Sunday Thunder in Michigan

For a brief couple of runs Thursday I had vague hopes for an accessible warm front chase on Monday. But that evening’s 00z GFS brought me back to reality, and ensuing runs of the NAM and GFS have painted a blander, cold front scenario for Michigan. As an amateur, decent but still quite formative forecaster rather than a professional meteorologist, I have the freedom to speculate and dream a little on this blog, with the understanding that five days out is fuzzy territory, often more wishcasting than forecasting.

With models coming together three days ahead, I think it’s safe to say that there ain’t nothin’ gonna happen around here on Monday. By then the system will have moved through with zilch to work with in the way of instability, and we’ll start seeing its chillier back end. I’m consigning myself to the compensation prize of a possible bit of thunder around here Sunday night, maybe very early Monday morning, as the cold front moves through. I’ll take that. This early in the season, it’ll be good just to see a little lightning. For that matter, it always is. Storms don’t have to be severe in order to be exciting, beautiful, and worth enjoying.

Looking ahead, more activity could be shaping up for the middle of next week. The Gulf is doing business and the time has come for me to follow the forecast models more closely.

Chasing the Great Lakes Superbomb of 2010

Until early yesterday morning, I was pretty certain that I wasn’t going to be chasing yesterday’s squall line associated with the record-breaking low pressure system that’s moving across the Great Lakes. With storms ripping along at 60 knots, what kind of chasing is a person going to do?

Then came the 7:00 a.m. phone call from my chase partner, Bill Oosterbaan, informing me that the Storm Prediction Center had issued a high risk for the area just across the border in Indiana and Ohio. With the rapidly advancing cold front still west of Chicago, we’d have ample time to position ourselves more optimally. This would be an early-day storm chase. It would also almost surely be our last chase for the next four or five months. What did we have to lose?

I hooked up with Bill at the gas station at 100th St. and US-131, and off we went. The storms had moved into Chicago by then, and as we dropped south, it became apparent that we would also need to break east and then stairstep down into Ohio, buying time in order to let the line develop with daytime heating. Satellite showed some clearing in Ohio,

suggesting a better chance for instability to build. Catching I-94 in Kalamazoo, we headed east toward I-75, with the Findlay area as our target.

Off to the northwest in Minnesota, the low was deepening toward an unprecedented sub-955 millibar level, sucking in winds from hundreds of miles around like the vortex in an enormous bathtub drain. Transverse rolls of stratocumulus streamed overhead toward the north, indicating substantial wind shear. (Click on image to enlarge.)

By the time we crossed the border into Ohio, tornado reports were already coming in from the west as the squall line intensified. Soon much of the line was tornado warned. However, while the warnings were no doubt a godsend for a few communities that sustained tornado damage yesterday, they weren’t much help to Bill and me. Chasing a squall line is different from chasing discrete supercells.

We had in fact hoped that a few discrete cells would fire ahead of the line. But the forecast CAPE never materialized to make that happen, and we were left with just the line. In that widely forced environment, tornadoes were likely to occur as quick, rain-wrapped spinups rather than as the products of long-lived mesocyclones. Even with GR3, the likelihood of our intercepting a tornado would require a high degree of luck. It was harder to identify areas of circulation with certainty; I found myself using base velocity as much as storm relative velocity on the radar, and comparing suspect areas not with easy-to-see hook echoes in the reflectivity mode, but with kinks in the line. It was pretty much a game of meteorological “Pin the Tail on the Donkey.”

North of Kenton, we headed west and got our first view of the squall line. For all the hooplah that had preceded the thing, it didn’t appear very impressive. Just your average storm front–much windier than most, but also a bit anemic-looking compared to some of the shelf clouds I’ve seen. Still, it was a lovely sight, watching those glowering clouds grope their way across the late-October farmlands.

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Neither of us was quite ready to end the chase, so with the storm rapidly closing in, we scrambled back into the car and stairstepped to the southeast in the hope of intercepting a likely-looking reflectivity knot that had gone tornado-warned. It was fun playing tag with the storm, driving through swirls of leaves spun up by the outflow. But there really wasn’t much incentive for us to continue the game indefinitely. Eventually we turned back west and drove into the mouth of the beast.

For a few minutes, we got socked with torrential rain and some impressive blasts of wind (and, I should add, absolutely no lightning or thunder whatever). Then it was over. Time to head home.

In Kenton, we grabbed dinner at a small restaurant. Then we headed toward Cridersville, 28 miles straight to the west next to I-75, where there had been a report of “major structural damage” from a tornado. The report was accurate. A small but effective tornado had torn through the community, uprooting and snapping off large trees, taking off roofs, and demolishing at least one garage that I could see. Of course we couldn’t get into the heart of the damage path, but a few passing glimpses suggested that some of the damage may have been fairly severe.

