Finally, after completing some site maintenance and resolving an issue with our router, I can finally post the video of the tornado at Grand Forks, ND on Thursday, June 17. The video shows an entire occlusion cycle of the tornado, which was high-contrast with a classic cone shape. Enjoy!

Thursday afternoon, optimal conditions were in place for severe storms over the northern and central Plains states. Boundary level moisture conditions were forecast to be excellent, with dew points in the high sixties/low seventies over parts of North Dakota to mid-eighties dew points over Minnesota. A high amplitude shortwave trough was forecast to translate northeastward through the region, with strong cyclogenesis expected to commence at the surface in association with the upper level system.

After analysis of the 1800Z GFS and RUC model forecasts, I decided on northwestern North Dakota as my initial target area. Instability for the region was expected to reach CAPE values of 2500-3000 j/kg by afternoon peak heating, and surface winds were forecast to be backed out of the southeast at 35-40 kts, yielding good wind shear and helicity values for supercells and tornadoes. I departed Winnipeg for Grand Forks at 10:00 AM CDT.

Stopped for lunch just after arriving in Grand Forks at around 2:00 PM. Light convection from earlier in the morning had mostly dissipated, but cloud cover was still intact over the area. I was initially worried that this could be problematic for the afternoon heating and initiation of storms later in the afternoon, but visible satellite imagery showed the clouds were thinning out and moving on to the northeast. Temperatures were in the low seventies already, and surface winds were from the east southeast at thirty knots. The wind shear was good, all that was needed was a little more surface heating to get things started.

By around 4:00, convection was beginning to develop rapidly further south, with numerous cells starting to appear on the GRLevel3 data feed. There was a storm to the west of Grand Forks near Devils Lake that was showing pronounced rotation for approximately fifteen minutes, but it lost intensity and dissipated a short time later. I downloaded a quick update of surface conditions, and decided to stay put Grand Forks, as instability was good and winds were almost easterly at 40 knots.

At 4:00 PM, the cold front moving in to southwest North Dakota could clearly be seen on GRLevel3, as it was producing a well-defined squall line with embedded supercells. I held out hope that some discreet storms would develop in the warm sector ahead of the cold front, before the whole show turned into a mess of linear storms, and no hope for tornadoes.

By 4:30, a robust supercell appeared to be developing just to the south of Grand Forks, between Northwood and Reynolds, moving to the northeast at about 40 knots. GRLevel3 showed robust rotation at the center of the storm, with good gate-to-gate shear apparent on the lowest tilts of the radial velocity scans from the Grand Forks NWS. I decided to attempt an intercept just south of Grand Forks, and proceeded south on I-29.

I was totally surprised and frustrated by an unforeseen construction delay on I-29. The west half of the once twinned highway was closed, and traffic slowed to a crawl as the roadway was pinched down to just two lanes in a drenching rainfall. As I crawled along with the traffic, I noticed what appeared to be a very dark wall cloud to the west, so low that it appeared to be touching the ground. I knew I had to get the car turned around so I could parallel the storm as it traveled north, but there was no place to even stop the car, let alone turn around. Finally though, I saw a chance to pull off the road and grab a quick U-turn. It was a turnoff where a new bypass was being built, but the road wasn’t paved, and was the consistency of a swamp. I should have gotten stuck, but the car somehow managed to swim through the mud and get back on to solid pavement.

When I finally got the car turned around, I saw a vigorously rotating wall cloud just to the west of the city, and clearly visible form the interstate. Small vortices were appearing just beneath it, then evaporating like mist before they could touch the ground. Several other chasers were stopped near me on the shoulder of the highway, admiring the spectacle and taking video and photographs. Just before 5:00, a well defined funnel cloud appeared, and snaked its way toward the ground. It was a high-contrast funnel cloud, and the sun could be seen shining through the clear slot to the southwest. A debris cloud appeared just below the tip of the slender funnel. Touchdown!!

