub. One cell near Dodge City, where outflow and dryline convergence had produced more organized storms, gave us hope however, and we moved to intercept. Intercept occurred in Hanston, KS, where the storm showed us the closest thing to a tornado we had seen all day (Figure 2) when she showed us a lowered rotating wall cloud. The storm was tornado warned for about 15 minutes, and then lost rotation as it merged with other cells and became a QLCS (quasi-linear convective system).

Figure 2: A lowered, rotating wall cloud is visible on the far right. Taken looking south from Hanston, KS

Figure 2: A lowered, rotating wall cloud is visible on the far right. Taken looking south from Hanston, KS

We raced ahead of the squall line to our hotel in Great Bend, the same hotel we stayed at just two nights ago, and made it there just in time.

We appear to be very close to our target tomorrow in central Kansas, although the passing of the shortwave trough that created today’s low will create some downward motion of the atmosphere which may inhibit strong updrafts.

-Isaac Bowers

Click this link for an interactive chase map!

 

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WKU Storm Chase 2016 – Day 11

Posted on May 25, 2016 by
Today;s route map. An interactive version is available below

Today’s route map. An interactive version is available below

Much weaker low pressure and the presence of much weaker and more diffuse boundaries meant today would likely be a slow day for storms across our target region, although instability and mid-level shear would be enough to support supercell development in any updrafts that were capable of breaking the moderate cap. Tornado risk was much lower today due to the aforementioned lack of a strong outflow boundary/warm front that would back low-level winds. However, the boundaries that did exist seemed to converge near Salina, KS, and we targeted that location for initiation. Low expectations and proximity to the target region meant a late start, and we departed Great Bend, KS at 10:30 AM CST.

En route to Salina, the SPC upgraded nearly the entirety of eastern Kansas to a slight risk as model data indicated an expected bulge in the dryline just south of the low pressure center. The convergence provided by this boundary may support sufficient lift to initiate supercells that would thrive in the unstable environment ahead of the dryline.

After lunch at the Cozy Inn in Salina, KS, 3 PM satellite and surface analysis indicated that a strange double-boundary was setting up, pushing our target either north or south to two separate dryline/boundary interaction points. We chose the southern target, and moved to Florence, KS to make further decisions.

Initiation occurred southeast of Wichita, KS at 5:15 PM CST. It appeared unimpressive on radar, but it was the only cell in the area that fired, so we moved to intercept. In El Dorado at 5:45 PM We viewed the storm as an impressive updraft formed (Figure 1), but the updraft was thin, and as we chased it became entrained and was choked off (Figure 2). It was believed the storm could have been over-sheared.

Figure 1: An impressive updraft on the El Dorado cell

Figure 1: An impressive updraft on the El Dorado cell

Figure 2: The El Dorado cell chokes itself off

Figure 2: The El Dorado cell chokes itself off

After calling the chase and on our way back to Wichita for the night, an interesting supercell formed to the southeast of the city. Again, it appeared unimpressive, but it was the only storm that was sustaining itself, so we decided to investigate. Upon intercept, the storm remained unimpressive on radar and was non-rotational (although the naked eye could see some rotation in the lowered base), but it did provide some impressive sunset views.

Convergence ended up being better at the northern bulge, closer to the low. A tornadic supercell was spawned near Bennington KS. Surprisingly, convection struggled to sustain itself in the southern environment. This was again likely due to a weaker boundary than the northern target zone.

Tomorrow a classic baroclinic low will set up in western Kansas, providing a much higher risk for severe weather across central Kansas. It should be an active day!

-Isaac Bowers

Click this link for an interactive chase map!

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WKU Storm Chase 2016 – Day 10

Posted on May 25, 2016 by
Today's route map. An interactive version is available below.

Today’s route map. An interactive version is available below.

Words cannot describe the feelings I experienced today.

I could say I was awe-inspired, and it would not be enough. I could say I was terrified, and it would not be enough. I could say I was exhilarated, and it would not be enough.

So much happened today that it was difficult to keep track of every event, but I will try my best to recount today’s remarkable journey.

