Posts Tagged: thunderstorm
May 15th 2013
On July 19, 2016
- 2013 Storm Chases
Surface analysis 12Z Wed May 15 2013
As night turns to day slowly, the morning rays of sunshine reveal showers produced by elevated thunderstorms moving in along a warm front.
Here's a radar shot showing the first target storm as it tracked southeast from Shelburne.
You can see it is the dominant storm cell in the line. At around this time I'm making my way east on the 407 to head north on the 404 for an intercept.
This was one of the few dominant storm cells approaching me from the west.
I raced north along highway 404 and stopped on Stouffville Rd just east of the highway. The thunder and lightning was nearly continuous as the storm moved ever closer. It seemed far more intense than it really was.
The storm cell was still highly elevated, it produced some small pea sized hail and heavy rain. There was virtually no wind at the surface.
You can see the back side of the storm as it passes, this particular shot was taken looking Southeast.
Here's my position relative to the storm to give you a better idea of what I was seeing.
Fresh towering cumulus going up to my immediate west along a turbulent zone of convergence and mixing aloft near the leading edge of the prior convection.
This was the second storm cell which later spiked on radar.
When this photo was taken it was still in its infancy but at this point the surface warm front was getting closer and it was later in the day so boundary layer mixing was increasing. This allowed the storm to mix down further and at least appear to be getting closer to the ground.
A little while later the same storm seen in the previous image is now east of me and beginning to hit 65dbz on the radar. You can see the rain shafts from the storm directly in front of the power lines.
Here's the radar showing how intense the storm actually appeared on radar despite its benign appearance visually.
This is a stylized image of the storm as it continues eastward. I've used a graduated neutral density filter to darken the sky and create this vibrant image. At this point the storm was hitting 68 dBz and producing some small hail. A warning for Durham Region was issued, and this storm eventually made its way out over Lake Ontario.
I tried to keep pace with the storm but gave up, it was moving at well over 80 km/h.
Here's a quick analysis of the surface showing the warm front and the storms well ahead of it near the green line.
FYI - I know the occluded front is backwards, I drew as if it was a cold front by mistake
April 18th 2013
On July 19, 2016
- 2013 Storm Chases
Surface analysis 18Z Thu Apr 18 2013
Hard to believe that less than a week after the ice storm I was out chasing a large ragged bowing squall line with temperatures around 25 Celsius. April is really a month of extremes!
Storm motion with this bowing segment was 59 degrees (Northeast) at 57 knots (105 km/h)
You'll see how the storm progressively bows as it progresses north along the line
Here's a quick screen grab from my tablet showing the radar at the end of my storm chase day. You'll notice the a large bowing segment heading off towards Uxbridge, that there is the storm which bowed out right over my head in Bolton/Caledon.
July 14th 2016
On July 16, 2016
- 2016 Storm Chases, Uncategorized
Surface analysis 00Z Fri Jul 15 2016
July 8th 2016
On July 10, 2016
- 2016 Storm Chases
The first really active chase day of the year for Southern Ontario that was not a bust with widespread convection and severe weather ranging to hail to wind and even some local flooding. The entire day basically focus around an incoming low pressure system from Michigan with a trailing cold front that was crashing into very hot and humid air as a 500mb shortwave scooted past to the north.
After a quiet May and June, the storms were welcomed and helped to ease the drought conditions imparted across much of Southern Ontario thanks to a very dry and storm free spring and early summer.
Surface analysis 21Z Fri Jul 8 2016
I started the chase day in Woodstock Ontario around 2PM as I focused on two possible targets eventually narrowing it down to the area around Goderich. As with every storm chase, looking at the surface observations and being in position early rather than late is always important and critical! Playing catchup or being unaware of the atmospheres potential is never a good thing and can really make or break a chase day.
This was one of those days, plenty of potential with clearing skies and otherwise good timing for the storms. A cold front was swooping in from Michigan while a warm front lifted through Southern Ontario bringing in hot humid air!
TD's jumped significantly just behind the warm front and boundary layer moisture was aided by rainfall overnight from a weak MCS that pushed through.
I stopped in Woodstock and eventually Mark Robinson (a fellow chaser) met up with me. We then headed off to intercept a storm that was slowly coming across the lake. This was the view over an hour before the storm was due to arrive.
Long before the storm arrived this shelf feature was visible on the southern periphery of the storm.
