Monday, July 25, 2005

what's your tilt?

over the past few days and weeks, i've been noticing the relative lack of tornadic supercells--not only over canada, but over north america.

what would cause such a dearth?

well, the ingredients are pretty much all there. moisture--no problem--dewpoints have been in the 20s in the regions of interest. instability--no problem--capes have been well over 3000 j/kg. for the most part. shear--no problem. sort of--0-6 km shears have been on the order of 40 to 50 knots. but i'll get back to this in a bit. trigger--no problem--warm fronts and cold fronts have been in abundance.

so what is it?

i think it's the tilt of the upper troughs passing through.

what are you talking about, dave?

if the trough axis is oriented nw-se, it is said to have a negative tilt. if it's oriented ne-sw, it is said to have a positive tilt. if it is aligned north-south, it has neutral tilt.

well, most of the troughs coming through on potentially explosive days have been neutrally or positively tilted.

so what does that mean for the storm environment?

well, in a nutshell, the more negative tilt the approaching trough has, the more the surface winds will back. the more the winds back, the more you increase your storm-relative low-level shear.

so put that all together, and the troughs moving through the upper atmosphere have been promoting very little backing of the low-level surface flow. so instead of being tornadic supercells, the storms are perhaps exhibiting brief supercell structures but quickly transitioning to bow echoes or other linear modes of storm.

Sunday, July 24, 2005

a tough experience

i admit it. i got suckered in.

yesterday the spc upgraded to a moderate risk over eastern nd and central mn. i took the bait and swallowed every bite, driving down to south of fargo.

moisture was huge, and thus so were capes. shear profiles were great, due to a jet impinging on the region and a good se low-level jet. the trigger was there in the form of a warm front.

but then there was the cap.

looking back at it, i should have forecast no surface-based storms south of about berens river.

so what was i doing?


ignoring the cap. ignoring the fact that my analysis had 14 degrees at 700 mb advecting into the area.

and now i have egg on my face and 1000 km more on my car.

sigh. hope that'll teach me.

Tuesday, July 19, 2005

now back at home

well, i wanted to get philosophical. i wanted to get contemplative. i wanted to get teacherly.

then i remembered bowman. ;)

for the inaugural canadian storm chase university class, things went remarkably smoothly. i mean, don't get me wrong--there were a lot of things we'll need to work on and change for next year, but by and large, the trip went well.

too bad the weather didn't completely cooperate.

really, though, it was pretty good. we saw wall clouds, we saw shelf clouds, we got outflowed, we saw some violent upward motion in growing towers. not a bad catch for a fly-by-the-seat-of-your-pants set of days.

wxdog, jay and i will be getting together over the next few weeks (likely sooner than later) to go over what went right and what went wrong. we'll talk about changes we'll need to implement and things we hope never change.

thank you all for being part of the first ever storm chasing course in canada. we all really enjoyed getting to know you (although i must say, i likely learned more than i needed to know, and i'm looking at you, yoyo.) (grin.) but seriously, i don't think we could have asked for a better group. you all participated lots, and your eagerness and keenness kept us on our toes and reminded us every day why we do what we do.

don't think this will be the end of blogging here, though. this is just the beginning. i admit, the entries may become less frequent, especially over the winter (where i'll probably talk about cool weather stuff--winter and summer) but i'll keep updating with thoughts, ideas, and streams of consciousness. and, of course, chase summaries. of which i hope some (or all) of you will be a part.

there's lots of chasing yet to do this summer. :)

Sunday, July 17, 2005

thanks, jay

we're currently at doolittle's american grill in alexandria, mn. we had a good dinner, and i even ate some of yoyo's prime rib and some of jh's fettuccini. then jay decided to buy me a huge dessert--a mocha mud pie. when i say huge, i mean that it was colossal. i had a tough time finishing it off.


but i rose to the challenge, jay, and i hope you're proud!

good thing, too. maybe now i won't have to eat for a month now. ;)

the chase is done...

we just abandoned. a couple of calls were completed to get some data (finally!) and we heard about the fact that the cold front is still far ahead of us and moving quickly. as well, there's apparently no deep moist convection going on in our area of interest.

