Monday, May 31, 2010

May 31, 2010: tornadoes

We ended up near Springfield, CO this afternoon.

Good choice.

There was apparently marginal deep shear over the area but that didn't stop a multiple tornado-producing supercell from taking aim at the area.

We were on the storm from about the time of dissipation of its first tornado, which we did see for about a minute. Then we stayed and stayed on the storm, remembering that patience is a virtue.

We watched the storm cycle up and down and up and down, at times putting out very pretty funnels about halfway to the ground.

We were running a little low on gas. We decided to book south to the nearest town to find a station. On the way, though, Dee (who was watching what had been a "meh" mesocyclone for us) told us there was a good funnel and that we needed to to stop. Justin took us off the road to a safe parking spot (hint hint to all you would-be chasers!) and we jumped out of the truck to see another beautiful funnel reaching about halfway to the ground.

Only this time it didn't stop there.

It proceeded to produce about 20 minutes of one of the most beautiful tornadoes I've ever seen (certainly top 3). We were in a perfect spot for the lighting and it was moving so slowly that I could take time-lapse photography of it. I ended up taking 900 pictures today. Seriously.

The tornado lifted and got obscured by precipitation. Soon after, though, another tornado appeared to the right of where the other one had been, and with the lighting where it was, I managed to get pictures of a tornado and a rainbow in the same shot.

Another 10 minutes later the storm we had given up for dead surprised us with yet another brief tornado.

So not too shabby for a low-expectations day!

So tomorrow we'll likely be playing somewhere between the Nebraska/Kansas border and Omaha. Things look pretty impressive there if the low-level jet can line up with the upper wave and the warm front.

This trip we're now on is a total success: great storm structure, great friends and a spectacular tornado. Anything we see tomorrow (today, now) is just gravy.

I apologize that I can't upload any pictures right now. As I said, I have 900 of them and they're all extremely large files. I will need to take a couple of days to sort through them before I can shrink them suitably for here and post them. But post them I will. I promise.

Sunday, May 30, 2010

May 29, 2010 wrapup and May 30, 2010

So yesterday we ended up mainly north of Grand Forks, trying to play the warm front/outflow boundary. Storms formed nicely in the region but they were a bit too numerous and outflow-dominant (not enough low-level flow) so we had to take what we were given.

We did see some incredible shelf cloud motions and some small hail--about 1 cm diameter, which was not worth reporting. As well, we experienced an easily severe outflow wind from a storm in Minnesota. Our estimate of the wind speed was well over 50 knots, I thought about 60 so that's what we reported to the NWS. Here are the reports from the day.

All in all, it was a pretty great day.

Today we don't really have high expectations, although we should see storms, maybe pushing the severe limits. Wichita, KS is our initial target. More later.

And speaking briefly on the rain in Winnipeg, all I can say is wow. I hope the flooding is minimal. I'll now present the special weather statement issued by Environment Canada in its entirety.

AWCN11 CWWG 301141
Summary weather statement issued by Environment Canada at 6:41 AM CDT
Sunday 30 May 2010.

Over the last few days thunderstorms rumbled across southern
Manitoba bringing locally heavy rainfall. The following are
unofficial rainfall totals from Environment Canada weather stations
for the period ending 6 AM Sunday morning.

Location total rainfall total rainfall
Last 24 hours last 48 hours

Winnipeg, the forks 73.6 mm 95.0 mm
Winnipeg, airport 57.5 mm 82.6 mm
Emerson 102.2 mm 110.4 mm
Portage la Prairie 89.8 mm 91.4 mm
Pinawa 80.6 mm 87.8 mm
Brandon 63.0 mm 63.0 mm
Carberry 46.2 mm 46.4 mm
Great Falls 34.6 mm 40.4 mm
Delta marsh 32.0 mm 33.8 mm
McCreary 38.6 mm 41.4 mm
Wasagaming 26.8 mm 27.2 mm
Melita 24.2 mm 32.8 mm
Carman 23.4 mm 49.4 mm
Cypress river 22.8 mm 46.6 mm
Gimli 18.0 mm 26.0 mm
Oak Point 17.8 mm 24.0 mm
Roblin 17.0 mm 17.4 mm
Dauphin 14.0 mm 18.4 mm
Fisher Branch 13.2 mm 15.5 mm
Sprague 13.2 mm 48.4 mm
Deerwood 7.2 mm 26.8 mm
Pilot Mound 2.6 mm 16.4 mm
Morden 0.2 mm 20.0 mm

