high risk

I'm expecting something similar to Wednesday, as have a similar combination of high CAPE and fairly high downdraft CAPE but no shear. Storms will pulse, and there will be some impressive wind events, but it shouldn't be anything too organized.

Heavy shower has strengthened into a thunderstorm now as it moved to my east. Moderate rain and distant thunder here. Seems to be a developing signal for some stronger winds as the cell moves across Anne Arundel county.

Winds definitely hit severe criteria in southern Howard County. Wow. Power went off but has thankfully returned.

That's a nasty wind signal over Silver Spring now. Hearing that it was pretty bad as it passed through Bethesda.

I think that the warnings were for the surging outflow, but new storms are now firing on that outflow boundary. Tricky day to forecast, as the lack of shear keeps allowing the outflow to surge way out ahead of the storms, so we rely on re-development for the downstream threats.

I think that the issue with the HRRR being dry today (and for the past couple of days) is that it's overmixing the boundary layer, and the dew points out ahead of the storms are too low.

I definitely expect one. Totally agree with SPC that the shear is completely lame, but it's clear that we have a shortwave approaching at the right time of day into an environment with good instability and downdraft CAPE. And the fact that yesterday overperformed in a fairly similar setup will definitely factor in to the decision to box us.

This is total hindsight, but a severe box covering northern VA, central MD, and southeast PA would have easily verified today. I don't blame SPC for being bearish on the chances for organized severe here, given the lousy deep layer shear, but a good amount of downdraft CAPE seems to have led to an overachieving event.

Some fairly good agreement of some "partially organized" storms advancing west to east across the metro area around dinner time. The HRRR is somewhat of the dry outlier, but it can't be ignored that most of its cycles yesterday were dry for this area.

Ha! But you're in a good spot.

Right on schedule….

pretty good support in the CAMs for a line of heavy showers on the front later this evening for those north and northeast of DC.

I think this is the main opportunity, as that batch will likely reduce the instability, and there will likely be some subsidence behind this feature. Can’t rule out some stronger cells popping up again this evening, but having a quick intensification of the approaching system (which seems possible but not likely?) seems the best chance for more organized severe. That’s certainly what the HRRR has been showing.

Same. Might as well issue the warnings for eastern Howard County now…..

We’ll see what details come out of the guidance today, but this right now feels like a setup for tomorrow in which we waste really good shear with debris from a dying Midwest MCS.

I'm modestly intrigued by Sunday. It's clear unclear how much instability will be available, but deep layer shear looks respectable. There isn't much agreement on how intense storms will be or what the coverage will look like, but the CAMs have overall trended towards at least scattered storms in the area later Sunday. At this point, I'd just be happy with some rain.

big-time outflow boundary passage here in southern Howard County. Gusts definitely exceeding 30 mph. Not sure if I'm going to cash in on some rain.

Definite competing factors today. As noted above, the instability, deep layer shear, and low-level lapse rates are really good. On the downside, low-level westerly flow here (which occurs when the surface low is well to our northeast) tends to dry out the lower levels and limit convergence along the cold front. The threat is certainly better the further east and northeast one goes, but the overall trend in the CAMs for the local area is positive, especially with the HRRR seeming to come on board this morning.

Still a lot of activity to the west, and the HRRR is pretty emphatic that much of the area from DC north will get storms in a few hours.

I would think you'll cash in at some point, but it's tough to use the guidance this afternoon, as very few solutions (other than perhaps the ARW2) have a good handle on this lead line.

seems like at least a 2 line event. first line filling in from north of Baltimore to west of DC. Line 2 trying to form back to the west. Some guidance hints at a third line later in the evening.

hopeful for the scenario of one round of convection late Saturday afternoon and another during the evening hours. If that pans out, anything extra on Sunday will just be a bonus.

I agree with everyone that the best signals for intense storms are for DC and points south, but there are plenty of CAMs that still have 40 dbz storms north of town. It's reflected in the 12z HREF output which shows a 90% chance between 19 and 23z of 40 dbz within 20 km of a point for much of the area in: To be clear, that's a probably of a storm with 20 km of a point, so the activity could be scattered, but I'll happily take that map.

Interesting. The guidance had been suggesting that early evening had the best potential over north central MD, and the radar is lighting up.

I ended up with a nice storm with a decent soaking - definitely a win. I expected the best chance to occur around now (where there are few cells scattered to my north and northwest, but instability has been somewhat wiped out), but I didn't expect the initial afternoon cells to crank out such a strong outflow boundary that helped initiate storms further south much earlier. But ultimately, the guidance that showed storms generally staying in north/northwest of Howard and Montgomery Counties ended up being pretty accurate.