that's too bad.

but as well, that's the nature of chasing. something promising can turn into something deflating. and that's what happened today.

still on the road

we're currently near the thriving metropolis of clontarf, mn. (find that, google maps!) heading eastward but we're still in the post-frontal air. i don't know if we're going to see anything. it's getting awfully late awfully early, frankly. i mean, the post-frontal air is still pretty moist, but the moderate west winds (about 25 knots) are not encouraging. where's the cold front? could be just over the next hill, but (more likely) it could be approaching minneapolis. if it's there, we're sunk for today.

i'd really like to have data right now--see if there's any point to what we're doing today. but the wireless networks are few and far between, and libraries are now closed. so unless we can get a network, we'll have to chase blind. chasing without data is not one of my favourite things to do.

this part of minnesota is pretty good for chasing, aside from all the little towns you have to go through and slow down in. the terrain is really flat and there aren't too many trees. i'm in chase 3, still not driving. that part is great--i was really bagged by the drive through the rain and construction outside of minot last night.

will we see anything? will we get a wireless network? will we even get a lightning strike? stay tuned...

on the road

we're driving along (no, i'm not behind the wheel right now!) from minot to jamestown and then we're going toward fargo and into minnesota. we've seen a couple of interesting things along the way. we saw a lake, a water tower, a field of flax, anamoose.


we're going to pass through the cold front this afternoon. we had it pegged between jamestown and fargo this morning, and it should be through central minnesota around prime time. we're not really expecting to see any tornadoes, but you never know. if nothing else, we should see good funky cloud structure. dewpoints are in the low 20s over the entire state, so low cloud bases should happen.

tomorrow we're going back to winnipeg. the pattern looks pretty craptacular for a couple of days after that--silly august pattern. of course, how often do you get a category 5 hurricane in july? (okay, it was a suspected 5, based on one flight-level wind, but whatever--strong 4 or marginal 5, it's a major hurricane, and it's seriously disrupting the flow--getting rid of the stormchaser's flow.) but later next week doesn't look too bad. i have time off work until the 25th, so maybe i'll be doing some chasing. and based on the response i've been getting, i won't be chasing solo anymore. :)

a long day

a short sleep was ended by restlessness and i got up to get my bearings.

after the shower i took off down the hall to check on the day's happenings and was dismayed--no, discouraged--to see that my concerns for the day had already come true. there was more lift than i had been hoping for and there was already a big cloud shield over most of southern saskatchewan. this would mean that less insolation would lead to less instability. not a good thing if you're wanting to see severe thunderstorms.

we did our analyses on the road and stopped in watford city, nd for a pit stop and to reassess. i got hold of the college of dupage and they were thinking along the same lines as we were. southeastern saskatchewan. but they also had concerns about pollution from the cloud in place. they were cautiously optimistic, though, as we also became after a data stop in weyburn. (best. library. ever.) a broad area of clearing was showing up just southwest of us and there was an area of enhanced cumulus development within it, indicating an area of persistent lift. we figured that was the area to go to.

as we got there we saw a pretty good storm, albeit short (my estimate was 30000 foot tops) trying to get going. it wimped out but we saw some lowerings off to our north. we took off on a gravel road to get a better look and were treated to a good shelf/possible brief wall cloud. the motion wihin this thing was incredible.

when we got the outflow we decided to move along to stay ahead of it. but after about 20 minutes' worth of going at 110 km/h, it was becoming obvious that this wasn't feasible.

so we took off in the direction of the best-looking outflow (complete, it appeared, with dust flying throught the air--looked sorta like a haboob. (or is that an haboob?!)) we got some really strong winds soon after. my anemometer measured 69 km/h, but it sure felt like more. i think i need to calibrate it to find out its accuracy. that seemed more like 100 km/h than 70. but i digress.

