May 28, 2001

Trinidad, CO Tornado & Training Supercells

Chase Account by: Scott Blair
Chase Team: Scott Blair, Jason Politte.
Later met up with: Chris Kridler, Dave Lewison.

The previous days chase had ended abruptly near Garden City, KS thanks to a large piece of metal that jammed into my tire from an overturned semi. Jason Politte and I pulled into the Days Inn before sunset. While it was somewhat disappointing to end the chase early, it was beneficial for forecasting for the next day. After reviewing several model outputs, we decided without a doubt that we would go to Colorado. While most discussions and a high instability setup favored the TX Panhandle, we liked the upslope flow. We awoke at 6:30am the next morning. The new model runs continued to favor our target area of SE CO. It was a classic upslope setup with excellent wind profiles. The lack of deep moisture was a concern, but when we observed 50 Td along the CO/NM border advecting north, we took a sigh of relief. High upper vertical velocities and convergence was pegged over the area. Memorial Day had the potential to be very interesting once again.

The first line of business was to replace the doughnut tire with a new one. We arrived at the local Wal-Mart around 8:30am. This was surprisingly painless as there was virtually no wait. The tire was balanced and put on before 9am. The quickness of the repair gave us time to make final preparations before the chase began. I changed all my tapes in the camera, loaded the still cameras, and other miscellaneous items. After paying close to $2 a gallon for gas, we departed Garden City on Hwy 50/400.

We arrived in Colorado at 11am, 10am MDT. (Note- MDT will be used for rest of the account) A large canopy of cirrus with some breaks covered the area. We thought it would be wise to make a data stop. We pulled into the Loves Truck Stop in Lamar, CO around 10:45am. Jason grabbed the laptop and connected online. We soon discovered that our concentration would be tested while we crunched the data. The innocent looking machine with a claw one can use to acquire stuffed animals inside began making erratic, loud, and annoying beeps. At first we dismissed it, but the infrequent and differential tone beeps made it difficult to keep a straight face. At any rate, satellite showed much better clearing along the front range across SE CO. Higher dewpoints were also quite attractive in that area. Still, no signs of cumulus were present. After reviewing data, we still were happy with our target area.

We continued west on Hwy50 and pulled off onto a gravel parking lot at 12:30pm in Las Animas, CO. We waited here for a considerable amount of time listening to NWR and discussing updates with nowcaster Phillip Flory. For some reason, I was unusually upbeat about the possibilities of the chase day. I guess a good night sleep helped.

The situation finally became more interesting as a few cumulus were spotted towards the front range. We jumped back onto Hwy50 towards La Junta, CO. From there, we moved southeast on Hwy350. The drive on this highway was very enjoyable. There were absolutely no other vehicles through long stretches of the drive and the small towns and wide open grasslands made for a beautiful sight. We observed a struggling LP storm near Thatcher, CO but it never really showed signs of a promising storm. Our attention was focused on a developing supercell with a large anvil south of Trinidad, CO along the NM/CO border.

At 3:35pm, we reached Model, CO as a severe t-storm warning was issued for Colfax County near Raton, NM. We continued southeast and arrived in Trinidad, CO just before 4pm. The mountains with the associated elevation of 6,013ft abruptly greeted us. Our chase cars struggled up the mountains on I-25 heading south through town. While we only had brief peeks at the storm through the high terrain, it was obvious this storm packed a punch. We jumped just south of the border into New Mexico and pulled off in Raton. We found a little more favorable terrain for viewing purposes in the area. The storm carried a well defined precipitation core with numerous inflow bands. At times, it appeared that scud was condensing and attempting to organize into a wall cloud. Either way, large scale rotation was certainly evident in the overall storm structure.