The following unofficial rainfall totals are from Manitoba
agriculture weather stations for the last 30 hours, ending at 6 AM
Sunday morning.

Location total rainfall in the last 30 hours

Selkirk 78.0 mm
Portage, east 71.1 mm
Virden 65.2 mm
Starbuck 52.2 mm
Woodlands 51.2 mm
Forrest 51.1 mm
Elm Creek 49.6 mm
Minnedosa 48.6 mm
Hamiota 44.2 mm
Dugald 43.0 mm
Souris 42.2 mm
Gladstone 41.8 mm
Glenboro 39.4 mm
Steinbach 37.4 mm
Pierson 36.8 mm
Ste Rose 36.2 mm
Letellier 35.7 mm
Killarney 34.2 mm
Birtle 32.8 mm
Teulon 32.0 mm
Moosehorn 30.6 mm
Treherne 29.4 mm
St Pierre 26.2 mm
Russell 24.0 mm
Eriksdale 21.8 mm
Arborg 16.4 mm

Saturday, May 29, 2010

3:00 PM May 29

We're sitting between Grand Forks and Devils Lake. The warm front/outflow boundary is just off to our north, and cumuli are going up nicely. It appears initiation should occur within the next 2 hours or so. Wish us luck!

On the road, 12:30 PM May 29, 2010

So we're right now in southern Pembina county and heading toward Grand Forks.

The visible satellite imagery is showing an interesting outflow from this morning combined with the warm front extending west from GFK. Moisture is starting to pool west of the area and it looks like it could be a good target.

Follow us on Spotter Network.

PS: In Canada we were on Rogers network for wireless internet, which was more or less useless along highway 75. As soon as we got into the states and hooked onto Verizon, BOOM! It's really fast. I hope the Rogers thing was just an aberration.

Wind much?

At Brandon about an hour ago they had a wind gust to 55 knots, or 102 km/h.

Now this line of storms is north of Portage. Check out the Doppler scan of the RADAR.

The greens in there signify wind potential of around 70 knots, or 130 km/h. Wow.

May 29, 2010 morning

Looks like a bow echo is blasting its way across southern Manitoba this morning. Have a look:

So this chase should be easy. All we have to do is find the outflow boundary this thing lays out there and play on it this afternoon. It should be close to the international border.

Friday, May 28, 2010

May 28, 2010 evening: southern Manitoba

Nocturnals have begun north of Winnipeg.

Check here for an explanation of why they happen.

So check out the surface map:

And now have a look at the Mayville, ND VAD:

How about the energy and shear the storms will have to work with:

If you're in southern Manitoba, keep an eye out for these. There could be a good light show tonight.

Forecast for day 1 of our Manitoba chasers' chase

Well, the current data and model output from 00Z all point to somewhere between Morden and Fargo. That means that everyone is going to get to sleep in. Sweet.

Moisture and lift:

Dews above 65°C and good convergence.


So there's cooling coming at 500 and 700, as well as 700 mb temperatures cooler than 10°C.


Good deep shear and okay low-level shear.

All together, it looks like a good day, not far from Winnipeg.

And by the way, you can follow us on this website, although I don't know how to isolate just us. (We're called "Winnipeg Wx".) CoD does it for themselves here.

Now: 3 PM CDT May 28, 2010

It's looking more and more likely that things will blast off during the daylight hours today. The location is likely to be near Bismarck, ND.

Here are a few things to look at:

Wow. 5000 J/kg.

Good deep shear.