The tornado went through several occlusion cycles, touching the ground and retracting back into the wall cloud. Although it wasn’t a large tornado, it put on a spectacular show before it finally roped out after about eight minutes.

All told, a fantastic chase day, and well worth the short distance traveled. I was saddened today, however, to learn that the tornado I witnessed destroyed a home, and fatalities occurred in neighboring Minnesota along with heavy property damage.

My heartfelt condolences go out to the affected families.

A series of powerful tornadoes carved a deadly path through the southeastern U.S. Saturday, killing at least 10 in Mississippi and leaving dozens injured.

The storms were part of a large scale disturbance and cold front that swept through the southern U.S., spawning a series of tornadoes as it moved through Texas on Thursday.

The worst of the damage occurred at Yazoo City, Mississippi, about 370 kilometers north of New Orleans. The 1.2 kilometer-wide funnel claimed ten lives, including three children, as it tore through an estimated 100 homes.

At last report, thousands were still without electricity as rescue workers continued to comb through the debris for survivors.

Tornadoes and injuries were also reported in Louisiana, Arkansas and Alabama.

Satellite image courtesy NOAA

Departures from the normal range of sea surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with observed patterns of convective weather in the tropics indicate a strengthening El Nino pattern that should persist at least through the end of the Northern Hemisphere winter.

Sea surface temperatures in the eastern Pacific have ranged as much as 1.5 C higher than average, while below the surface, anomalies ranging from 1.5 to 5.0 C have been observed in the upper 300 m layer, patterns that are consistent with an established El Nino event.

Temperatures at the ocean’s surface have a large influence on the weather above, as thermal energy is transferred from the water to the air. Persistent areas of higher pressure consistently form in the atmosphere above warmer ocean waters, a scenario that NOAA forecasters expect to unfold over the coming months.

Most of the forecast models used to predict the strength and duration of El Nino suggest that it could last into the March-May 2010 period, with its intensity likely peaking within the moderate range and lasting through the Northern Hemisphere winter.

That could be very good news for people who enjoy mild temperatures and less snow in the north-central United States and southern portions of the Canadian Prairie Provinces, where the potential impact of El Nino is expected to include above normal temperatures and below normal precipitation during the winter months.

A very warm and moist air mass resided across southern Manitoba Thursday afternoon, with dewpoint temperatures reaching 25 C. A cold front, in association with an intense upper trough, was forecast to sweep northeastward from North Dakota into southern Manitoba Thursday evening. Ahead of the cold front, severe thunderstorms – with a primary threat of large hail – were a high probability.

I observed a large, isolated thunderstorm developing just north of the International Border around 7:00 PM, moving northeast at 30 km per hour into southern Manitoba. I opted to intercept this storm as it approached highway 75 near Morris, MB.

As I intercepted the storm, it was apparent that it was evolving from an isolated cell into a linear MCS, with intense electrical activity, wind gusts measured to 85 km/h and quarter sized hail.

In summary, this storm was well worth the short trip south of Winnipeg to witness the amazing “anvil crawlers” that lit up the sky in almost every direction. I found a nice vantage point just north of the precipitation to take some memorable pictures of this event that persisted until well after 11:00 PM. Opportunities like this are a rare treat in September.

At first glance, it looked as though Friday would have good potential for severe weather, and possibly a few tornadoes in North Dakota, with plenty of instability in place (3000+ j/kg) and good low level shear. Gulf moisture had been advecting across the central and northern Plains since early morning, aided later in the day by the development of a respectably strong low-level jet (LLJ).

I proceeded to the south part of the state, where temperatures had reached 83 F by just after noon, with dewpoints into the high sixties and low seventies. Everything looked primed for some explosive convection, especially with a 500 mb short wave trough rounding the crest of the ridge over the central CONUS. I was parked in Fargo, ND for most of the afternoon, waiting for things to pop in that blanket of low level moisture.

