Eyeballing Monday for Severe Weather

Thursday Night

If the GFS is in the ballpark, then Monday by the Michigan border could be a chase day. Things may look better elsewhere in the country, but I have to stay local this coming week and take what I can get. I’m not going to slap up a bunch of weather maps right now because it’s too early to be definitive and too late at night for me to want to get very involved. The NAM will kick in tomorrow, and then things will become more interesting as I compare notes with it, the GFS, and the Euro.

Right now, though, the GFS is calling for a warm front laying down by the Indiana/Michigan border, with a surface low just to the west inducing strongly backed winds in the vicinity of the boundary. A stiff H5 jet core blows directly overhead, with shear to spare. SBCAPE of 1,000 J/kg-plus will be right in the neighborhood. The wild card looks to be whether sufficient moisture and instability will make it close enough to the boundary for helicity to do its thing.

The SPC’s current long-range outlook for Monday puts all of the action well to the south, from central Illinois and Indiana down to Dixie Alley. But I’m thinking that there’s a chance for tornadoes much closer to home. Not that I’m betting on it, but I am most definitely going to be keeping a close eye on the forecast models to see how they trend over the weekend.

Update: Ugh!

As of this Friday morning, the last two runs of the GFS and now the NAM are painting a very different scenario around here from what I’ve described above. Monday’s outlook for this neck of the woods look good for storms, but with the winds unidirectional from the southwest the setup appears to be quite linear. The warm front looks to lift up into Michigan and there’s bound to be some backing of winds along that boundary, but whether they can hook up with surface-based instability is the question, and the cold front will be breathing down their neck, rocketing in and shoveling up the moisture en masse.

I should mention that this is the more hopeful picture per the NAM, which places the triple point in southwest Michigan by 18z. The faster GFS has blasted the cold front through by that time, with the low center well to the north, and the Euro is uncharacteristically even more aggressive. I had read that it and the GFS were in good agreement previously, but I don’t see that reflected here.

That’s as of the 6z GFS and NAM runs. The picture has changed, but chances are it’ll change again. The only thing to do is sit back, watch this pot bubble, and see what comes of it.

Another Lower Great Lakes Storm System

The eastern Great Lakes looks to be once again under the gun for severe weather, with a setup that looks reminiscent of last week’s, albeit with some variations. The low is weaker but there’s juicier moisture, helicities may integrate a little better with instability, and it seems to me that the 500 mb jet is better positioned. Once again, though, surface winds veer rapidly south of the warm front, so while the mechanism for another batch of supercells is in place, the tornado potential is less certain. The SPC convective outlook shows a 5% tornado risk. That seems about right, though maybe part of the area will get upgraded this afternoon.

After looking at the morning NAM and RUC, I once again like the area south of Toledo. Bowling Green was my initial target last week, and I’d pick it again this week if I wanted to drive that far. If I chase storms at all today, I may just wind up dropping south down 131 toward the warm front, depending.

By the way, I haven’t posted a thing about Monday’s tornado fest in Oklahoma and I probably should. I wasn’t there to experience it, but my buddies Kurt Hulst and Bill Oosterbaan teamed up for it, and Ben Holcomb made it down there as well, and everyone scored. Bill tells me that he and Kurt saw seven confirmed tornadoes.

Me, I watched the outbreak unfold on the radar and ate my heart out. It really was a heck of a thing to observe. The SRVs were jaw-dropping, and I saw one low-level Delta velocity of 177 knots. Those storms were the real deal, and a huge contingent of chasers was on them. Among the highlights was the Wakita, OK, multi-vortex that a number of chasers captured on video. The clips I’ve seen show what looks like a basketful of snakes dancing.

Unfortunately, five people died in the storms. If there’s anything positive that can be said about the loss of life, it’s that the paths of the storms through mostly rural areas no doubt kept casualties lower than they could have been. One supercell dropped tornadoes in Oklahoma City, and all it takes is one. But that’s better than multiple population centers getting hit by storms the intensity of Monday’s storms.

The Cap Won

I don’t know why so many storm chasers decided to chase in northern Missouri this last Monday. I could have told folks it had “cap bust” written all over it–didn’t fool me for a minute, as you can see by reading my post written the day before.

Ahem…right, so I got snookered too. The GFS was spot on about the cap, and the NAM way underforecast it. As a result, Missouri chasers wound up sitting under relentlessly empty skies waiting for convection to fire. It finally did in northeast Kansas–after dark. Storms ignited along a boundary (the warm front? ) and a couple went supercellular and even tornado-warned for a heartbeat before the cap re-exerted itself and squenched them.

The real action, ironically, took place in central Illinois and Indiana, well east of where most folks–including me–had expected. Supercells cut a swath along the warm front through Terre Haute, Indianopolis, and parts east and southeast into Kentucky, and a number of purple boxes lit up the radar screen. Nevertheless, SPC storm reports list only one confirmed tornado that touched down near Hillsboro, Illinois, northeast of Saint Louis.

