OceanStWx

Real good chance I end the water year with more liquid than I get inches of snow this winter (closing in on 60 inches now).

I would have to dig in a little deeper to see if there was any MCV or something like that (didn’t see much evidence of the vort max that early), but 0-1 km shear was 20-25 kt. Significant tornadoes become more likely as you push 20 kt.

Loss of shingles is upper end 100 mph, trees are sketchy damage indicators at best, I’ve never really seen them rated higher than 100 mph unless they’ve been debarked (and then you’ll have better damage indicators around).

Possibly a fourth TDS near Avon, MA. Hope they got to finish their morning coffee at BOX before the warning t-shirt cannon started.

I’d still watch that tip of the comma. Looks interesting still.

Maybe another Valley Falls crossing into Mass. Warm front GW.

Agreed.

Yeah, Johnston is pretty bad from BOX, but this one moved with the storm. I think the giveaway is ZDR. It’s chaotic with turbines but near zero in the TDS.

Nice TDS for Scituate, RI

I see folks have already confirmed this is tornado debris. But for those who want to learn you have to use CC in conjunction with other radar variables to confirm. You'll want to pair this CC up with differential reflectivity (ZDR), reflectivity (Z), and velocity (V or SRV). So the drop in CC must be collocated with sufficient Z (> 20 dBZ would be ideal if not higher), a V couplet, and near 0 ZDR (debris tumbles like hail and looks neither tall or wide to the radar). Now one caveat is that Z and CC are sampled by the radar first, and then V. So it is possible that the couplet may be displaced slightly ahead of the TDS because of storm motion (especially in fast moving storms), but it shouldn't be far away. A commonly misidentified TDS is in the inflow region of supercells. Dust, bugs, etc. are all very low in CC too, so a quick check of Z will show that dBZs aren't high enough to be a true TDS.

Mini spinnies everywhere! But the best looking one is definitely near BED.

Forecast hodographs look great, so it's no wonder the radar is taking that same curved shape.

That little cell between 495 and 128 is definitely spinning. SPC mesoanalysis says we're not capped right now, but the question is do we have enough low level instability to speed up the updraft and stretch it.

We'll get 'em next time.

Please report only your largest failstones

I love the shade SPC throws about wind. "Isolated 45-60 mph gusts"

I imagine some non-standard layer had 7+ lapse rates, but our 17z sounding had 6.5 from 700-500. Huge CAPE (2500) for around here, and 50 knots shear.

Half dollars at our old condo. Had my wife (then girlfriend) running around the deck to find the largest stone because I was at work.

Average temp at BOS on 12/23 is 33.3 degrees. You have to walk it back to 12/14 before you get an average temp warmer than that (33.7).

@Damage In Tolland got his tree topper and nothing more.

But sounds like the access road is a mess from all the rain/flash flooding. Also yes, if you head up from the Loop Trailhead it is quite steep, but the Brook Trail is more gradual. I wouldn't recommend looping it down the to the Loop Trailhead though, because you have to climb down through the ladders and rock cave. Going up is much easier in that stretch I think.

Head scratcher to me. Doesn't really match what the radar said, with a two scan TDS for Easton that's more than 400 yards. And Brockton definitely had a TDS too. Microburst don't throw debris into the air.

Yeah most of the time the tornado path looks like it's around 300 yard (but some of that could be RFD damage, hard to say when it's all sporadic trees), and at its widest around 450 yards. From the centerline to Ridgewood was nearly 3/4 of a mile. Far enough that could've been NBD. Given the environment, the RFD would've been the next windiest part of the storm, and a good deal south of Ridgewood. This wasn't the type of storm with a massive forward flank wind on it.

Based on the warning motion vector and the damage path, it was on the ground for around 8 or 9 minutes. Which matches the TDS, it was there for two scans which is at least 4 minutes but not quite 10. It's also clear that this wasn't continuously on the ground either. There are lots of roads it crossed without any damage indicated by BOX so far. So a weaker circulation that was "skipping" is likely.

It's definitely going to be a tornado. I'm following along as BOX uploads the damage points into our system, and it looks like mostly (all?) tree damage. High end EF0/low end EF1 type stuff. The still photo in the tweet above you can get the sense of what BOX is looking for beyond the damage itself. You can see the downed trees, while chaotic, are crossing paths showing convergent wind vs divergent straight line.