WxUSAF

Let’s just say I’m going to be asleep and not reading the meltdowns in the obs thread when it’s 53F at DCA at midnight

Euro laughs at the NAMs and ICON. DC purple’d

Haven’t looked myself that it allegedly inched north relative to its 0z but it ain’t no GFS

Tommy T ain’t having it (much like a covid vaccine)

Cooper Kupp O/U yards receiving today against the ravens? 120? 150? 170??

Which is why expectations should be kept in check.

@CAPEliking a blend of the 12z GFS and 6z Euro for his yard. 15-20” seems reasonable

This storm seems primed to bring the HoCo-MoCo deathband out of retirement.

We could just lock all the threads until 6am tomorrow?

Mrs. WxUSAF got us a La Crosse model. Posted a pic in December Banter a few days ago. I wanted a Davis VP2, but hard to justify $700.

Well, more than that because your high today will probably be 63F

@mappyis politely humble and then will double DCA’s total lol

I tend to agree, but take a look at the cross section plot in my post from an hour ago. Clearly shows 2 areas with max omega in the DGZ. One north of DC in the colder air, one south with the frontogen max.

I bet the mean/consensus of today's 12z runs will be about where it ends up. The storm is forming now and the models are "seeing" the diabetic energy release.

Congrats on 17"!

Brand new weather station says 0.6" fell after about 730pm yesterday.

It's gonna snow! So what does this storm have going for it that we didn't appreciate 72 hours ago or before? (except @CAPE). 1. The increasing separation between yesterday's warm rain and the cold from that will pass through later today gives this storm room to amplify, while also giving the cold air just enough time to filter in ahead of it. Watch how the shortwave has gotten distinct from the cold front (indicated by the blue offshore and to our N/NE over the last few days: 2. With this increased separation, we are getting MUCH better dynamics to support a broad expansive precip shield. Beautiful positioning in the right entrance region of the strong jet streak over New England supports strong lift. The 500mb low is passing in ALMOST the ideal position. 6z GFS tweaked it back south every so slightly, but here is the 0z GFS which shows Position A for DC snowstorms: with a closed 500mb low passing along the VA/NC border: 3. Take a look at the strong 700mb (also at 850mb) frontogenesis (in the insert image below). This is basically a measure of where temperature gradients are strengthening and a proxy for strong vertical lift and thus heavy precipitation. It's focused near DC and just south, where things should be ripping 24 hours from now. The cross section shows the DGZ (between the dashed red lines) and the very strong upward motion within the DGZ through the region. Ideally, that DGZ would be a bit deeper, but we've seen far worse before. If the GFS is right, at around 12z tomorrow, we're puking dendrites all across the region. Ok, so what's working against this? 1. It's moving fast. Euro is <12 hours of snow in DC. GFS is a bit longer and GGEM even a little shorter than the Euro. There's just not that much time to snow. This is what happens in fast flow/unblocked conditions. 2. It's going to be 60F today. This is not a problem because 4 inch soil temps or some shit like that are too warm. No, it's just because we have 30F to cool down from! That just takes time, even with a strong FROPA like we'll get today. So, it very well may start even as rain briefly in DC and points south and/or it will be snowing with temps in the mid/upper 30s to start and take some time to cool down to freezing where it can accumulate more efficiently. But this is a very different situation than the anafrontal wave that this looked like 3-7 days ago. That's much more of a "cold chasing precip" sort of situation and we are not in the situation now. Still, freezer doors open tonight wouldn't hurt.

Rock solid rain forecast for VA beach.

Yeah. It could be a warning level event for some, but it’s not a ton more. Definitely reminds me of some of the 13-14 type events without Atlantic side blocking.

It has potential to be big for someone for sure, but the track is going to be touchy and I wouldn’t be surprised to see it bounce around more. Without any blocking, it’s just a shortwave riding along the longwave trough and where that longwave trough axis is will dictate where the storm develops and tracks. Also a stronger shortwave would cut in this situation because there’s no blocking. But there’s a lot of baroclinicity to tap into between warm ocean and a solidly chilly airmass.

Hrrr and RGEM too?

Nice visual. Increasing separation from the northern stream with a stronger southern stream shortwave. Maybe even a slight negative tilt on the 18z??

The best forecasts American dollars can buy!

Happy hour might even make DT love the GFS

Think it was time for the Monday event even though it will probably only crush our spirit. Friday storm thread is crazy talk.