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A burst of snow Tuesday morning will refresh area snow cover, helping many of us to a white Christmas (more than 1/2" of snow on the ground at 7AM Wednesday). There's a separate thread for the 7A Wed 12/25 snow depth. Snowfall may be impressive for short time, coating all untreated surfaces with slippery broom able fluff.

Welcome to Meteorological winter! A nice wintery start!

Winter discussion/outlook for January 2025.

Let the speculation begin!

No guarantees on what will happen. Modeling showa a pair of closely following short waves diving southeast toward the mid Atlantic coast, sharpening the mid level trough. While too far offshore for a 4+" event, the 850 MB weak warm advection, 850MB vorticity from s central NYS sewd to NNJ and under running boundary layer northerly flow is going to produce a little bit of snow. For CP, think it needs to measure after sundown Fri. Outskirts of NYC from NNJ-se NYS-sw CT across LI should see 1/4" to maybe as much as 2", with potential for 3" near the NYS-PA nw NJ border. 4AM NWS has not posted any snowfall for NYC, so the probability (attached) for 0.1" in CP is very low (26%). Added 08z WSSI-P graphic and the NWS 08z/18 Blend of Models. If the system ends up weaker and not sharpening, then this modeled event fritters (850 vort trough just becomes general northerly CAA flow instead of what is modeled now). Should the miD level trough sharpen a bit more then that boosts confidence for NYC metro spirits brightened by snow on the ground Saturday morning. If PHL measures, that would be their first of the year. BOS already has measured. Reserving comment for Christmas possibilities to the general Dec thread for now, will we get through 12z Sat. Click graphics for clarity.805A Added OBS to the title at 748A/20 and one updated prob graphic for NYC CP