this storm was now clearly outflow-dominant. it had an outflow tail extending from 20 miles northeast of us to about 50 miles southwest. i can only imagine what it looked like on satellite imagery. we tried to catch up to it but it was just screaming along. after giving up on it we decided to go southeast, in pre-positioning for tomorrow, on the way we managed to catch up to the outflow (in that direction, anyhow), and some interesting things were happening. the outflow was providing good convergence and some solid towers were going up along the line. in fact, one tower went up so high that it punched through the anvil from the parent storm. the tower ended up collapsing and the neat thing was the fact that it, as well as the anvil it had punched through, got compressionally warmed and dissipated almost entirely. so picture it--a broad anvil from a good storm, and a small hole in one corner of it. very unique.

we went to estevan and decided to go to minot for the night, so as to minimize the trip for the next day. well, bad choice.

why a bad choice?

first off, we all got stopped at the border and they took about 45 minutes to process us. we had nothing to hide--i guess either they have a quota to fill, or we looked suspicious. at any rate, it took a lot of time.

then we got into road construction for a good 15-mile stretch on the american side. and then it started raining. the van bottomed out once really hard, and there was some pretty sludgy mud around. i think the vans will need a wash soon. ;)

we finally got here and now i'm typing this out, and i think i'm ready for sleep.

tomorrow looks only okay. south-central minnesota. we'll make the call in the morning--do we want to play that, or maybe just meander back to winnipeg?

either way, i'd call this a successful trip.

Saturday, July 16, 2005

super 8 motels

we've stayed at super 8s for the past 2 nights. why is the shower head at eye level? i'm not a very tall guy--5 foot 9--so what do really tall people do?

things are still looking pretty good for the target area today. there's only one fly in the ointment, one i've been concerned about for a couple of days--too much lift. the satellite imagery shows a lot of cloud over southeast sk and northwest nd, but surface obs are showing that it's thin enough to allow good surface heating. i certainly hope so.

the shear is definitely there--minot's radar is showing good low-level turning on the vad. moisture shouldn't be a problem--dewpoints over the area of interest are already in the high teens, and look to go higher with evapotranspiration. lift is certainly there. lots of convergence at the surface low near williston. and instability, well, if the sun can peek through enough but still have us stay capped for most of the day, we'll be golden.

i wonder if the college of dupage guys made it to minot.

hey guys, if you're reading this today, give me a call--or i'll try to call you in a while.

bowman, nd

we did the black hills today. a few clouds pulsed up, and that was about it. it was way too capped. really. what we might call a nuclear cap. there were clear skies and lots of sunblock today.

tomorrow is the day we've been talking about for a while. everyone's excited about it. college of dupage. tempest tours. the verkaiks. and of course, the university of manitoba.

we had a pretty wild evening tonight. we took pjm out for his birthday. he's seen more tornadoes on or near his birthday than during any other time of the year. this time is what we call prime time anyhow, and things tend to set up this time of year.

pjm plays pool well when he's had a few.

i don't. ;)

not much to talk about tonight--because i've had .... well, due to an intoxicated situation i can't really recall all that's happened, but hopefully tomorrow i'll have lots to write!!

Thursday, July 14, 2005

day 1

sitting in space aliens bar and grill in bismarck. today we got down to east of jamestown and saw a good storm building off to our nw. it was showing a pretty good wall cloud for a while but then the outflow cut off the moist warm inflow. we continued trying to see good storms to the se but they were staying undercut by the outflow. the storm structure was awesome, though. i wonder what else was reported--but it looks like we were near the tail-end charlies. they just didn't have enough inflow (speed, mainly) to really get going, that's fine, though. we saw a supercell today.

actually, on our way back to bismarck, west of jamestown, we pulled off the highway to look at a storm that, although it was in the outflow, was looking kinda impressive. it dropped what appeared to be a wall cloud, but maybe i'm just seeing what i hope to see. whatever it was, it was photogenic and worth stopping for.

now i've gotten everyone here expecting great things, so i certainly hope this place delivers.

all in all, not a bad first day.

tomorrow it looks like south dakota, looking for storms to fire off the upslope flow of the black hills. we'll look at the model output and what the spc decides on and make a decision from there. alberta looks like it could be interesting--a good setup for hailers, but i don't think that we're anywhere close enough. so we'll probably make the south dakota play.