What was interesting with this storm was that it was sitting in the center of a meso low, perhaps thermally induced? Whatever the case, it was in an area of enhanced vorticity and there were winds curving into the storm from the Southeast. This was very interesting to observe, especially since the night prior the WRF-NAM basically forecasted this and was spot on!
The favourable low level winds were also effectively pushing the supercell composite index up ahead of the storm. At one point there was a strong TVS signature visible over the waters of Saginaw Bay. So there was definitely verifiable rotation occurring and all the dynamics were drifting east with the storm.
Mark with his periscope feed running!
The shelf from the storm was slowly getting closer and strong knuckle convection could be seen above the shelf feeding from left to right (south to north) into the storms dominant cell.
The storm at this time was now about 50 kilometers away and beginning to pickup forward velocity.
The latest radar scan had the storm taking on a bowing appearance with a persistent pocket of rotation in the NW quadrant where you would normally find a bookend vortex signature.
These little fingers of moisture were getting lifted all along the edge of the forward flank downdaraft.
As the storm continued to close in the structure now becoming visible was just awesome!
At this point in time the rotation in the northern portion of the storm seemed to simmer down somewhat. I'm not sure if that's due to the storms distance from the radar increasing or if the rotation was actually falling off, but whatever the case, the storm still had a very impressive radar signature.
Believe it or not, this is a single 11mm image. I cropped out the shoreline (didn't like the look of the grass). The storm was much closer than it looks in this image!
At this time the storm is about 10 kilometers away!
This is one of those moments where breaking out the 70-200mm lens was a good idea! It's hard to explain, but sometimes you just need to zoom in and focus on the key points of structure that are just amazing.
The structure on this storm was more reminiscent of a high plains supercell or a moisture packed HP storm roaring through Nebraska, but this was Canada over Lake Huron.
Despite this storm having a more linear and bowing appearance on radar, the curvature literally bent around into the primary updraft giving it that power high precipitation supercell look. The shear values were right, so this storm was definitely a super cellular hybrid of sorts.
Here's a panorama stitched together from three separate images. What a beast of a storm, just beautiful!
Around this time, the couplet was back on radar and the storm was looking even more powerful with higher dBz values showing up in the strongest portions of the storms core.
What not a true mothership in the classic sense (that's reserved for LP supercell storms) this stacked shelf really had a nice curl looked to it that had that mothership type look. If you look near the edge of the leading shelf, thanks to light refraction, you can see a thin dark line marking the edge of the marine layer. You'll not the storm bends it upwards and eats it!
I zoomed right in to show just how green the area inside one of the folds along the stacked shelf cloud was becoming. There was definitely some hail growing but the 30C air at the surface with the very high humidity was ensuring that most, if not all of it, would melt before reaching the ground.
The storm was probably only 3 kilometres away at this point. The air was still calm if not blowing slightly towards the storm at the lookout location I was perched upon.
This was the last image I took before packing up and heading out. Again, this is super wide at 11mm, but rest assured, the storm was virtually on my head and I had very little time to spare.
There were many lightning bolts crashing all around me which was the other reason for the rapid retreat. Lightning is the biggest danger, you can't predict it and don't see it coming until it's too late and I don't mess around, it's a killer.
I'm not sure how far away this strike was but it must have been no more than a few hundred meters at most. There was no delay between the sound and flash. A few other chasers were just getting in their car when this struck.
While less dramatic than the first frame of video, this gives a better idea of what was getting struck, and I'm still not sure? Was it a tree? Rock? Dock? Whatever got zapped sure felt it though!
Mark, John and myself bolted east to try and get ahead of the storm. This part of the province is pretty wide open and flat with only the occasional row of trees to obscure the view!
Dashcam Video from Exeter with strong winds blasting in.
March 28th 2016
On March 29, 2016
- 2016 Storm Chases
09Z Analysis - A strong low with substantial dynamics aloft and a very large warm sector, fed by tons of daylight ahead of what was a rather narrow stretch of frontal cloud cover worked into Southern Ontario. With the low came some early season thunderstorms which had small hail but were highly electrically charged.
The storms were not propogating in the usual sense, instead they were bubbling up along theta-e lines and sort of drifting north. It was odd and meant the lightning was not situated anywhere predicatbly. Plus, it was 2AM and I was actually exhausted from Easter Sunday. So I was not in the mood for a drive and figured I would try my hand from the window.. without a tripod... which I left in the car.. DOH!
The initial lightning display was great!
But then as the storm cell drifted north, the bulk of the lightning decided to hide behind the front tree. Maybe I should have gone for drive???!!!!
