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https://forecast.weather.gov/product.php?site=NWS&issuedby=OKX&product=AFD&format=CI&version=1&glossary=1&highlight=off A potentially historic winter storm will impact the Tri-State area today into Monday. This is a dangerous situation with blizzard conditions expected to develop tonight. All guidance has converged on the evolution, track, and intensity of the system. There are some subtle differences with the global models taking a 970 mb low close to the 40N/70W benchmark by Monday morning, while the hires models are slightly farther west. The latter could be the difference for even higher snowfall amounts than currently forecast. Low pressure will quickly develop off along the North Carolina coast this morning and rapidly intensify this evening into Monday morning as it slowly lifts north-north east towards the 40N/70W benchmark. The 00Z ECMWF has come into better agreement as it has generally been on the eastern envelope of the operational guidance. This slight shift has resulted in the model QPF coming more into line with the current forecast. Forecast liquid equivalent amounts are mainly between 1.5 and 2 inches. Initially, snow ratios will start out 10:1 or even a bit lower today, then increasing to 12-14:1 by daybreak Monday as colder air wraps around the system. NBM snow ratios have been consistently too high through the event from start to finish. While deep-layered lift in the snow growth region (-10 to -20C) favors dendritic growth and high ratios, high winds will likely result in fracturing of the crystals, lowering rates. Putting this all together, expect 1 to 2 ft across the tri-state. This is up a few inches from the last forecast. On the higher end, the NBM (01Z) supports 23 to 30 inches across the area, due to a bit more QPF and the aforementioned higher ratios. Its 90th percentile supports close to 3 ft across much of the area. The NAMNest is also on the higher end with 2 to 3 inches of liquid equivalent. This is likely due to its more westward track. The 06Z HRRR which is similar in its track is very much in line with the current forecast. However, a reasonable worst case could put totals up to 3 ft. While the highest totals are expected along the coast, heavier bands of snow (strong frontogenetic forcing) can rotate inland and usually on the cold air side of the best forcing. These bands are ofter a challenge to forecast and often leads to localized higher amounts. Light snow, or a mix of rain and snow, will develop this morning, mainly from NYC and points west. This initially is associated with an inverted trough extending back to the NW across the lower Great Lakes. In fact, as the coastal low deepens later today, there may even be some drying out at the leading edge of the precipitation shield. It may take until this early this evening for steadier snow to arrive at the coast and then overspread the remainder of the area. The heaviest snow will occur during the overnight hours with 1-2"/hr rates and at times as high 3"+/hr. The bulk of the snow will come from 7 pm this evening to 7 am Monday. Snow this heavy combined with strong winds will result in whiteout conditions. Visibilities are expected to be below 1/4 mile for much of this time. Bands of moderate to heavy snow will continue into Monday morning within the comma head of the storm (typically to the N and W of the center of low pressure). These lingering bands will diminish as the low pulls away Monday afternoon. There is also a chance of a few lightning strikes in the heavier banding tonight into Monday morning. While not included in the forecast, it cannot be ruled out. Winds will be quite strong with this storm. Model soundings show boundary layer winds along the coast 40-60kt with decent mixing. Coastal locations can expect to see gusts up 45 to 55 mph, possibly even stronger across far eastern LI and southeast CT up to 60 or 65 mph. Inland areas will be weaker, but should see frequent gusts 35 to 45 mph. The highest winds will occur tonight into the first half of Monday. The blizzard warnings were expanded to include Orange and Putnam counties in the Lower Hudson valley due higher confidence in considerable falling snow, strong winds, and poor visibility.

WB 6Z 3K NAM gives more moisture to western burbs than 0Z.

MQS range between HRRR and NAM is identical to our upgraded winter storm warning of 16-22”. Sounds like a solid call at the moment.

It composes of the current (no lag like the NBM) cycles of the HRRR, WRF-NSSL, WRF-ARW, FV3, and NAM 3km models (00z cycles)... So only the high-resolution stuff.

