Extreme Cold, Snow & Sleet: SECS 1/24 - 1/26

[Stormlover74]

1 minute ago, RU848789 said:

Just got in from shoveling a 3rd time, but this was the 2" of mostly sleet that have fallen since around 1 pm (6" worth of 10:1 snow by mass) and it was tough.  So, between 3 and 5 pm we got 1" of pure sleet giving us 2" since 1 pm, when we had 8.3", so we're now at 10.3" of sleet/snow, besting my 10.1" guess.  It's up to 17F and hoping no ZR in the last 0.4-0.5 QPF the HRRR says we'll get (mostly sleet) by midnight, but the HRRR is showing 0.1" ZR.  What a storm!

Do you also measure snow/sleet depth? Just curious how much compacting there has been

[mgerb]

26 minutes ago, Stormlover74 said:

Do you also measure snow/sleet depth? Just curious how much compacting there has been

I had 7.6" around the time of transition, and every time I went back out to measure each hour, it remained at 7.6". So there was enough compaction to counter any sleet accum. Haven't been out since 4 PM though, so will check again at 7:00. Hopefully have resumed a bit of accumulation since then, rather than only making the existing back denser (but not deeper). 

[RU848789]

32 minutes ago, RU848789 said:

Just got in from shoveling a 3rd time, but this was the 2" of mostly sleet that have fallen since around 1 pm (6" worth of 10:1 snow by mass) and it was tough.  So, between 3 and 5 pm we got 1" of pure sleet giving us 2" since 1 pm, when we had 8.3", so we're now at 10.3" of sleet/snow, besting my 10.1" guess.  It's up to 17F and hoping no ZR in the last 0.4-0.5 QPF the HRRR says we'll get (mostly sleet) by midnight, but the HRRR is showing 0.1" ZR.  What a storm!

As of 6 pm, we've gotten 2.5" of mostly sleet since 1 pm (1/2" the past hour, which is 1.5" worth of snow as we've been under an intense band); that brings our total up to 10.8" of snow/sleet and we have a shot at a foot. 17F.

[mgerb]

I also don't clear the board except for ob time. If I cleared the board at transition, would obviously have more, but that's not really kosher (at least for CoCoRaHS). 

[RU848789]

4 minutes ago, mgerb said:

I had 7.6" around the time of transition, and every time I went back out to measure each hour, it remained at 7.6". So there was enough compaction to counter any sleet accum. Haven't been out since 4 PM though, so will check again at 7:00. Hopefully have resumed a bit of accumulation since then, rather than only making the existing back denser (but not deeper). 

Clear the board after a change from snow to sleet and combine the two measurements.  I've gotten 2.5" of sleet after 8.3" of snow for 10.8", but undisturbed areas have about 10" right now, due to compaction (I have a crusty 2" from last weekend, so I can use the snow on top of that for a good measurement).  https://theconversation.com/how-is-snowfall-measured-a-meteorologist-explains-how-volunteers-tally-up-winter-storms-175628

 

[mgerb]

9 minutes ago, RU848789 said:

Clear the board after a change from snow to sleet and combine the two measurements.  I've gotten 2.5" of sleet after 8.3" of snow for 10.8", but undisturbed areas have about 10" right now, due to compaction (I have a crusty 2" from last weekend, so I can use the snow on top of that for a good measurement).  https://theconversation.com/how-is-snowfall-measured-a-meteorologist-explains-how-volunteers-tally-up-winter-storms-175628

 

Yup, saw that's how what you do. That's not how it's done in CoCoRaHS and COOP, so I don't really agree with this article. Rather, the maximum accumulation over the prior day of all snow/sleet is what is reported each day. That said, passing this along to some "snow experts" to see if they've ever heard of this practice. 

[wishcast_hater]

Whats going on with the Low Pressure developing off the coast?

[RU848789]

Sleet finished up around 9:15 pm and we added 0.2" more sleet for 3.5" total sleet + 8.3" snow for a grand total of 11.8" (unless we get some light snow overnight, which is possible), exceeding my 10.1" guess which I actually thought was aggressive yesterday morning, lol.  Season total is up to 29.3", which is more than an average winter (about 28" in NB) and we have a lot more winter to go with plenty of cold air over the next 2 weeks and a few chances for more snow.  Just reached our high temp for the day of 20F.  My 4th and last shovel of the last 2" of dense sleet was tough - gonna sleep well tonight.  

