Relatively routine hazardous icing event I84 corridor mainly 1/1 and terrain above 1000 feet in particular.

[wdrag]

1/1 530AM Update: No significant change to the previous days messaging as noted below. Will add graphics to the latest post on p5. 

12/31 5AM Update: Little change from 12/30 603AM. Timing the start probably closer to the end of the ranges listed below, and emphasis for event beyond 3 hours is for the  terrain above 1000 feet. Snow, if any,  is less than 1" far northern edge of the forum, but sleet a possibility at the start in many areas. Probably worth tracking wet bulbs for this mainly at night event... think it suggests longer duration than meets the eye but the model dew point forecast may be too low. mPING will be of value.  Valleys, below 700 feet should have mainly wet roads after initial treatment and possibly the same higher up.  Worthy of caution and best we can do for marginal thermal profiles.  It should be noted that the NAM3K is trying to hold onto icing into the morning daylight hours highest elevations northern fringe of the NYC subforum - that may be an outlier, but not impossible. 

12/30 603AM Update: QPF down to .4-.8" for the forum for this event, and slowed a touch from yesterday.  Otherwise my concerns have little change from yesterdays 12/29 reassessment. This event will be a problem for the Poconos, interior se NYS high terrain with less qpf and impacts for the CT River Valley, but otherwise I84 high terrain should do okay. Sleet or freezing rain develops ne PA/nw NJ (maybe even down to I78) between 2-5PM and probably changes to non freezing rain during the night all, except elevations above 1500 feet where it may be freezing rain throughout. Since temperatures will be briefly above freezing prior to the event - midday Friday, icing on treated roads, after initial treatment will probably be limited, but otherwise all untreated surfaces become icy, especially after sundown. Expect a slight glaze on untreated surfaces near I-78 (Easton PA, Warren County NJ) ranging up to about 2 tenths of inch above 1000 feet northern Sussex County NJ (northern Wantage-High Point-Vernon) and ne PA. Meanwhile, N CT and interior MA should see sleet and snow develop between 5-8PM Friday, with a possible 1-2 inches before a change to ice, and then probably non freezing rain after 2 AM Saturday. Glaze there a little less than ne PA.  CT River Valley should see less impact due to near freezing temps. Boston: a little sleet/snow Friday evening then changes to rain or freezing rain during the night with much less certainty there on details. After sunrise Saturday, melting and improved weather!  We'll start getting some short range ensemble guidance tomorrow morning that will help us detail impacts. Hopefully this is a reasonable assessment as presented above. I prefer not to comment again on this event til Thursday morning as model variations may skew me one way or the other, too soon. 

12/29 530AM update: Decreased model qpf has dropped the impact level to what i think is a relatively routine 3/4" to 1.5" qpf event with sleet and glaze expected I84 corridor.  I dropped the front end concern on the 31st since it's minor, maybe a bit of snow or ice mix in the higher Poconos with the CFP. I'll begin a new topic for 1/3 late today if its still modeled by the GFS para and EC but prefer GGEM on board.That one would be very low confidence for what could be a grazing fast developing nor'easter w snow somewhere close to NYC??? Again low confidence but on GFS parallel and EC OP. Edited this pgh at 549A got delay new topic for 1/3. 

Timing for renewed precipitation seems to have delayed about 6 hours from prior modeling with 6-10 hours of ice anticipated for the I84 high terrain, beginning midday the first in the Poconos-far nw NJ-se NYS and late day CT/MA portion. Treated surfaces may be just wet during the daylight hours, but if it's several hours of sleet, then a bit of a different story. Glaze, probably 1/4" or less even if .75" freezing rain occurs. This will need much more refinement as we move into mesoscale-fram analysis. So I see this as an advisory hazard NY afternoon/evening for at least parts of I84. Unsure if temps can remain at or below freezing long enough to have glaze approach 1/2" in our I84 corridor high terrain.  As of this time, would not favor that higher end impact but worthy of monitoring. Flooding rain is probably no longer a risk,due to less qpf.  However, those who had sump pumps running for the 12/24 event, may see a resumption-not that this is a big deal, provided they are operational,  but in our area of nw NJ, it's unusual for this to occur in December. No new graphics today. 

--

12/28 535 AM Update:  5 days in advance so I may be too detailed and too cold in my thinking-therefore uncertainty. Also the overnight WPC guidance does not support my concern. So caution on the following: Don't bet on it,  but if you wish, keep it in mind. 

