wdrag

Snow fall past 24 hours via CoCoRaHs and a sophisticated evaluation program (NOHRSC). LSR's not yet updated. May add late today?

Hi! I'll add a verification snowfall map around 9A today... for the first part of the storm and then do the two day tomorrow. Kudos to the long rangers for pushing the Canadian block potential impacts. Nothing a done deal but it does look interesting. For now, biggest wintry impacts here in the interior next Thu-Fri per first attached WPC graphic; BUT, in my opinion I can see coastal cities getting 2"+ of snow all along I95, before any change to rain. Why? Better cold air resource nearby to the northeast.... I think that plays. What I see see in two of the three ensembles (EPS and GEPS) is one heck of digging trough into the Great Lakes-Northeast that has a better chance of spawning a southern storm that can take over, but unfortunately probably move directly nne along the coast to merge with the upper low barreling sewd through the Great Lakes. That's my scenario...hopefully ballpark. ALL BETS OFF if the weaker GEFS prevails. Also, added EPS 2M temp for 12z Thu (6 days out), and the 850MB temp anomaly prior to yesterdays storm (12z/15 where GEFS and EPS initial analysis Wass identical, and the EPS modeled 12z/22 Thu 85-0 MB temp anomaly (due to change but by how much??). You can see projections start out a little better. Hopefully this ensemble D6 projection is reasonable.

One other note: I check GFS positive snow depth change and it did very well repeated cycles leading to this event for eastern PA/NJ and I think as well the rest of the I84 corridor. PLEase check it yourself on Tropical Tidbits. No matter: we can't be using 10-1 in this abnormally warm thickness situations where type is mixed and the models assign mixed as a 10-1 ratio.

Hi! I'll add a verification snowfall map around 9A today... for the first part of the storm and then do the two day tomorrow. Added below my thinking based on the op models. I like what is ahead and Kudos to the long rangers for pushing the Canadian block potential impacts. Nothing a done deal but it does look interesting. I may switch to the main Dec thread in couple of days if snow to the coast looks more likely. For now, biggest wintry impacts here in the interior. Big winter is here the next two weeks. I'll detail the wrapup elevation wet snow shortly. Ahead is a Rockies to the East Coast heavy duty dose of winter cold and snow events. Details to be determined. Plan on some sort of snow accumulation across basically the entire eastern half of the USA (excluding southern GA and FL) sometime between late next Thursday the 22nd and Wednesday the 28th. This will include the coldest air of the season so far arriving near Christmas. But let's not forget today. Today-tonight below: Poconos: Your winter storm warning continues. Expect an additional 2-5" of wet snow-sleet between 6AM and midnight. Power outages in your area should increase a bit today. Slippery at times, especially elevations. Sussex County NJ: Mainly near Montague, High Point, northern Wantage and possibly Vernon. Intermittent rain-wet snow-sleet-freezing on some surfaces above 1000 feet. Looks to me like an additional inch or 2 of wet snow possible, mainly elevations above 1000 feet near the Kittatinny ridge. Most roads just wet. w CT and western MA: Valleys may pick up 1-3" of manageable wet snow, mainly this afternoon-early tonight. However, northern Litchfield County CT and the Berkshires should receive anywhere from 3-9" of additional heavy wet snow between 6AM today and 2AM Saturday. Power outages may develop there. Ashford CT and Bostons northwest suburbs: Wind swept rain possibly mixed with wet snow at times but no accumulation today. However rain changes to wet snow tonight...with 1-3" likely between 10PM tonight and 8AM Saturday. Later Thursday through Friday Dec 22-23: A potentially high impact - much more extensive and stronger storm with heavier snowfall than what occurred yesterday from North Carolina northward to Canada. It could bring some snow to the big cities of Boston-NYC-Washington but just far too early to know details. There may be a short period of rain-ice? Wind may gust 50-60 MPH everywhere in the northeast USA for a few hours each day next Friday-Saturday. Ensemble probability map (click for clarity and see legend) attached for possible 3+" of snow. Dark green is favored but the coast is not excluded. Christmas (24th-27th): Blustery with the coldest temperatures so far this winter, for a couple of days. I had 3" in Wantage as of 250AM.

Wantage NJ 3.0" in this southern part topped by some drizzle. Might be slightly larger before rain/drizzle. 32.7F now. TD 32.5.

Also: NO cold air to the northeast to be drawn southwest into the system. ORH 36 is not what I look for in a pretty good snowstorm here in SC.

I try to comment to assist perspective on 10 to 1, positive snow depth and Kuchera. I'll continue. My guess is that this will end up best as a Kuchera-positive snow depth blend (Ferrier replace positive snow depth change on the 3KNAM). It's not over so I donate want to presuppose the HPC HREF is slightly overdone but I certainly don't see anything more than what isa on that 12z/15 24 hr prediction for 12z Friday. What we may need to watch for near sunrise Friday is little residual southward down the Hudson River marginal freezing air invading far NNJ??? This as presssure falls slip to our east. Cross isobaric CAD drainage. Still 1.8" here at 7 and just a mix of sleet/light snow near this time of post. Possibly my last of the night. Walt 759P

Wantage NJ 1.8" as of 520PM. Attached the 12z HREF amounts by 12z Friday. Very little snow after 2AM. Already modeling may be too snowy in southern Sussex County? Anyway, will let this play out. 32.2 and riding here in Wantage and all of the state above freezing except northern Sussex County NJ.