By around five in the afternoon, nothing was happening over Fargo, or any other part of southern North Dakota. The GR Level3 software was showing a large squall with possible embedded supercells progressing ESE just north of Grand Forks, so I opted to head north on I29 to intercept the band of thunderstorms, which was showing several tornado warned cells and TVS (tornado vortex signature) markers.

When I arrived on the outskirts of Grand Forks around six, the tornado sirens were wailing in the city. The edge of the squall did look impressive, with a prominent shelf cloud, powerful gust front and drenching rainfall. But no tornadoes were in sight, especially in the low level grunge and scud that rolled and boiled beneath the shelf cloud.

I suspect that the tornadoes sighted within the squall line were more than likely gustnadoes, or perhaps a bookend vortex or two in the mix.

All in all, an exciting and fun chase today, but the prize of a high-contrast tornado photo remained elusive.

May, a month that normally sees ample active weather across the Great Plains, may go down in history for 2009 as one of the poorest on record for supercell storms and tornadoes, which is extremely bad news for the Vortex II research project that began field operations on May 10. No storms equals no data, and wasted time for scientists trying to unlock the enigma of tornadogenesis.

Currently, GFS model forecasts portray a persistent blocking pattern over the central CONUS, and a resulting north west flow regime that will keep most of the moisture from the GOM locked up at least until the end of the month.

The annual northern migration of the polar jet means that any severe weather outbreaks to occur in June will be more likely to occur in the central or high plains areas, assuming that moisture-rich GOM air is able to once again advect northward during the period.

Throughout the first half of May, the positioning of upper-level flow and lack of good surface moisture return into the Plains states has hampered the development of photogenic storms. Yesterday, the swift passage of a trough and associated cold front resulted in a significant severe weather outbreak from central Oklahoma to the Great Lakes states. Most of these storms went linear shortly after initiation, and there were reports of tornadoes in OK and near Kirksville, MO. These tornadoes rapidly became rain-wrapped, and dangerous to chase. Strong forcing and MLCAPE values of near 4000j/kg resulted in mostly linear storm complexes with a few embedded supercells, with widespread reports of straight-line wind events and very large hail.

For this reason, we opted not to chase yesterday’s event, as the probability of intercepting any photogenic storms was too low to warrant travel distance and the risk of equipment damage.

GFS model guidance suggests that adequate moisture returns from the GOM and upper flow characteristic of sustained severe weather events likely won’t return to the Plains states until the final week of May.

Current Status: Standby

The Storm Prediction Center has issued strong warnings of the possibility for sustained supercell development and a risk of long-track destructive tornadoes in NC OK and SC KS for today and this evening.

Several short wave impulses translating through the base of a large upper trough, currently positioned over NM and W TX, will promote large scale ascent ahead of the frontal boundary over TX/OK/KS this afternoon. Continued moist advection into the warm sector of this system will likely increase later today, as an 850 MB low level jet strengthens into this evening.

As MLCAPE values to 2500 j/kg develop late this afternoon, strong heating will promote widespread destabilization. Current model guidance suggests that a favorable kinematic environment, with high helicity values and large curved hodographs will allow for sustained supercell development later this afternoon and into the evening. Significant tornadoes are possible in this environment.

A large upper trough progged to move into the central/southern plains Saturday and Sunday will bring an increased chance of severe weather across areas of TX panhandle,N OK, and SC KS.

A Pacific cold front is expected to sweep through N TX, W OK and SW/C KS Saturday and Sunday. At the surface, a strong LLJ will result in dewpoints in the low 70’s across much of the region, allowing initiation of scattered thunderstorms late Saturday afternoon. Forecast soundings suggest vertical shear profiles favorable for supercell development and isolated tornadoes Saturday evening.

