RU848789

Looks like this is where the band has set up. Could be 6" or more in these locations and travel is going to be rough. Special Weather Statement National Weather Service Mount Holly NJ 1134 AM EST Mon Dec 2 2019 NJZ001-007>010-012-PAZ055-062-021745- Morris-Hunterdon-Sussex-Somerset-Middlesex-Warren-Monroe-Northampton- 1134 AM EST Mon Dec 2 2019 ...AN AREA OF HEAVIER SNOW AFFECTING NORTHEASTERN HUNTERDON... MORRIS...SUSSEX...WARREN...SOMERSET...MIDDLESEX...NORTHEASTERN MONROE AND NORTHEASTERN NORTHAMPTON COUNTIES... At 1132 AM EST, an area of heavier snow continues to slowly move across much of northern New Jersey. Snowfall rates up to an inch per hour will result in an increase in accumulations on untreated surfaces and also significantly reduce the visibility. Remember, bridges and overpasses tend to be colder and therefore be more slippery. Conditions can deteriorate rapidly in winter weather situations. Be prepared that untreated roads will quickly become slush to snow covered during heavier bursts of snow. Slow down and allow extra time when traveling. Locations impacted include... New Brunswick, Perth Amboy, Morristown, Somerville, Port Jervis, Newton, Montague, Mount Pocono, Somerset, Edison, Old Bridge, East Brunswick, Bridgewater, South Brunswick, Sayreville, North Brunswick, Carteret, Dover, Madison and Hopatcong.

It's been said by many before, including me, but if you work in the area and are at work now and can head home, I'd highly advise it, since snow at this rate will accumulate even on major highways and we all know what happened on 11/15/18 in a similar situation. I just advised the emergency management Merck folks in Rahway, who I used to work with (I retired last week after 30+ years) to consider sending people home early: my weather notes continue to be sent to about 400-500 people there, even post-retirement, which is kind of cool.

Snowing close to heavily now here at 32F with 1/2" on the ground as of noon. Gorgeous out there folks - go take a Jebwalk Accumulating well on all surfaces now, which is easy at this rate and with the low sun angle.

Started snowing lightly here around 10:30 am at 33F and had a dusting as of 11:00 am. Snowing moderately here now with 1/4" OTG as of 11:30 am - it took awhile to overcome the melting, especially with the very wet ground, but now snow is accumulating on all surfaces including paved ones; in addition, temps have dropped from 33F to 32F.

Thought summaries of the NWS Philly/NYC forecasts and the relevant snowfall maps might be helpful. Significant bust potential exists on the low side for NWS-Philly and on the high side for the NWS-NYC, IMO. This is really going to be a nowcasting event, i.e., watching the radars and the sky. Where do I sign up for the 4-7" forecast for me? So let's get to what the NWS-Phillly is saying. Warnings are now up for 5-8" of snow for Bucks, the Lehigh Valley, Mercer, Hunterdon, and Somerset, A warning is up for 4-7" for Middlesex Warnings are up for 6-10" for the Poconos, Sussex/Warren/Morris. Advisories are now up for 2-5" for Montco, W. Chester, Berks, W. Monmouth, Ocean, and Burlington Advisories are up for 1-4" for E. Chester, Delaware, Philly, Gloucester, Camden, and E. Monmouth. And what the NWS-NYC is saying. Warnings are up for 5-7" of snow up for W. Union, and W. Essex Warnings are up for 5-10" of snow for Passaic, N. Bergen, Orange, Putnam, Rockland, N. Westchester, and N. Fairfield Advisories are up for 2-4" for eastern Union, eastern Essex, southern Bergen, Hudson, Bronx, Manhattan, Staten Island, Queens, Brooklyn, S. Westchester and N. Nassau (and 4-6" for interior CT/3-5" for coastal CT).

Not true. As of this 2014 thread, the 6/18Z scores were slightly worse than 12/0Z, but much better than the 6-hr previous model run, which is mostly a function of being 6 hours closer to the event, which will almost always result in a more accurate forecast, given numerical modeling of chaotic systems, like the weather, where forecast errors always get worse the further out in time one goes. I also recall reading more recently that the 6/18Z gap had narrowed further, but couldn't find that in a quick search.

6Z Euro was a major improvement vs. 0Z Euro for CNJ and NYC metro/LI...