As everyone can see via the modeling the big warm windy event days ago modeled for 1/1 is gone and snow/sleet/freezing rain has increasingly been added to the mix near I80 northward ,with what I think is a likely hazardous advisory situation for the I84 corridor, especially Poconos-se NYS NY Day morning-midday.  For now I left HIGH impact in the headline because I've seen these situations with sw 850MB WAA flow-not scour out whatever 32F airmass creeps into the interior, and the supposed change to non freezing rain does not occur or is delayed 6-12 hours.  This whole event may become a routine 1-3" qpf event with an advisory event for the interior and if it becomes completely evident, I'll withdraw HIGH impact. This situation doesn't mean the temp cannot burst into the 40s /low 50s early on January 2, but I'm cautioning on literally believing an above freezing forecast, especially from MOS guidance, IF and only IF, the subfreezing airmass does sift back down into our area NY eve.  QPF as per WPC--still outlooking 1-2" and I think there is potential for 3", wherever the max qpf axis, which seems to have slipped south to PA/NJ/LI.  Whether this causes any flooding of rivers is unknown, but it does not look major and it's possible that the icing will lock up or delay-spread out runoff a bit in the interior, so the river response is contained within the river banks. It is good to know that that qpf in DEC has been 150% of normal with about 2" in 24 hours, threatening to cause some river flooding, and renew sump pump action in homes where sump pumps were still active yesterday. 

Big wind is no longer a threat.  

So the questions: how much sleet and freezing rain for the interior, inclusive of nw NJ, ne PA, on up the I84 corridor to Worcester, MA.  The precip comes in waves, with the primary event NY Day. I am expecting a slippery-hazardous morning across ne PA/nw NJ developing northeastward into interior CT/MA but particularly ne PA/nw NJ on all untreated surfaces. Roads during the daylight hours, after initial treatment probably just wet but this ever changing situation should be monitored.  Glaze amounts of 1 tench inch foreseen for parts of the interior high terrain, maybe ~1/4" if my concern is correct about temps not warming above freezing until the primary burst of heavier qpf has passed out to sea late on the first or early Jan 2. I didn't speak of snow amounts but there could be some coatings of snow included on NY Day morning at the beginning of the primary event, if an even colder scenario evolves. Again, remember, WPC has no outlook for 1/4" of frozen water equivalent here (but which I dont think includes glaze). 00z/28 GEFS has an over 50% chance of glaze in the interior n of I80. 

Then there's the trailer short wave for later the 2nd into the 3rd....I think it needs to be monitored for an eventual colder wintry impact here...probably light,  IF ANYTHING at all this far north. 

Finally: for NY eve celebrants and pandemic considerations do not recommend , but if you're outside on the lawn for some reason, there could be an interlude of no precipitation near midnight (between the earlier in the afternoon cold frontal passage and onset of the NY morning qpf). 

Please be aware that I saw the 00z/28 GFS para which finally has 1+ qpf here (delayed a few cycles from the GFS) but it's temps are warm with no ice threat here in our area- It's a warm option but I think highly unlikely.

Graphics are the NAEFS 52 member sfc pattern (NO EPS in this mix, just GGEM ens and GEFS), the GEFS prob of icing, the FFG for 6 hour amounts and our Dec 2020 % above normal qpf. 

------

12/27 620AM Update.  Evolution of this topic continues as 12/29 is gone (except a few I-84 snow showers) . This includes dropping graphics for 12/29 as 12/21ish modeling completely missed this non-event for our area.  New graphics will be added Monday morning as modeling consensus grows for 12/31-1/2. 

This system for 12/31 and especially Jan 1-2 is trending toward broad high impacts, ranging from at least a period of advisory or warning ice and possibly advisory snow for the I84 corridor (high terrain above 1000 feet especially), to a multiple slow response river flood response (minor to moderate flood stages in our NYC forum), depending on new qpf (not including any remaining snowmelt) and how much of that qpf is ice and remains ice through Jan 2. In my mind this is complex. 