Well, we are just twelve weeks out from December, so I thought I would start a spec thread... I actually like these ideas in the article below: https://www.severe-weather.eu/long-range-2/winter-2024-2025-first-snowfall-predictions-united-states-canada-europe-fa/ I tend to think that our best shots at winter will be late November to late December, and then it gets warm and maybe stays warm. That said, as others have noted in the main discussion thread for fall, the strength of this La Nina is important. The IO is important. The PDO is important. The MJO is very important. PDO -> The September Cansips has the PDO staying solidly negative for the winter, and not really even coming up for air at that. MJO -> This will tend to favor warm phases as phase 8 will be cooler than normal and that limits convection there. IO -> Off the coast of Eastern Africa, there is warm water depicted. That would favor phases 1-2 of the MJO. It also favors warmer than normal water over the Maritime Continent which favors 4-6. 500 Heights over NA -> November a ridge is shown to be out West. It transitions eastward as December progresses, and then parks itself over eastern NA for Jan and Feb - monster SER of sorts. Maybe by April it relents. The NAO might be negative for the first 1/3 of winter before returning to a net positive state. It would not surprise me to see the pattern relax by April, and we see chances for snow in early April (especially the mountains). SSTs -> The La Nina on Cansips appears to fade significantly by February. By next summer, we might be seeing Nino conditions for the western 3/4 of the Pacific. We have talked about gradient. @Typhoon Tiphas mentioned gradient many times(I think I have the correct poster). That means the delta (difference) between the La Nina and the waters around it matters. The steeper that gradient, the more of a stimulus we get. El Nino was kind of a washed out gradient last winter, and we got washed out results on the EC. From the recent climate.gov ENSO blog, "Said more simply, it’s not just how much warmer or colder than average that part of the tropical Pacific is that jumbles up the tropical atmosphere, it’s the difference in warming or cooling compared the rest of the Pacific. And that’s where the relative ONI comes in! So where do things stand? The regular ONI for May-July was +0.2°C. But the relative ONI was already down to -0.4°C. That means there could be a scenario later this year where the ONI is not yet below -0.5°C, but the relative ONI already is, and the atmosphere might start reflecting La Niña-like impacts. Doesn’t that seem like a pain to communicate? " To me, since the Pacific basin is warmer than normal, La Nina might well have a threshold warmer than what we saw maybe 30 years ago. That means that what we see as a weak La Nina might actually be a bit stronger than we think. So, the weak La Nina forecast below might well be a bit stronger given that La Ninas might have increasingly warmer SSTs. Overall Forecast: I do think we see some crazy cold air masses at some point. I do think the Mountain West does really, really well in terms of snow and cold. In fact, the higher elevations there are already getting snow. Their winter has already started above 8,000'!!! I do think that middle and western portions of our forum will see a colder and snowier winter. But beware, if this truly turns out to be a weak La Nina....all bets(and I mean all bets) are off the table. Weak La Nina's in E TN can often be bitterly cold. So, instead of doing a monthly J-F forecast, I am going to simply put out a general forecast. One, well-placed cold shot during Jan-Feb could really skew things. During 2017-18 we had a crazy cold shot that straddled late December to January. It didn't snow much but was crazy cold. We were below freezing at TRI for seven straight days! The monthly climate data doesn't really show that cold shot as it straddled the end of one month and the beginning of another. That winter was also a weak La Nina. I am liking that analog year 2017-2018. If we had any precip in that pattern, we would have been buried. As it was, it simply froze things solid. December was -0.8F . Jan was -4.5F. Feb was +9.4 F. March was -2.1F. April was -4.1 F. Maybe we had a strat split late that winter??? I am going to go ahead and add these. And I am far, far deeper into this than intended...Sorry, this is kind of a "stream of thought" post, and maybe not as scientific as it should be. I also want to add 16-17 into the mix at it was a first year La Nina and should be weighted equally or more to 17-18. But here is why I am far less confident this winter. See the 94-95 moderate Nino listed in the graphic at the very bottom of this post. This past winter reminded me of that type of winter - blah and not a lot of chances. Now, what came after 94-95? The winter that shall not be named, because I just won't invoke a winter that is a benchmark winter of my lifetime, and it was true winter. It was a weak La Nina following a moderate El Nino. It is also a winter that maybe doesn't fit the current warm basin look of the Pac which is why I haven't used it. That said, it might deserve some weight though I haven't given it any. Just beware. So, for now, I like the 16-17, 17-18 blend of weak La Nina winters. December looks chilly. Jan is a tossup, but leans warm. Feb looks warm. I did break down the 16-17 winter by month as well as 17-18. I also provided a blend of the two which I tend to like better, and is probably pretty close to my thinking. In addition, the 16-17/17-18 analog blends might be of better use as they are recent analogs, and not almost 30 years old. Plus, those two analogs came from a weak El Nino which I think is a better fit. Notice that the March blend is not overly warm on the EC. I do think maybe some late season chances exist north of I-40, especially in E TN and the southern Apps. ***The following would be my best guess for winter temps.*** Refer to the article at the very top of the page for snowfall anomalies. Those looked about right. Reference for ENSO graphic list: https://ggweather.com/enso/oni.htm And if you made it this far, thank you for reading this! I intended to make a short post, but ended up just saying, "Screw it," and wrote a long post. LOL. I normally don't like long seasonal forecasts, and really, those long posts end up being very wrong much of the time. I really think seasonal forecasting often involves false correlations, and I am sure my post is guilty of some of that. In other words, sometimes my seasonal forecasts might "appear" to be correct, but often it is just blind luck that they even got close. In other words it is like saying TN is going to win a ballgame because of Nico, but really they win because of great defensive line play. They won, but not really my line of thinking. So, have some fun with this, but don't take it as the gospel. This is just for fun. Feel free to post your winter ideas in this thread. And this thread is not meant to be the December 2024 winter thread. That will have its own thread. This is merely a speculation thread, and won't be rolled into a winter thread. If this verifies, we could see some cold college football playoff games during December....