the vans seem divvied up well. chase van 3 is ... interesting, what with some fairly ... shall i say, interesting discussions that will forever stay within the walls of the van. remember the monkey pointing. that's all i have to say about that.

time for beer and ribs. guess which one i'm going to have more of. (6)

in grand forks

we're currently standing around in a circle on the grounds of und in grand forks. we're discussing the target for the afternoon, and right now i think jamestown would be good. it sounds like the analyses are bearing out what i'm thinking, too.

i hope we stop to get some lunch soon.

out the door...

preparations are made. vans are ready. i'm freshly showered (you'll all be thankful for that!) and raring to go.

ready, set.....

Wednesday, July 13, 2005

last forecast blog before we leave: july 13 forecasts

we leave tomorrow. i'm ready. are you?

july 14: grand forks/fargo. this'll take an intensive analysis in the morning, though, because it appears the best shear (we know the instability will be there) might be north of the border.
july 15: sw sk/northern mt--but it looks marginal (nam) or saskatoon (gem) or swift current (gfs). this day might turn out to be better than it currently looks.
july 16: minot-regina (nam) or devils lake (gem, gfs).
july 17: if the pattern is a touch slower than currently shown, grand forks (gfs). otherwise nowhere (gem).
july 18: red deer-lloydminster (marginal) (gem, gfs).
july 19: swift current (gfs) or regina (gem).
july 20: swift current (big setup) (gfs) or glasgow, mt (gem)

we'll see. i'm willing to bet that one of my forecasts from the past couple of days will be right. ;)

what do i personally think we'll see? i think we'll see great storm structure. i think we'll see severe thunderstorms. i even think it's likely we'll see a supercell or multiple supercells. will we see a tornado? keep in mind that, although the number varies depending on whom you ask, but only a small percentage--somewhere in the 10% range--of supercells is thought to produce tornadoes.

so here's hoping we get that one in ten! :)

Tuesday, July 12, 2005

new toys

so it's 3:55 and now i'm typing on this mac. it's kinda neat--a little different as i'm not used to using a mac--of course, nor am i used to using a laptop!

i've now got to take care of setting up the gps. this could get fun. or funky.

2 days till the chase. i can hardly wait. :)

update: d'oh! the gps will only interface with a pc--not a mac. grumble.

july 12 forecasts

well, it looks like, as the time comes closer and closer, the solutions are settling down. at least in the shorter term. one thing that seems fairly certain: we're in for a lot of hot weather. with the moisture in place all across the prairies, i'm cautiously optimistic.

july 14: fargo, nd.
july 15: moose jaw (gem), swift current (gfs), or medicine hat (nam-marginal day).
july 16: fargo, nd to mobridge, sd (gem--this solution looks odd to me, though) or pilot mound
july 17: maybe minneapolis. otherwise nowhere.
july 18: edmonton (gem) or kansas city (gfs).
july 19: lloydminster (gem) or west of red deer (gfs).
july 20: estevan (gem) or coronation, sk.

a couple of things: first, after about day 3 the models are still having difficulty. i imagine this is because of a) the remnants of dennis in the system, b) emily (who, they're forecasting, will likely become another major--that is, category 3, hurricane, and c) the fact that forecast models (especially the long-range ones) suck. second, don't be disappointed if we have a non-chase day. what we'd really like is what happened to wxdog and me in the summer of 2001--where the flow stayed pretty much stationary over the area and we didn't have to go very far each day. but if that doesn't happen, what we can expect to happen is that systems move through and pop storms one day in ab, the next in sk, then the next in mb; the next day being a travel day to catch the next wave coming in off the west coast into alberta.

whatever it turns out to be, it should be fun.

i forgot to mention--or maybe i did mention and i just can't remember that i mentioned it. at any rate, try to bring some compact diversions along. cards. hacky sack (which i'll try to find amidst the boxes of stuff in my house). frisbees. footballs. you know, stuff. if we hook up with cod they usually have a bat and a softball, and if there's some wait time, they'll go to a park and play a game of bat and catch. we'd join them. (i can't really call it a game of anything aside from bat and catch--last time i played with them, in kansas, one team kept going until the batting order was exhausted. i was one of the last people in the batting order and i was, i think, the 7th out.) (oh, and the ball they use is extremely soft--no need for a glove.)