Measurable snow on the Euro Op is largely confined to areas NW of Sussex/Warren and N of 84, with significant snows only inland of Williamsport to Albany to Bangor, ME. So, GFS/CMC are decent, but the Euro is a miss for the 95 corridor - I'd take the reverse any day of the week, lol.

Impressive and only 6-7 days away!!

Unlike our ursine relatives, the winterweatherweenie undergoes what is essentially "reverse hibernation," only coming out of a deep, 6-month sleep, from May through October, when the WWW senses that there might be a long range global model out there on the internet showing a BECS (or at least some flurries) over a week away. And so, I'm back. A little disappointed nobody posted the Euro, lol. Let the games begin...

It's an old tale, since there simply haven't been enough snowy November events in the historical record (especially before about the 20th) to draw statistical conclusions on what that means for the season. And logically, I simply find it hard to believe that getting measurable snow early in the season, giving that season a head start, would somehow translate to less snow overall in that season.

As per comments above on the active pattern over equatorial Africa, this is the first time I recall the NHC calling attention to a wave actually still over land in Africa, although I'll admit I don't look at this graphic every day. Do others recall seeing a wave over Africa being evaluated like this? NHC has a 70% chance of formation over the next 5 days, which is also quite high for a system that is over land.

Would've been much funnier if you had not included "up."

Flash flood warning just issued for NE Mercer, SE Somerset and Central Middlesex up to just about Metuchen. Up to 1-2" more rain to come in the next few hours. https://forecast.weather.gov/wwamap/wwatxtget.php…

We got incredibly lucky here in Rahway. Had no rain from 9 am until 1:00 pm, allowing setup to proceed for our big BBQ (1500 people) without any issues and giving us the first 90 minutes (11:30-2:30 pm BBQ, with most people visiting before 1:30 pm) rain-free, when that entire time the radar had it raining <5 miles north of us in most of the rest of Union County. Got some spotty showers until 1:30 pm and then the rain hit with a vengenace. Been raining moderately to occasionally heavily since 1:30 pm. Kind of funny to see everyone hanging out under the tents we have (enough for about 500) and then those who forgot umbrellas walking away under the plastic tablecloths being used as rain gear. Luckily I'm under a gazebo with my equipment (I'm DJ-ing the event) and everything is dry. Could've been way, way worse...

Yep, just saw the new first paragraph; latest 3 km NAM and HRRR keep the Rahway area dry through 2-3 pm, which is what we need; of course the 12 km NAM has showers for us in that time, as do the globals. Going to be a close call...

If purely judging by existing radar returns, we look to remain dry for the next few hours; unfortunately, convection has to start somewhere and can't rule out cells that pop up over us in that timeframe. Still, looks better than it did last night...

Last several runs of the HRRR showing a lull in precip/storms from about 9 am until 2 pm, which would be perfect for our BBQ; crossing fingers...

Turns out I postponed our Thursday, 6/13 BBQ at 3 pm on Monday, 6/10, given too high of a probability of rain on Thursday. Ended up being a good decision as 1-2" of rain fell in the Rahway area on Thursday morning and even though the afternoon ended up being dry and cool, the fields were a muddy, puddly mess, which would've sucked for an outdoor event other than mud wrestling (which could've been a sight to see, lol). So, folks, have another event tomorrow with questions: we have a Rahway Site BBQ (different group at work) scheduled for 11:30 am to 2:30 pm tomorrow, rain or shine (we'll have tents for up to 500 people). Still can't get a good handle on tomorrow at this time from the 12Z models. GFS/CMC look quite rainy, but the more granular (in time and scale) mesoscale models are iffy. 12 km NAM just shows a passing shower, while the convection-allowing 3 km NAM shows a more robust line of storms over much of the 12-2 timeframe; presumably the 3 km NAM should be better for this kind of setup. WPC shows tomorrow as being at risk of heavy rain/flash flooding, but little risk of t-storms (same from SPC, which has us under "marginal" risk of convection). Since this is rain or shine, there's not that much to do other than hope it doesn't rain a lot and keep attendance down, especially since t-storm risks look low. Anyone have additional insight to share? Thought the NWS-NYC discussion from this morning was spot on, given the high uncertainties associated with mesoscale summertime showers along stationary fronts. As I've told the event organizer, this could easily be a dry event, but one also can't rule out a couple of showers with the potential for brief downpours and that we'll likely not know for sure until 6-12 hours before the event (and even then could be surprised). .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... The pattern doesn`t change all that much tonight and Tuesday, with rain chances being driven by the timing of weak waves of low pressure at the surface and aloft. There`s somewhat better agreement among the models for likely PoPs eventually reaching all parts of the forecast area at some point tonight and then lasting into a portion of Tuesday. Without sufficient confidence to lower PoPs from the previous forecast, will leave in likely PoPs across the entire area through all of Tuesday. With that said, there will likely be more time when it isn`t raining on Tuesday versus when it is, and greater overall coverage of rain is probably in the morning into early afternoon. Instability and lift remain lacking, so although an isolated TSTM cannot be completely ruled out, will leave it out of the forecast for now.