I just checked EC... I still feel okay on my SCX amounts. I don't have any members in se NYS so I don't forecast there. 12z EC gives you 6-8 western OC with heavier Sullivan. It could be that we get all we are going to get by 10PM down here in NJ...one more good shot late this afternoon-eve here. The the big lift passes by and low lvl mess begins again. Not tracking you as closely.

Wantage NJ 4SW 3PM 0.7" on everything except treated roads wet with slightly slushy shoulders. 30.6/29.7. Light north wind. Think I am too conservative on amounts up here in Sussex County.

Wantage NJ at 1249PM: 30.4F. light ice pellet showers nearby Frankford Township.

919AM update: Main snow-ice damage on this storm for ne PA/nwNJ is Noon-midnight. Not changing snow forecast but adding that I am now pretty sure it will be very slippery near the Kittatinny ridge in Sussex County NJ (both sides) and that's where I'd put the odds for best chance 4-5" of snow-sleet. That includes Sandyston-Montague, western and northern Wantage-High Point area for a period of very slippery travel all untreated surfaces between 2P-midnight. For southern Wantage---not sure of more than 3" and pretty sure the valley from below 600 feet elevation Newton south is less than 3".

Just letting you know that 11z HRRR temps seem absurdly warm at midday into western NJ... not sure what the problem is. If they are that warm... there won't be much accumulation in SC. That temp of 34 at KORH is bothersomely warm at 7AM. Lots of uncertainty in Sussex County NJ and probably up to POU in the modeled Kuchera snow gradient.

Good Thursday morning everyone. Dec 15. Snow amount confidence is below average for the I84 corridor because of mixed snow-sleet-rain, and temperatures marginal for sticking. Attempted details follow, along with 3 maps inclusive of the 3AM NWS snow amount forecast. Note there is very little cold air to draw into this storm with temperatures already above freezing from Boston all along the east coast and Worcester is sitting only at about freezing. This combined with the rather warm 1000-500MB thicknesses poses a challenge for 4" amounts occurring nw NJ (FWN) to POU. Power outages seem to be a potential problem Poconos-Berkshires in 32-33F heavy wet snow of 6+" tonight and gusty winds 25-35 MPH. mPing: Anyone notice its posting delays for businesses now. I still think models selecting precip types and assigning snowfall in each time period is questionable. 00z/15 EC is down. In my opinion: temps at 1PM here in nw NJ will decide how much sticks. If it's 35, the warmer models prevail. If its 32F the colder models prevail. Later Thursday through Friday Dec 22-23: A potentially stronger storm with heavier snowfall but also a possible change to rain-ice? Wind may gust 50-60 MPH everywhere in the northeast USA for a short period of time. Christmas (24th-27th): Blustery with the coldest temperatures so far this winter, for a couple of days. Maps attached: The NWS deterministic forecast that went into this mornings forecasts. An ensemble map of snowfall by sunrise Friday and an impact severity map. Please click the maps for greater clarity, using the color bar for your area of interest and see a little explanation of each one. Use the color bar for the experimental winter severity index, the SPC HREF only through 7A. Friday, and the NWS deterministic forecast for their 4AM forecasts of this morning.

06Z/14 EC and latest 09z/14 SREF say I'm an inch or 2 too low on high amounts Poconos extreme nw Sussex County and w CT/W MA. Not guaranteeing anything. Willcheck again at 6P today. Have fun with this.

Good morning, I'm probably an outlier and possibly wrong but am concerned about model snow conversion rates in mixed events and 543-546 1000-500MB thickness . NAM tends to be better in these situations with mid level warming so I am conservative on this. I don't like embarrassing myself so I put this out there, with low confidence on all this being reasonable and I could be too low on my expectations. Just don't like the NAM warming aloft. It. continues to look like the northeast USA will see two or three wintry impact storms between the 15th and 28th, sandwiching a briefly much colder than normal period between the 24th and 27th (Christmas weekend). Thursday-Friday Dec 15-16: Mainly I-84 corridor north to Canada. Baltimore starts it off with a little ice 4A-9A Thursday morning which should slow the morning commute, otherwise mostly rain there. Philly area may see a little ice or snow at the beginning 8A-11A Thursday but it too is of short duration and low impact, except possibly the distant western Philadelphia suburbs. Advisories are posted. I-84 corridor itself will see a few hours of snow-sleet Thursday afternoon-night eventually change to rain by Friday morning, then possibly end as snow or flurries late Friday. Timing of the changes is stated with low confidence. The longer it snows, the better chance for heavier amounts but for now the breakdown follows: Easton Pa-Warren County: Snow sleet begins 11A-Noon and changes to plain rain 6P-9P Thursday with maybe an inch or 2 of slush. It may be very slippery for a time. The rest of the storm is rain. An advisory is posted. Poconos: a Winter Storm Watch continues: Snow-sleet-freezing rain begins around Noon Thursday changing to virtually all rain by midnight Thursday night (except ice highest elevations) then back to snow midday Friday. All totaled: looks like 3-7" before the snow ends Friday night. Confidence on details is low... but it will be very slippery at times Thursday afternoon and evening. Sussex County NJ: snow sleet should begin 11A-1P Thursday changing to all rain by midnight Thursday evening, except possibly several hours of ice along the NYS border-High Point. My expectation is 1-4". Best chance of 4"=High Point area while best chance for lower amounts of 1 or 2" is Newton southeast to Byram-Hopatcong area. This storm could end as a little wet snow Friday afternoon-evening but most areas would see less than 1" additional, if that. w CT and interior MA: snow should begin 4P-8P Thursday then turn to sleet and finally over to rain by sunrise Friday or possibly continue as wet snow parts of w MA. Most of this area should see 1-3" of snow before the change to rain, but the Berkshires and Litchfield Hills might end up with 4-8" in a few spots--maybe more un there in the Berkshires?? Ashford CT and Bostons northwest suburbs I see you an inch or less with snow with possibly mostly rain this event. You might get most of your snow Friday night as the storm heads out to sea... NWS deterministic forecast at 3A today; plus NWS ensemble probs for 2" and 4+". Click for clarity and use color bars.