Another weak surface low developed overnight in southwest Kansas in a similar setup to yesterday. The upper-level trough was parked over the Mountain West, and continued providing almost daily ejections of vorticity and wind speed maxima into the central and southern Plains. This low again provided an anchor for the dryline that draped southward across west Texas, as well as some low-level convergence needed for lift. This low however lacked a clear warm front, which would have encouraged low-level shear by backing the winds near and along it. This problem was solved by yet another outflow boundary from an MCS in Kansas that stretched west-to-east across southern Kansas in the morning. We forecasted that this outflow boundary would be pushed north in the afternoon to align with the low pressure system and act as a warm front in this environment. Our target was where we thought this “triple point” of low pressure, dryline, and outflow boundary would align; southwest Kansas, specifically Greensburg for initiation.

It should be noted that this environment is an extremely similar setup to yesterday, so we were initially wary of being overzealous.

We had lunch in Greensburg and a 1 PM CST analysis of satellite imagery showed that the placement of the dryline and outflow boundary pushed our target to the south and west. We decided to move to Meade, KS and wait for initiation. We tossed a Frisbee in Meade City Park until around 4:15 PM CST, when we believed that the only tornado of the day would be located in Scott City, KS. As we moved north, it was noted that directly overtop of Meade, a large convective updraft had fired and was growing quickly. We turned around to intercept in Minneola, KS. This was a decision that shaped our entire day.

Very quickly it became apparent that this cell was taking advantage of the abundant low-level shear, as the base quickly lowered and began rotating. We were able to watch as the updraft lowered a funnel in front of our eyes (Figure 1). The sheer speed that the column was rotating was incredible to us, and we were able to watch clouds lift and form just feet from the ground. We rooted on our little funnel as it twisted over the empty fields of Kansas.

Figure 1: The Minneola supercell drops a funnel

Figure 1: The Minneola supercell drops a funnel

The funnel touched down briefly at first, kicking up dust circulation near the ground. It then planted itself firmly and became a full fledged tornado, and grew in size from a small rope to a thick cord and larger (Figures 2 and 3). The giddiness of seeing this awesome structure became tainted with a small amount of fear. This destructive force was growing unchecked. What was a fun, cute rope tornado was now looking like an EF-1 and strengthening. As we chased the storm north, the first funnel withdrew and roped away, but it was the first of many tornadoes that day.

Figure 2: A rope tornado forms from the Minneola cell

Figure 2: A rope tornado forms from the Minneola cell

Figure 3: WKU students watch as the Minneola tornado intensifies

Figure 3: WKU students watch as the Minneola tornado intensifies

We watched the storm cycle through two to three more independent touchdowns as we chased, one occurring simultaneously. When we next stopped, a large funnel, the 4th of the storm by our count, had slid up the base and the storm was again going through vortex cycling (Figure 4). In seconds, the storm threw down two twin rope tornadoes, and the storm had three tornadoes on the ground at once (Figure 5). Never before had I experienced whatever emotion I felt in that moment This storm that contained three tornadoes was headed directly for Dodge City. My adrenaline was roaring, and recognition of this storm’s incredible power really resonated for the first time. This was obviously something incredibly special and incredibly dangerous.

Figure 4: The supercell undergoes vortex cycling southwest of Dodge City. Two tornadoes are visible at once

Figure 4: The supercell undergoes vortex cycling southwest of Dodge City. Two tornadoes are visible at once

Figure 5: The lower vortex becomes multi-vortexed, dropping sister tornadoes. Three tornadoes are visible on the ground

Figure 5: The lower vortex becomes multi-vortexed, dropping sister tornadoes. Three tornadoes are visible on the ground

After 9 visible tornado touchdowns and quickly deteriorating road conditions became a problem (Kansas dirt turns to Kansas mud very quickly), we decided to escape the area, as storms to the south and west were quickly cutting off our escape route as the storm moved through west Dodge City. As we raced west on the south edge of the storm, we were able to view some damage in the storm’s path. Power lines had been completely ripped from their bases and were no longer at the side of the road, having been carried by the winds to the middle of some far-off field. Fences had been ripped from their posts. Heavy rain and hail from a ventilating storm to our south blocked our view of some power lines that were hanging mere feet from the road, almost until it was too late. A powerful downdraft pushed a semi-truck into the oncoming lane, and we had to swerve to narrowly avoid it. (A large thanks goes to Dr. Durkee for saving our lives).

We passed through Cimarron, KS where we learned that both roads east into Dodge City had been closed, so we proceeded north and east to our hotel in Great Bend, KS. We stopped to show that beauty can be found even in the most violent of situations (Figure 6).