Them’s the breaks. I didn’t chase that day, and I’m glad that I didn’t because I’d almost certainly have gotten skunked in Missouri when I could have driven straight south down US 41 to Terre Haute, not even having to mess with Chicago traffic, and waltzed on into the sweet zone.

Ah, well. I chased today–if chasing is what you can call a guaranteed grunge fest–down toward a warm front by the Michigan border. The trip was my compensation prize for not heading out when it really counted these past few days. The SPC had outlooked a five percent tornado risk this afternoon, and supercells were making their way northeast across Illinois toward Indiana. I figured that if they held together, I might catch them, but not surprisingly, they mushed out.

That was okay. I was chasing blind, with no radar and few expectations other than the hope that I’d at least see some lightning. I did, and called it good. The main storm season is still on the way, and there’s no need to fret over spilled milk when the cow is just priming its udder. It won’t be long now.

June 8: Mini-Supercell in Northern Illinois and Severe Squall Line on the Lake Michigan Shoreline

This is really part two of the previous post. After chasing a potent, monster hailer of a supercell north of Saint Joseph, Missouri, I overnighted at a hotel outside of Des Moines, Iowa. When I stepped outside the next morning, the air was much cooler and drier, a stable atmosphere that wouldn’t produce so much as a sneeze, let alone a tornado.

But I knew that the SPC had outlooked the area to my east across northern Illinois, and for several days I myself had been eyeballing my home state of Michigan, where the NAM-WRF had been consistently indicating the possibility of tornadoes. With a little luck, I hoped to make it back in time to chase whatever convection might pop up along the warm front.

As I approached Davenport, I observed  towering cumulus muscling up through the troposphere. However, I didn’t pay them any attention–that is, until Bill Oosterbaan called to inform me that the SPC had just issued a mesoscale discussion for the area just east of me. Even as we talked, I noticed a lowering on a cumulus tower a mile or two to my northeast. When it continued to develop, I decided to investigate. Leaving I-80, I parked across from a truck stop at the Atkinson exit to watch.

The next cell to my west quickly grabbed my attention. It had a nice rain-free base, and as I watched, scud began to form and ascend in an obvious updraft, coalescing into a small, ragged wall cloud. Grabbing my camera and getting out of my car, I noticed right away that the air was very different from back in Des Moines–considerably warmer and with plenty of moisture. The wall cloud fell apart before I could get a pic, but the overall structure remained interesting.

A mini-supercell approaches Atkinson, Illinois, just north of I-80.

A mini-supercell approaches Atkinson, Illinois, just north of I-80.

More brief, non-rotating wall clouds formed and dissipated one by one, so I figured I’d head north of town and observe. With surface winds veering and the overall flow unidirectional, I had no expectation of seeing tornadoes, but the mini-supercell made for some fun and interesting viewing.

Ragged, non-rotating wall cloud.

Ragged, non-rotating wall cloud.

Distant wall cloud and back side of main updraft tower.

Distant wall cloud and glimpse of updraft tower.

I was tempted to follow the storm, but decided it was a red herring. If at all possible, I wanted to make it back to Michigan in enough time to chase the setup there, and that left me no time to play around on the western Illinois backroads. So I headed back to I-80 and busted east.

The first Michigan supercell fired up earlier than I’d hoped, and I bit my lip as I followed its progress on GR3 and watched it hit Lansing. If only I had driven east last night for two more hours, or left in the morning two hours earlier… But the previous day’s chase had left me exhausted. And you know, one of the downsides of being a Michigan-based storm chaser is, you just don’t have very high expectations when it comes to your home state. I mean, it’s Michigan. Home of convective table scraps, squall lines, and embedded supercells that don’t produce squat.

As it was, I watched several more storms fire up and develop rotation along the warm front that stretched across mid-Michigan. I was making decent progress and still had hopes of catching up with some of the southernmost cells. But by the time I crossed the state line, the action all had shifted well to the east, and it became clear that I wasn’t going to see any of it.

Instead, taking fellow chaser Mike Kovalchick’s suggestion, I headed toward the lakeshore at Allegan Beach to intercept a short but potent squall line. I’m glad I did. The backdrop of Lake Michigan and its dunescapes lends a breathtaking drama to incoming storms. The following photos depict the progress of the arcus cloud moving in across the waters. What these images can’t convey is the full, awe-inspiring sweep of cloud, big lake, and shoreline; of the solemn foreboding of some great event about to unleash itself upon a landscape cloaked in storm shadow; of the shelf cloud moving silently overhead like the furrowed eyebrow of a dark, scowling giant; and of sand spray blowing and trees thrashing in the wind as the gust front arrived.

I’ll let the photos tell their story as best they can, and leave the rest to your imagination.

An arcus cloud advances toward the Lake Michigan shoreline at Allegan Beach.

An arcus cloud advances toward the Lake Michigan shoreline at Allegan Beach.

View to the north.

View to the north.

Looking south...the storm closes in.

Looking south...the storm closes in.

Looking north...closer still.

Looking north...closer still.

Almost overhead.

Almost overhead.

One last shot to the north, then it's time to make a dash for the car.

One last shot to the north, then it's time to make a dash for the car.

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.