Quincy

21z SREF low centers, in weenie range, but:

SREF is trending west as well ASOUT On a trajectory for Maine

I find it interesting that prior to this year, all of the dry summer periods occurred prior to 1980. You also have to wonder if the dry conditions helped support the heat, to some degree. (Borderline days where moister existing conditions would have supported upper 90s, while drier soil allowed temps to crack 100+) Either way, it’s definitely been an anomalous pattern across the Southern Plains this summer.

Had a one off, Hail Mary chase trip to south Dakota today and caught an intense, long-lived supercell. It spawned multiple tornado warnings, but the main stories were hail and prolific lightning production.

Lower 70s dew points across parts of eastern Colorado now. Convective initiation is underway just north of Flagler. Wouldn’t be surprised to see a few tornadoes given anomalously rich moisture on the High Plains, backed low level flow and extreme instability in place. (>4000 J/kg SBCAPE)

Two target areas today for late-day supercell thunderstorm potential: Near a surface low/warm front across the Northern High Plains and a more conditional threat near a remnant outflow boundary near the NE/SD border area.

Chased a few HP supercells in northeastern Nebraska today. Supercell potential ramps up more over the next few days…

A belt of enhanced flow looks to affect much of the Central Plains through the rest of this week. Expect daily severe weather threats during the afternoon/early evenings with MCS potential bringing bouts of heavier rains to parts of Nebraska, Missouri, Kansas and possibly even into Oklahoma. No particular day stands out as a higher-end severe event, but isolated to scattered supercell potential continues for the foreseeable future.

Scattered supercells expected today across multiple regimes from eastern Wyoming, into the Nebraska panhandle and eastern Colorado. Can’t remember a year in recent memory with so many frequent supercells and large/very large hail producing storms.

A last minute chase and the road network was pretty bad, so not much to show for it. This was the backside of the storm that went on to produce softball sized hail: I saw a few golf ball to tennis ball sized hailstones, but with no radar/cell data and a limited, questionable dirt road network, I wasn’t getting any closer. The storms initially deviated well south of model guidance, but then shifted back SE as winds veered a bit. There is an outflow boundary draped across the OK/TX panhandles. Due to the SW displacement, it seems like the best wind profiles may be slightly NE of where convective initiation is most likely later on. CAMs generally show storms clustering or growing upscale prior to reaching the area with larger hodograph curvature. Still, depending on storm evolution, there may be a window for a surface based supercell or two later on around the TX panhandle vicinity. Other isolated supercells are possible across eastern CO again, but longevity and intensity are uncertain.

Complex setup across much of the High Plains today. A residual boundary from earlier storms has chewed away at some of the environment across east-central Colorado. Approaching belt of enhanced upper level flow looks promising, but height tendencies are near-neutral, particularly south of the Denver convergence zone. In atypical Colorado fashion, most convective initiation will probably be delayed until close to 00z. If the timing is just right, air mass recovery suggests an environment highly favorable for supercells across much of eastern Colorado. I remain a bit skeptical, for storm chasing purposes.

Chased northeastern New Mexico on Wednesday. A very similar chase to June 22nd. SPC is very aggressive with the latest day 1 outlook. 10% tornado probabilities across southeastern Colorado. CAMs show no convective initiation prior to dark, but the parameter space does look pretty impressive. We’ll have to see what happens in the wake of ongoing convection through this morning.

Stayed in Salina last night, my original plan was to go into Nebraska, but whatever happens will go HP fast and Colorado puts tomorrow’s target into closer range. I do think there’s a window for something in Nebraska, but given High Plains vs. lower elevations to the east, I’ll almost always favor the western target.

