wxmvpete

Glad to see Sterling and I are on the same wavelength: https://www.wpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=qpfhsd

Right?! But seeing the evolution of some the members did give me flash backs to Boxing Day 2010 and late January 2015. Seeing a couple more southern VA and NC snow storms shows those southern tracks too. It shows the true top end of what could happen here as you eluded to. It also shows the misses, and at this range, they should be plausible scenarios. Unless we see those same norther S/W trends we saw last week for the recent weekend storm. Then perhaps we are talking something more impactful forum-wide.

I want to be clear I am also NOT calling for that, but out of curiosity, I looked at the CIPS analogs and felt it provided past winter storms that show the range of scenarios this setup has. https://www.eas.slu.edu/CIPS/ANALOG/DFHR.php?reg=EC&fhr=F156&rundt=2026012612&map=thbCOOP72

Read about it here for a national view: https://www.wpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=qpfhsd

I know the guy who wrote that

That is correct

I think it is just simply flying to its destination tonight. Maybe it will collect "some" data, but we requested recon into that feature (plus into the Gulf and Atlantic) for the next few days. We know the current plan is to do a sampling mission starting tomorrow at 00Z.

Heh sorry, thought the map legend went over. It shows MSLP and precipitation rate. In this case it shows 12-hr precip rate in mm. 1 mm is roughly 1 cm of snow (obviously ratios will be different, just a general rule of thumb per ECMWF)

He is referring to Google AI model that you can view on the ECMWF charts: https://charts.ecmwf.int/products/graphcast_medium-mslp-rain?base_time=202601181200&interval=12&projection=opencharts_north_america&valid_time=202601250000

I did find it interesting seeing the Day 8-14 CPC analogs and noting some of the Januarys/Februarys that would unfold as a result of this pattern. It is important to note that these seasons' ENSO states are different from year to year and what drove their corresponding storm tracks, moisture transports, and cold air available all differ to some degree. Also not every year listed caused a big storm. But just a 40,000ft look from above, seeing some of those events that unfold either during or say ~1-2 weeks following this analog pattern makes you go "huh...". Lastly, the correlation score isn't that high, so it is not a perfect match by any stretch.

About 6 miles northeast of Westminster and 1,000ft in elevation, I am measuring 2.0" on my deck. Snow now finished here.

Here it is! https://bsky.app/profile/wxmvpete.bsky.social/post/3mcj3bnaps226

I shared some thoughts on the setup late next week on X and Bluesky: https://x.com/wxmvpete/status/2011988376480534897

6:00AM snow was wrapping up. I had 4.5" here.

Ding ding ding. I am essentially in the triangle NE of Westminster, W of Hampstead, and SW of Manchester.

I have 0.3" of snow from my 1,000ft residence 6 miles northeast of Westminster.

You and I are both on the winter desks this weekend when this potential storm is inside 72 hours. We'll see how this trends over the next couple days!

Here are a couple shots I took just off route 27 between Westminster and Manchester, MD.

If I can find any of note I'll post them. One other site you could try to use is https://xmacis.rcc-acis.org/ and search either by individual station or mulit-station and look back to see if maybe RIC, SBY, or even WAL may have some useful data that aligns.

And it just dawned on me (trying to read the posts) that @MillvilleWxand others made reference to that storm lol. But the CIPS analogs at least had some extra links to review them.

I hope this link to the CIPS Analogs works. https://www.eas.slu.edu/CIPS/ANALOG/DFHR.php?reg=EC&fhr=F108&rundt=2025021512&map=thbCOOP72 Just clicking around, I thought the January 25-26, 1987 event has some similarities and was at least closer to the snowfall look you mention. Obviously it has some flaws, but the MSLP and 850mb representation isn't too dissimilar. But to your point, if you look at the mean snowfall probs, most of those snowfall areas were more north.

From an "upper-level axis" standpoint, the initial lead wave provides modest PVA aloft to where it still produces WAA "front-end thump" type snow probably regardless for most of the region. But the last 5 runs of the EPS shows some fundamental changes. 500mb trend loop: There is a clear separation of the TPV lobe over the Midwest and the lead southern shortwave. When they were phased, a stronger source of PVA/500-700mb WAA was placed more favorably over the Mid-Atlantic. As the two separate, the TPV which was faster and could help capture the leading low-level circulation spawning out ahead of the lead southern shortwave trough simply isn't fast enough or amplified enough to "tug" on the southern feature and key the storm closer to the coast. 300mb streamlines loop: This loop shows the faster southern S/W and separation of these two features in action. The mean 300mb axis is faster and heights are not necessarily as suppressed, but less influence in connection with the TPV is making the southern S/W so progressive and WAA aloft is weaker to where heights are not as high from previous runs. Final graphic via Tomer Burg's site (500mb skewness): Now the question is: Is this a trend or noise? There is still a case to be made that the TPV could speed up, and in turn catch up to the southern shortwave trough. The speed/depth of the lead shortwave trough can also change. The EPS skewness page, which shows heights that are more sensitive or less confident in placement/strength, shows the TPV heights in the Mid-South being closer to yellow (still higher than usual spread), while some lighter green colors are off the Mid-Atlantic coast. That could be more related to the strength, speed, and orientation of the trough axis. This is unfortunately what we get with Miller B's. Despite model guidance improvements over the years, these subtle and intricate details: axis position, timing, depth, and interaction can make the difference in a 50-100 mile shift. This could very well shift north with the lead shortwave and still produce a healthy SECS without the help of the TPV. But that TPV merger will be the key in a MECS or larger.

Will be a nice test for the GFS Graphcast as well, which has been pretty insistent that this storm makes the turn up the coast.

We have the divergent right-entrance region of a 300mb jet streak aligning with sufficient mid-level moisture aloft to thank for the prolonged period of snow into this evening.

The latest 18Z WSO (probabilities of exceeding warning criteria) expanded noticeably to the north. This is likely taking into account the more recent CAMs and northern extent of some of the ensembles. We've seen those southern tracks still in place but that's a notable increase across northern VA on east into the eastern DC/Baltimore metros. I also added the WSO probabilities for Freezing Rain for southwest VA. A strong signal for significant icing in those parts.