After watching the cell for about 30 minutes, it was time to reposition. We left Raton, NM just before 5pm and headed back north on I-25. The storm appeared to be weakening as it continued its eastward track. As we approached the NM/CO border, we encountered another problem. Moderately sized hail from the core had accumulated several inches deep on the interstate. While this usually wouldn't be a problem, the steepness of the mountains required a much higher level of cautious driving. Driving over pockets of hail resulted in waves of little solid white balls of ice to come slamming into the sides of the chase car. At the same time, the mountains were white capped as if it had just snowed. Snow plows were actually called in later to clear the roads. A large traffic jam eventually resulted five miles south of Trinidad. Vehicles crawled at 5mph through the hail swath before it finally ended south of Trinidad.
* Base Reflectivity 5:04pm MDT - Supercell #1

A nice new updraft exploded just to the west as we approached the city at 5:20pm. A severe t-storm warning was issued for Las Animas County. We pulled off on exit 11 at a gas station's parking lot that contained an excellent view to the west. The previous storm had died visually, so we concentrated our efforts on the new storm. The storm rapidly developed into a supercell with magnificent structure. Inflow bands were everywhere, coming in from almost every direction. The bands wrapped up into the rotating updraft of the storm. A strong and persistent beavers tail stretched from the northeast. The storm contained violent mid level rotation as it progressed towards our location.
* Base Reflectivity 6:14pm MDT - Supercell #2

As the storm pushed nearly overhead, we abandoned our position in Trinidad and took I-25 to exit 13. A few quarter sized hail stones began erratically dropping on us as we approached our exit. The hail continued and increased in frequency for the next twenty minutes as we pulled off the road on Hwy350, just north of the Hwy160/350 intersection. The hail briefly let up before another round of dime size hail struck our location. During this hail encounter, we met up with chasers Chris Kridler and Dave Lewison as they pulled off the road and waited for the hail to pass. Eventually the hail ended and we exchanged greetings. There was a brief down period which allowed us to chat and watch wild horses jump around on top of a hill.

Around 6:45pm, things quickly resumed back to the norm as yet another storm developed off the front range and spread out an anvil. At first the cell slowly developed before exploding into excellent organization, transforming into a classic supercell. This storm was full of mid level banding and striations. The vault region was massive and impressive as it slowly pushed closer to our location. A large beavers tail took off from the updraft as scud began to scream into the updraft region. Shortly after, a wall cloud developed and persisted, showing obvious signs of decent rotation. Scud was lifting off the mountains into the updraft. All of these factors provided a phenomenal sight as the monster looking supercell marched toward our location. Eventually, rain and hail wrapped around the south side of the updraft. This was likely a hook echo on radar. Much warmer inflow was noted around 7:15pm. We bumped up the road just a tad to get a better view. Shortly after, the cell gusted out and slowly died away.
* Base Reflectivity 7:30pm MDT - Supercell #3

As the storm died, an excellent sunset fell upon the area. An orange ball sun touched the horizon as a plethora of colors mixed with rain streaks. This was a beautiful and relaxing sight as we all stepped out and admired the show.

Just as the color ended, the final supercell developed around 8pm. We still were observing along Hwy350, eleven miles NE of Trinidad or seven miles NE of the Hwy160/350 intersection. The new supercell looked disorganized at first, but rapidly tightened up nicely. As the base pushed closer, a sharp clear slot associated with the RFD punched in. The RFD quickly started the process of occluding the mesocyclone. The meso pushed within a mile away as rotation slowly became organized at the lower levels. As the rotation increased, a long ragged funnel developed. It stayed slow to organize further until an interesting event occurred. As the RFD had almost occluded the meso, strong downward motion developed on the southeast side of the wall cloud. A horizontal layer of clouds rapidly moved down the wall cloud taking the appearance of a cascading waterfall of clouds. During and immediately after this event, the funnel formed into a classic finger and condensed downward. Now stretching 3/4 to the ground, it formed a tight needle as it continued to reach. The condensation funnel stayed there for the next three minutes. While no contact of condensation or debris was observed, it's very likely that some kind of weak tornadic circulational influence was present on the ground. The tornado eventually took on a snaky appearance as the rapid motion increased. It was now well less than a mile away as the RFD occluded the entire meso and the tornado lifted and roped out. The rope out was very beautiful as the long, snaky tube curved back and forth into the clouds. Finally, the condensation funnel disappeared into the twilight colored clouds. Everyone was silent on the radio throughout the entire event. It was honestly a breathtaking sight.
Vertical Two-Piece Images

Evolution and Decay of Trinidad, CO Tornado
* Base Reflectivity 8:31pm MDT - Cell #4 / Tornado
* Velocity 8:16pm MDT - 15min before Tornado

The supercell continued to move along as a tornado warning remained in effect for Las Animas County. A new meso rapidly developed to the east of the previous one. A wall cloud had clearly developed and we decided to move northeast to get a better look. However after a few miles, darkness and quarter size hail filled the area. We decided to turn around and call it a day. We dropped south out of the precip and watched the meso slowly deteriorate. We headed back into Trinidad and met a few other chasers at a local diner. Everyone was quite pleased with the event. Big thanks to nowcaster, Phillip Flory. Phillip gave some excellent updates during the day.