Figure 6: Mammatus clouds form in the wake of the violent supercell

Figure 6: Mammatus clouds form in the wake of the violent supercell

Today proved to me just how important an understanding of meteorology is to our society, and how nature can be as beautiful as it is destructive. The feelings I felt today are feelings I believe I will never feel again. I trembled as we left that storm, and I still feel the power of it this evening. I know I speak for all of the students when I say that this is a day we will remember forever.

-Isaac Bowers

Click this link for an interactive chase map!

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WKU Storm Chase 2016 – Day 9

Posted on May 23, 2016 by
Today's route map. An interactive version is available below

Today’s route map. An interactive version is available below

Morning observations identified a weak surface low over the extreme western Oklahoma Panhandle as a result of a shortwave trough rotating through the region that would provide some convergence and an anchor for the dryline draped in a southwest-northeast fashion across the Panhandle region. Model data indicated that CAPE values would reach the 4-5000 J/kg range by mid-afternoon, and steep low-level lapse rates would advect into the area as well. Ample moisture and weak capping in this environment indicated strong updrafts would be possible capable of producing severe hail. Bulk shear values between 35 and 45 knots that would increase throughout the day pointed to the likelihood of supercells capable of producing tornadoes. A convective outflow boundary from an MCS (mesoscale convective system) moving out of central Oklahoma would cross into Texas by early afternoon, and would provide an area of enhanced shear due to the forced backing of the low-level wind profile along this boundary. We decided to target the southeast Texas Panhandle for initiation; specifically Clarendon, TX. Due to the distance of the target from our Nebraska hotel, an early start  of 8:30 AM CST was required, and it was uncertain if we would even make it to Clarendon by initiation hour.

10 AM CST SPC Mesoanalysis indicated decent low-level shear and Effective SRH (storm relative helicity) maximums in the 400’s already in place over the target region. This caused STP’s (significant tornado parameter) to rise above 2 over the target area before daytime heating even occurred, which was very impressive. By 2:30 PM CST, model guidance and mesoanalyses began aligning and agreeing on the southeast Texas Panhandle for the best chance of tornadic supercells. Inititation took place around 3:40 PM CST less than 5 miles east of Clarendon, TX, a bullseye hit on our target selection. We were still about 40 miles away, so we changed route to intercept the storm south of Shamrock, TX.

We intercepted the LP (low precipitation) supercell east of Clarendon, which began entering a mildly capped environment shortly after we arrived (Figure 1). Although the structure was impressive, it was very similar to storms we chased yesterday in Nebraska, so we opted to move to better looking storms to the southwest. As we made our way there, all other initiated cells seemed to once again struggle when moving east away from the dryline. The SPC offered the possible explanation of a lack of low-level convergence in this area, but with storms already initiated, it seemed that they should be able to support themselves in such a rich environment. We began scratching our heads once again in Memphis, TX as we waited for a better cell to organize.

Figure 1: The Clarendon cell disintegrates shortly after initiation

Figure 1: The Clarendon cell disintegrates shortly after initiation

With daylight fading, we began a last ditch effort to chase a cluster of storms developing west of Memphis. As we chased, the cell south of Alanreed, TX began to show signs of rotation and a hook echo. We changed our route to intercept the storm since it was the best looking in the cluster. On our way there, we decided to take a questionable road (County Road E on the map) to get a better look at the storm. We had to turn around when it got too muddy, and as we tried successfully to 100-point-turn our way out, a TVS appeared on radar, and reports of a brief weak tornado over nearby I-40 also appeared. We returned to a higher quality road and viewed the nearly stationary storm from an excellent vantage point, but never viewed another funnel from the storm (Figure 2).

Figure 2: Post-tornadic cell beginning to shear its own updraft off

Figure 2: Post-tornadic cell beginning to shear its own updraft off

The storm eventually twisted its own updraft off in a similar fashion to yesterday’s storms as it entered a more stable environment to the west, but it looked remarkably unusual. The updraft seemed to feed a much larger area of downwind precipitation than it could support for its size, and it appeared to twist and rope away from a far-away and miniscule inflow base (Figures 3 and 4). It was a structure I’ll never forget.

Figure 3: The updraft begins twisting itself off. The rotation is clearly visible.

Figure 3: The updraft begins twisting itself off. The rotation is clearly visible.

Figure 4: The updraft completely separates from its cloud base.

Figure 4: The updraft completely separates from its cloud base.

The sun set shortly after the tornadic storm dissipated, and we were able to take some excellent photographs of a supercell to our south whose colors were so vivid they barely needed to be edited (Figures 5 and 6). We proceeded to our hotel in Shamrock, TX for the night.