Monday, July 11, 2005

okay, so i missed a day; july 11 forecasts

yeah, i missed a day. i went out chasing yesterday afternoon (caught a shelf cloud and that's about it) and for other various reasons, i didn't do the extended forecast. i'm sure you've pretty much got the picture by now, though, that long-range models are somewhat useless in terms of forecasting for chasing. regardless of that, i'm going to do this up till the day we leave.

july 14: fargo. most models are now pretty much converging on this area being a focus for that day. now i'm not saying it'll be definitely near there, but as we draw nearer and the models converge on a solution, i can be more confident in the forecast.
july 15: regina-moose jaw (gem) or southeast-central montana (gfs).
july 16: pilot mound-devils lake (gfs) or glasgow, mt (gem). boy, now they're really diverging.
july 17: maybe eastern nebraska (gfs) or a good setup near virden, mb (gem).
july 18: eastern kansas (gfs) or bismarck (gem).
july 19: nowhere (gfs) or pilot mound (gem).
july 20: both gem and gfs indicate nowhere.

it just goes to show the variability amongst the models and the changeability from run ro run.

Saturday, July 09, 2005

forecast, july 9

here we go again. in general, the gfs and gem global have us in a storm chasing pattern through the duration of the well as before and afterwards. in the previous times i've been going mainly with the gfs (for ease of use), but tonight i'll use both it and the gem global. this should be fun.

july 14: estevan to saskatoon. depends on the cap.
july 15: lethbridge (gfs) or dauphin (gem).
july 16: far western (gem) or central (gfs) montana.
july 17: yorkton (gfs) or lloydminster (gem).
july 18: emerson or nowhere.
july 19: yecch. nowhere.
july 20: medicine hat.

wow, what changes! :)

Friday, July 08, 2005

july 8's forecasts

a new model run, a new forecast.

july 14: north battleford. still looks like a pretty good setup, but if it shifts much farther to the west, we won't make it in time.
july 15: grand forks, nd. looks better than the previous run.
july 16: maybe northwest sd. maybe. or the battlefords.
july 17: estevan. not a bad setup.
july 18: watertown, sd.
july 19: north-central nebraska. i'm not kidding.
july 20: sioux land. maybe.

already a couple of the days have changed radically. it just goes to show how fickle the forecast models can be.

hurricane dennis is a category 4 as i write this. it's setting up to smack cuba. i hope everyone there is safe.

on a completely different note, things popped pretty huge this evening in far southeastern sk and southwestern mb. (there's currently a pretty good thunderstorm going on here in the city.) there were a couple of tornadoes (and we got pictures of them--sorry, not allowed to share these, by request of the photographers) along the mb/sk border and baseball hail. this morning it looked okay, shearwise, for supercells. well, maybe not even okay. marginal. but i guess we didn't count on the capes getting up so high. late this afternoon melita was reporting a ridiculously humid t/td of 29/26 and the associated cape was in the neighbourhood of 7000 j/kg. yes, seven thousand.

we think that the dew cell in melita might be a bit goofy, as it seems to read the dewpoints a little higher than the surrounding regions. but still, with a dewpoint around 23, the capes were still in the 5000 j/kg range. it seems that, especially in july, extreme capes like that need a little less shear to spin up tornadoes. they don't usually end up putting down long-lived ones--that's for the highly-sheared environment--but still, they can tube from time to time.

whenever i'm chasing i play the cape/shear game and, time and time again, i get burned by being attracted by the high capes, when modest capes and better shear usually end up producing the better storms. time and time again, i say.

i just hope i no longer get suckered like that.