It's time for the 11th annual Mid-Atlantic snowfall contest! First, thanks to @Roger Smith for pointing out that last year's contest, which was billed as the 9th one, was actually the 10th, as Roger unearthed records of the first one, which occurred during the 2014-15 snow season, and was won by @nw baltimore wx. So he has been added below to the list of previous winners, including last year's winner @Kmlwx Second, those who participated last year will recollect the consensus that a Strong El Nino was going to end the Mid-Atlantic snow drought, but that did not happen. So, it appears that snow lovers in our region will have to put their faith in a Weak La Nina this snow season. That may not sound too promising, but perhaps the consensus will be wrong again. Also, I note that we are nearing a solar maximum, which just maybe will somehow, some way upset the apple cart and bring ample snowfall to the Mid-Atlantic. In any event, the focus of this contest is forecasting the total snow that will fall during the 2024-25 snow season at BWI International (BWI), Reagan National (DCA), Dulles International (IAD), and Richmond International Airport (RIC). In the event a tiebreaker is required (that happened 6 years ago), please choose one of the following two airports: Salisbury, MD (SBY) or Lynchburg, VA (LYH). Choose only one. Please note that you are forecasting the total snowfall for the entire snow season (NOT just Dec/Jan/Feb) to the nearest one-tenth of an inch. Generally, snow does not fall after early April at any of these airports, and so the contest is usually finalized by early to mid-April. The winner will be the entrant who has the lowest combined absolute value departure for all four airports. For example, if you forecast: BWI: 0.0" DCA: 0.0" IAD: 0.0" RIC: 10.0" And the actual seasonal totals turn out to be: BWI: 2.5" DCA: 2.5" IAD: 2.5" RIC: 2.5" Your absolute value departures would be: BWI: 2.5 DCA: 2.5 IAD: 2.5 RIC: 7.5 Thus, your total departure would be 15.0. Please use the following format when posting your forecast, in this order: BWI: DCA: IAD: RIC: Tiebreaker (SBY or LYH): The deadline for entries is Sunday, December 1, at 11:59pm. You are welcome to update your forecast at any time up to the deadline. However, please do not edit your original post -- either submit a new post or send me a private message. If there's any accumulating snow before the deadline, please include that in your forecast as well. I think the best approach is to submit your forecast in advance of the deadline and update if necessary, just in case you get tied up on December 1st, when the contest will lock -- no late entries will be accepted. The winner gets an E-trophy made of snow and an induction into the Hall of Fame with the previous winners: 2014-15: @nw baltimore wx@S@S@Shadowzone 2015-16: @Shadowzone@Stormpchadowzone 2016-17: @StormpcStormpchadowzone 2017-18: @olafminesaw@Storm @olafminesaw 2018-19: @olafminesaw (tiebreaker win against @Stormpc) @Stormpc 2019-20: @Prestige Worldwide 2020-21: @NorthArlington101 2021-22: @IUsedToHateCold 2022-23: @LittleVillageWx 2023-24: @Kmlwx Everyone is encouraged to play, including lurkers, new members, and people outside the region. Good luck everyone!

38/30 14-18' hopefully

Added the 1/18 CPC FEBRUARY outlook and the new CPC week 3-4 issued 1/26. Both posted here on 1/26 748PM. While the anomalies are warmer than normal the first two weeks of February, it might not mean absurdly warm preventing snow in NYC. The warmer than normal anomalies seem to be more centered up in Canada, modifying the potential for true arctic intrusions down here. Guidance suggests the potential for several east coast storms In February and the possibility of snows from Asheville to Boston - I95 westward. That may be climo combined with the El Nino pattern of potentially above normal precip southern USA and up the east coast to NYC. So, can the NYC CP Feb snow total exceed our January total? Temperatures may chill down a bit in mid February? Will add on here Friday evening the 26th with the new 1/26 CPC guidance. May also add Don's stats if he has any for this pattern for Feb. Thank you all. And now the CPC Jan 31 update for Feb. Looks a little higher prob of not so much qpf, and chilled New England a bit. On March 2 attached the Feb verification. Looks like our local take verified OK with the mid month chilling, and twice the Jan paltry snow total at CP. and the CPC trend to below normal qpf also worked out with east coast events trailing off the coast south of our area.

Different than the refresher powdery event of Sat Feb 17, and this past Tuesdays Feb 13 wetter snowstorm, it still has possibilities for adding to our winter snow totals with modeled "potential" for half a foot or more for the I84 corridor inclusive of the Poconos-extreme nw NJ interior sections se NYS-CT. Possibilities even exist for an inch or four down to I95 and NYC though for now, odds are less. This could be one warmer more rainy event the 22nd and then a following rapidly intensifying coastal storm Fri-Sat the 23rd-24th. As generally usual higher terrain-inland best chance for snow. A strong short wave in the eastern Pacific this weekend will move through the southwest USA early this coming week and probably be ingested into a series of northern stream Canadian short eaves that dive southeast into Midwest and form a sharp amplifying trough over the northeast USA by next weekend. Details tbd. This probably will be of NYC subforum interest for some of us the next few days as winter potential refuses to go away. Added 10 to 1 SLR, 24 hour 00z/17 global ensembles and the NWS 04z/17 very low chance 3+" snow D6-7, to look back upon when whatever transpires. Title tightening up and downgrade update at 537AM/20. Verification attached for a failed event- useless thread. Numerous traces of sleet -snow-rain mix I84 into NNJ 3P/22-9A/23 but modeled short waves remained separate with one tracking across se Canada and the other actually trailed and dropped down through the Carolines. Was over early per the poster comments.