Expansive slight risk today with SPC delineating an enhanced risk area across parts of eastern Colorado into Kansas and Nebraska. Glancing influence from a 40-50 knot jet pivoting east across the north-central states will coincide with a sagging frontal boundary to kick off scattered to numerous thunderstorms later today. Storm modes should be messy with deep shear vectors nearly parallel to the front, although large instability and some backing of lower level winds may result in a few initial supercells across Nebraska. A somewhat greater supercell risk may evolve farther NW across northern Colorado and Wyoming, in a post-frontal regime. Here, while instability may be less robust, stronger deep layer wind fields should yield elongated hodographs. The environment will be conditionally favorable to support a longer lived supercell or two, IF any dominant storm can remain at least somewhat isolated. Overall storm evolution favors clustering and upscale growth, hence the enhanced risk for an increasing wind damage threat this evening.

Here we go again… A pattern characterized by an extended period of seasonably strong upper level flow is anticipated across the central U.S. much of this week, along with SLGT risk convective outlooks each day, through Day 5. If ensemble data is correct, the pattern could linger into next week. It looks more like an early to mid-June pattern… as this odd severe weather season continues. One analog even compared this setup to late May 1996, as a suppressed ridge across the Texas vicinity allows somewhat anomalous flow to coincide with favorable moisture/instability from eastern Colorado into Kansas and surrounding areas. Details are to be ironed out, but the High Plains, including parts of the Southern High Plains, toward the Central Plains will likely see isolated to scattered severe storms each day this week. The thread has been generalized to cover June and July, as the pattern reloads for the foreseeable future…

Several stations in southwestern Oklahoma exceeded 110 degrees today for the actual high, including 113 at Altus. Wichita Falls also hit 110, but their daily record high is 117, so not even close.

More video clips from yesterday’s tornado: Complex setup is evolving today across the Missouri Valley/Midwest. A locally higher tornado threat may exist across parts of central Iowa, but complex storm modes and storm mergers may limit the extent of the threat. Still, enlarged hodographs near an outflow boundary and rich moisture advecting northeast into southwestern Iowa could conditionally support a strong tornado later this afternoon.

Not the greatest or most compelling footage out there, but here’s a 16ish minute clip showing a large portion of the life cycle of last night’s tornado, from my vantage point:

That is really sad to see. It seemed like a mostly rural area and the warning echoed that, but obviously there was some unfortunate destruction. I’m processing a 15 minute wide angle video of the tornado. Not only was it a slow mover, but the motion was really erratic. I’ll share when it’s up. It was a great chase, but it’s ever great to see damage like that.

Just witnessed a long-lived, slow moving tornado south of Granada, CO. Limited bandwidth, so posting this for now:

Multiple tornado warnings at the moment across central Wyoming. A tornado watch is in effect for parts of eastern Wyoming and vicinity. Other storms will be possible up and down the High Plains, immediately ahead of a dryline. Storms could interact with an outflow boundary near the Texas panhandle and convective initiation is also underway on the nose of a dryline bulge in southeastern Colorado. Tomorrow may be the final day for a bit with relatively widespread severe potential across the sub forum, as a shortwave ejects east across the Dakotas. Details are unclear, but the severe potential seems to be focused on Iowa and surrounding areas.

I stayed away from the Denver hail and tornado, favored more discrete supercell development in northeastern New Mexico:

When you get 70 dew points to the Caprock, big/bad things can happen. Today’s High Plains environment looks slightly less volatile, along with slightly less juiced moisture. With that said, several modified boundaries could be the focus for widely scattered supercell development this afternoon and evening.

Well thank you, but not even sure that’s my best. Probably my favorite from this year though. The Northern Plains storms are something else, especially with the open country and relative lack of other chasers. The northeastern Colorado tornado-fest makes sense in hindsight, while most of us were blinded by the potential for more discrete activity in southeastern Wyoming.

Pretty wacky environment near the outflow boundary in the Texas panhandle. Deep layer shear may be modest, but CAMs show 6000-9000 J/kg MLCAPE by peak heating. SPC has an enhanced risk near that area and also near the CO/NE/WY border region. One of those events where you can see multiple intense supercells form over widely spaced areas.