Where's the convergence and surface moisture? Hmmmm. ;)

So I think that a tornado watch will likely be issued by 4 PM for the area, although initiation is still a few hours away. Maybe after dark, actually, because of the cap (not shown on the SBCAPE map but apparent here):

700 mb temperatures of about 12°C. Not exactly ideal.

The decision not to go today because of time constraints looks like a good one. Unless things go significantly far this side of Bismarck, then going would have meant nearly no sleep tonight.

Well, maybe. Justin and I have been debating tomorrow's destination on text--he's busy working right now and can't afford to take that much time away. Soon, though, soon.

Crap crap cap cap

So I woke up this morning to the sound of thunder in Winnipeg. Take a look:

What does this all mean? Timing. Storms are all about timing. This tells me that the wave that caused all the lift for these storms is nearby. Where's the next one, then?

Try and pick it out. I dare you.
The point is that there's no obvious wave emerging out of the base of the trough--and there very well may be one--and so the chase is too conditional. As well, the 700 mb temperature forecast isn't ideal:

We've discussed it amongst ourselves and decided to call off the chase for today. It very well may go, but if it does a) it'll be late and b) it'll be farther south than we can reasonably do.

As wxdog says, there'll always be more storms.

Besides--I still have a bunch of stuff to do before Justin, Dee, Shear and I go off chasing tomorrow (we're leaving at 4 AM) so this'll give me the chance to get it done.

Now off to take care of those things to the soothing background sound of thunder.

I will blog about tomorrow's chase later today.

Thursday, May 27, 2010

May 28, 2010

So looking at the 0Z model runs makes me pretty certain I'm going to chase tomorrow.

Moisture is there already. Low 60s dewpoints are in most of North Dakota.
Instability is there--3000 to 4000 J/kg SBCAPE this evening in Montana.
Lift is in place with a pretty strong warm front.
Shear is looking not bad, especially for low-level shear near the front.

That's how things look this evening, and there have been a couple of tornado reports in Montana.

Now, let's look at the NAM. Focus on the area near Minot, ND.

Moisture and lift (for lift look at the convergence at the front):

Dews in the mid 60s. Nice.


3000+ J/kg. Nice.


Good 40+ knots of deep shear.

And even 25 knots or higher of low-level shear.

The minus for tomorrow is that this could be a cap bust. I have to go, though, because this is a high risk/high reward setup. (Although "high risk" doesn't necessarily mean SPC will issue one, but more that going there would be risky in terms of potentially not seeing anything.)

May 28: planned day chase

Justin and Dee don't get into Winnipeg until tomorrow night, and there's a pretty awesome setup not too far from here, so Andy (of Elie tornado rap fame) and I will hit the not-so-dusty trail and try to catch some good storms.

I am about to head out for a few hours, so I will blog more in-depth about it this evening, let's say, when the new model runs are in.

Tuesday, May 25, 2010

Today's long range outlook

I'll be on the road tomorrow so I won't be able to do this, so here goes.

May 29: Chamberlain, SD (GFS) or Ogallala, NE (GEM)
May 30: Nowhere (the mix of CAPE and shear is close in west-central MO) (GFS) or maybe Lusk, WY (GEM)
May 31: Garden City, KS (GFS) or Brush, CO (GEM)
June 1: All of Nebraska and Kansas (GFS) or Ogallala, NE (GEM)
June 2: Dodge City, KS (GFS) or maybe Des Moines, IA (GEM)
June 3: Oklahoma City, OK (GFS) or nowhere (GEM)

It just keeps changing. The only constant, it seems, is that day 1 of our chase looks to be somewhere in SD or NE. The SPC seems to agree with us.

Monday, May 24, 2010

Long-range forecast

Yeah, so I missed a couple of days on the long range. That's okay. What I'm going to do here is do 2 days' worth--yesterday and today. And we'll see how things change from run to run.

