wolfie09

Also, greater Syracuse is quite borderline for snow amounts, and incoming models will help us determine whether to maintain high end Advisory or adjoin Onondaga to the existing Warning to its north and west. It is a close call, because while the overall snow totals appear a bit foreboding, only 4-6 inches of it is anticipated with the storm itself overnight followed by a relative lull in the morning to midday before snow showers redevelop in the afternoon-evening as lake enhanced to lake effect gets going.

Here was kbuf morning map.. Looks like the 9" over 24hr type warning..(eastern lake Ontario)

NWS picking up on the mixing with sleet after 1 am which many of the SR models have.. How long it last determines how much snow we see lol Forecast solid even with sleet mixing in.. Tonight Snow after 10pm, mixing with sleet after 1am. The snow could be heavy at times. Temperature falling to near 17 by 8pm, then rising to around 29 during the remainder of the night. Southeast wind 13 to 15 mph. Chance of precipitation is 100%. New snow and sleet accumulation of 3 to 5 inches possible. M.L.King Day Snow, possibly mixed with sleet, becoming all snow after 8am. Areas of blowing snow after 3pm. High near 31. Northeast wind 6 to 11 mph becoming northwest 13 to 18 mph in the afternoon. Winds could gust as high as 31 mph. Chance of precipitation is 100%. New snow and sleet accumulation of 3 to 5 inches possible. Monday Night Snow before 1am, then snow showers likely after 1am. Areas of blowing snow. Low around 10. Blustery, with a northwest wind 17 to 21 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 5 inches possible.

Not an expert here by any stretch but Hrrr is marginal between 1-3am.. Culprit right around 850 mb..

Lol.. Yeah it has a big blob of yellow right over matt and SW Oswego at that frame..

I have to LOL that map for obviously reasons..

The heavier banding could sneak into SW Oswego county.. This map is not far off from the 6z Rgem..

3k nam is pretty wet, not all snow verbatim but we take lol Looks like around 1.75" liquid near BM in Oswego..

Hrrr is solid for the first part of the event, it has 1 hr of mixing that just pops up around 3-4 am lol Through Sunday night

Precipitation Type/Snow:Water Ratios... The strong surge of warm advection in the warm conveyor driven by the 80+ knot southeasterly low level jet may bring enough warm air aloft into play to allow for a brief mix with sleet tonight for a few hours. The mix with sleet may last a little longer across Central NY and the southern Tug Hill region. Across Western NY, the mix with sleet will be brief enough to not significantly impact snow amounts, but it will hold down amounts in Central NY to some extent. Snow:Water ratios tonight in the warm conveyor will likely be fairly low, around 10:1 or even a little lower. A deep isothermal layer beneath the dentritic growth zone in the mid levels suggests heavily rimed conglomerates resulting in an "icy" snow initially. Snow:Water ratios will steadily increase from west to east on Monday as the thermodynamic structure improves within the deformation zone, and as the column cools. By late Monday afternoon ratios will likely be 18:1 or better, especially in areas of developing lake enhancement

Looks like WPC added some mixing..

GFS is a good deal colder than the NAM..CNY slots pretty good...

Yeah both the Hrrr and hi Rez 3k want to pop a little bubble of +0C(850) near the syracuse area and lift it north lol Doesn't last long but interesting..

Nam is still warm but it went from+4c at 850 to +0-+1, some improvement..lol

Hrrr FWIW Still a little wrap around left..

The backside may be all we have lol We'll see..GFS was solid once the system passed our latitude..

Last Canadian lol 18z high Rez, pretty similar to last run..Has some mixing but tries to break it up as the band moves north fwiw

18z Ggem... No surprise given what the rgem 18z showed..

Member#7 and the board would melt lol

Several of them definitely trying to screw over CNY lol Member number 17 please..

Precipitation went up close to a third of an inch on the GFS (1.3"ish) but once again 10-1 maps don't reflect that lol Not sure if that's a PW thing or some in-between frames mixing lol

Model uncertainty... The 12Z/15 NAM right now has the biggest impacts on snowfall amounts. If it where to verify, there would be a period of mixed precipitation for a period across parts of the CWA Sunday night. This would lower snowfall totals from current forecasts. That said, most all other guidance is still colder aloft. Although, the GFS and ECMWF do get close to 0C aloft (850 hpa) when the warm conveyer belt moves through the region. So can`t completely rule out a change over for some locations or a mix but thinking the NAM is a bit too warm and the outlier. As was previously said, have opted to keep it all snow. However, wouldn`t be surprised at all if some sleet mixes in from time to time for a brief period. Will need to closely monitored this potenial as the event nears. Next concern, where will the advertised strong deformation zone and trowel actually set up. 12Z/15 Canadian-NH guidance pivots it slightly to the west of Western NY and then across Lake Ontario. This would focus the heaviest snowfall across northern portions of the Niagara Frontier and along the south shore of the Lake Ontario. The GFS/ECMWF has it focused across Western NY to Rochester in a more of a SW to NE orientation. Only time will tell or until all guidance gets in line. Synopsis... Snow will rapidly overspread the area from south to north Sunday evening. This initial phase of heavy snow will be driven by a powerful 80+ knot southeasterly low level jet and warm conveyor on the front side of the system, transporting copious amounts of Atlantic moisture into NY. Strong forcing from DPVA ahead of the mid level wave, a coupled upper level jet structure, strongly diffluent upper level flow, and strong isentropic upglide within the warm conveyor will come together to produce a period of deep, strong ascent. Forecast soundings show strong ascent through the dendritic growth zone, which is quite high in the 10-15K foot layer, with a deep saturated layer and ascent below supporting ongoing collection of supercooled water for snow falling through the column. Snow will likely continue over Western NY overnight Sunday through the early morning hours and into early afternoon. That said, as was previously mention above there could be some sleet. Precipitation then pulls eastward across Central NY and the eastern Lake Ontario region from mid afternoon through early evening as the surface low accelerates into northern New England. The heaviest and longest lasting snow will likely be found across a portion of Western NY which will then likely weaken with time and have less residence time with eastern extent. As far as accumulations go, storm totals are forecast in the 12-20" range across much of far Western NY, and 8-12" across the eastern Lake Ontario region. Again, to hammer this home. Placement of the deformation zone is key to the higher amounts. Also, if the NAM trend shows up in other guidance the added sleet will knock down accumulations. So don`t focus on the higher end of these ranges just yet. Overall, confidence is still high to achieve warning criteria across Western NY with Winter Storm Warning still in place. A Winter Storm Watch still remain in effect east of Lake Ontario where forecast amounts are lower due to less precipitation anticipated. Monday night, some lake effect snow will develop following the exit of the widespread synoptic snow. This will add several more inches of accumulation southeast of Lake Erie for the Chautauqua Ridge, and also areas southeast of Lake Ontario from the Monroe County shore east to Oswego County. Winds will be relatively light initially in this event Sunday night through Monday morning, with 20+ mph winds limited to the south shore of Lake Ontario. Winds will increase markedly later Monday afternoon and Monday night as the pressure gradient tightens in the wake of the system, with wind gusts of over 35 mph likely areawide. This will result in blowing and drifting snow during the latter stages of this event.

GFS is drier out west, little wetter east.. Really all noise at this point..