Meet the new boss - same as the old boss, lol. Just noticed that the old GFS is gone and the "new and improved" GFS-FV3 is here to stay. Below is the NOAA press release. No mention of what seemed like poor performance with overpredicting snowfall all last winter. Performance was only addressed in a general fashion as performing "better" than the old GFS, which will be retired in September of this year. I assume the "GFS" on Tropical Tidbits and Pivotal and other sources is now the GFS-FV3 (Pivotal still lists "GFS-Legacy" which presumably is the old GFS). "The GFS upgrade underwent rigorous testing led by NOAA’s National Centers for Environmental Prediction (NCEP) Environmental Modeling Center and NCEP Central Operations that included more than 100 scientists, modelers, programmers and technicians from around the country. With real-time evaluations for a year alongside the previous version of the GFS, NOAA carefully documented the strengths of each. When tested against historic weather dating back an additional three years, the upgraded FV3-based GFS performed better across a wide range of weather phenomena. The scientific and performance evaluation shows that the upgraded FV3-based GFS provides results equal to or better than the current global model in many measures. This upgrade establishes the foundation to further advancements in the future as we improve observation quality control, data assimilation, and the model physics." https://www.noaa.gov/media-release/noaa-upgrades-us-global-weather-forecast-model

Here's the NOAA press release. No mention of what seemed like poor performance with overpredicting snowfall all last winter. Performance was only addressed in a general fashion as performing "better" than the old GFS, which will be retired in September of this year. I assume the "GFS" on Tropical Tidbits and Pivotal and other sources is now the GFS-FV3 (Pivotal still lists "GFS-Legacy" which presumably is the old GFS). "The GFS upgrade underwent rigorous testing led by NOAA’s National Centers for Environmental Prediction (NCEP) Environmental Modeling Center and NCEP Central Operations that included more than 100 scientists, modelers, programmers and technicians from around the country. With real-time evaluations for a year alongside the previous version of the GFS, NOAA carefully documented the strengths of each. When tested against historic weather dating back an additional three years, the upgraded FV3-based GFS performed better across a wide range of weather phenomena. The scientific and performance evaluation shows that the upgraded FV3-based GFS provides results equal to or better than the current global model in many measures. This upgrade establishes the foundation to further advancements in the future as we improve observation quality control, data assimilation, and the model physics." https://www.noaa.gov/media-release/noaa-upgrades-us-global-weather-forecast-model

That's certainly the plan, since I have until 4 pm Monday to decide without being charged...

Hey folks - was looking to see if anyone has any input on how serious the rain threat is for Thursday afternoon in the Rahway area. We're scheduled to have a big BBQ for work and almost every major global model right now is showing what looks to be a fairly vigorous upper level trough digging pretty far into the SE with a surface low then tracking NE towards our area, with fairly significant rains from Weds night through Thursday afternoon (NWS NYC/Philly offices are talking about potentially decent rainfall that day in their AFDs). We need to make a call on having it or postponing by Monday at 4 pm - and we do have a couple of covered pavilions in case of a shower or two, but a steady rain would be worth postponing for - so there's still some time to sort things out, but it's not looking great right now. Any insight would be appreciated - thanks!

Don't need Don to tell you that climo says April snow is rare and given the less-than-stellar pattern forecasts beyond about 2 weeks this winter, I wouldn't get too caught up in what anyone says today about early April.

Well, the 12Z GFS, FV3, and NAM are all showing an inch or so for Friday late afternoon/evening (it better be after 4-5 pm if we want accumulations without heavy snow in March), while the CMC shows very little. The GFS, FV3 and CMC also all show some decent snowfall at the beginning of the Sat night/Sunday storm, with several inches possible well to the NW of 95 (like NW of 287/80 and N of the Tappan Zee), with the FV3 (of course, bringing decent snowfall the closest to the 95 corridor). So some mild interest in tracking these, although I doubt we get much from either system along 95.