With so many awesome pictures posted in our forum from the storms this week, I wanted to get a thread going to share here.

I'll try to kick this off with an image from England in the 1300s: I'm hoping that's Boreas blowing in some cold winds under a storm cloud in the top right corner.

This post is at the seeming urging of multiple models this weekend offering a period of snow to the NYC subforum. Presuming it occurs, it could begin late Thursday the 18th, or it could linger into early Saturday the 20th. The coldest air of the season so far in NYC, may follow on gusty northwest winds next weekend, the 20th-21st. There doesn't seem to be anything definitive per this Jan 14th issuance, except that a period of snow is expected for at least a portion of NYC subforum on Friday with below normal temps. It's a strong positive tilt trough that approaches from the Great Lakes-Ohio Valley late this coming week. Attached the 12z/14 GEFS 500 MB mean left panel and 500 MB ensemble membership right panel. The NWS Sunday 'day' shift ensemble chance of 1/4" or greater snow-ice is attached as well as the 12z/14 EPS 24 hour positive snow accumulation ensembles ending around midnight Friday night. The 18z/14 GEFS was lighter for the same period so I extended the 24 hour positive snow depth ending time to sunrise Saturday whereas the CMCE was faster with the snow so I ended it 00z/20. Overall this Dec-Jan winter, it is my impression the GEFS tends to be conservative forecasting snow, the CMCE more liberal with more abundant qpf as well. I may have to add rain in the tags for the coasts as we draw closer to the proposed thread day... for now the colder solution was favored but uncertainty exists. Title addition 1/17/24 503AM: Event OBS. Tags: added rain/snow mix.

Attached are two 24 hour EPS graphics from the 12z/10 cycle that are significant for D6-7. The CMCE and GEFS are much less of snow risk for the northeast USA, so far. This thread is started because of the several consecutive cycles, although variable placement, EPS persistent snow threat for the I84 or I95 corridor, and it's possible snowfall outcome for NYC. Also is attached the 19z/10n Blend of Models from the NWS as a sketchy idea for I95. Reminders: The CMCE and GEFS are weak with the snow risk. Tags may be adjusted in a few days as it becomes clear whether our NYC subforum only gets a short period of snow/flurries in the wake of a strong windy cold frontal passage with single number-teens wind chill by Wednesday morning, or we realize a nice coastal wave of low pressure that produces hazardous wintry weather for the majority of the NYC subforum, then followed by a shot of the wind driven cold. This system is not as clear cut at D6-7 as previous storm threads in Dec-Jan, so uncertainty exists. [Typo on headline Thread. updated 854PM/10]

WWA up for the CWA - KYW traffic report earlier this morning had noted several times that it had been snowing down in Baltimore and that was causing some road issues there. Currently 24 here in NW Philly with dp a desert-like 6.

The modeled next powerful storm into the Great Lakes region should add around another inch of rain in 6-12 hours Friday night, possibly causing renewed urban, basement and small stream flooding and probably extending on-going mainstem flooding in the NYCsubforum through the weekend. Maximum south-southeast coastal gusts possibly capped around 50 MPH along the shore Friday night but when the storm gets into Canada, backside westerly gusts might hit 50 MPH anywhere in the NYC subforum for brief periods of time later Saturday into Sunday. So some power outages are possible. Coastal flooding does not appear to be a large threat. Snow-sleet-freezing rain is anticipated at the start Friday afternoon-evening along the I84 corridor bordering the northwest portion of NYC subforum with "possible" short duration amounts generally 1/2-2" mainly in the high terrain above roughly 1000 feet. I84 corridor valleys, probably little or no accumulation. Max rainfall from this storm maybe ~2'? This thread will also serve as the OBS thread for this anticipated event.