And so the night went, the rest of the bolts hid behind the trees out of clear sight. Eventually I decided to call it a night and hit the pillow!
That was until I was awoken by the extremely hard rumbling cracking sound of small hail hitting the steel roof! I called it a night right after this.
March 16th 2016
On March 28, 2016
- 2016 Storm Chases
Well, it started out as a cold, dreary, barely above freezing morning. This was the scene downtown as heavy rain along the impending warm front poured down in the still dominant cold, windy easterly flow!
The warm front burst through around 3PM and cloudy, rainy, cold skies gave way to warmth and abundant sunshine. A shortwave moving in from the southwest was also bringing shallow instability with steep lapse rates and strong directional wind shear.
Not a chase per say. I was at the airport due to work and the storm associated with the shortwave slowly grew and came into view on the North-Western Horizon.
A short while later the first of the storms was literally on top of my location at the airport! I could tell by the look of the storm that there were going to be some very strong surface winds.
The storms looked mean but were basically just a mix of rain, small hail and gusty winds. You can see how this storm has a very cold look to it.
The whispy ice rain bands about to hit!
Looking northwest, about to hit!
The storm blew through in literally 2 minutes producing winds of 95 km/h!!!
This poor umbrella became an instant victim of the storm!
Later in the day a second storm cluster began to move towards Toronto from Guelph.
The storm produced some heavy rain and lightning but fell apart as it entered the city thanks to diurnal cooling during the evening.
September 9th 2015
On October 21, 2015
- 2015 Storm Chases
Not a storm chase per say. While on vacation in Florida this tropical thunderstorm about 70km away lit up the horizon with awesome lightning!
June 8th 2015
On June 11, 2015
- 2015 Storm Chases
This was one of those somewhat unusual setups where storms were poised to fire along a trough from a secondary low behind a weak cold front. The initial cold front brought weak storms and drenching rains overnight and into the morning.
The day started with dense cloud cover and dreary showers. Despite the washed out morning conditions, clearing and warm air advection began to ejected energy from Michigan northeast into western portions of Southwestern Ontario. The lingering cloud cover also began to clear from west to east. The environmental conditions quickly began to become favorable for storms and some weak convection initiated in Michigan.
A few storms began to form over central Michigan and track towards the border. I decided that it looked decent enough to head out and traveled west towards Exeter.
I took a few minutes to stop and visit the Exeter Radar Site since it was literally along the way into town.
Just west of the radar site the skies began to clear and the extent of the deep rich low level moisture became apparent and thick super low level cumulus started to form. You can see how wet the ground is from the storms the previous day and the early morning rainfall.
I stopped in Exeter, grabbed some A&W for lunch then headed north. While I could hear thunder an incredible amount of haze had fomented itself around me. Just north of my local two discrete cells popped up as the nose of warm air from Michigan began to break through the cooler air from the morning.
This was the first storm to my west. I could see very little structure due to the haze and cloud. I sat and watched before I eventually decided to travel south.
The storm soon appeared to look more organized and I could see core structure as well as outflow features.
This pile of scud looked like a wall cloud briefly but it was most likely an outflow only feature.
As the storm drew nearer it has a pretty solid looking core and a ton of outflow wind. Unfortunately I could not see any solid inflow structure to the southwest which sort of worried me.
I stayed right on the edge of the storm but it was just chugging along at a good clip and dumping tons of rain and outflow crap in its wake. I eventually met up with fellow chasers Scott Burlovich and David Piano and we regrouped to head west towards another storm.
As we headed towards another storm this was a neat shot looking back at the first cell. You can see the core of the storm to the immediate top of the photo (north) and the whales mouth to the right (east). This entire whales mouth feature was a massive outflow boundary that was slowly pushing south away from the parent storm.
As we got closer to the second storm which we had targeted it began to fall behind the outflow boundary from the first storm. As this happened it was apparent that there was little structure and likely no surface inflow. This was a half hearted attempted at a shelf cloud.
Eventually we fell south and a new weaker cell began to form ahead of the outflow washed storm. In littler three radar scans it jumped from a weak rainy storm to something more impressive little. As we punched through the storm and wound up on the northwestern flak we had a good clear view of a nice flanking line and good inflow structure.
This storm had now managed to meet up with that big outflow boundary and started to pull in warmer air south of the cold pool at the surface.
I took the opportunity to grab a photo of Scott while he photographed the storm.