Yesterday's forecast:

May 29: Dickinson, ND to Scottsbluff, NE (GFS) or Ogallala, NE (GEM)
May 30: Omaha, NE (GFS) or Limon, CO (GEM)
May 31: Topeka, KS (GFS) or nowhere (GEM)
June 1: Lusk, WY (GFS) or maybe Lusk, WY (GEM)
June 2: Liberal, KS (GFS)
June 3: Dodge City, KS (GFS)

Today's forecast:

May 29: Glendive, MT (GFS) or Brandon, MB (GEM)
May 30: Salina, KS (GFS) or nowhere (GEM)
May 31: Oklahoma City, OK (GFS) or Broadus, MT (GEM)
June 1: Yuma, CO (GFS) or Lusk, WY (GEM)
June 2: Valentine, NE (ugh) (GFS) or Valentine, NE (ugh) (GEM)
June 3: Kearney, NE (GFS)

Some of these locations are pretty static, and some of them change a whole lot. Even the static ones are static just by chance, as the reasoning for the locations still changes from day to day.

Wow. Forecast models. If we relied on them all the time, especially in the long range, we'd be in trouble.

Sunday, May 23, 2010

May 24, 2010

This day looks pretty interesting. Actually, now that I think about it, it reminds me a lot of a day back in 2005 when I caught 4 tornadoes. Good moisture, not ideal storm motion but oodles of shear.

The juxtaposition of all the ingredients (I'm out of town and way too lazy right now to post them all) points to storms near the warm front, which should be draped along the ND/SD border. This makes for an interesting decision because, as I mentioned before, Lake Oahe runs north-south from Bismarck, ND to Pierre, SD. And the instability will likely cross this lake at a 90%deg; angle.

So where would I go? I'd sit in Mobridge, SD, where I could cross the lake if need be, but likely lean to the east side, just because the storms will be moving toward the northeast.

May 23rd, 2010...Video(s) from the CAPE eating monster on May 22nd

Yesterday's meteorological set up was perfect for monster storms to develop in Central South Dakota. Instead of monster storms plural, it was a monster storm that developed and realized the 6000+ CAPE that was present along and just south of the warm front. The tornadoes that formed from the parent supercell were spectacular to say the least. They reminded me of the Manchester/Woonsocket, SD tornadoes in June 2003.

The main question earlier in the day was if the cap was going to break or did of course and convective initiation focused itself along the N-S Branch of the Missouri River near Lake Oahe which is located North of Pierre. The storm developed a volcanic eruption says Rob MacDonald a friend/chaser from Ninette, Manitoba.

I was nowcasting for him yesterday to make sure he'd get up close and personal with this beast. He started in Pierre, SD and I got him to position himself somewhere along I-90 near Kadoka...I was trying to get him in position to be near the triple point. As heating and moisture got pumped into the region the warm front established itself North of Pierre, SD...I sent him there and he said that towers were trying to go up North of him but were hitting the cap. He kept rolling North and he was not far away when a tower finally broke through the cap and rooted itself in the boundary layer. He was closing in fast when the storm developed its first wall cloud and he was there when it put down the monster tornado. He has video of it, but the storm from certain angles had terrible contrast so he has video of the other touchdowns from the same storm. I'm so envious of him...this is a dream set up that yielded great results...

One lonely monster in great chase country, close to home (Canada), not late in the year, and great visibility early in the storm's life span before rain started wrapping into the tornado. Below is a low angle doppler velocity scan during the storm's had amazing gate-to-gate shear indicative of a tight circulation near the ground.

All-in-all it was a great day and I wish I was there...few more days Dave...I just hope the pattern remains active in the long range!

Below are videos that are surfacing from yesterday's tornado...they are INCREDIBLE!!!

I will add that storm chasing in the States is starting to turn into a $h:t show...too many chasers that don't know what they are doing. I blame Discovery Channel for this, they should be saying that only educated professionals should engage in storm chasing, one video below shows chasers running out of road yesterday as a dying tornado closes in. They ended up driving through a freshly planted soybean field. Terrible!!! This is making us look bad, someone is going to get killed and that will ruin it for the rest of us who take storm chasing seriously!