Scenario is a weak northern stream short wave passage on the 31st dragging a cold front through the NYC forum accompanied by rain, (possibly a little snow or ice I84 high terrain). It's possible NY eve celebrations will be precip free for a few hours? Meanwhile the southern stream short wave may split into two pieces, leaving something behind for the 3rd, but of little or no impact here. It's the preceding newd lift out of the Gulf States short wave that is going to be a potential high impact player here on the first and second of January. How this plays out is uncertain but clearly the 00z/27 GFS and EC op have trended colder while the run to run inconsistency of the UK and ICON continues. In essence though...it appears to me that a warm front to our south will provide the necessary lift with a southerly jet of 50kt (PWAT 1") impinging on it,  to dump heavy qpf on a large part of the NYC forum, on the order of 1-3". I am tending to lean widespread heavier than 1.5". That front may eventually lift north of LI/I80 but I think there is a chance of an occlusion and waves of low pressure moving out to the s of LI. That leaves potential for heavy icing parts of I84. So, tbd, if this read is generally reasonable but worthy of comment-updates. Wind:  50+MPH gusts...still possible for LI/NJ but less likely.  Have left the Topic TAGS as is, but updated the topic headline.  Basically done w this for 24 hours. Thank you for your updates-impressions of the modeling. 

--

12/26 612 AM edit.  Ensembles (GEFS, EPS, NAEFS) favor a primarily warm wet windy solution for early Friday-NY Day, but thereafter there is some uncertainty.  UKMET and to some extent the 06z/26 GFS are suggesting a separation of short waves across the eastern USA with a trailing southern stream significant short wave rotating northeastward as the NY eve cold front is draped somewhere across our forum, possibly even down to the Mason-Dixon line. The UKMET op is an erratic model swinging wildly at times and at 120 hours, am a little reluctant to put much stock in its suggestion. Still, other models are suggesting a more sw wind at 850MB into early NY Day which tells me that the northern stream short wave is not initially digging into the Ohio Valley this time, as per this most recent damage/flood event.  However!!! this is a low probability chance but one that I do not want to discard, yet, till I see all models wet-warm-windy with little or no snow behind it, across I-84.

That leaves us with a 1-2" qpf event mainly 6PM NY eve to 3PM NY Day, most of it probably in a 6-9 hour period. This would exacerbate-extend the already projected minor-moderate flooding on some of the NYC sub forum rivers, and probably result in even higher stages and a few more streams-rivers into flood. Regarding wind- recent model cycles are offering a short period of 50-55 MPH southerly gusts NY eve night or thereabouts. GEFS and EPS 850MB winds after already over 50 knots. Operational models suggest 850MB winds 80 knots. This event may end up 5-10 MPH less than that of early 12/25,  but it could be a bit warmer (more sw wind at 850MB than due south) in some areas, so that downward momentum transfer is slightly better (less of an isothermal boundary layer). With ground already softened by recent rains and snowmelt, and largely unfrozen by the time of the coming Thursday-Friday event, this could yet again result in power outages from limbs and trees down. So, some things to ponder, at least for me.

I'll adjust this topic by sunrise Monday, once the event evolution becomes solidly wet windy. 

---

 

12/23/20 538AM edit:   December 29 probably won't happen as snow I84 even though the EC EPS is coming around to the GEFS digging trough. Probably a little too late to prevent rain, instead of snow for I84-though I haven't given up hope for slower and further south on the digging short wave but for now,  this first date option of the 29th has less chance of working out as snow. Also, for now, the less digging scenario now generally advertised means the event is faster, more likely occurring mainly on Monday the 28th. 

1/1/21  An event is coming late NY Eve or NY Day.  It too may be rain but for now has a little greater chance of snow, especially interior. No time to assess as 12/24-25 is my primary consideration. 

--- previous below from Monday 12/21

 

The normal amounts of uncertainty exists for an 8-12 outlook, but because of the general blockiness near Greenland and the modeled wave train from the Pacific into the southern  USA the next two weeks, suspect there is an above normal (vs climatology) chance for 1 or 2 coastal storm events near the mid Atlantic coast.  The 200MB jet is almost constantly between 30-40N from the Pacific across the United States, favorable for southern stream short waves and above normal precipitation.  Our temperature climatology is cooling day by day so that even above normal temperatures do not rule out wintry precipitation.  There will be opportunity for northern stream short waves to interact  with the southern stream, but whether they phase is highly questionable. Modeling continues the -NAO and +PNA for at least another two weeks, and the MJO does not appear to be major player in the stable Nino 3.4 assessed LaNina background state, though it's behavior to date has been more wintry than expected using the current accepted science of winter predictability.

Some modeling has been trying at various times to develop a strong coastal around the dates listed.  Whether it's Dec 29,  or Jan 1?, one of these should become significant.  Please allow for 1 day time error either side of the 29th and 1/1.   My guess this is an I84 centered 3+" snow event(s) but if blocking increases after the 12/25 trough moves out of the northeast, that would sag the cold enough snow thermal profiles southward to I95 (even w NC/far n GA???).