Figure 4: A vivid sunset lights up a southern supercell

Figure 5: A vivid sunset lights up a southern supercell

Figure 6: Sunset on the van

Figure 6: Sunset on the van

Hopefully Shamrock can provide us with some luck as we proceed north and east to chase tomorrow!

In addition, one of our students, Lucas Cantos, took several time-lapse videos of our amazing structure day in Leoti, KS on Saturday. They are some epic glimpses at the storm’s motion, so follow this link to have a look.

-Isaac Bowers

Click this link for an interactive chase map!

 

 

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WKU Storm Chase 2016 – Day 8

Posted on May 23, 2016 by
Today's route map. An interactive version is available below

Today’s route map. An interactive version is available below

Morning model data indicated a broad area of severe risk, but two specific areas of interest became clear to us. A surface low began to form overnight in northeast Colorado as a result of the upper-level trough moving in from the west. A dryline extended from this low down through southwest Nebraska, eastern Colorado, and the western Panhandle region. Ample moisture on the boundary indicated storms would likely fire from the northern Plains to Mexico. However, deepening of the low throughout the day, as well as the presence of low-level convergence and backing of low-level wind profiles provided by this low led us to choose southwest Nebraska as a target region. It was argued that the central Texas panhandle may provide some organized convection, but the lack of a decent cap over the region indicated that storms would be messy and numerous, which makes them difficult to chase and observe. Combined with the sheer distance from the target our hotel was, this eliminated the Texas panhandle as a target.

After lunch in Colby, KS, the same city as our hotel was located, we headed north to North Platte, NE. We set up in an initiation holding pattern just south of the city near Lake Malone and waited. Similar to yesterday, initiation took much longer than expected for the given environment. As better shear entered the region, all signs pointed to an explosive day. By 5:50 PM CST, the cap broke and we began chasing the initiated convection northeast. Storms far to our north were much more impressive, but in an area that harbored far worse chasing conditions such as hilly terrain and few side roads.

We proceeded to Maxwell, NE to view the storms (Figure 1), which seemed to struggle inexplicably as they moved northeast. After some truly harrowing chasing (and excellent driving) on the sandy back roads of central Nebraska. We cycled through chasing about three cells. By the time we were able to return to pavement, most of the cells had weakened, and one cell to the south seemed more impressive. We turned around and viewed this storm from the side to try and gain an understanding of why the storms the initiated in this environment struggled so much (Figure 2).

Figure 1: WKU Meteorology student Jessica Dobson documents an initiating convective updraft in Maxwell, NE

Figure 1: WKU Meteorology student Jessica Dobson documents an initiating convective updraft in Maxwell, NE

Figure 2: A twisting, bent updraft visible in the last storm of the day

Figure 2: A twisting, bent updraft visible in the last storm of the day

The helical structure of the updraft and the bending back that took place in these cells caused many of the updrafts to quite literally rip off the tops of the storms and kill them. This would usually indicate a high-shear, low-CAPE environment, but CAPE was reaching the 3500 J/kg threshold, which would sustain updrafts even in a higher-shear environment. After some research, we determined that a likely cause was a shortwave trough rotating through the southwest Nebraska region that was visible on water vapor imagery. This trough would have provided sinking air to the target area from above. This, combined with impressive instability, caused updrafts to be limited in height and, as a result, these updrafts were forced to bend backwards. The high shear in these storms then had ample time time twist and distort these updrafts until the were ripped free from their associated thunderstorms. This explanation is speculation, but it does provide a reasonable answer for the lack of HP and sustained rotating supercells.

After a nutritious dinner at Runza in North Platte, NE, we headed home for the night in Lexington, NE. We will likely target the Kansas-Oklahoma border tomorrow, as a more classic setup seems to be moving into the region.

-Isaac Bowers

Click on this link for an interactive chase map!

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WKU Storm Chase 2016 – Day 7

Posted on May 21, 2016 by
Today's route map. An interactive version is available below

Today’s route map. An interactive version is available below

A forecast discussion last night in partnership with College of DuPage at our hotel pointed out an area of instability ribboning from Amarillo, through southwest Kansas, and north to the Cheyenne Ridge in northeast Colorado. A moisture axis paralleled this ribbon of instability, and upper-level divergence over western Kansas  would encourage lift along the dryline. This lift would provide enhancement to an otherwise similar setup to yesterday, assisting storms in breaking the cap. Both HRRR and NAM model data placed a strong convective cell over western Kansas, and supportive shear values and lapse rates indicated this cell would likely be supercellular and at least contain large hail. We targeted Garden City to await initiation and departed at 9:15 AM MT.