For Sunday, a short wave impulse ejecting NNEWD across the central plains is expected to be the focus for convective development late in the afternoon. An axis of rich surface-based moisture with SBCAPE values in excess of 2800 j/kg will exist in a narrow corridor extending NNEWD from the eastern TX panhandle to SC KS Sunday afternoon, providing increased instability as a plume of steep mid level lapse rates advect eastward.

Supercells capable of producing very large hail and isolated tornadoes are likely across the central plains Sunday afternoon and evening. However, the strenthening of an 850 MB 55 KT LLJ will contribute to increasing moistening of the boundary layer and large clockwise-curved hodographs, particularly over SC KS Sunday evg. The possibility of long-track destructive tornadoes in or near this area cannot be overlooked.

850 mb and surface maps courtesy College of DuPage

During an outbreak of severe weather and tornadoes across much of west central Kansas Friday afternoon, Skywatch7 intercepted a tornadic supercell in Lane County, KS. The storm produced a large tornado just after 4:30 PM that tracked through several counties, and was spotted by chasers near Wauneta, KS.

A DOW (Doppler on Wheels) unit, operated by Joshua Wurman of the Center for Severe Weather Research, performed multiple scans of the supercell’s core region to determine if there was ongoing tornado production. Although the TIV (Tornado Intercept Vehicle) was also tracking this storm, no intercept of a tornado was attempted. –SEE PHOTOS–>

Skywatch7 will be departing the Watertown, SD area this morning and proceeding to areas in NW Kansas. An intense low pressure system has stalled over the area, and copious moisture from the Gulf of Mexico has surged into the area overnight. Deep layer shear values should produce high helicity; these conditions, coupled with steepening lapse rates and increasing instability with maximum daytime heating, should produce supercells capable of producing tornadoes late this aft.

Following inspection of the damage path that extended through Racine, MO, the National Weather Service has concluded that a single long-track tornado of EF4 strength developed in northeast Oklahoma and moved northeastward.

The tornado flattened nearly 20 blocks of the town of Picher, OK before moving into Newton County, MO where its winds reportedly threw automobiles as far as 1/2 mile. —SEE PHOTOS–>

Skywatch7 was positioned just northwest of Oklahoma City, just ahead of the dryline and along a wind shift boundary during passage of Tuesday’s trough and associated cold front. Although timing and location seemed to be right, lacklustre wind shear resulted in lack of supercells, with any convection being mostly linear in nature.

Positioning of the trough didn’t lend itself to severe thunderstorm and supercell development. The trough was positively tilted (oriented NE to SW), and winds were blowing mostly parallel to the front. With an established NW flow regimen currently in place, there is little chance of any significant weather event on the Plains for at least the next four or five days.

No still pictures or videos were collected of severe weather, but we did collect some hail on the windshield.

Skywatch7 is currently on standby in Oklahoma City, ready for possible severe weather conditions in west central Oklahoma on Tuesday. On Sunday we surveyed damage from the long-track EF4 tornado at Racine, MO. Photos of the survey will be posted shortly.

As many as 34 tornadoes touched down in the southeast, with deadly consequences. The hardest hit region was in southwest MO, where 10 fatalities were reported from tornadoes north and northeast of Racine, MO.

Skywatch7 arrived in MO in the early evening hours, and was not able to make any intercept attempts. It was reported that the tornadic storms were moving at extreme speeds of 60 mph or greater. This, in conjunction with difficult chase terrain (road networks) made intercepts extremely difficult for those in favorable positions.

As per the SPC Day 4 outlook, the potential for severe thunderstorms exists in areas of the eastern Plains Saturday aft. and into the evening hours.

A trough developing over the Rockies will progress sewd into the mid-MS valley. At the surface, robust moisture return will flow northward ahead of the trough from OK-KS. Steep lapse rates will likely reside over the region Saturday, and modest shear will enhance the possibility for supercells over the region.

Skywatch7 will be arriving in Kansas City, MO Saturday afternoon to monitor developments as they occur.

