A Minnesota Dryline

Almost two months have elapsed since my last post. An entire winter is now nearly behind me, and with meteorological spring having sprung as of yesterday, my eyes turn once again to the coming storm season. MN Dryline 5102011Going through my old radar images, I came upon this one. Click on it to enlarge it, then note the station obs and wind barbs on either side of that fine line west of Minneapolis. That sure looks like a dryline to me, but what's it doing wandering around central Minnesota like a little lost orphan? The Great Lakes are not the land of drylines, but we do get them occasionally, and as out in the Great Plains, they can serve as a forcing mechanism for severe weather. Notably, in the 1965 Palm Sunday Outbreak, what Theodore Fujita called a "dry cold front" featured prominently in his analysis of the synoptic conditions. Although Fujita called the air behind the front "cooler," a look at the station observations reveals that what really characterized the difference on either side of the "front" wasn't a rapid drop in air temperature but in dewpoints, and a change in wind direction, with surface winds veering abruptly from the south to the southwest. The radar grab shows similar conditions on May 10, 2011, with supercells initiating along a line of strong convergence. Where the southernmost cell is just starting to fire, check out the obs on either side of the fine line. The temperature is the same, 90 F degrees, but the dewpoint drop is as much as 13 degrees. That may not be as radical as what you'll find in the Texas panhandle, but in the Great Lakes, it's an eye-opener. There were tornadoes in eastern Minnesota on this day: May 10, 2011, SPC Storm Reports. The location of the three reports on the SPC graphic leads me to think that the cell I mentioned in the previous paragraph may have been the culprit. With dewpoints in the upper 60s to low 70s, it appears to have had plenty of juice to work with. For a dryline to occur in the Great Lakes means that a system is potent enough to wrap in dry air this far east from the desert Southwest. That means that a lot of things have fallen into place to create a potentially tornadic setup, including not only an obvious lifting mechanism but also ample bulk shear and moisture, and southerly or southeasterly surface winds. In other words, here in my backyard, a dryline is a red flag that things are about to pop and a chase day is at hand.

First Great Plains Chase of 2011 This Wednesday

At last, the setup I've been waiting for--one that warrants dipping into my tight finances in order to make the 1,000-mile drive to the Southern Plains. To date, this present system has been a miserable disconnect between upper-level support and instability, with a nasty cap clamping down on the whole shebang. Last night it managed to cough up a solitary tornado in South Dakota. That was it. I'm not sure what today holds, but I haven't seen anything to excite me about it or tomorrow. But Wednesday...ah, now we're talking! The SPC places a large section of the Great Plains under a slight risk, and their discussions have been fairly bullish about the potential for a wide-scale event. At first I couldn't see why. My mistake--I was looking at the NAM, which with straight southerly H5 winds has not provided the best PR for Wednesday's setup. But once I glommed the GFS, I got a whole 'nother picture, one which the SREF and Euro corroborated. That was last night. I haven't looked at today's SREF, and the new ECMWF gives me a slight pause as its now somewhat negative tilt has slightly backed the mid-levels from the previous run. But only slightly. The H5 winds still have a nice southwesterly flow, and taking the three models together, everything you could ask for is lining up beautifully for tornadoes in the plains. The event promises to be widespread, with a robust dryline stretching from a triple point in southwest Kansas south through Oklahoma and Texas. Positioned near a dryline bulge, Enid, Oklahoma has drawn my attention for the last couple of GFS runs. Check out this model sounding for 00Z and tell me what's not to like about it. Everything is there, including a voluptuous hodograph and 1 km SRH in excess of 300 m^2/s^2. Other places in the region also look good, though. Farther south in Texas, Wichita Falls shows potential. Helicity isn't as persuasive as Enid, but the CAPE tops 3,000 J/kg and there's less convective inhibition. Here's the sounding for you to compare with Enid. I haven't been as drawn to Kansas so far, but with the triple point perched there, storms are bound to fire up just fine in the Sunflower State. The details will work themselves out between now and Wednesday evening. Significantly, the tyrannical cap of the previous few days no longer appears to be an issue. The bottom line is--it's time to head West! This evening I'm taking off for the plains with my long-time chase buddy Bill. At last! Time to sample what the dryline has to offer, and--now that I'm equipped with a great HD camcorder--finally get some quality footage of a tornado or two. There's no place like the Great Plains! YeeeeHAW!!!!!

Wedging into Tornado Season

Bill called to say that he and the crew just saw a wedge out there in western Oklahoma. The LSR gives the town of Crawford, near the Texas panhandle border, as the location. Good for the lads--and the lass, as I understand there's a new female member of the crew. As for me, sitting here in my La-Z-Boy sofa, nursing a chest cold and watching the radar, naturally I feel like shooting myself through the head. A wedge on a PDS day--and the show is just getting started. And I'm not there! AAAAAHHHHHH!!!!!!! If there's any consolation, it's knowing that I've been able to make myself useful doing a little nowcasting. And it sounds like the team got some cool footage. Can't wait to see it. Mostly, though, I can't wait to kick whatever is causing this blasted chest congestion and get out to take some video of my own. Tornado season 2009 is underway! Shifting gears, last night's gig at One Trick Pony with Francesca and Friends was a blast, even if I was feeling under the weather. Wright McCargar and I had a discussion about the impact of musicians on each other's playing. In my experience, one bad musician can drag a whole group of good musicians down; and, conversely, one great musician can kick good players up to the next level. There's nothing like being with really good musicians, and Francesca and her rhythm section are exactly that. Moving back to storm chasing, it's time for me to publish this post and then check out the radar. The storms bumping off of the dryline look to be going tornadic, and I'm thinkin' that my buddies will have their hands full for the next five or six hours. Sure wish I was with them. But GR2AE ought to keep me entertained; maybe I can capture a few radar grabs to correspond with the photos that I'm sure will be coming back from out west.

Not Enough Tornadoes

Here is a conversation you're unlikely to overhear at a restaurant: "I'm going to move." "Why? Vermont is such a beautiful state." "Not enough tornadoes. I'm thinking maybe Hays, Kansas." Nope, you just won't hear most people talk that way. A generous supply of tornadoes simply isn't a big selling point for the average homebuyer. On the other hand, if you're a storm chaser, it could be a compelling reason to sell your chalet near Boise, Idaho, and move to Wakeeney. I just finished perusing a thread on Stormtrack where chasers were considering this question. The earnestness of the discussion struck my funny bone. I mean, the concept of moving somewhere because it has lots of tornadoes is utterly foreign to most Americans, who are unmotivated by tornado accessibility. In fact, I'd venture to say that many people would consider the idea downright weird. ("You're moving where because of what?") Chasers, however, seem to see nothing unusual about factoring in tornado statistics as a motivating factor in home buying.  It's weird. And the reason I laugh is because I can relate. I'm not ready to pack up my bags and move from Michigan, because busted economy or not, I love this state. But if I ever do move, it won't be to California because of the ocean, or Florida because of the warm weather, or Vermont because of its rural New England beauty. It'll be to the Great Plains because of the dryline. Realistically, I can't see it happening anytime soon. I might be able to find a location with a decent brewpub, such as Wichita, but where would I go to hear some decent live jazz, let alone play it? That side of me is as important as the storm chaser in me. Maybe the two can be reconciled. To be honest, I'm not too worried about it. It's just fun to think about, and certainly worth laughing about. I do kinda wonder, though, what it would cost to build an underground bunker as a vacation home in the Texas panhandle.