The above hopefully encapsulates the likelihood of two upcoming significant east coast storms. Changes will occur from the some of the attached supporting graphics but we're in line for more significant weather and I'm sort of concerned about flood potential. This time maybe wet snowfall NYC.? Please consider limiting NYC snow enthusiasm with the stats attached from Don, at least until we get Jan 4-5 (if snow is still in the possibilities). It is hoped the Bluewave produced lack of 2" snowfall at CP can be put to bed, but it's possible that next Sundays probable wintry event will shift a little more inland with rain dominating along the coast. The event for the 10th could be brief snow or ice to heavy rain and snow melt, presuming we accumulate anywhere close to the attached 00z/31 EPS prob of 4" axis. Wind damage graphic via the EPS for the 10th... expectations are more of an e-ne wind (nor'easter we hope) for the 7th with gust potential 40-50 MPH along the coast and maybe minor coastal flooding (tide cycles are LOW for this storm). The event around the 10th "may" have stronger winds gusts vicinity 60MPH along the coast and a better chance of coastal flooding (tide cycles 10" higher to start). Power outages possible but impossible to predict without 24 hour confidence on wind gusts/qpf amounts/ptype/temp if and when it snows. This thread was started since I think there is general interest in snow, also flood potential for this weather interested forum. I may comment once/day but it's all yours. OBS for the 6th-7th will go in here. For whatever occurs the 10th...may have to separate out the OBS in a supplemental thread late 9th, but that's 10 days away and at least a portion of these ensemble expectations may be less than out looked through the 00z/31 cycle and therefore less impact and more routine. No guarantees here but definitely worth monitoring. Edited title 1156AM-Jan 6 to include obs and tags added obs and sleet. Edited title 645 AM Jan 8 iso include OBS for Jan 9-10 and removed the ? behind damaging wind.

Most of our long range looks are well into December now. Hopefully we can have a better winter than last year, which was an all-time worst here. The first week of the month looks to be near normal temp wise and probably drier than normal, even though CPC favors AN precip.

Carver's spoke of creating an early winter spec thread recently, and after another day in the 70s in August, I figured why not get the ball rolling. This for general long term talk about the potential winter patterns, etc. Right now, the EPO has went negative, it's at -12, and is in the East descending phase. In 2021-22 it fell into the negative in May and stayed deeply negative until the following May. So it should descend throughout winter. Below, average pressure anomalies over NH when the QBO is negative. Higher in the PNA/NAO region, lower over the south and eastern U.S. (These maps may initially appear confusing, since they greens are positive numbers. It just means that the they are higher by those margins over those areas or lower by those margins over those areas when there isn't a -QBO in place. Just keep in mind green = lower pressure and cooler temps during -QBO years) There tends to be higher pressure over the North Pole during a -QBO, which results in a weaker jet stream/polar vortex on average. During an El Nino/-QBO combination our forum region is slightly BN for temps DJF and pressures are quite a bit lower across the Southeast (our storm track). The map doesn't look unlike this for temps, but BN for Texas, Tennessee, North Carolina and up the east coast is more prominent than the CPC map here. Especially over Texas.

The downward slide into winter begins. Post your Obs/Discussions here.

All mid to long term discussion is in met fall at this point. This should carry us until Nov 20th or so, when December/winter starts showing up on models. Blah weather to begin fall, if the GFS is correct. Lingering heat that clings on like an unwelcome in-law on it. If the GFS is being it's normal, likely ridiculous self, we may be lucky. The Canadian says "what heat?" over the next 10 days.

Thought this one was fired up already since fall started a couple weeks ago. Just realized I was posting in the spring/summer thread still. Of course love to keep winter storm obs in the storm threads for later reading all in a single thread. But these are good for daily obs or notable events outside the storm threads. That said, I hit 47.3 this morning after a day time high of 69 degrees yesterday. Pretty similar temperatures for this same period in September 2015 when we got a nice first cold front of the season on 9/13 and had two days of great temps. It was 70/46 on 9/13 and 66/43 on 9/14 that year. Current temp is 71 degrees here, sunny. It was 72 about an hour ago but dropped back a little. In 2015 we never got back above the 84ish range after the front. It had been in the upper 80s for days on end leading into it.

There is likely going to be some warmth during mid-month - and maybe extreme. So, I am not starting this thread w/ any sugar coating. That said, models are sniffing out a cold shot to start this month which wasn't seen on some modeling even 24 hours ago. In life we go one day at a time. Let us not borrow the troubles of tomorrow until they arrive. 12z Yesterday and 12z today of the GEFS.

With some decent consensus between the GFS/NAM/CMC/EURO for flakes, maybe even measurable snow Saturday, figured I’d spread this out from discussion on our longer range looks. Sorry if this thread kills things entirely!

Looks like the first ten days or so will be warm, but that is not a lock. After three years of La Nina, we are probably closing-in on our last few months of this ENSO phase. La Nina's often yield warm Januarys, but something makes me think we buck the trend this month for at least part of the month. I have January as AN in my seasonal forecast, but a portion of the last 20 days of the month could be quite cold. I still expect some wild swings this winter w/ a base warm pattern and very cold interludes.