Current GFS models are predicting the evolution of a large cyclone over NW portions of the CONUS, that will advance SE into the Great Plains region Thurs-Fri. Moderate to strong capping into SE KS and NE OK may limit the potential for svr. threat over this area. However…steeper lapse rates further north, esp. SW IA and NW MO may encourage supercell development ahead of the cold front. With favorable deep layer shear expected afternoon and evening across the region, potential exists for rotating storms.

Svr. potential will be highly dependent on development and progress of the cyclone across the region, as well as moisture return across the region.

With the start of the 2008 storm season close at hand, Skywatch7 is upgrading equipment and adding a live tracking feature to the chase car to display position in real time, using a combination of GPS and amateur radio equipment. –VIEW CURRENT MAP–>

The Storm Prediction Center in Norman, Oklahoma has issued a Moderate Risk (MOD) for areas of the southern and central Plains for today.

A strong upper-level trough is expected to advance over the southern and central Plains early this afternoon, ahead of a strengthening Pacific jet streak. High surface dewpoints in the warm sector ahead of the advancing cold front, coupled with strong low and mid level windfields are expected to create conditions favorable for the development of severe thunderstorms across the region beginning this morning and into tonight.

High CAPE values within the warm sector exceeding 1500j/kg, and deep layer shear values of 50 kts will be more than sufficient to produce strong supercells, with the potential for a few long-track strong tornadoes.

After reviewing new video footage, Environment Canada has upgraded the destructive force of a tornado that struck Elie, Manitoba to F5 – the most violent winds to ever touch the ground in Canada.

The powerful tornado touched down north of the Trans-Canada highway near Elie on June 22 at around 6:30 PM. The tornado moved slowly southeast, throwing a tractor-trailer unit from the highway before striking a flour mill on the outskirts of Elie, creating over $ 1 million in damages. Four homes were destroyed when the funnel moved into the town where it remained almost stationary for nearly five minutes.

Environment Canada originally categorized the the tornado as an F4, producing winds from 331-415 km/h.

New amateur video was provided to Environment Canada that clearly shows an entire home being hurled into the air, where it explodes in a cloud of debris. A vehicle, believed to be a van loaded with drywall, is also lofted several hundred meters during the footage.

Severe storms meteorologist Dave Carlsen of Environment Canada said that kind of destructive force was worthy of an F5 rating, indicating winds of between 416 and 510 km/h, the highest wind speed range on the Fujita scale.

The Elie tornado has now been recorded as the first F5 tornado in Canadian history.

Photo Credit: Lori Raymond

Twenty years ago today, at just before three o’clock Friday afternoon a phone call to Edmonton’s weather office warned of a tornado sighting just south of Edmonton at Leduc, the beginnings of a mammoth storm that would produce Canada’s second deadliest tornado in history.

At 3:25 PM, the tornado slammed into the southeast Edmonton community of Mill Woods at F2 strength, intensifying as it began shredding entire neighborhoods. By the time it reached Refinery Row, it was producing F4 damage and had claimed 12 lives. The monster storm wasn’t through yet, flexing its muscles as it obliterated homes in the Evergreen Trailer Park, killing 15 of its residents.

By the time the tornado dissipated at 4:25 pm, over 300 homes and other property had been left in ruins, with damage totals exceeding $300 million.

Elie, MB – Children played games and chowed down on hot dogs and hamburgers as bright sunshine and warm temperatures provided a placid backdrop for a family cookout held outside the Blessed Sacrament Church. The calm blue sky above offered no trace of the rage and raw fury it inflicted upon the residents of Elie just over two weeks ago.

On Friday, June 23, vicious thunderstorms spawned at least two tornadoes in the area, with one packing destructive winds of nearly 400 km per hour. The powerful twister chewed its way through a flour mill on the outskirts of town, then made a direct hit on four homes, turning them to splinters and leaving families shattered.

