high risk

The I-95 corridor of Howard County was total Loserville today.

For those of us north of DC, there seems to be a fairly decent signal in the 12z CAMs for showers/storms to develop over the upper Eastern Shore and Bay during the mid afternoon hours and rotate to the west into the Baltimore area and northern AA, Howard, and Montgomery Counties.

I was surprised by the box, given no MD and the fact that we're cooling post-sunset. But the parameters on the SPC mesoanalysis look pretty good.

While the location of the max is jumping around (as it often does), the last several consecutive HRRR runs all have a 2-4" max somewhere in north-central or northern Maryland.

That NAM3 run thinks that most of the convection will die before reaching Delaware - it has a few scattered cells moving across the state much later tonight. It's not an unreasonable solution that convection will not be widespread at the unfavorable time of day. That said, there are other CAMs that generate enough forcing ahead of the front to compensate for the limited late-night instability, and they have more widespread and heavier rain in eastern areas later tonight.

I'm mostly on board with the severe threat, although the coverage of storms during the severe "window" (roughly 21z to 02z) will be limited. Might transition to more of a flash flood threat later in the evening.

I didn't pay close attention to guidance yesterday, and the potential for Sunday to not be so nice of a day really snuck up on me.

What's happening now in the PHL-TTN corridor this evening would have been us with a slightly further west and slower track for Ida.

I'll say this: there seems to be some agreement that this line to our west will sweep through in a few hours. The HRRR hodographs are garbage, but even though the 18z NAM Nest weakens the shear, it keeps the sfc winds more backed, and I can't rule out a TOR or two if that solution ends up correct.

The HRRR has another nice convective band moving through early this evening, but low-level winds are progged to significantly veer by then, so I'm not buying much of a TOR threat unless those forecasted wind profiles are really off.

Any school system on the east side of the Potomac that didn't dismiss early made a mistake today. The Annapolis tornado hit right around dismissal time.

The only event I can recall is the April 27-28, 2011 event when we were under a tornado watch here for over 20 straight hours. But that was an instance of SPC continually reissuing the box. I can't recall an event with two separate events (with a break in between) requiring tornado watches on the same day before.

18z IAD special rob has a 0-1 km helicity of 261 !!!

It's broad, but I would be erring on the side of extreme caution today if I were at LWX.

That cell just east of Waldorf looks great!