After lunch in Garden City, we met once again with our friends at the College of DuPage to watch a weather balloon launch (Figure 1). This balloon would help us diagnose the strength of the cap over the region as well as bulk shear. Preliminary data observed dry adiabatic lapse rates or greater in the low and mid levels, indicating quite an unstable environment. We left our friends in Garden City and headed northeast to Marienthal, KS to await initiation.

Figure 1: Dr. Victor Gensini of the College of DuPage launches a radiosonde from Garden City, KS

Figure 1: Dr. Victor Gensini of the College of DuPage launches a radiosonde from Garden City, KS

After arriving in Marienthal at 3:30 PM CST, radar indicated a dryline boundary colliding with an axis of moisture convergence over the northwest Kansas region. After waiting an unusually long time for initiation for such a ripe environment, SPC Mesoanalysis indicated an area of mixed-layer CIN capping the region, which would explain the lack of convection. Initiation finally occurred directly west of us at 5:45 PM CST. After viewing one storm after another from a park in Marienthal (Figure 2), radar indicated weak rotational couplets on the backside of three thunderstorms. We moved to intercept the strongest of these couplets, which became tornado warned on our way.

Figure 2: Convective initiation west of Marienthal, KS

Figure 2: Convective initiation west of Marienthal, KS

While chasing the storm on KS-25, a funnel cloud developed and visibly touched down. However, the storm contained an unusually high lightning threat, which prevented us from exiting the vehicle to document the tornado.

We continued to chase the nearly stationary storm for several hours, and documented its incredible structure (Figure 3) until the light faded and we were forced to scrub the chase near 9:30 PM CST. The storm total accumulation product indicated over 8 inches of rain had fallen over 4 hours, and this became evident as we attempted to travel north to our hotel in Colby, KS. We ran into a very flooded wash on KS-25 and were forced to turn around (Figure 4).

Figure 4: WKU students, along with Dr. Josh Durkee, document the Leoti, KS supercell

Figure 3: WKU students, along with Dr. Josh Durkee, document the Leoti, KS supercell

Figure 4: Flooding on KS-25 just south of the Logan County line (Photo credit: Grady Dixon)

Figure 4: Flooding on KS-25 just south of the Logan County line (Photo credit: Grady Dixon)

Tomorrow looks to be the most active day of chasing thus far, and we will likely proceed to southern Nebraska to intercept storms produced by a deep upper-level trough.

-Isaac Bowers

Click on this link for an interactive chase map

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WKU Storm Chase 2016 – Day 6

Posted on May 20, 2016 by
Today's route map. An interactive map is available below

Today’s route map. An interactive map is available below

Marginal instability and low but sufficient moisture, as well as a moisture boundary moving into eastern Colorado led us to target Colorado Springs this morning. The lack of upper level divergence, lower level convergence, and frontal boundaries forced us to rely on the topography of the Rocky Mountains for lift. Low-level southerly flow would push moisture and instability north against the mountains, and an upper-level trough provided northerly flow, which would push any storms that formed southeastward along the moisture boundary. This led us to go ahead and book a hotel in Lamar, CO for the night.

We departed Raton, NM at 9:15 AM MT and arrived in Colorado Springs, CO for lunch at 12:15 PM MT. We enjoyed a quick Jimmy Johns and proceeded to the eastern suburbs of Colorado Springs to await initiation by 1:15 PM. Mesoscale analysis at 2:30 PM indicated an axis of instability stretching from Amarillo to Colorado Springs, and a moisture boundary approaching from the south was visible on radar, as well as to the naked eye. A cumulus field to the south demarcated that boundary. If a storm was going to occur, it would occur here.

By 3:45 PM, after waiting nearly two and a half hours for initiation, it became clear that initiation would likely not occur. Several updrafts attempted to rise (Figure 1), but instability was too low for updrafts to break the cap, even with topographic forcing and moisture present. We decided to proceed to our hotel for the evening.

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Figure 1: Convection attempts to initiate east of Colorado Springs

Tomorrow appears to be the beginning of a very active few days for us. An upper-level trough will begin to dig across the region, and the central Plains will see excellent moisture return over the next day or two. We will likely target the area of highest instability in southwest Kansas tomorrow afternoon. Stay tuned!