We fell south with the storm and I quickly noticed some crazy spin in the cloud directly ahead of us. We both stopped and started taking photos and video. I can't explain it with still photos, but the rotation was very pronounced.
This was the inflow/outflow part of the storm where had there been a tornado, it would have been located.
Again, the outflow began to get ahead of the parent storm and trigger a cool whales mouth. By this time the visible rotation had diminished.
This was the area where new towers were growing but not precipitating. These clouds were super low!
Eventually everything just became a big pool of outflow and fresh storms failed to really successfully fire while whatever was on radar quickly fell apart. Getting out south ahead of the outflow the air was 26C and it was hazy and humid.
I noticed on radar a new storm had started to brew to our northwest but visually we could not see much of anything. I suggested to Scott we head in its direction and once we were about 4 km out we stopped and had this interesting view!
The storm was unusually laminar looking with mid level inflow present. It's unusual to see this type of structure in Southern Ontario so I was very enthused!
I had to grab the Fisheye lens, this storm had such a cool look to it! Despite being very laminar it had no rotation that I could see, at least not on a ground relative level but mid-level inflow banding was very very present.
This wall of cloud which almost had a roll cloud look was just to the southwest of the main storms core region.
Interesting to note is that the storm had this beaver tail like feature. Again, this storm was hauling in mid level and low level inflow so it makes perfect sense to see moisture just streaming in from the southeast.
The edge of the storms core was just coming across the trees in distance. I figured this was a cool photo and I only had about 30 second after taking it before the rain hit.
Eventually Scott and I fell back southeast and punched through the storms core. It was very underwhelming but it was fun to watch Scott try and fight with the rain to photograph some crepuscular rays breaking through the rain.
I waited for a bit and watched some lightning trickle out of the storm with Scott. It was nothing that would be easy to photograph so I called it a night and headed home parting ways with Scott.
April 30th 2015
On June 1, 2015
- 2015 Storm Chases
This was the real start of my chase-cation. There was a very marginal potential for severe storms and tornadoes were a virtual impossibility based on probabilities. It was a usual weird as could be high plains setup where by some miracle of the storm relative wind fields and near non existent moisture, the high plains would somehow produce storms which would grow in strength by evening and eventually everything would be pushed out by a cold front sinking south from Wyoming. Weird things happen above 1500 meters in elevation!
After spending the night in Denver we headed north towards Fort Lupton. Both parts of Wyoming and northeast Colorado looked great for storms. Near for Lupton I had to stop and take a photo of this mountain with a nice grass-hopper jack in the foreground.
After hanging out near Fort Lupton for a while I headed east to follow and watch one storm cell that was just fluff near Dearfield. The thing with these storms that roll off the mountains is that you never know exactly which one will become "the storm". Eitherway, it was still early and the mix of high based and low topped convection was not good!
By this point I decided to head north on I-25. These storms just west of Ft. Collins looked like they were trying to organize but still low topped and high based.
The radar was showing something interesting starting to come together in Wyoming with the storm tracking SSE at around 20 knots while the stuff in Colorado still looked mushy. The thing with chasing on the edge of the front range is that often the storms go up super dry and the radar can be very deceiving. Your eyes are the best tool since you'll often still be able to see more than whatever the radar can see.
On the way to Cheyenne there's a super flat wide open part of I-25 that's always windy where the elevation jumps to 1900 meters! On the way to this particular storm I was being buffeted like crazy, it was hard to stay in my lane!
Once in Cheyenne, the storm began to quickly look more and more organized as it moved into a deeper more moisture rich boundary layer.
The inflow base had that nice chiseled look where each little stub of cloud was condensing right at the lifting condensation level.
I quickly blasted south and east to get around Cheyenne and put myself back ahead of the storm. At this elevation to see a storm registering with reflecitivities so high means that hail is guaranteed. I think the largest stones at this time were around 1 inch.
After popping out from under the storm I was shocked to see it had transformed into a beautiful classic supercell. The storm was super low precipitation, I think dew points were like 40F and cape was only on the order of 1000 j/kg but there was enough directional shear relative to the storm motion to produce this supercell.
Considering conditions were marginal at best I don't think this is all that bad!
I stayed with the storm which was super easy given the 80 MPH speed limits. Unfortunately another storm had developed about 100 miles south in Colorado and outflow from that storm was quickly headed north.
The outflow from the stuff in Colorado killed my nice Wyoming supercell and I headed towards the Colorado storms.