Thursday, July 07, 2005

countdown, july 7

here i'll start the long-range forecast of target areas for the 5 days of the chase.

it'll be mainly based on the gfs (also known as the goofus) model, but also influenced by the canadian gem global. i'll try to do this every day until the trip. i emphasize try. also keep in mind that this is all based on long-range models, which are notoriously fickle. especially right now, because hurricanes are notorious for contaminating forecast models.


july 14: saskatoon. pretty good directional shear. left exit of a 75 knot northwesterly upper jet.
july 15: red deer. not a great-looking day. but in that kind of pattern, if storms go anywhere, they'll go in alberta.
july 16: kindersley. again not a great setup, but it's one of those diffuse times. could be more interesting than it looks. or eastern nebraska.
july 17: edmonton. good setup for hailers that day. or northeastern kansas.
july 18: lloydminster. another good setup. or central nebraska.
july 19: estevan. or central north dakota.

i reiterate, this is mainly to show you the fickle nature of the models. tomorrow i'm willing to bet that a lot of these--maybe all of them--will be completely different.

and that's just fine with me.

i much prefer forecasting using real data.

Wednesday, July 06, 2005


i just marked the first couple of questions on the exam, and while i did so i looked over the answers on the rest of the exams. it looks like everyone did pretty well.

today tropical storm cindy hit the gulf coast near mobile, alabama. the radar was showing good spiral banding around a fairly large eye. a pretty storm, albeit a dangerous one.

the northeast quadrant of tropical storms has the setup for tornadoes in the storms embedded in the spiral bands. it's a neat phenomenon, mainly based on weak to moderate instability (obviously due to plentiful moisture) and strong wind shear. the spc has a tornado watch out for the area and, from time to time, a tornado warning (doppler-based) goes out.

why am i talking about tropical storms? well, last year paul from the college of dupage took a couple of days off in the fall, flew out to florida, and went hurricane chasing. well, he wasn't impressed. it was windy, and it was wet. that's pretty much all he could say. i suppose he was hoping to witness a spiral band tornado, but the tropical storm he intercepted seemed to lack something to make tornadoes that time.

as i type this there's a band of weak thunderstorms making its way eastward from portage. it should be here by 10:30 or so, assuming it stays intact.

well, time to update the forecasts!

Monday, July 04, 2005

pics are up

the pictures from my chase near pilot mound, mb, are up.

check the link out on the science page.

Sunday, July 03, 2005

for the course...

i know it's still relatively far into the future, but i'm encouraged by what i see.

the forecast models are all tending to agree on a favourable pattern for severe storms across our area during our chase vacation. hot and humid, with a moderate southwesterly upper flow across the southern prairies.

just perfect for slow-moving supercells. :)

another chase, another 2 tornadoes

yesterday didn't look all that impressive for tornadic storms, although it looked like a solid supercell producer. there was plenty of moisture and instability, a surface trough was swinging through southern manitoba (lift), and the left exit of an upper jet was to impinge upon the area in the evening, providing some speed shear. and more lift.

the surface winds, however, were southwesterly, lessening the directional shear.


i say "mostly" because this has a bit of an impact on what happened.

around 5 pm i was at home watching the radar show a pretty neat little supercell west of brandon, but the environment wasn't great for tubes. the winds there were west, and they were west all round. the instability was pretty much the same all over southern manitoba, and so it was a matter of waiting for the shear. using the satellite pictures you could actually see when the influence of the left exit region of the jet/stronger area of lift was being felt on any given area. first near regina, then estevan. i timed it out and decided that we should leave at around 5:30 to get to the area of influence in time--morden-ish. what heightened my interest, though, was the wind observation from carman--it was northwest all day, but at 5 pm it suddenly turned to southerly. directional shear. let's go!

we got to carman and saw some towers going up to our southwest. we decided to chase the most southerly of the bunch, and it turns out it was southwest of morden. we tried to get to it for a while, but then 2 things happened: first, we came to the pembina river valley just west of highway 31 (who knew the roads in manitoba ever got that steep?) and couldn't cross safely. second, the storm itself petered out. so we only had one choice left. go north back toward highway 3 and see what was what. as we approached the highway, wxdog called me and asked where we were, and was happy to know that we were there. he told me that radar was showing a monster supercell just off to our west-northwest, and there had been reports of golf ball hail with it. as well, radar showed some very strong rotation within it. storms farther toward the saskatchewan border were dropping tornadoes sporadically, so this provided added chance for a tube. we saw the storm and it wasn't that far away, so we bombed off in that direction.