May 28, 2001 was without a doubt a classic chase. It's uncommon to observe four beautiful supercells with fantastic structure that train over the same general location during a time duration of five hours. At the same token, the ability to observe the evolution and decay of a mesocyclone and tornado at very close range without changing locations is another difficult task. Everything worked out thanks to Mother Nature, forecasting, and strategies. It was a beautiful chase filled with so many experiences. Indeed a classic- Scott Blair




NCDC STORM DATA - Event: Tornado - State: Colorado - County: Las Animas
Begin Date: 28 May 2001, 08:31:00 PM MDT
Begin Location: 1 Mile East of Hoehne
End Date: 28 May 2001, 08:32:00 PM MDT
End Location: 1 Mile East South East of Hoehne
Length: 0 Mile - Width: 30 Yards
Magnitude: F0 - Property Damage: $ 5.0K
Description: A brief touch down occurred, damaging a garage.

SPC MESOSCALE DISCUSSION 0918 FOR NERN NM/SERN CO CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
THUNDERSTORMS MOVING OFF THE HIGHER TERRAIN ALONG THE CO/NM BORDER WILL LIKELY INCREASE IN INTENSITY BY EARLY THIS EVENING. A WEATHER WATCH MAY BE REQUIRED IN THE NEXT 1-2 HOURS. THUNDERSTORMS HAVE DEVELOPED ALONG THE HIGHER TERRAIN FROM SOUTH OF PUEBLO CO TO JUST NORTH OF RATON NM. VERTICAL WIND SHEAR PROFILE FROM TCU PROFILER INDICATES SUFFICIENT SHEAR FOR SUPERCELLS...WITH SOUTHEAST 850 MB FLOW OF 15 KNOTS VEERTING TO WESTERLY AT 40 KNOTS AT 500 MB. SOUTHEAST LOW LEVEL UPSLOPE FLOW AND MODERATE INSTABILITY WITH MLCAPE OF 1000-1500 J/KG ARE FAVORABLE FOR THUNDERSTORMS TO MIGRATE OFF THE MOUNTAINS INTO THE HIGH PLAINS THIS EVENING. LARGE HAIL WILL BE THE MAIN THREAT...ALTHOUGH SUFFICIENT LOW LEVEL VEERING IS IN PLACE FOR A COUPLE OF TORNADOES.

TORNADO WATCH NUMBER 312 STORM PREDICTION CENTER NORMAN OK 454 PM MDT MON MAY 28 2001
THE STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF SOUTHEAST COLORADO NORTHEAST NEW MEXICO EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 500 PM UNTIL 1000 PM MDT.
DISCUSSION...SUPERCELLS AND ISOLATED TORNADOES POSSIBLE THIS EVENING IN ZONE OF MODERATE /20 KT/ LOW LEVEL SELY FLOW OVER THE SRN HI PLNS. DEEP LAYER SHEAR EXPECTED TO INCREASE OVER REGION DURING NEXT FEW HOURS AS 50+ KT MID LEVEL SPEED MAX ASSOCIATED WITH NRN AZ UPPER TROUGH OVERSPREADS REGION. SURFACE DEWPOINTS IN THE UPPER 50S ARE CONTRIBUTING TO CAPE AROUND 2000 J/KG...AND LOW CLOUDS HAVE KEPT TEMPERATURE/DEW POINT SPREADS FAIRLY SMALL.

Other Chase Accounts From May 28, 2001
*Jason Politte
*Chris Kridler
*Dave Lewison
*Tim Marshall
*Bobby Eddins
*Mike Umscheid
*Sam Barricklow
*Ian Wittmeyer
*Greg Thompson
*Jim Reed
*Aaron Blaser

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