eduggs

On the subject of temperature records... is anybody concerned about how temperature departures are calculated? Is averaging the daily high and low temperature even all that representative or comparable? Should it matter if a low temperature was achieved after a brief but precipitous drop vs. a constant temperature for 16 straight hours? All this fussing about reference periods and minor anomalies... when the method of calculation is hardly precise or rigorously scientific.

I dislike long range operational charts, but what the hell.

There are at least 3 shortwaves beginning on or around Thurs. Feb 27 that could conceivably bring precipitation to our area.

Apparently. I'm running behind all coastal regions from Cape May to Cape Cod since 2021.

Meh storm. Just a couple inches.

The Feb 28 - March 3 period is still worth watching. There's a tendency to amplify the flow for successive waves with marginal cold air and a modestly favorable longwave pattern. The 12z ICON, CMC, UK, and EC-AI show significant coastal storms during this period, though with mostly non-frozen precipitation. As usual, the nuances of wave interaction will be key to determining if we can sneak anything wintry out of it.

The Hudson Highlands area had an OK winter this year, especially when you factor in a few early season localized light/moderate events and the sustained snowpack. But I drove through parts of Orange and Putnam yesterday and there was a lot of bare ground on southerly, sun-baked aspects and the usual late-winter snowbanks on the sides of roads were largely missing. People were ice fishing out of the lakes, but the vibe was of a low-snow winter. Down in northern NJ this is the 3rd winter in a row essentially without snow, particularly east of the I-287 terrain boundary. It's been a miserable stretch for snow lovers.

Yup. Days and days of fairly steady modeling showing a miss despite an anomalous setup. Absent a few 5-7 days runs with coastal impact, this has been well telegraphed. You can't even hang your hat on any particular fantasy SREF member anymore as of 15z.

Japan has had a relatively warm winter. Despite that, some of the "heavy snow regions" have had a snowy winter... probably partly due to the warm anomalies in the Sea of Japan. Or are you referring to a different year?

NMB9 showing the extreme (weenie) solution.

A quick look at recent SREF members shows the kind of upper level evolution that would be required to get snow into our area from the coastal. The amount of modeled snow is closely correlated with the orientation of the height lines out ahead of the ULL (area highlighted below). In the very few members that show a few inches of snow for our area (from the coastal and not ULL pass), the 500mb height lines are oriented nearly south to north, indicating an ULL taking on a neutral or negative tilt. Note the 12z 12km NAM is on the more extreme end of the spectrum although not the most negatively tilted compared to the full 9z SREF suite. In the majority of members and models that show no snow from the coastal, the trof is positively tilted and height rises in this area are less pronounced. This connection is probably obvious to most. But I still find it somewhat illuminating to look at the individual SREF members since they show variation far outside the likely envelope of solutions.

The 12z RGEM actually made a similar shift to (/toward) the 12z NAM aloft in terms of adjusting the ULL position slightly west and raising heights out ahead. Unfortunately this only translates to a very slight northwestward shift in SLP and precipitation shield. But if you're tracking for the loooongshot chance of a big model bust, then you'd want to see a continued adjustment in this direction. The RGEM also has some snow with a norlun type feature as the ULL passes.

I think you discount the GFS slightly here because of the other guidance, but definitely not entirely. The GFS shows that if some aspect of this evolution is not favorable, the whole thing could fall apart. A miss southeast is still very much on the table. I'll be looking for run to run consistency from the other models in upcoming cycles; minimizing the variability will increase confidence. And of course any improvement in the GFS will be welcomed. But there could easily be occasional misses across guidance for the next few days. It is almost always like that at this range in advance of major storms.

As modeled on the 12z ECM, this is a 12-18hr event, depending on location across our area. Several of the individual members that gain more latitude also provide a longer duration event because we spend more time in the CCB as it pivots over our area.