Officially, Environment Canada called the tornado an F4, “as bad as it gets” in this country.

Mike Nwosu, Pastor of the Blessed Sacrament Church and one-year resident of Elie, calls it a miracle.

“We held a celebration of Thanksgiving,” Nwosu said, “for the lives that were spared here that day. It was God’s will that no one perished in that storm, and for that we are thankful.”

The degree of destruction in the tornado’s path, and the debris that still hangs like surreal ornaments in nearby trees, betrays the idea that families escaped with their lives from obliterated homes. Automobiles thrown by the horrific winds lay crumpled in fields, and trees stripped of their branches still bow to the winds that disappeared as quickly as they came when the storm moved on.

But the little town’s community spirit, and its will to recover is not as easily swayed and broken. “The day after (the tornado), we must have had a thousand people out, moving through each yard to remove every piece of debris,” said Kim Howard. “Everyone came out to begin removing any trace of what happened here.”

Evidence of ongoing cleanup operations are evident as a tractor pulls a plow through soil where houses once stood, removing chunks of debris that may be hazardous to scores of volunteers who have descended on the area to begin rebuilding homes for families they consider to be their own.

The tornado that touched down at Elie was unusually intense for southern Manitoba, and was part of a complex of severe thunderstorms that formed in an environment of high dewpoint temperatures ahead of a low pressure system in the early evening hours. Warm temperatures aloft acted as a “cap”, suppressing storm development for most of the day, but a lake breeze boundary sparked development of thunderstorms that rapidly grew severe.

“The sky was clear, then suddenly a lot of rain came out of nowhere,” Howard said. “I was in the kitchen cleaning up after dinner when I saw it through the window. It was the biggest storm I’ve ever seen.”

While the town goes about the business of repairing or replacing what they can in the wake of the storm, the memory of its destructive power will leave an impression on those it affected for a long time to come.

“Every time a strong wind blows, we pray it won’t be another tornado,” Pastor Nwosu said. “People were deeply affected by this, and it will take them some time to get over it.”

Following the severe weather outbreak of June 22-24 that included multiple tornado touchdowns and widespread straight-line wind damage, southern Manitoba appears poised for another severe weather event this weekend.

A surface low over western SD and an associated inverted trough stretching NE into southern Manitoba should be the focus for convective development late Sunday afternoon and evening. Latest forecast soundings indicate that steep lapse rates and weak capping due to cooler temperatures aloft will enable convective development along and ahead of the trough to commence with maximum daytime heating, with some thunderstorms becoming severe.

A mid level jet moving eastward over the northern Rockies will produce 0-6 km shear values in the 40-50 kt range, producing a favorable environment for rotating storms, and the possibility of isolated tornadoes from southwestern Manitoba into the northern Dakotas.

Latest GFS model output (00Z) for Sunday afternoon progs MLCAPE values of between 1500 and 2000 j/kg for the region, suggesting that large hail will likely be the main threat with these storms.

Saturday, May 5, 2007 saw high levels of instability over the central plains, particularly in Kansas. We departed Russell, KS at 12:00 pm, moving to intercept storms 70 miles south of Hays. At the time, Doppler radar indicated a line of storms with embedded supercells with 1.5″ hail, moving north.

Enroute to these storms, radar indicated diminished shear parameters and a reduced chance of tornadic potential, so we proceeded to Wakeeney, KS for data updates. At 2:00 pm, Doppler radar indicated evolving storms ahead of the dryline, merging into a MCS extending from the OK panhandle to SC NE. Embedded supercells were developing in a favorable shear environment, and we elected to intercept one of these cells southeast of Great Bend, KS.