Hi... I've seen 12 and 18z/13 guidance and the slight eastward drift--- heavier snowfall for the I84 corridor Berks/Litchfield to the Pocs/nw Nj and Easton PA. Hopefully this holds. I'm not committing to this being correct... have too often seen that the snow turns to sleet with modeled temps to 0C between 900-750MB. NAM3K is colder than than the 12KM NAM. Hope that's right! VV will be important. Meanwhile RGEM trimming slightly. or me... Sussex County 1-5 allowing higher side based on 12z/18z general trends. I think NWS Watch is solid for the POCS. No matter, I see a slippery Thu eve commute here in nw NJ/all of ne PA. Will rearview at 6A Wed.

I think the NAM and GFS GGEM should start melding through 00z/Fri on this 12z/13 run. You'll know before I... always hope. This is not completely locked as posted 6A-8A today.

Hi! Please see new guidance posted at 8A... a couple previous post. I just think overall this has to be less than Sunday but I could see Pocs 3-6... a little less Litchfield and Berks... follow NWS as well. Will be gone all day. 809A/13

Always hope.. 06z/13 EC snow depth change is only 1" less than Kuchera. Also attached 09z/13 SREF snow depth change ending 15z/16. Use as you wish.

Quick note: am playing this one for the I84 corridor as LESS snowfall than that of this past Sunday. Impact may be similar due to occurrence mostly between 4P and 4A Friday but so far, can't get excited about snowfall above that of Sunday. nw NJ Sussex County: am thinking 1-2" snow will suffice for now with some sleet and probably a touch of ice.

and. the 18z EC has about 1" in western NJ by 06z/16. I can live with an inch or 2 as a start in nw NJ with the heavier snowfall in the Pocs. I just don't yet buy the further se GFS/RDPS. Also with these warm thicknesses, unless the short wave can burrow beneath us, I think the future NAM cycles will warm mid levels and more ice faster northwest. Fingers crossed that I'm real wrong but I would not brief an EM on the heavier scenario of the GFS/NAM...only note in passing but preparation for the lesser still slippery onset is I think best at this time.

Thanks. Unfortunately GFS. I hope GFS locks on at 60-72 hours. Next several cycles should indicate something steady. I did see the 18z RDPS is well southeast of its prior inland heavier snowband. !8Z EC slightly colder but with sleet to HP arriving 00z/16 which makes sense to me at a 546 thickness.

Few notes: Again I wouldn't go 10-1 ratio. Two reasons: split model ptype always adds snow 10 to 1. IP is treated as snow. If you want, at early stages, I'd merge positive snow depth change with 10 to 1. For sure NWS just doesn't use a straight 10 to 1 in producing its snowfall, exception possibly for a short 6 hr period in the event. In this case: I checked Sparta NJ thermal profile and it has temps near freezing ~750MB Thursday evening... and the 1000-500 thickness is above 540. I think it helps to be a little cautious at early stages. Main upper low at 500MB is west and northwest of us. Anyway, hope you're right about as much or more snow here in nw NJ than what we enjoyed yesterday. Dendrite growth on the 18z/12 NAM is supportive of a 2-3 hour inch/hr, provided it doesn't get any warmer at 750MB here in Sussex County. Fingers crossed.

Hi... saw the 18z NAM. First batch 1-5" east to west, and most of the accumulation, if not all, starts just west of I95. Here are 12z/12 ensembles through 360 hours (15 days). Again favors interior. Doesn't lock out the coast, but interior I think is best choice until we see a considerable eastward shift in the ensembles. Not impossible to shift east but for reliability considerations, I favor inland. NWS blend of models, also 12z/12, attached last (only through 10 days). So it too allows a little on the coast, but favors interior. TOP yo bottom: EPS, CMC, GEFS through D15. Bottom is the NWS blend of models through 10 days.