As I said at the beginning, this chase will likely have been my last of the year. I never know for sure until the snows fly, but it seems like a pretty safe bet that I won’t be heading out again after storms until March or April. It’s hard to call this chase a bust since our expectations weren’t all that high to begin with. Plus, tornadoes or no tornadoes, it was an opportunity to engage with a historical weather system. Like other significant weather events such as the Armistice Day Storm and the 1974 Super Outbreak, this one will be given a name in the annals of meteorology. Me, I’m calling it the Great Lakes Superbomb of 2010. In a number of ways, it hasn’t proved to be as impactful as was forecast, but it’s not over yet. And regardless, I’m glad I got the chance to get out and enjoy a final taste of synoptic mayhem.

Troughy Weather for Next Week

Here on the back end of a 996 mb low, dry Canadian air has dropped the moisture along with the heat in Caledonia, Michigan. We’re presently socked in with clouds, and temperatures are supposed to peak at just 65 degrees. It feels a lot like fall outside.

This latest cold front has meant business, and to me it signifies the arrival of autumn’s transitional weather pattern–a time when the upper atmosphere begins to cool and conditions become more conducive to bouts of severe storms.

Our next round of stormy weather may be arriving by next weekend. Granted, it’s pretty early to be looking so far ahead, but the SPC has been eyeballing the next trough in their long-range discussions with a good amount of confidence. Seems like a question not of whether something will happen, but when.

Not having access to many of the SPC’s forecasting tools, I have to go by what’s available to me. The GFS and Euro both depict a pretty deep trough. The GFS, typically, wants to move it along faster than the Euro, but both models agree that there will be something there to move. Both also show a robust surface low developing and drawing in dewpoints in the mid 60s. The northern plains may get hammered later this coming week. By the weekend, Michigan may get a crack at some severe storms. Or not. The crystal ball is murky this far out, and as always, the caveat is, we’ll find out when we find out.

Whatever happens, it’s nice to think that the weather machine may be lurching out of the summer doldrums and getting set to ramp up the action. September furnishes some nice opportunities for taking photos of squall lines blowing in at the lakeshore. Maybe this will be one such occasion. Maybe it’ll be even better than that. It’s not premature to cross our fingers.

Friday’s Outlook: A Real October Leaf-Stripper

Whichever model gives the more accurate picture–the GFS or the WRF-NMM–one thing is sure: we Michiganians can say good-bye to the leaves. This Friday’s weather system promises to be a real October leaf-stripper, with a formidable low-pressure center deepening rapidly as it moves through Ontario.

The two forecast models continue to differ in timing, with the GFS moving the cold front rapidly through the state’s mid-section by 18Z, while the NAM plays it more conservatively and backs the surface winds considerably more. The NAM is also much more aggressive with 850 mb winds, with the 12Z run calling for 75 knots (!!!), while the GFS dribbles out a paltry 55-knot LLJ.

I have a hunch that the GFS is closer to the truth, though of course, time will tell.

Both models agree that instability will be non-existent. Not much there to gladden the heart of a storm chaser. But by golly, we’ll be seeing some wind. Bye-bye leaves!

For the sake of comparison, I took a sampler of 6Z model soundings for both the GFS and the NAM for Jackson, Michigan–a nice, central location that should offer a good compromise between both models. The differences are striking. Click on the images to enlarge them. For 21Z, I’ve shown only the NAM; by that time, the GFS has the winds lined out.

Forecast hours for Friday, October 30

15Z

GFS

NAM

18Z

GFS

NAM

21Z

NAM

Painted Trilliums and a Mid-Week Storm Chase

Painted Trillium

The painted trillium, trillium undulatum.

You’re looking at one of Michigan’s rarest wildflowers, the painted trillium.

With plans for a picnic in place and nothing but sunshine in the forecast for today, Lisa and I headed east with our cameras for a Michigan Nature Association preserve near Port Huron. The location is one of a handful where the painted trillium grows in this state, keeping company with the red trillium, which is also uncommon but far more widespread than its painted cousin.

Good luck finding this in the Michigan woods!

Good luck finding this in the Michigan woods!

Out east in the Appalachians, the painted trillium is fairly common. But in Michigan, if you ever catch a glimpse of this plant, count yourself fortunate indeed. The images in this post are a prize, and it was a double blessing that I got to share the experience of capturing them with Lisa, who loves the outdoors as much as I do.

But enough eye candy. Turning from wildflowers to weather, Wednesday looks to be shaping up as a chase day in Illinois. It’s nice to see the action coming close to home. The question right now isn’t whether there will be a severe outbreak, but where will be the optimal chances for tornadic activity. With a strong cold front moving in, a squall line seems inevitable. But with the winds veering strongly from the surface up to 500 millibars, hodographs are nicely curved and helicities ought to be formidable. Play the warm front? Maybe. It’ll certainly be a tempting target, within easy reach of Grand Rapids. But I want to see what happens with clearing. It would be nice to see a buildup of CAPE in northern Illinois.

Wait and see is the name of the game. Right now all eyes are on the NAM and GFS. But Wednesday morning will tell. I’m crossing my fingers and toes and hoping to see signs of clearing on the satellite.