The storm complex which look good on radar became a real mess by the time I got where I needed to be. The high terrain this far west is a blessing and a curse. It helps storms form without needing any of the usual 850mb parameters but at the same time dries out the atmosphere and limits moisture. In this case, as the storm complex moved east the atmosphere became deeper as the elevation dropped but the moisture did not increase with depth and the storm fell apart.
As the storms grew and died in a strange twist they generated their own local moisture fields and began to re-saturate the atmosphere.
Eventually another more organized storm complex formed and started to take root. Strangely enough the inflow was situated on the north side, but given the odd wind fields its no surprise.
This storm which began to exhibit some weak rotation was actually a -counter-clockwise rotating storm but had clockwise reversal of the features. Weird, I know!
Eventually everything became outflow dominated and the storm fell apart.
Near Logan Colorado the fields and road were coated with a covering of hail stones ranging from pea sized to nickle.
Lot's of hail.
The hail drifts at the side of the road were half a foot deep in places after rain had washed the hail aside.
This years chase vehicle! The top antenna is a cellular amp, K40 on the left is for the CB, middle antenna is a Diamond CR-8900 quad band (10, 6. 2 & 70) while the right antenna is a 5/8th 2m whip.
May 18th 2015
On May 25, 2015
- 2015 Storm Chases
Today was the first “real” Southern Ontario chase that presented any possibility of actual thunderstorms. Having gotten back from tornado alley I was not storm deprived but I was not expecting much either. After chasing down in the alley, Southern Ontario can be pretty boring. I usually don’t feel the storm vibe here until late June or early July when SDS (storm deficite syndrome) begisn to set in again.
The play was going to be along a cold front swooping in from Michigan. There were indications that there could have been some storms earlier in the day around 18Z/2PM along a pre-frontal trough however mid level subsidence crushed everything. I spent a few hours at the Cambridge Onroute service centre. Things inititally looked somewhat promising but then the cu field quickly began to show signs it was just turning into pancake cloud. Pancake cumulus is a term often used by pilots to describe cumulus that hit an inversion and stop growing vertically but instead flatten out and turn into stratus, from the air they look like pancakes apparently.
Again, the only area of pre-frontal convergence was right between the lake breeze boundaries just west of Hamilton and you can see how the clouds are flattening out and not growing any taller. They were all hitting this nasty 600mb inversion and it was just halting their development.
After hanging out in Camebridge for what felt like too long I decided to head west towards Stratford. There we're some storms cells popping up in Michigan and slowly heading towards Lake Huron. I figured I may as well get into some sort of half decent position should anything survive the trip across the lake.
This was the sky outside of Dublin. I took this photo using my fisheye lens which captured around 180 degrees of the horizon. You can really see how the there was a spur of cu and tcu growth in the area. As the front approached lapse rates began to pick up but the problem was there was stabilization from the marine layer being pushed on land by the southwesterly surface flow.
Another similar shot showing both low level and mid levels clouds indicating instability in both levels of the atmosphere.
Just as I was twiddling my thumbs I saw a dust devil spin up in the field beside me and I gave chase. Of course it was a fruitless chase since I eventually lost soft of the dust devil but it did cross the road in front me which was cool.
A few moments after my dust devil chase John Scheer caught up with me. He's another local chaser who lives in the Stratford area and decided to swing by and say hello.
After hanging out and chatting for a while John and I headed towards Bayfield to intercept one cell that seemed to be surviving the trip across Lake Huron.
The storm near Bayfield started to look okay. It was not severe or anything but the sun was creating some nice backlighting.
Unlike may of the other great lakes, the problem with Lake Huron is that often there are huge drop-offs down to the waters edge. There are only a few places along the more southern shores of the lake that are a straight to shot to the waters edge. This was one of those drop-offs where we were forced to shoot from above without actually being able to head out to the waters edge.
Once the storm began to make its way inland, both John and I headed back east to keep ahead of it. The setting sun really made the storm look beautiful. It tried to produce a shelf cloud of sorts on end but it never really materialized. Some other chasers on the northern edge of the cell (Laura and Scott) really got a beautiful shelf cloud!
Again, another shot of the storm. The light made the contrast pretty intense.
It was nice to see the sun through the rain curtains of the storm. Again, nothing severe here, just a pretty sky.
I was running out of time and daylight. I needed to be for 4AM the following morning and decided to give up on the storm early. There was some lightning but I did not feel it was worth my hanging around since I had a good two hour drive ahead of me. It was a fun little chase.