Regarding the above NAM snow maps (Mitch vs Ji), one is Kuchera and the other is 10:1

Noise. Overall, the whole evolution has grown more impressive incrementally over time. Speaking only about the rgem. Bigtime event inbound.

What should I be paying attention to on mesoanalysis website for hints of where the inverted trough might show up? I'm going all in hoping to get inverted trough vs ccb band. The slant wise convection in that ccb is insane on the models. Which means there is going to be an area somewhere in this viewing area whose going to be have flurries for hours on end while 40:miles either direction is getting smoked. Sent from my SM-S731U using Tapatalk

Track seems further SE than other models... Sent from my motorola edge 2024 using Tapatalk

6z not reduced much....

Its struggling. Less snow than the last run.

Brooklyn

00z HREF. Sum the two to get your total:

Lol. You just can't stop can you? What is wrong with you? The 2 major metro areas, Baltimore and DC, went from 12.9" to 8.3" and 9.1" to 6.7" respectively. That's not cherry picking.

RGEM not as crazy as I thought it could have been but that was jet fuel at 500mb.

2+ feet at 10:1 will work

Its game time! Flakes start flying in the next 4-6 hours. The goods get here around 4-6pm

Snip of the 320 LWX AFD... As of 315am, light snow has been observed over the Alleghenies with light to moderate pockets of shower/drizzle over the Shenandoah Valley. Elsewhere, cloud cover continues to increase with some virga as the atmospheric profile begins to moisten with large scale ascent ahead of the approaching upper level trough. Precipitation should begin as a mixture of light rain and snow for most, with all snow above around 1500 feet. Expect precipitation to remain relatively light through mid to late morning then turning steadier later this afternoon as the main lift from the trough/coastal low move overhead. Surface temperatures will initially be in the mid to upper 30s at lower elevations, and should hold in the mid 30s through mid-late afternoon (prior to 6pm). As a result, much of the region will experience several hours of mixed rain and snow "white rain" that won`t accumulate and will largely be unimpactful other than making for wet roads. However, snow will accumulate across the higher elevations (i.e Catoctins, Alleghenies, and crest of the Blue Ridge) above 1500 feet throughout the day. Temperatures will gradually fall later this afternoon and evening as dynamical cooling ensue from the approaching coastal low and upper level trough. The large scale ascent from these features will allow the atmospheric column to cool allowing for the rain/snow mix to transition over to all snow across the forecast region. Temperatures will fall from the mid 30s into the upper 20s and low 30s during this time as the heaviest precipitation moves in Ratios will also climb during this time with 1:1-5:1 ratios outside of the elevations above 1500 feet during the day climbing to 8:1 to 13:1 overnight into Monday morning. Either way expect a wet character to the snow given the high liquid equivalent. This will make it hard to pick up with a shovel (heart attack snow) compared to pushing with a plow or removing with a snow blower. The greatest impact from snow locally is expected later this evening through predawn Monday morning as the coastal low tracks off the Delmarva and the upper axis trough moves overhead. Expect two areas of enhanced snowfall: one with the coastal low that will encompass the western shore of the bay up into the northeast/central MD and another with the inverted trough (or norlun trough) across the Catoctin/Potomac Highlands. In addition to this expect heavy upslope snow/squalls over the Alleghenies given strong north/northwest flow. The first area of enhanced snowfall rates will be close to Chesapeake Bay, where mid- level frontogenetic forcing to northwest of the coastal low will be strongest. Uncertainty remains in how far west this area of heavier snow gets, but most solutions show it only impacting the counties immediately adjacent to Chesapeake Bay in our forecast area (St.Mary`s northward through Cecil). Snowfall rates could approach an 1-2 inches per hour at times in this area between roughly 7 PM and 3 AM. Near blizzard conditions are also possible with gales over the waters and gusts in excess of 30-40 mph. The second area of enhanced snowfall rates will be along an inverted trough axis (sometimes referred to as a Norlun trough) that will extend north to south through north-central portions of the forecast area. Dynamically, this will occur along a low-level trough axis (in the 900-700 hPa layer) where northeasterly winds in response to the developing coastal low offshore converge with northwesterly winds advancing beneath the upper trough. Model guidance remains in good agreement that such a feature will occur, but there is still some uncertainty with respect to the positioning. 