At approximately 5:30 pm, the storm began to exhibit some vigorous rotation, and a slight lowering of the cloud base. A funnel cloud protruded from the lowering, and debris circulation was observed on the ground, in spite of the fact the funnel never fully condensed. –SEE VIDEO->

My chase partner Andy and I arrived in central Kansas on the morning of Friday, May 4, 2007 with the anticipation of two marksmen on the opening day of hunting season. We had come to the central plains to see and document supercell thunderstorms and tornadoes, the most violent winds on the face of the earth. The journey had been planned for several days already, as a deep low pressure trough would be digging its way into the central United States from the Rocky Mountains that weekend, and a significant outbreak of severe weather was expected.

The Storm Prediction Center had drawn the red circle, depicting a moderate chance of severe thuderstorms around most of central Kansas and the Oklahoma panhandle the previous evening, which meant that chances were good of at least seeing a beefy thunderstorm or two. As we viewed the updated outlook for Friday afternoon at a guest computer at the Quality Inn at Salina, Kansas just after lunchtime, our anticipation began to build as we glared at the large flat panel monitor. The SPC had drawn a smaller fuschia circle around central Kansas and part of the Oklahoma panhandle, meaning the entire area was then at high risk for severe thunderstorms, and possibly tornadoes. We knew that Kansas was going to be under the gun, and the very area we were traveling in was now in the crosshairs.

The mid afternoon sun was bright, but diffused slightly by a fine haze of humidity that hung over the plains like a smothering blanket. Temperatures were in the mid seventies, with dewpoints only three or four degrees lower. With southeasterly winds at the surface siphoning even more moisture up from the Gulf of Mexico, we knew the atmosphere above Kansas was like a giant powder keg, just waiting for the first hot spark to ignite it.

Our data eventually led us to the conclusion that western Kansas would be the area of initiation for convective storms, given the position of the dryline, the boundary between the dry, cooler Pacific air and the near-saturated warmer air mass that now engulfed most of Kansas and all points south. We arrived in Hays, KS around 5:00 pm, and waited for the dryline to make its late afternoon journey east, hopefully sparking the massive supercell thunderstorms we were seeking.

The sky above Hays showed signs of strong capping, meaning that a layer of warm air at the middle altitudes was preventing the moist, buyant air at the surface from rising into a colder environment to create the updrafts needed for a thunderstorm. Masses of fluffy cumulus clouds drifted aimlessly on the southeasterly winds, with no sign of a storm in sight. Conditions were looking ripe for a cap bust, when Andy said “just be patient, it’s going to happen and it’s just a matter of where and when”.

After close to an hour of watching nothing but small globs of moderate precipitation come and go on the laptop screen, the Baron Mobile ThreatNet finally revealed the presence of a small developing storm well to the east of us, along highway 9 between Densmore and Logan. It was beginning to present a healthy precipitation core, so Andy swung the car around and we blasted up the highway to intercept the storm.

As we rushed further east toward the blob on the laptop screen, the massive anvil of the now severe-warned supercell began to come into view. It was flat and solid on the top, with angry dark knuckles of chunky cumulonimbus gathered beneath it. The storm was beginning to display very high reflectivity values, and was starting to drop hail as we approached it from the west.

The closer we got, the more the massive supercell grew in the window. It now had the bean-shaped appearance of a classic HP supercell, and the laptop screen now showed an area of rotating winds on its southwest flank. The shear marker revealed wind speeds of over eighty miles an hour, so the storm was beginning to become well organized.

When we got close enough to the base, the mesocyclone was beginning to show signs of vigorous rotation. The sky turned ink black as we advanced beneath the cloud base, and torrential rain and golf ball sized hail stones began their assault on the chase car. Through the rear view mirror, it was plain to see that we were not the only chase team to take notice of the huge supercell. A long line of headlights appeared behind us in the rain, all jockeying to get the best view Intense CG lightning began to stab the ground on all sides of the road.

The ThreatNet screen revealed the supercell’s southwest flank was beginning to wrap in on itself cyclonically, producing one of the best hook echoes I’d ever seen. The meso was rotating fast now, and we parked in a clearing off the side of the road, along with several other interested chasers and chase tour vans.