[mulen]

• 25.5 My cousins house Pearl river NY sweet . Me 0 inches Port ST Lucie Fla.

[IrishRob17]

10 minutes ago, mulen said:

• 25.5 My cousins house Pearl river NY sweet . Me 0 inches Port ST Lucie Fla.

mulen, good to see ya!

[mulen]

Thanks go back to the TWC days time flies then they threw us out lol been doing the tropical thing the last 10 yrs living down here glad you guys have ole man winter kicking ass i was wondering if weatherfella is still around ? 

[rclab]

1 hour ago, mulen said:

Thanks go back to the TWC days time flies then they threw us out lol been doing the tropical thing the last 10 yrs living down here glad you guys have ole man winter kicking ass i was wondering if weatherfella is still around ? 

Yes he is and as active/sharp as ever in the New England forum. I renem him being one of the few posters to get a straight up compliment from DT in the old forums 30 plus years ago. As always …..

[RU848789]

12 hours ago, RU848789 said:

Sleet finished up around 9:15 pm and we added 0.2" more sleet for 3.5" total sleet + 8.3" snow for a grand total of 11.8" (unless we get some light snow overnight, which is possible), exceeding my 10.1" guess which I actually thought was aggressive yesterday morning, lol.  Season total is up to 29.3", which is more than an average winter (about 28" in NB) and we have a lot more winter to go with plenty of cold air over the next 2 weeks and a few chances for more snow.  Just reached our high temp for the day of 20F.  My 4th and last shovel of the last 2" of dense sleet was tough - gonna sleep well tonight.  

But wait, there's more. We got 1/4" of snow overnight, bringing our total up to 12.0". I feel beat up after yesterday after shoveling ~18" worth of snow (3.5" of sleet has the mass of 10.5" of 10:1 snow and we had 8.3" of snow that was probably about 12:1 or ~7" of 10:1 snow). And driving wise, as I showed last night, driving on sleet is probably worse than on snow as it slides more easily, plus it melts more slowly.

My 12.0" is higher than most in my area, but that's because I followed meteorologist Bill Syrett's (from PSU's renowned weather lab) guidance to measure the sleet separately to avoid compaction (would've been 11.0" just measuring depth); until this storm I've been lower than folks in Metuchen and Edison this winter.

https://theconversation.com/how-is-...-how-volunteers-tally-up-winter-storms-175628

[NorthShoreWx]

A couple of my half-baked thoughts about the modeling in general:

Good job for the most part with QPF (not withstanding the bizarre ukmet qpf hole and some other model run faux pas)

Decent job with the sleet extent once they caught on to the warm nose.

I thought I had a good handle from the modeling on what was going to happen in this region, and that was correct.  I had a lot less confidence in what was going to happen in the Mid-Atlantic region.  Seemed like more variation in the modeling for there, although I didn't look at it as closely.

Most modeling held off too long on flipping LI back to snow last night.  I had the impression we'd wake up to some freezing drizzle and temps between 25 and 30; 18⁰ and snowing is what verified.  At least on the north shore we were going back to snow around 10pm.  My loosely considered model consensus had a substantial warm nose persisting through most of the overnight.

Overall for my insulated little corner of the world, my landscape looks very much like what I was expecting it to a few days ago...moreso than usual so subjectively, the modeling was very good.

The NWS did a good job too.  They more or less stayed with a forecast that eventually verified well through many forecast cycles.  Complaining about tweaks like adjusting P&C totals from 9 to 14 inches down to 7 to 13 inches is petty, especially when both pretty well reflected the eventual outcome.

[RU848789]

17 hours ago, mgerb said:

Yup, saw that's how what you do. That's not how it's done in CoCoRaHS and COOP, so I don't really agree with this article. Rather, the maximum accumulation over the prior day of all snow/sleet is what is reported each day. That said, passing this along to some "snow experts" to see if they've ever heard of this practice. 