as we approached it, near pilot mound, we saw the wall cloud. it was pretty low to the ground, ragged, and slowly rotating. at this point wxdog called again and relayed our report to environment canada.

at this point we were almost due south of the storm, and a gift from the heavens in the form of highway 34 going north appeared to us. we took it, only to be foiled of a view of the wall cloud by trees alongside the road.

then it happened.

all of a sudden, from light and variable, the winds picked up to easterly 20 to 25 knots. my conceptual model ideas kicked in and i realised that this could be only one thing: an inflow jet. i pinned the accelerator and told my chase partner why i was doing it; in essence, with this inflow jet, i figured the storm could/would put down a tornado anytime.

we got past the trees and stopped. the wall cloud was about 3 km to our west. no sooner had i put the car in park than it happened. tornado on the ground. no wait, 2 tornadoes. okay, now 3, all rotating about one axis. yes, folks, we had a multiple vortex tornado. i called it in to environment canada and was glad to hear that they were already in the process of drafting up a tornado warning for the storm.

we sat there for about 10 to 15 minutes watching this thing go multi vortex to elephant trunk to no condensation funnel but still debris, and back through the cycle again. the storm was barely moving and so we were able to take numerous pictures. i called environment canada back to let them know that the tornado was still on the ground.

then it started to move. it wasn't moving to our left, and it wasn't moving to our right, but it was getting bigger. we hightailed it out of there, back south on 34 to highway 3. we stopped a couple of times for quick pictures, but all of a sudden this thing was cooking. we had to drive through the hook echo of the storm, that is, the wraparound precipitation in the downdraft, and i was a little worried about this. we had no other choice, but sometimes extremely large hail is embedded in this part. luckily, though, not this time. it was a 1 km wide swath of light to moderate rain and winds 35 to 40 knots.

when we were on highway 3, the tornado was passing about 5 to 7 km to our north, and the contrast was pretty bad. we could barely see it, but when we could, it was evident that this was a wide tornado, what some would call a wedge. my estimate was that it was about 3/4 of a km wide, but that's just the estimate of a guy hopped up on adrenaline.

there were 3 bright flashes in the tornado, spaced apart by about a minute each. one was pinkish and the other 2 were blue. the duration and location (and colour of one!) were pretty wrong for lightning, so i figure it was probably transformers exploding. this is something you usually only see in kansas or oklahoma. amazing.

finally the tornado lifted but there was still violent rotation in the cloud. again i called environment canada to let them know that the tornado had finally lifted (after about 25 minutes!) but the storm was still very capable of producing another tube.

we continued east, toward home, when my partner pointed out more stuff to the northwest. we were just entering the town of la riviere when we saw a condensation funnel 3/4 of the way to the ground, and a bit of a dust cloud being picked up. tornado #2! we got a couple of pictures but this one didn't last very long--maybe 20 seconds. we got back out of la riviere (pretty town, but horrible cell coverage and brutal for storm chasing visibility!) to see that the original wall cloud had occluded out, but a new one was forming. its rotation was a bit more lazy, and the scud being sucked up into it was a lot more ragged. at this point, because of darkness and seemingly less vigourous rotation, we called it an evening and drove the hour and a bit back to winnipeg.

a successful chase!

i hope to have pictures up on weather central today (sunday) or tomorrow.

Friday, July 01, 2005

the second interview

it went well, too. although not a single person called in! that's okay--it seems i like the sound of my own voice. ;)

despite still being busy moving into the new house, there appears a chance i'll go for a local ("spot") chase tomorrow around the red river valley. my confidence in this just went up, as a tornado warning (based on a spotter report, but radar also looks pretty impressive) was just issued for areas just east of regina, sk.

why, pray tell, would this make me more confident that tornadoes are possible around here tomorrow? well, usually these things tend to produce tornadoes day after day as they travel across the prairies. i guess the properties of the atmosphere are just being advected across the area from day to day, and the potential remains there.


have a safe canada day!