I've added the 00z/21 NAEFS outlook for qpf, surface temp, sfc pressure the day before (nice high in southern Canada) and day of (nice low off the coast with variability options northwest)  and 1000-500MB thickness the day before, as a starter. Also the operationally modeled single member snow depth at its thinnest point around 12/25, before it potentially expands again east and south. That may assist redevelopment of surface lows to the south of the snow pack. 

This topic will update as time allows and anything becomes more definitive, including upgrades in tags, should it become necessary.  For now, playing it as a moderate event on one of these two dates (keep it somewhat close to climo), with option for something more important to cover at least a part of the NYC forum by late 1/1. 1038A/2

[NEG NAO]

[NEG NAO]

[NEG NAO]

Too Warm as of now

[NEG NAO]

[NEG NAO]

as you can see from all of the OP runs of the various 12Z models I just posted because of the first batch of cold air escaping along the coast after Christmas there is no cold air in place for the redeveloping coastal low and it then hugs the coast coming north resulting in warm ocean air along the coastal plain in NYC metro need this setup to change in order to get a snowstorm early next week IMO. 

[White Gorilla]

25 minutes ago, NEG NAO said:

as you can see from all of the OP runs of the various 12Z models I just posted because of the first batch of cold air escaping along the coast after Christmas there is no cold air in place for the redeveloping coastal low and it then hugs the coast coming north resulting in warm ocean air along the coastal plain in NYC metro need this setup to change in order to get a snowstorm early next week IMO. 

Plenty of time for shifts 

[NEG NAO]

Just now, White Gorilla said:

Plenty of time for shifts 

Agreed

 

[NEG NAO]

[wdrag]

My once/day update to allow the models to be variable eventually coming to a consensus on both coming events. I've seen a few posts and agree.  

29th: I don't think LI/NYC I80 south can get much if any snow out of the event late 28th and 29th. I think snowfall, whatever it is, is restricted to the I84 corridor with the se edge maybe 20 miles south of I84.  How much, yet to be determined but a WET sticky snowfall seems more probable than a crystalline cold. I've added the 00z/22 NAEFS which shows a low in the eastern Great Lakes with a receded High over Nova Scotia, which eventually has a secondary s of LI merge and potentially rapidly deepen near Cape Cod on the 29th (00z/22 GEFS is interesting on the negative tilt eased deepening of the 500MB trough toward CC). The 0C sfc temp is near I84 to  late on the 28th (last image) while the 1000-500MB thickness at 00z/29 (first image) is surprisingly cool. So that is my reasoning to keep faithful to an I84 3+" event with much less chance of snow this storm for NYC.  Thinking could change in the future but for now, since models are all over the place, it is probably smart to choose a wetter scenario for NYC and not overpromise there. 

NY Day may be another story... I think snow is in the mix and to me it looks to be a better chance of some sort of lead WAA snow thump, before a possible change to rain for our forum. Just tooo far in advance for me to offer anything else, confidently. 558A/22

 

[snowman19]

Unless there are some big changes soon, I don’t think we can be real optimistic about next week for a major snowstorm 

[snowman19]

1 hour ago, wdrag said:

My once/day update to allow the models to be variable eventually coming to a consensus on both coming events. I've seen a few posts and agree.  

29th: I don't think LI/NYC I80 south can get much if any snow out of the event late 28th and 29th. I think snowfall, whatever it is, is restricted to the I84 corridor with the se edge maybe 20 miles south of I84.  How much, yet to be determined but a WET sticky snowfall seems more probable than a crystalline cold. I've added the 00z/22 NAEFS which shows a low in the eastern Great Lakes with a receded High over Nova Scotia, which eventually has a secondary s of LI merge and potentially rapidly deepen near Cape Cod on the 29th (00z/22 GEFS is interesting on the negative tilt eased deepening of the 500MB trough toward CC). The 0C sfc temp is near I84 to  late on the 28th (last image) while the 1000-500MB thickness at 00z/29 (first image) is surprisingly cool. So that is my reasoning to keep faithful to an I84 3+" event with much less chance of snow this storm for NYC.  Thinking could change in the future but for now, since models are all over the place, it is probably smart to choose a wetter scenario for NYC and not overpromise there. 

NY Day may be another story... I think snow is in the mix and to me it looks to be a better chance of some sort of lead WAA snow thump, before a possible change to rain for our forum. Just tooo far in advance for me to offer anything else, confidently. 558A/22

 

Agree with you. Next week looks real doubtful for a snowstorm in the metro area, even New Years Day. New England may be a different story, especially central and northern New England. 