Saturday, May 22, 2010

SPC day 1, May 22, 2010

I'm out of town so can't chase but if I were able to go, I would hit up somewhere in central South Dakota.

But curiously, on the 6Z issue SPC issued a 5% tornado risk extending into southern Manitoba.

Could this be real?


Okay, this isn't bad. 850 mb dewpoints in the teens. Juicy.


40 to 50 knots. Sweet.


Oops. Not even close. In fact, let's take a look at a prog sounding from farther south. This is from west of Grand Forks:

So there must be some fudging going on here, as the surface-based instability isn't forecast anywhere near the southern prairies. And as any meteorologist worth his salt will tell you, tornadoes ingest surface-based air parcels.

What's the fudging for? It looks like model variations is the reason. Check out this forecast for 00Z from the GEM-regional.

It has SBCAPE over 1000 J/kg over parts of southern Manitoba.

Anyhow, as of the 13Z update, SPC has decreased the risk extending into southern Manitoba.

And based on the surface plot, I have to agree:

Notice the good dewpoints (60+) are still down in Nebraska. Maybe another day and they'd make it but not this time, I don't think.

My virtual target: Pierre, SD. Today is an edge-of-the-cap play.

A note to chasers: Lake Oahe is a pain. Essentially you have to decide which side you're going to chase on, as the crossings are few and far between: Bismarck, ND, Mobridge, SD or Pierre, SD.

Thursday, May 20, 2010

Chaser convergence

I was lamenting how I would like to have been out there chasing yesterday. I stand by that, given that I haven't seen a tornado since 2007 (Elie), but a couple of things brought to my attention have lessened my jealousy.

First off, there's a video out there about how some chasers were driving extremely irresponsibly.

Then there's this post by Josh Wurman, which I present without any commentary.

Maybe living this far north, away from Oklahoma, has its advantages.

Model output

In 8 days, Justin and I (along with a couple of other friends) will be taking off for a few days to go chasing.

I got a text this afternoon from Justin talking about how the model output was depressing in the long term. I wouldn't go so far as to say that the text was panicked, but it seemed more than a little worried.

Well, let me say not to worry. At least not yet.

Since the U of M storm chasing trip started in 2005, I have been posting, as the trip nears, model output from day to day in order to illustrate how bad the models are. And yes, I put it that way. The models are horrible, they are always wrong and they give both false hope and false disappointment.

So as I've done before, here are the forecasts for while we're away. These are based on the 00Z model runs.

May 29: Brandon, MB (GEM) or Minot, ND (GFS)
May 30: Wall, SD (GFS) *
May 31: Beatrice, NE (GFS)
June 1: Hebron, NE (GFS) **
June 2: Des Moines, IA (GFS)
June 3: Waterloo, IA

*The GEM-Global (At least what I can access) only goes out to 240 hours.
**The GFS has only okay shear until June 1st.

So there you have it. I will keep updating this most every day (although not tomorrow, as I'll be on the road) but we'll see where the models think the action will be and how that changes from run to run. (Justin, do you want to take this up tomorrow?)

I will say this: lamenting about long-term model runs is a fruitless and frustrating thing. Granted, the closer you get to the day you're forecasting for, the more accurate the forecast will be (although I maintain that the models will never be right), and I usually start to pay attention when things are about 5 days out.

I will use as an example of this the trip I was on in 2001 with the College of DuPage, when we saw this:

And that was only a couple of days after we had written off seeing anything because the models were painting crap instability and crap flow.

I'll reserve judgment until we actually get out on the road.

Wednesday, May 19, 2010

Now: tornadic supercell in west-central Oklahoma

College of DuPage has caught a tornado already today, and the storms are just beginning.

This storm could maintain itself along the warm front with long-lived tornadoes. I hope people in Oklahoma City are paying attention.

Here's the watch box, and you can see the tornadic supercell near the western edge of it:

Today, May 19, 2010

Wow, this morning things look even better. Or worse, depending on your perspective.

