vortex95

Dec 23, 1997 is one of the biggest "modern day" busts ev-A for SNE. Another one is Mar 7-8, 2013 (4-8" at best from the ECMWF, and Blue Hill gets 30!"). Another one? CoastalWx super favorite - Dec 9. 2005. 100+ mph gusts? Only in hurricanes do we get that in SNE! And reliable reports in Andover MA area of SNOINCR 9! TS+ all over the place. Dec 23, 1997 the following day BOS Herald front page headline - "THEY BLEW IT!" and have all the OCMs on the previous evening photos (Harvey Leonard was on vacation, so they did not show his photo). Typical Herald w/ a cheesy headline (it goes way back, Sep 13, 1988 for HU Gilbert front page headline "KILLER'CANE!!!" Your Acton SNOINCR 7 jibes well w/ the SNOINCR 8 in Ayer MA. Nice to have verification! The low itself was rather small and not that deep (1000 m I think) And there was a little bubble high over nrn ME, which likely played a role in keeping it just cold enough. This was a watershed event in some regards. The following year the the SNE Wx Confernce, WFO BOX talked about DGZ. Totally new concept, at leas to me at the time. Not all snowflakes are created equal!

Trend is your friend!?

12z GFS 1" DCA, 18z GFS 13". What a piece of crap. And had zippo for SNE 12z and now 18z trying to do some weenie lagging trough thingee for ern MA. CoastalWx will be pleased!

That's when Machester-by-the-Sea had the weenie OES 23"?

-12 to -18 C. That sound right, Perhaps I was thinking the HGZ (hail growth layer) or the ideal charge layer for LTG for mixed phase!

-12 to -16 C in the DGZ is key for the big dendrites, but where are the good UVVs and does high RH overlap? It's tricky. I recall a long-duration event in Jan 1994 w/ sfc temps in the single numbers at the sfc much of the time in ern MA, and it was largely sand. I guess it can be *too* cold at times for fluff!

"lost in the trenches of forecasting an upcoming event... this definitely feels like we're turning a corner in SNE compared to last 4 years." Does CoastalWx agree?

I did not read back on all the posts in the last 18 hr on the upcoming storm, so pardon the repetition or if I state the obvious already said. First, "hope floats" for CoastalWx seems to working. He has consensus on his side at least!. LOL Second, wow, what a change from ydy on all global models. The lagging 500 s/w in the Midwest is *much* stronger now, and complicates things a lot. Perhaps this is the "English" CoastalWx was relying on for the TICK to the N? So it may be the initial sfc low off the coast is more of a flat wave, and does not push the baroclinic zone too far offshore, and then rear backup upper-level support pulls things back for a new sfc low. 00z ECMWF was quite aggressive w/ this, but the 12z backed off. GFS now flatter than a pancake, but GDPS and UKMET both suggest what the ECMWF has been doing. 11 of the 20 12z GEFS members show a hit for SNE. So it appears it all hinges on what the lagging 500 s/w does in terms of depth and how far S it can dig. You can clearly see the differences in the 138 hr 500H anomalies I attached from the 12z GFS/ECMWF/GDPS/UKMET. Looking at the pattern across NAMR. There are some problems. First, the wavelengths are too long, and the western ridge much too far W. Also, there is little in the way of s/w ridging in the NATL. So the Midwest trough is more or less a straight shooter W to E. It goes from positive tilt in the Great Lakes to neutral farther E, but then just stays neutral w/ the trough neither weakening or deepening as it moves across the NEUS. Even so, that does not mean CoastalWx should panic. You don't always need a classic pattern/setup to get a weenie event (see March 6-8, 2013 and a few others from the mid 2010s). Slight changes can be huge in this case for sensible wx in a region/area.

And it was quick hitter in much of MA/RI. I got about 15" in 8 hr in Woburn Snow began not long after midnight and it was clearing out by 9am!

That evening when I heard on the wx radio that LGA has TS+, I said, "no way it can be tucked that far NW and not get BOS!!!"

CoastalWx applying "English" to TICK the weekend storm N!? UKMET does so and GDPS is tryin'. GFS and ECMWF say no, but a "MIDLO" blockbuster for the Mid-Atlc. This is quite interesting. There is literally nothing at 500, at least I can't find anywhere close to the sfc low. When it is just off Delmarva, the flow close and over it is actually a bit anticyclonic! The trough/vort is way W in MKE-DSM area. I don't think that vort here is driving it. It's a classic Miller A "bottom-up" system. Strong from sfc-850, but MEH above that. The Feb 11, 1983 blockbuster was like this. CoastalWx LUVs this one b/c it was fcst NOT to hit SNE, and a big surprise. South Weymouth NAS had TS+ and BDL SNOINCR 5. Also SNOINCR 5 at ABE and LGA had TS+. New all-time 24 hour snowfall records were set at PHL, CXY, and ABE. Max amount of 35" at Glengary WV. This event was not a deep sfc low, about 994 mb at its closest approach to SNE, and the weekend storm looks similar. Also, like Feb 11, 1983, a very cold Arctic air mass was in place over the NEUS, and suppression of the storm track was a big fcst issue!

