Terpeast

I’m starting to wonder if the mesos have a bias for more qpf in the 24 hours leading up to the event. We know the nam does this, but do other mesos have that same bias? I think the HRRR was onto something with the local minima over Loudoun.

I would have done better had I stuck to my initial forecast. It does look like my thoughts on the max strip from MoCo through SE PA verified warning criteria, but busted for the dmv. Some in the dmv were lucky enough to break an inch, and that would have verified on the low end. Still calling it a bust because precip came a bit early and temps took a while to catch up, and that hurt us from the start. Had it been an hour or so in our favor, we would have added another inch everywhere here. 4” would have been greedy, but a general 1-3” call would have been achieved if the precip band was an hour later. These things come down to luck and timing as always. Glad those to the NE got theirs, though!

12/5: 1.5” 12/14: 1.0” Total: 2.5”

Ended up with 1.0”

At least everything is white. Pretty with the xmas lights!

I was at 33 at 7 pm, then went up to 37 and once precip started back down to 33 and just now 32 as the back edge nears. The 4 degree rise can be attributed to the pooling of warmer air ahead of the front, kind of like the burst of temps before summer tstorms arrive. You should do much better over there, CAPE.

We all thought the rates would overcome, but it seems warm air pooled just ahead of the arctic front, making it a bigger issue for the dmv. North to fdk and along i-70 seem to be doing fine though.

Maybe an hour till back edge clears mby. Close to an inch

Seems the ops led the way on this one (provided the non-torch verifies)

Just checked other pws obs, most are at 32 and mine seems to be a warm spot. Maybe others nearby are doing better than me. eta: dropped to 32.9 and seeing some back building on radar, maybe we got time

0.5”, coming down good but temp still at 33. Maybe I was wrong about temps not being an issue

Snowing, 0.1-0.2” so far. 33

Few drops, 36. Precip band just to the NW should move SE with the cold air push. Patience is needed.

Nothing falling atm imby, 37. Didn’t think it was supposed to start this early though

Based on radar, expecting precip to start within the hour.

34.7

35 here too. Dew at 29. Don’t think temps will be an issue

Yeah i gotcha, I don’t like changing my forecasts too much. Maybe once after an initial call, but that’s it

This will be my last one

My updated forecast and final call (Note BR and cacotins can be double my numbers)

36.9 as of 5:15p in ashburn

I think this is the best hrrr run for loudoun, and its been more conservative than other models with the SW tail end.

If 0.4” qpf is correct for mby, thats a solid 3”+ which I think is the boom scenario. Very achievable though

Just now there is. Eastern Loudoun as well

Yeah anyone east of the BR is in the game, just the vibe changed when the models shifted main band NW, which isn’t surprising to see.