-Isaac Bowers

Click this link for an interactive chase map!

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WKU Storm Chase 2016 – Day 5

Posted on May 19, 2016 by
Today's route map. An interactive version is available below

Today’s route map. An interactive version is available below

Although morning observations indicated a decent boundary in extreme south Texas and model data suggested sufficient instability to produce thunderstorms, sheer distance and the necessity to set up for our next few events prevented us from traveling there. We instead decided to side with slightly longer range data that indicated moisture return and trough placement over the next few days may be sufficient for initiation near eastern Colorado and western Kansas by Saturday or Sunday. We began driving to Raton, NM for the night at 9:15 AM MT

Since we would not be chasing throughout the day, we decided to take advantage of the beauty rural New Mexico offered and visit White Sands National Monument in southeast New Mexico. On the way, we crossed the Organ Mountains and traveled through the White Sands Missile Range (Figure 1). After a brief but harrowing experience at the US Customs and Border Patrol checkpoint just south of White Sands due to a Brazilian passport mishap, we arrived at the monument’s Visitor Center (Figure 2).

The Organ Mountains with White Sands Missile Range HQ visible in the center left

The Organ Mountains with White Sands Missile Range HQ visible in the center left

Figure 2: The storm chase team poses at the White Sands National Monument (Photo credit: Josh Durkee)

Figure 2: The storm chase team poses at the White Sands National Monument (Photo credit: Josh Durkee)

We paid a small entrance fee and began the Dunes Drive through the monument. The sand was nearly blinding, but once we stopped and removed our shoes, we found the desert floor to be remarkably cool and wet. It was possible to build sandcastles in this sand! After Dr. Dixon tested the sledding possibilities (Figure 3), we decided to leave our mark on that beautiful place (Figure 4).

Figure 3: Dr. Dixon tests out a friendly stranger's sled

Figure 3: Dr. Dixon tests out a friendly stranger’s sled

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Figure 4: WKU Storm Chasers leave their mark on White Sands

After a stop in nearby Alamogordo for lunch at Blake’s Lotaburger, we traveled northbound until we happened to encounter the only severe storm in the Plains near Fort Union National Monument in north central New Mexico (Figure 5). While not tornadic, the storm did drop some pea size hail on us before we managed to snag a shot of the back side, when it gave us our second double rainbow in two days (Figure 6).

Figure 5: Severe thunderstorm over Fort Union National Monument

Figure 5: Severe thunderstorm over Fort Union National Monument

Figure 6: Rainbows on the back side of the Fort Union storm cell

Figure 6: Rainbows on the back side of the Fort Union storm cell

Tomorrow we trek further east to set up for what looks to be a chaseable day on Saturday. Stay tuned!

-Isaac Bowers

Click this link for an interactive chase map!

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WKU Storm Chase 2016 – Day 4

Posted on May 18, 2016 by
Today's route map. An interactive link is provided below.

Today’s route map. An interactive link is provided below.

Morning observations indicated a stalled cold front along I-10 corridor, and model data suggested this front would be weakening throughout the day. Therefore, this cold front would become less of a forcing factor in afternoon thunderstorms. Yesterday’s convection along and south of the front also stabilized the atmosphere, so very little instability existed except in far west Texas where storms had been spotty the day before and cloudiness was reduced so ample heating could occur. This area of marginal instability coincided with the location of the center of convergence that had dropped into northern Mexico overnight, and indicated the area most likely to produce thunderstorms. We initially decided to target Big Bend National Park, since we needed topography and convergence to provide lift because of the greatly reduced instability.

The 11:30 AM CST SPC Convective Outlook update lowered the slight risk over our target area to marginal due to further reduction of expected instability and the persistent cloudiness that prevented surface heating. The only area that retained a slight risk was the El Paso region and the upper Mission Valley area. This, in conjunction with consistent HRRR data prompted us to change our target to the El Paso region by 12:30 AM CST.

We stopped briefly in Van Horn, TX after lunch in Fort Stockton, TX to await convection initiation and for those initiated storms to cross the border. Initiation occurred in northern Chihuahua, Mexico at around 4:30 pm CST, and we began our intercept course. Intercept occurred south of Alamo Alto, TX, less than 1/3 of a mile from the banks of the Rio Grande. Although the storm was neither tornadic nor severe, it was impressive to see the storm cross the Samalayuca Dune Fields to the south (Figure 1) and the structure of the storm provided some excellent photo opportunities (Figure 2).