00z CAMS have trended slightly west with this features extending from Washington/Frederick counties down through Jefferson/Loudoun/Fauquier counties. Such features typically are very, very narrow in width (likely only 10-20 miles from west to east), and are notorious for producing very heavy snowfall rates. Most guidance shows hourly QPF values of around 0.2- 0.4 inches, which would translate to 1-2 inches per hour of snow. This feature will likely be either stationary or very slow moving over several hours tomorrow evening into early tomorrow night. A narrow band of 6-12 inches could occur as a result. Due to position uncertainty, we spread this enhancement in precipitation out over a slightly wider location than will likely occur in reality. Our current forecast hedges the placement slightly more toward the eastern solution (Washington County to Loudoun County), but has an enhancement over that broader region. This is also why the Winter Storm Warning extends southward in Fauquier Co. and wraps around the DC Metro area. The immediate DC Metro will likely fall within a relative min between these two areas of precipitation enhancement, but will still experience several hours of accumulating snow this evening into tonight. Another localized minimum will be between the inverted trough and the Allegheny Front where downslope flow could diminish accumulations especially in eastern Mineral and eastern Grant counties. Very little in the way of snow may end up falling in the shadow of the mountains just to the east of the Allegheny Front and also in the Central Shenandoah Valley. Snow totals will be heavily elevation and snow rate dependent. With such marginal temperatures in place, a lot of the snow will be lost to melting at lower elevations with surface temperatures above freezing, while higher elevations have lower temperatures and accumulate more efficiently. Snowfall: 2-4 inches is expected in the DC Metro, although there could be locally lower totals at the lowest elevations if warmer temperatures and lighter precipitation rates verify. 4-7 inches is expected along the Bay shore from St. Mary`s northward through Baltimore City, with higher totals of 6-12" from Carroll eastward toward Cecil. Higher totals of 8-16 inches are expected in the Catoctins, where snow will accumulate more efficiently throughout the event. Snow will also accumulate efficiently southward along the Blue Ridge, where a general 6-12 inches of snow is expected. To the west of the Blue Ridge, snow totals will be heavily elevation dependent, with 3-6 inches expected at higher elevations between the Allegheny Front and Blue Ridge, while lower elevations in the Central Shenandoah Valley and Potomac Highlands see little in the way of accumulation. A general 1-3 inches is expected at lower elevations along the I-70 corridor to the west of the Blue Ridge, with the exception of near Hagerstown, where they could receive significantly more snow under the inverted trough. For now, that inverted trough area which extends southward from near Hagerstown into Frederick and Loudoun is forecast to receive around 3-6", but as mentioned before, the gradient will likely be tighter than depicted, and the max there will likely be between 6 and 12 inches. In the Alleghenies Winter Storm Warnings are in effect. Snow will linger much longer there throughout Monday within upslope flow behind the departing low. Snowfall accumulations there are expected to reach 6-12 inches by Monday evening. Elsewhere, snow should wind down by mid-morning Monday.

If some of this verifies for LI, I hope my job is kind. When Nemo hit, my street didn’t get plowed for almost 48 hours after the snow stopped.

Stop cherry picking negative things just to incite the board That’s something a bored troll would do. Really fv3??

So far it looks like the 6z runs have reduced snow totals compared to prior runs. Heavy returns seem to be staying up north more. I'm don't have the ability to post maps. Still looks like a 8-12 for the metro Philly area and more towards the shore

Just waking up, so have models shifted SW with the higher totals?

Some place within 20 miles of Sayreville to Freehold NJ could have those kinds of totals (30-36 in) and severe drifting. They may be driving snowmobiles down the NJ Turnpike rescuing stranded people.

RGEM about to clobber the area

Latest HRRR

Moron, Pivotal maps are different and I said "some places COMPARED TO 0Z." Why have you become the belligerent jerk? You act like a hungry, tired child. Grow up.