An overnight MCS rumbled across northern Oklahoma last night. This pooped out an outflow boundary that's currently sitting near Oklahoma City, and this is just reinforcing the baroclinicity of the warm front. This warm front wends its way west to a low-pressure area near Amarillo, TX, south of which (so very conveniently) extends a dryline.

The intersection of the dryline and the warm front is prime territory for tornadic supercell formation and maintenance. However, with the deep shear in place, supercells, possibly tornadic and likely containing large hail, will be likely throughout the more or less uncapped warm sector.

SBCAPEs will likely be over 3000 J/kg and deep shear 50 to 60 knots. Low-level shear will be a bit harder to come by, but backing winds near the intersection of the dryline and the warm front should make for a highly favourable setup for a long-lived, damaging tornadic supercell.

So today will be all about monitoring the outflow/warm front and its intersection with the dryline. I suspect that by this time tomorrow we will be hearing stories on the news about how a bunch of chasers caught a picturesque tornado today.

My chase vacation (#1 of 3, that is) begins in 9 days. I wish it were sooner.

Tuesday, May 18, 2010

Back to today

Today's chase, May 18, 2010, looks to be a pretty decent one.

First off, let's look at the latest water vapour picture. This one shows a good solid jet moving eastward, its centre somewhere around southern Nevada or northwest Arizona. It's moving along at a good clip, but it's still slow enough that it'll allow the airmass near the surface to cook for a while.

And the visible image over the Texas panhandle is showing boundary layer cumuli forming.

Moisture is a little bit lacking, though. Dewpoints aren't great, mainly in the mid 50s to low 60s.

Essentially it looks like storms will form after the passage of the upper short-wave ridge (looks to be around 3 or 4 PM) and with the shear there will be supercells. Tornadic supercells are a bit more in question because of a) the lack of moisture and b) the only okay low-level shear. The other thing that's bugging me is that there's no obvious forcing mechanism, at least right now. Maybe the dryline will sharpen up; maybe a mesoscale convergence line will set up. I dunno.

Still, though, today is a very chase-worthy day. My current point would be Amarillo, TX. Sit there, have some BBQ and wait for things to go so that I can reposition--any direction is easy to get to from there.

May 20, 2010

This looks like a great day! A classic setup of supercells, likely tornadic, is on tap. After looking at things, I can say that this day is the one I would desperately love to chase.

Moisture - it'll be there. The dewpoints in the low 60s are already close by, and here's the 925 mb dewpoint forecast:

Instability - there's an impulse coming in at 500 mb:

The lapse rates will provide for serious CAPE:

Lift - how about the convergence along, say, a warm front and/or dryline?

Shear - check it out. Plenty.

And the best part? The storms aren't going to be cooking along:

All this points to a very chaseable day. SPC has issued a moderate risk and they might keep it thus; however, with all these ingredients coming into focus I believe a high risk isn't out of the question. The only caveat would be the storm mode: whereas tornadic supercells are possible, the more likely outcome is HP supercells, given the modest low-level shear. Kick that up a bit, even locally, and there's a bad/good day tomorrow.

My initial virtual chase target is west of Oklahoma City, say about Weatherford. (I've typed *that* location a few times here!) As storms develop I expect a couple to dominate, and if they interact with either the dryline or the warm front, magical things could happen. Heck, there'll likely be enough helicity in general to cause a few spinny things. Oklahoma City watch out!

Monday, May 17, 2010

May 19, 2010

May 19 looks like the beginning of a couple of good chase days.

First off, a 500 mb low is forecast to be near Denver by evening, and flow around it is forecast to be at 40 to 50 knots.

So shear shouldn't be a problem.


That's pretty good.

How about instability?

That looks pretty good. So if I pull up a prog sounding for the area where they look to juxtapose, in northwestern Oklahoma, here's what I get:

Closer to the warm front, south of Dodge City, KS, the low-level shear looks better but the instability not so good:

Perhaps there'll be a place in between that will have a more favourable combination of CAPE and shear, but if not it should still be a good day with HP supercells of the hail-making variety.

I'll talk about the 20th tomorrow.