high risk

heavy gusty shower with small hail

Yeah, Friday is kinda interesting. There isn't much CAPE at all in the forecast soundings, but a 500 mb temperature of -25C is certainly worthy of attention.......

Definitely a better event than I was thinking earlier, as the deep layer shear is better than progged earlier. That said, while I can see the stronger cells acquiring some broad rotation, you can't get strong low-level rotation with this wind profile: unless the model is way off with the weak low-level speeds that it's showing. It also doesn't look very good with the instability, but if lapse rates are better, there is plenty of dry air below cloud base to generate some intense downdrafts.

Yeah, trends are definitely good, and the full 12z suite of CAMs is quite encouraging. That said, despite some decent mid-level flow and inverted-V profiles, low level winds in the forecast soundings are quite weak. So, I'm enthusiastic about stronger storms in the area later today, but I think that not going any higher than MRGL right now makes sense.

(5:30pm) That's a really interesting storm just northwest of Winchester....

The 12z parent NAM giveth, the 00z taketh away.... Not very excited about Tuesday now, based on what I've seen in the evening runs. I'm on board with the MRGL for Monday - looks like some stronger convection later in the day (especially north of DC), in an environment that isn't great but isn't awful either.

One thing to watch is a secondary cold front that will move through in the very late afternoon. NAM Nest is most aggressive is actually generating a line of very gusty showers on the front. The frontal passage itself will likely enhance the winds even further.

Yeah, Monday and either Tuesday or Wednesday (per the Euro) seem to have at least some potential next week.

We have a MRGL today for areas generally north of the Capital Beltway in MD and Rt 7 in VA. CAMs suggest that the small window of opportunity for a few small clusters of northeast-moving cells with modest wind potential exists around dinner time, and the best chances *may* be in north-central and/or northern MD. A decent line on the cold front will approach the far northwest sections by early evening, but due to winds veering in the DC-Baltimore area behind the lead surface trough, limited convergence will likely cause the line to weaken or entirely fall apart. I'll be happy with some rain and a few rumbles of thunder (neither of which is a certainty).

As it looks now, the early Friday period does have some very limited SVR potential, with a strong front pushing through amidst some fairly impressive wind fields. Ultimately, though, the poor timing of the front and limited moisture will likely eliminate any threat without some significant modification to the evolution. The GFS idea of a phased trough, instead of the northern stream system shown by most other guidance, would help.

31 this morning in southern Howard County

radar looks good along I-95 in VA for sure, although I think that this activity (except perhaps for the cells moving into Calvert County) is just behind the front which has now cleared IAD and DCA.

Several of the CAMs this morning do break out some showers on the east side of town in the 1-2pm hour, although it appears that they are actually just behind the front. This lessens a threat of big wind, although it may still be sufficiently mixed to bring some decent gusts to the surface. The question is still whether something can form just ahead of the front around noon. Only the HiResW ARW2 suggests this scenario.

I mostly agree with this. April tends to struggle to generate much SVR here (even the best setups often leave the Mid-Atlantic in a cold air damming scenario), but there are notable exceptions. And it certainly seems to be our best month for hail. It feels to me (and I'm too lazy to go check) that our best TOR threat here runs something like May 15-June 15 (maybe June 15 is a bit late, but I think you need to include at least the first 10 days of June), and after that, we get more of the linear or MCS severe threat. But I may be speaking out of my @ss on this.

The Euro is clearly in the "faster front camp". Seems like the GFS/ECMWF/HRRR camp gets things going either just east or a good distance east of our area. The NAM and several HiResWindows (some of which are initialized from the NAM...) have a slightly slower front which gives most of us east of the Potomac a good event. A 1 or 2 hour change in the timing of the front is going to make a huge deal.

I agree fully. Could be like that Sunday event in March when we had no lightning but had a bunch of wind reports. I still think, though, that the timing is the biggest factor that is *potentially* working against us. The HRRR is still faster with the front, and the better activity gets going just east of the area. The latest NAM nest is still good verbatim, but it has notably sped up the front, relative to earlier runs. A 1pm frontal passage vs an 11am passage could make all of the difference here.

One clear fail scenario being depicted is the front going through too early in the day, as shown in the 00z HRRR and 12/18z GFS. If I had to wager, I'd say that the GFS is too fast, and the HRRR gets some indirect synoptic influence from the GFS, so that *might* explain why it looks similar. But I'm not confident at all in saying that. Ultimately, the later the front arrives, the better the chances of severe.

check out the severe thread. The front is probably going through in the early afternoon, and there is some severe potential (mitigated somewhat by limited instability), but some guidance has the frontal passage in the late morning which would really limit the threat. Regardless, as you note, regardless of the timing of the front, the winds are going to howl behind it.

SPC did give us the day 3 MRGL, and the 06z NAM nest shows the idea of the scenario described above with a strong line of convection moving through the area (not an event for the western folks) early Wednesday afternoon.

It's not a pipe dream; I'll say that. It looks like there will be a line of forced convection just ahead of the front early Wednesday afternoon in an environment with fairly decent speed shear. It should warm up to the mid to upper 60s ahead of the front, but dew points will struggle to reach the low 50s. Forecast soundings have only a small amount of CAPE, but they show a strong inverted-V structure, suggesting some possibility of stronger wind gusts. It's possible that SPC puts us in a day 3 MRGL, although I don't think it's anything close to a given.

It's not awful, but it's overall not going to be a particularly nice stretch of weather ahead, with lots of clouds and below average temps. Not to bash LWX too much, but their forecasts haven't really conveyed this very well in their products.....

FWIW, the GFS is showing that we don't get above 60 throughout the DC metro area on 5 of the next 6 days, but it could very well be overdoing clouds, and it will be way too cold with its temps if we end up with more sunshine.

Yeah, that was some impressive mixing, but the dews rebounded a bit right ahead of the storms. I was thrilled to get a a nice storm here.

Unfortunately, the trends for the week ahead are not good. There is growing agreement that a coastal low will form, and while it probably won't be a washout for the Mid-Atlantic, it certainly (barring a flip back to not emphasizing that feature) seems like we are headed for several days in the 50s in the mid to later week period.

I think they spelled out the competing factors quite nicely. We want heating today, but too much heating is going to mix out the low-level moisture. There is probably a combination of balance somewhere in there, and most guidance is showing at least a few widely scattered stronger cells later today. I'm going to be watching the dew points closely. I don't buy the low 50s shown by the HiResW ARW (which shows basically no storms), so if we stay stay in the mid 50s, I think we can crank out a few cells. Anything above that probably increases the coverage (like the NAM Nest shows).