ILMRoss

GFS already in midwinter form

Vibe check: how we feeling? the -NAO is a lot of fun watching cut off after cut off swing through. hope we see that in january.

Today I wondered if my cats get thunderstorm anxiety and I realized that the reason I have to ask myself that is that Raleigh hasn’t had a good storm since when I got my cats (November)

I kinda made this as a little tongue-in-cheek response to this slow torture of a winter. I mean there’s a reason I called it the “Bermuda Basher”. I don’t think many people had legitimate aspirations for this storm, although I did think it had some potential. I think Webb put this really well... didn’t take much to change the game.

ok have at it

Too early, but will be a while until we track another one.....

Let's get one blue pixel on on a clown map first

This is our last shot of the year. If you want one more storm to get emotionally invested in, it’s this.

In a winter where vortex after vortex has verified weaker and further north than what models say at this range, I’m thinking “wow, I really wish that trough in the northeast that’s suppressing this system verifies weaker than advertised” is not a hard ask.

That’s a great signal this far out. .

I think everyone is a bit worn out after this winter, which is why next weekend is not garnering more attention. I just learned about it an hour ago lol I haven’t really been paying attention. But, uh, it’s got a shot if our typical winter trends don’t show up.

One thing that is completely boggling my mind is the strength of the warm nose- I cant ever remember a sleet/zr event with such a strong warm nose (10-12C, which feels completely ludicrous) - We're in uncharted territory in that regard and I am completely flummoxed on if the algorithms that govern model phase changes will be able to handle this.

There's a reason that the NAM family initialized dew points way too high- NAM consistently has less boundary layer mixing than GFS. On a day like today when when the sun is out and updrafts are bubbling up, there will be a lot of mixing up to about 850. The air at that elevation is drier; the more mixing there is, the more dry air is able to mix down to the surface. I don't know if current dew points (RDU holding at about 26 right now) will hold or whether they will shoot up once the sun goes down, but that's why we're seeing NAM dewpoint busts right now.

Don’t want to get anyone’s hopes up. But as this trough finally clears the coast later this week, Friday afternoon/evening could end up being a sneaky little snow chance if our friend, the northwest trend, shows up to amp this impulse up and drive precipitation further inland.

I will be interested to see how the sleet/zr transition zone resides. This is the battle of a few biases here- 1. Often models under-do the cold dome, and sleet ends up being more prominent than freezing rain. 2. I don't think these models are equipped with the thermodynamic capabilities of tracking the temperature of individual rain drops as they trek through a 10C warm nose. Will models be able to accurately get a grip on how deep the cold dome will need to be for drops to reform into sleet? Or could warmer drops hinder the ability to refreeze into sleet? Models are consistently flummoxed when phase changes get involved to the extent they are here.

This is how my power lines look outside my apartment if Raleigh gets ice it’s going to be the acc tournament before I get power back smh

Agreed I honestly thought the 18z HRRR precipitation type depiction was pretty wonky at the end and I’m tossing that into my mental recycling bin

Just going to throw this out there- there's a razor thin margin between sleet and ice that a lot of models won't be able to resolve. I think often what a model resolves as ice often verifies as sleet. In my opinion, I wouldn't necessarily take raw model outputs as gospel until the hours leading up to an event and there's a whole treasure trove of short range models (including hrrr) taking a crack at where each boundary will set up.

Yeah it's just a climatology quirk. I will say though that I'm surprised that the outer regions haven't been bit by an ice storm in a while. The February 2014 storm featured a "super CAD" that gave my parents in Wilmington and others at that latitude a pretty legit ice storm; my neighbor's tree came down. Other 10 mile strips (like the 158 corridor on Saturday) have been nabbed by some 0.25-0.75 events in various transition zones. but there hasn't be a catastrophic 2002 redux that hits the "middle sections" hard in a while, and frankly I'm surprised those types of storms don't come more often since CAD can be so readymade.

I've taken a few days off from watching models and living vicariously through my sister, who's a student in Memphis. I asked for a lot of pictures, but the high today is supposed to be 12 (!?!?) , so i kind of doubt she's going to be leaving her apartment very much. Otherwise, I can't endorse nodding off before the 00z GFS thoroughly enough, my sleep has improved drastically. Anyway, I'm pretty concerned with the storm later this week. Another textbook CAD, but this one seems to be much more consistent in modeling. The reason some "superwedges" last weel that went all the way to Alabama didn't pan out is because the high began to trend north- the strength of the high doesn't matter if the pressure in that critical zone between eastern PA and central VA keep on ticking down 1-2 millibars per model run! This cycle though, with a 1035-1037 being consistently modeled over the fingerlakes of NY, gives me more pause. This is when our "known errors" with CAD (cyclogenesis issues, temperature busts etc) can become a more powerful forecasting tool since the model high depiction is more reliable. Also somewhat concerning is the GFS muting the southeast ridge run after run- I think we're pretty close to seeing more pressure falls over the gulf stream help lock in a CAD. This has my attention now!

Yeah it’s definitely a buzzkill. But I’m happy that there’s a lot of people in the mid-south that are getting their once-in-a-generation pattern where every impulse leads to snow. They deserve it. How many systems stay dry around the western gulf before blossoming around Georgia? It’s not our pattern, and it happens. We still have about a month of fertile winter to track until we’ll need a Hail Mary for anything to pan out. On the bright side, I’ll be happy to get more sleep not staying up for the 00z suites!

pretty terrible cycle so far, my spiel on CADs isn't really relevant when your high is all the way in mid Quebec I'll give it a few more cycles but it will take some shifts to get out of the hole tonight put us in

man i am so glad i didnt splurge on that wxbell subscription for this storm

30-31 is ok for it if the winds are blustery enough and the rainfall rate is light enough. 28-30 is well enough to get the job done. With 30-31, if the winds aren't whipping and the rain is too heavy, a lot is lost as runoff. Also, with self limiting- that's moreso an issue in in-situ cads. While I don't think there will be there encroaching, backdoor front of zr sweeping through the region, I think CAA will be strong enough to maintain here for these NC/VA border regions. Anyone remember the ice storm back in March 2013? I think that was an event that had marginal temps but still packed a hell of an ice storm.

Hey all, couple of things to keep in mind for CADs as we go through another model cycle: 1. I generally don't like writing CADs and associated systems off until high resolution models get a crack at them. Seems pretty obvious, but in the equation governing the strength of CADs (which exists!) height of mountains is indeed a variable. topography is going to be better rendered on hi resolution models and mountains will be represented more accurately and not as smoothed out as globals. I trust them a little more! 2. Let's talk low pressure track. If you've been here a few years, it's probably been drilled into your mind that LPs can't just plow into wedges and stable air, and that's true! This is a true thing and generally low pressures will seek areas of lower pressure and ribbons of low level vorticity (almost always where the coastal front and CAD boundary meet). I think it's fair to be dubious of any low pressure track that rides up i95 if there's a 1035+ high anchored in the favored CAD region. Once again, this is something that high resolution models resolve a little better. 3. Now, one thing I want to clear up, is that it's perfectly reasonable, as the GFS showed, for a low pressure to track from Birmingham to Knoxville to Pittsburg. This is because you're on the other side of the Apps- there's no wedge here. In fact, lower pressures exist on the western fringe of the apps during CAD events, and some models are seeing this and tracking the parent low pressures up this lower side. The upper level vorticity, if it's spurring this, is likely too far away to really spark anything over the coast. Here's hoping the 00z cycles show some interesting solutions!