Yes, I know that's what CoCoRaHS recommends, which I disagree with and I'd rather follow the recommendations of Bill Syrett, head of PSU's esteemed weather observatory for decades.  For me the issue with sleet, in particular, is that when it falls on top of snow it will always compact that snow.  I had 11.8" of snow/sleet combining my separate measurements of 3.5" of sleet and 8.3" of snow before that, but that was 10.8" just measuring depth which is significant compaction, whereas if they fell in reverse order I likely would've had about 11.8".  I'd rather have a system that gives the same measurement independent of order. 

Furthermore, IMO, the meteorological community has always wrongly been focused on snow depth with forecasts/outcome, when their job is to convey impact and risk and frozen mass does a much better job of that than measured depth.  As a result, sleet, which has the same mass as snow for a given QPF, is greatly underestimated for impact based on depth.  For example, 3" of sleet at 3:1 has the same mass as 9" of 10:1 snow and i would argue they have the same impact with regard to transportation/driving and shoveling/plowing, where anyone who removes snow knows that mass is the key, not depth.  In addition, sleet melts far more slowly than snow, given its much lower surface area to volume ratio (as melting only occurs at the surface not in the interior). 

Given all of that, I'd rather not discount sleet even further by reporting a compacted depth which doesn't convey the true impact of that precipitation and going further, I think a way needs to be found to use frozen mass as the measure of impact not depth, but I know I'm probably just howling at the moon.  At the very least, though, the NWS and media mets could do a much better job of conveying the impacts from sleet, educating the public that sleet is ~3X more dense than snow, such that each inch of sleet has the same mass as 3" of snow.  

One more point.  While the NWS recommends the public to only measure once every 24 hours, that kind of makes no sense to me, since their instructions for measuring snow at NWS sites is to measure every 6 hours, clearing the board after each measurement and summing the 4 totals for the final total.  I think they only ask for one measurement per day from the general public so they don't turn everyone off from measuring snow (who wants to measure 4X a day other than weenies like folks on weather boards or those paid to do so).  And if every 6 hours is good enough for the NWS sites, it's good enough for me - and note that in yesterday's case, using the NWS approach, I would've measured 2" of snow at 7 am, 8.3" of snow at 1 pm, when it changed to sleet, so I would've cleared the board, and at 7 pm I would've measured 2.9" of sleet and another 0.6" of sleet at 1 am for a total of 11.8" snow/sleet, which is what I got by simply clearing the board once around 1 pm when the sleet started.  

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.weather.gov/media/coop/Snow_Measurement_Guidelines-2014.pdf

 

[NorthShoreWx]

4 hours ago, RU848789 said:

... For me the issue with sleet, in particular, is that when it falls on top of snow it will always compact that snow.  

I'm in the 'wipe the board on phase changes' camp. 

Here is an example scenario illustrating some of the possible outcomes of only wiping once per 24 hours and not at phase changes.   Some of it isn't that far off from the reality of yesterday's event:

 - location 1 gets 8" of low water content fluffy snow and the storm ends.

 - location 2 gets the same 8" of low water content fluffy snow which then switches to sleet and 2" of sleet accumulate on top of it.  By the end of the storm later that day the snow depth has compressed to 8" (or less).

 - location 3 gets 2" of sleet first, followed by the same 8" of fluffy snow.

- locations 1 and 2 report snowfall as the maximum depth of 8"

 - location 3 reports a maximum depth of 10" as the daily snowfall.

Location 3 no doubt had the deepest snow depth.  Location 2 and 3 had the exact same amount of snow and sleet, but a different entry in the climate record.

Location 2 had more than twice as much frozen precipitation as location 1, but the only way to tell that is from the SWE.  They each report the same amount of snow and sleet.

On thing that stands out as being lost in these examples is the standard that snowfall includes snow and sleet.  Does it really include sleet for location 2?

[RU848789]

Hey @mgerb- curious if you have any feedback from NWS folks or any comments on my long post above outlining my rationale.  TIA.  

[mgerb]

On 1/28/2026 at 9:45 PM, RU848789 said:

Hey @mgerb- curious if you have any feedback from NWS folks or any comments on my long post above outlining my rationale.  TIA.  

@RU848789 Not yet; haven't had the chance. I'll try to chime in this weekend!