WxUSAF

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The NAMs would save Friday happy hour. Pleaseberightpleaseberightforgodssakepleaseberightforonce

HM was mentioning again this morning the possibility for the moisture convergence to generate an area of precipitation tomorrow earlier than expected and lo and behold it shows up on the Nams.

Low of 12.7

Wow, what an overnight change. I truly have no idea what is going to happen here lol. Don’t think any modeling system is going to cover itself in glory for this storm, but it is a unusually sensitive set up as many of us have been saying for a week. A few observations from the guidance in the vein of my comments yesterday morning: 1. The “PRE” event is still on the table but it also appears quite sensitive to where the storm tracks. Look at the differences in how juicy that swath of precipitation is on the GGEM/RGEM vs the GFS and Euro. In hindsight, that makes some sense. Closer low to the coast, the better moisture transport toward us that that boundary can wring out. I still think a banding structure within that could surprise someone relative to whatever expectations we have 36 hours from now. 2. Unfortunately for us in the metro corridor, I haven’t seen any sign that ULL precipitation swath is moving north toward us on the guidance. If there’s a region that has an overlap between the ULL and the arctic front, it’s more likely to be within a ROA-CHO-EZF-RIC polygon. And if there is an overlap there, that probably means DC-Baltimore is largely skunked. 3. Obviously the metro corridor still has some prayer of being on the edge of precip from the coastal. I still have little hope for that, but may have to put our eggs in that basket? With how rapidly this forecast has flip flopped in the last 72 hours, more changes certainly to come!

Can you notice any difference in how it handles this energy over FL that HM identified?

It’s different but I’ve heard people mention it on Twitter. Nice that they also think there’s upside potential similar to what Pete Mullinax and HM have said. That and the ULL are what I’m watching.

It’s happened for like 5 different storms this month, but it’s still remarkable to me how the GFS is just kicking the euro’s ass all over the field this month. At least in terms of forecasting the broad evolution of major storm systems. Euro still has “won” at short leads with some details like precip amounts.

Euro also has snow from the ULL over central and western NC and southwest VA. Maybe we can get that north over the next 72 hours. Think that’s much more plausible than this coastal coming west enough to deform us.

I don’t see how it hurts.

It’s still closed off at 500mb at 72hrs over western NC.

Philly, like NYC, is much more dependent on the coastal. It’s more all or nothing for them, while we hopefully have a couple consolation offers at play. Although probably Philly area gets in on the Friday evening fluff.

It’s been the least consistent on this by far. But yeah, it’s rough.

So to speak on the second piece of energy that could extend/enhance our snow: the ULL pass. Look on Pivotal at the GFS 3hr precipitation over the Mid-Atlantic from hour 57-69. Watch an area of precipitation start near the Blue Ridge near Roanoke and the NC mountains and then it expands and moves east toward RIC. IF that happens farther north, and we get in on that AND the arctic front, we could get warning level snows west of the Bay.

The final position isn’t set. This run stopped the GFS trend to push that south and wobbled it back north. I was glad to see that. Sounding at 0z also looks a bit better than I’d seen earlier on the GFS. Stronger lift in the DGZ.

Yup. This is still my primary focus for MBY. If I had any hope for coastal love, this run ain’t what I’d want.

Ok, GFS about to role. Take all the jokes to banter.

I need to remember to move my snowboard to the eastern most point in my yard.

It’s kinda hilarious that our region seems to have relatively narrow goal posts on snow potential whereas areas both north and south of us have just enormous variance. NAM and GFS give eastern NC and southeast VA a MECS and Euro gives them a dusting.

Maybe I’m being a weenie, but I feel like that “should” follow the standard N/NW adjustments as we move toward game time more than the surface low in this case.

We certainly have some boom/bust potential (don’t we always?), but I think the goalposts are fairly narrow. Bust = dusting, Boom (west of Bay) = 6-8”. Now look at NYC!! 2’+ on the euro or dusting -2” on the GFS. Yikes.

A few thoughts this morning: 1. Even with some better model runs, the coastal gets marginal additional precip west of the bay. Maybe that changes but I’m skeptical. @CAPE and everyone on Delmarva are still very much in the game for that. 2. For the metro corridor and NW areas, we are in the game for the Friday evening precipitation that’s aligned with some deep upper air lift and the arctic air boundary sinking south. GFS has been pushing this farther south each run but Euro and GGEM have pretty consistently put it through NoVA and MD. Should have good dendrite formation in this. Encouragingly two very well respected Mets (Pete Mullinax from WPC and HM) have both said that there’s some good upside potential with this feature. 3. Then we have the ULL passage overnight into Saturday morning. The stronger and earlier the 500mb low closes off the better. It provides lift as it goes by to our south and serves to pull moisture off the ocean and wring it out over the area. Again, GFS is currently farther south with this (over central VA), euro farther north near the metro corridor and GGEM sort of in between. Again good dendrite production with this and some possible upside potential if that 500mb low can close off and make a good pass south of us. So, if one area can hit on both of those features and they both juice up a bit, I could see a somewhat coherent region of 4-8” west of the Bay and west of the consolidated coastal-driven precip swath. I think either feature alone can provide 1-3”/2-4” and hopefully nobody gets skunked.

DT is secsy

Agreed. The presentation has changed in several ways. As shown on the euro, I think most of the snow we’re (metro corridor) getting is not from coastal per se but from that gorgeous ULL. Seems GFS has that through northern NC and into VA. Euro is more over the metro area. Encouraging developments, but still 72 hours to go so more changes to come.

Then that’s a major victory after that 12z run. Need 11 more noise runs until it starts snowing.