Figure 1: Rain crossing the Samalyuca Dune Fields

Figure 1: Rain crossing the Samalyuca Dune Fields

Figure 2: Flavia Moraes photgraphs storm structure in Alamo Alto, TX

Figure 2: Flavia Moraes photographs storm structure in Alamo Alto, TX

As the storm crossed our path, we drove through the rain core to the other side. The back of the storm gave us a show in the form of a vivid double rainbow (Figure 3). With storms further to our south disintegrating after crossing the border, losing topographic lift, and entering a strongly capped environment, we headed north to El Paso for dinner at Rudy’s BBQ (Figure 4) and a well-deserved rest.

Figure 3: Double rainbow on the back side of our chased storm

Figure 3: Double rainbow on the back side of our chased storm

Figure 4: Texas brisket sandwich and potato salad at Rudy's BBQ, El Paso

Figure 4: Texas brisket sandwich and potato salad at Rudy’s BBQ, El Paso

The next few days look like some tourist-travel days as we wait for high pressure across the Central Plains to vacate and moisture to return to middle America. We plan to head north along I-25 and perhaps make a stop in White Sands, NM on our way to Colorado for the night. Stay tuned!

-Isaac Bowers

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WKU Storm Chase 2016 – Day 3

Posted on May 17, 2016 by
Today's route map

Today’s route map – available in interactive form below

Our morning forecast discussion was done on the road after an 8:45 AM CST departure from Amarillo, TX. The convective outflow boundary from yesterday’s storm complex descended southward overnight, pushing moisture with it and containing higher dewpoints in the south central Texas region. A convergence zone associated with yesterday’s initiation also descended, and was located in the southeast corner of New Mexico and west central Texas. The setup is similar to yesterday in that all of yesterday’s forcing events existed today, although further south. Initiation was forecast to occur near the convergence zone in west central Texas and low level flow would push initiated storms southeast along the boundary. We therefore initially selected Big Lake, TX as our target.

Initiation occurred just northwest of Crane, TX, and we altered our course slightly to intercept the initial storm. We stopped in the parking lot of Rancherita Mexican Restaurant at the corner of Ranch-to-Market Road 2401 and TX 349 to view the rotating wall cloud the storm had dropped (Figure 1). We followed the storm south to County Road 111 to continue viewing, and the storm became tornado warned on our way there. (Figure 2).

Figure 1: Storm initiation north of Rankin, TX

Figure 1: Storm initiation north of Rankin, TX

Figure 2: Panorama of Rankin supercell as it became tornadic

Figure 2: Panorama of Rankin supercell as it became tornadic

In order to follow the storm, we moved south through Rankin, TX and headed east to stay in front of the storm on US 67. Once we reached Texon, TX, further severe development ahead of the storm created a cold pool that staunched the inflow of the storm we had initially chased, weakening it. We took shelter in Big Lake, TX as hail cores to the south and east prevented our movement. It had been raining there for nearly an hour, resulting in impressive flooding in the area. After the hail core weakened, we cut across the north edge of the storm and attempted to move further south to catch the back side of the storm.

We reached Barnhart, TX and turned south. We turned east on US 190 and followed a storm that blossomed to the east of the cell that forced us to stay in Big Lake for a time. After reaching Eldorado, it became clear that cells would not achieve tighter rotation, so we decided it would be more worth our time to chase a beautiful shelf cloud that was throwing some excellent lighting. We stopped in Sonora, TX to photograph and stopped at several places along the interstate as we moved east on I-10 to our hotel in Kerrville, TX (Figure 3).

Figure 3: Shelf cloud associated with Sonora cell

Figure 3: Shelf cloud associated with Sonora cell

Something to add…at around 10:00 PM CST, our hotel in Kerrville, TX experienced tennis ball sized hail…the largest hail many of us have ever seen! Much of it shattered on impact, but we did manage to get a picture of some golf ball sized hail that fell. (Figure 4)

Figure 4: Golf ball sized hail that fell in Kerrville, TX around 10pm CST

Figure 4: Golf ball sized hail that fell in Kerrville, TX around 10pm CST (credit: Jonathan Piercy)

Tomorrow’s severe threat is reduced, but the greatest threat is near the Big Bend area of Texas. We will likely head there as we continue our search for tornadoes! Stay tuned!

-Isaac Bowers

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