We got out of the chase car beneath the meso, and the wind was dead calm, even as the clouds whirled furiously above, the storm’s updraft base sucking in the hot and humid air that was its fuel, its life blood. Slender fingers of rotating clouds would occasionally emerge from the rotating meso, searching for purchase on the ground, but would weaken and retreat. The storm was beginning to enter a dissipating stage, and would not produce a tornado on this night, in spite of all the earlier indications. After chatting with some of the other chasers on the side of the road, the setting sun convinced us to call it a night.

As we headed toward Russell, KS to find hotel rooms, Andy and I talked about our supercell’s impressive structure and how turbulent the skies were over Kansas. We had no idea as we headed toward Russell that a colossal supercell, part of a cluster of storms that had drifted northeast across the Oklahoma state line, had brewed a monster EF5 wedge over a mile and a half wide that was heading toward Greensburg. By the time we had arrived in Russell, and gotten the keys to our hotel rooms, that historic tornado had already scoured most of the city of Greensburg from existence.

We only became aware of the Greensburg disaster after the portable weather radio in my hotel room had sounded an alarm, and a tornado emergency message that carried an urgency unlike any I had ever heard before. It was seriously dangerous and destructive tornado, and my television screen was filled with the doppler radar image of the huge supercell that had given birth to it, accompanied by frantic warnings from the National Weather Service for any people in the path of the storm to take cover immediately.

As I went to sleep that night, weary from a day of chasing, the sky above still raged on.

Only with the light of morning on Saturday and the images from media uplink trucks did the gravity of what happened to Greensburg finally begin to sink in. The city had been decimated, reduced to a landscape of rubble and de-barked trees that reminded me of pictures from Hiroshima and Nagasaki after the atom bomb. The storms we chasers often refer to using “awesome”, “incredible” and other adjectives had done what they often do, destroyed property and lives. I felt sick inside, and began to wonder why we do what we do. I felt somewhat guilty about being so fascinated with a weather phenomenon that, in minutes, had destroyed so many lives forever.

As stories of the Greensburg tornado began to trickle out through the media, and Internet groups such as Stormtrack, it became clear to me that it is really okay to be fascinated with such fury. And, I also realized that we chasers also can find ourselves in the position of being able to give back to the communities that suffer. A number of chasers had been tracking the tornado on Friday night, capturing its images as lightning revealed its deadly path through the countryside. The speed and heading of the storm was relayed by chasers to the NWS offices in Dodge City, providing an element of “ground truthing” to the images captured on doppler radar. After the tornado chewed through the heart and soul of Greensburg, many of these same chasers pulled survivors from their wrecked homes to safety, risking their own safety as they did so.

I no longer felt the nagging guilt of a few nights ago. In fact, I felt proud of our community of chasers, and how they conducted themselves at Greensburg.

May Greensburg rise again, stronger and better than before. –VIEW PHOTOS–>

Skywatch7 will be departing for southwest Kansas today, after SPC predictions for a severe thunderstorm event were upgraded to MOD (moderate).

Synopsis: A strengthening trough, coupled with a strong upper jet max are currently moving into the central plains area and will result in rapid surface cyclogenisis by this evening. Surface analysis reveals that increasing low level southerly winds will add to already abundant surface moisture levels over central TX and southern OK, which will spread quickly into KS later today.

Intense surface heating will commence once low level cloud has dissipated early this afternoon, resulting in an extremely unstable air mass along and east of the dryline from from southwest KS into western OK.

Storms aided by upslope flow and backed surface winds from the east-northeast will rapidly become supercellular, based on observed shear profiles. Very large hail and a few tornadoes are possible, with the threat increasing with eastern extent as storms move into a more moist boundary layer.

01 HUDSON-LOCATOR REF: LINCOLN, NEBRASKA – READY
02 THOMPSON-LOCATOR REF: WINNIPEG – NOT PARTICIPATING