I would not put too much stock in Logan's record no 6" single snowstorm streak. Why? 1) The measurement hasn't always been at Logan. It used to be a bit more inland before the airport was built, and Logan is about the *worst* location for BOS city snow since it is surrounded by ocean on 3 sides (doesn't work well for true "city" temps either). Even in recent decades, it always hasn't been at Logan Airport, Starting the mid-90s for a number of years, as one example, it was taken 1 mi away to the N by a trained spotter. 2) The observer measurements have not always been up to par. Too low, too high, not brushing off every 6 hr or more than once every 6 hr, and gaps in observations of snowfall as well. This is not unique to Logan, and some major airports have great observers. I am just pointing out the caveats/shortcomings when it comes to BOS 6" snowfall gap record. 3) When the NWS Modernization occurred in the 90s, once ASOS was installed at climate sites, which are almost always at airports in the U.S., many routine snowfall observations where lost, and some came back, but snowfall was not considered a high priory overall. 4) Of all the major wx parameters we measure, snowfall is the hardest and least accurate due to many factors. Here is an article that covers some of the issues: https://news.ucar.edu/14009/snowfall-measurement-flaky-history The point is Logan had 5.3" from this event. Falling short of 6" by less than an inch is well within range of error, esp. for wet snow that compacts easily, and considering the overall challenges of measuring snowfall and long-term records not consistent or subpar at times.

Perhaps the sfc low deepened a bit more than expected or the more solid NNE gradient occurred earlier as the storm pulled away. Given the borderline BL temps and no high pressure to the N, small changes to things can make a big difference locally for sensible wx like snowfall. Non-standard setups can do odd things, and the unexpected, esp. b/c we don't have many or any past events to reference. And take note how wishy-washy both the global and meso models were leading up to this event, so that suggests a non-standard setup/pattern that the models struggle w/. Just re-enforces how weird this snow season has been. But what *should* matter to CoastalWx is the end results. But noooo, he probably pines still for the Bliz of '05 all over again!

That's a new modifier concerning snowfall -- "violently" beautiful??? Now everyone knows why I call CoastalWx the super UBER snow weenie! He makes up phrases to describe his ecstasy!

So the rear squalls verified well. HRRR did a great job. Was it bursty like snow squalls?

So you got your 6" and that breaks the 6" drought for Weymouth. Happy dayZZZZZZZZ are here again!? LOL. I don't want to hear it from you anymore. This winter is turning out pretty good now, esp, since we just filled the "snow hole" area in parts of RI and ern MA and given recent winters. And it will be *preserved* well for the next week being so cold except Thu, but some melting will actually be good b/c it will refreeze *hard* into a glacier block. Have lemons, make lemonade! But wishful thinking? CoastalWx already I bet: "The pseudo-Miller A this weekend will miss SNE and may give Norfolk VA its all-time record snowstorm. Why can we get that here???!!!"

Yes, CoastalWx oddly quiet now despite "WE SNOW/RIP" many locations. Must be MEH 1SM -SN in Weymouth!

That gradient is odd on the coast. W/ gradual cooling of the BL and the winds backing more N w/ time and freshening, the immediate coast should be close to what is inland. Also, it is not Dec, it is mid-Jan, so ocean temps are not nearly as much as a factor now.

I would not use 10:1 over RI and SE MA in this case.

But the site is the former South Weymouth NAS. So not in South Weymouth>

Really though you look at radar w/ all that yellow mesh, It should be giant dendrites S+. But looking at 700 temps, it is only about -7 C at 700 mb over SE MA. No -12 to -16 C for ideal DGZ! Does not look that impressive at Foxboro. Barely accumulating.

Sounds like CoastalWx's issue in Weymouth!

Ity-bity flakes? You know those tiny wet flakes that don't look like snow until to note they are falling slower than DZ?

I still like 2-5" for SNE, srn NH, and coastal ME. Now, will the rear weenie squall mesolow thingy push some locations to 6 or 7". As CoastalWx always said to me years ago, "WE'LL SEE!" (implied optimism in his tone). There is a distinct vort at 500 w/ this thing, and a clear twist/hook in the pcpn pattern as it gets just off Cape Ann. If there is TSW+ in Weymouth? LOL. Going back to ydy, 10.5" at Savoy MA for the max. That is among the biggest synoptic snowfalls in SNE I can recall for such a "lame" sfc low/track (weak and well NW) and SW winds sfc and aloft the entire time. It was screaming SW 30-60 kt 925-850 during the event, yet it stayed all snow. Not just elevated areas either. 4" in Haverhill MA and 4.8" Old Orchard Beach ME. So the piecemeal, piling on, lgt-mdt SN events continue this winter. Ydy was it central and west, today will be central and east. But CoastalWx still grumpy I bet. "I want a KU to end all KUs!!!" The 1.3" at Marianna FL this morning, did it w/ nothing atypical for a pattern across the CONUS. Fairly avg ridge/trough wave pattern currently. FL had accumulated snow 2 years in a row March 1954 and 1955. In Feb 2010, accumulating snow occurred twice in 3 days. CoastalWx *not* happy about the "cold 'n dry, kiss'em goodbye" pattern after today the global model op runs show?! But the GEFS gives hope for next weekend! Does look like a nasty snow/ice event from the Srn Plains to SEUS.

Seem like w/ time, N&W of 495 is becoming the target max for Sunday. Compared to 24 hr ago when we were worried about if the pcpn shield would get any further N&W than TAN! Models are hurtin', global and mesoscale, recently. Can't recall so many issues in the short range!