high risk

I got 0.02" which increased my August rainfall total to 0.05".

remarkably, there is one shower in the entire Mid-Atlantic this evening, and it's right over my house.

And it sure doesn't seem like a decent rain is coming anytime soon. I've seen many bone-dry Septembers, but having the rain shut off in early August doesn't happen very often.

There is a lot more support for the cooler solution in the evening guidance, including from the always-mixed and warm HRRR and HiResW FV3. There is also growing consensus that much of the area might not get out of the 60s on Tuesday

You beat me by 0.026"

Two clear trends in the guidance: 1) the timing of the storm chances for most is moving up from overnight Sunday to Sunday late afternoon / early evening 2) with northeast flow and clouds, Monday may not get to 80 degrees for most. Could even end up well below 80.

The 00z CAMs were quite bullish on afternoon convection, especially over central Maryland, but the 06z NAM Nest and recent HRRR runs have backed way off.

models are not particularly impressive for this afternoon, but none seem to have a good handle on the evolving area of widespread, heavy convection to our west. Radar is quite impressive.

You’re really looking to die on this hill, aren’t you?

Not sure why they used an 80 dew point to represent the surface, but that is not representative of a low-level parcel. The mixed-layer values (2800 CAPE, -6 LI) are far more realistic. Still a good environment, but the extreme environment that those "surfaced-based" values would suggest.

HRRR still wants a big show for many of us in a few hours

The HRRR is an outlier with focusing on the period around dinner time. Multiple other CAMs say that the period of interest for a good part of the area is much earlier. I recommend looking at the experimental RRFS on Pivotal It really crushes the DC/PG/Howard crew fairly early.

with 2" PW values? That's pretty tough to do. Our path to a SLGT is yesterday's 12Z HRRR or NAM Nest, with a semi-organized line arriving just after peak heating. The majority of the solutions this evening, which break out convection way early and not very organized, would likely only justify a MRGL for a few wet microburst events early in the event before it becomes a heavy rain situation.

Several evening hi-res runs now initiate storms in the area by early afternoon and possibly even a bit earlier.

Interesting that some of the evening CAM guidance initiates convection in the area MUCH earlier than previous runs. This would probably wipe out most of the SVR threat, but it could lead to multiple rounds of storms that enhance the flooding threat.