[wdrag]

What do you think about this digging?  I see wet snow...  but maybe I'm biased to the NAEFS and naturally biased to snow. This is starting to show confluence...a bit too far north...but I like how the GEFS is trying to carve out a hole in New England.  Might be too little too late but this is still 7 days out... plenty of time to change. 06z GEFS 500MB members and mean. 

[NEG NAO]

Early next weeks event the 28th - 29th has a very low chance as of now for frozen precip in most of NYC metro IMO - The 31st - 1st event is the one to watch as the block is more substantial and whatever storm comes down the pike is forced south and east of NYC Metro as illustrated on the 0Z EURO OP

[SnoSki14]

Looks like they'll be a ton of potential with consistent blocking up north and pacific shortwaves coming through every few days. 

Not all of them may be snow or produce but odds are greater than normal plus climo starts to become a lot more favorable for us. 

[eduggs]

57 minutes ago, wdrag said:

What do you think about this digging?  I see wet snow...  but maybe I'm biased to the NAEFS and naturally biased to snow. This is starting to show confluence...a bit too far north...but I like how the GEFS is trying to carve out a hole in New England.  Might be too little too late but this is still 7 days out... plenty of time to change. 06z GEFS 500MB members and mean. 

I see another New England snow event   Decent mean trof position, but I'd like to see more amplitude. Trying to keep the faith that something finally breaks right locally.

[EastonSN+]

21 minutes ago, NEG NAO said:

Early next weeks event the 28th - 29th has a very low chance as of now for frozen precip in most of NYC metro IMO - The 31st - 1st event is the one to watch as the block is more substantial and whatever storm comes down the pike is forced south and east of NYC Metro as illustrated on the 0Z EURO OP

Looks like a similar track to last storm. I would take it in a heartbeat.

[EastonSN+]

1 hour ago, wdrag said:

What do you think about this digging?  I see wet snow...  but maybe I'm biased to the NAEFS and naturally biased to snow. This is starting to show confluence...a bit too far north...but I like how the GEFS is trying to carve out a hole in New England.  Might be too little too late but this is still 7 days out... plenty of time to change. 06z GEFS 500MB members and mean. 

Thanks for posting here Walt!

Although next week's systems may rain, there seems to be a never ending train of systems. Also, blocking looks to continue according to CPC for the foreseeable future and looking at the MA thread it looks as though another polar vortex hit may occur early Jan.

Given the above and the fact that the tri state already scored a heavy snow event I like where this winter is heading! Hope you concur.

Thanks

[LibertyBell]

57 minutes ago, NEG NAO said:

Early next weeks event the 28th - 29th has a very low chance as of now for frozen precip in most of NYC metro IMO - The 31st - 1st event is the one to watch as the block is more substantial and whatever storm comes down the pike is forced south and east of NYC Metro as illustrated on the 0Z EURO OP

hmm I thought the next one would be a few days after new years?  I always get nervous when storms are spaced so close together....that usually doesn't work out.  

[LibertyBell]

3 hours ago, wdrag said:

My once/day update to allow the models to be variable eventually coming to a consensus on both coming events. I've seen a few posts and agree.  

29th: I don't think LI/NYC I80 south can get much if any snow out of the event late 28th and 29th. I think snowfall, whatever it is, is restricted to the I84 corridor with the se edge maybe 20 miles south of I84.  How much, yet to be determined but a WET sticky snowfall seems more probable than a crystalline cold. I've added the 00z/22 NAEFS which shows a low in the eastern Great Lakes with a receded High over Nova Scotia, which eventually has a secondary s of LI merge and potentially rapidly deepen near Cape Cod on the 29th (00z/22 GEFS is interesting on the negative tilt eased deepening of the 500MB trough toward CC). The 0C sfc temp is near I84 to  late on the 28th (last image) while the 1000-500MB thickness at 00z/29 (first image) is surprisingly cool. So that is my reasoning to keep faithful to an I84 3+" event with much less chance of snow this storm for NYC.  Thinking could change in the future but for now, since models are all over the place, it is probably smart to choose a wetter scenario for NYC and not overpromise there. 

NY Day may be another story... I think snow is in the mix and to me it looks to be a better chance of some sort of lead WAA snow thump, before a possible change to rain for our forum. Just tooo far in advance for me to offer anything else, confidently. 558A/22

 

Both are either rain or mix/change scenarios, I think the "real deal" will happen a few days after New Years.

 

[CPcantmeasuresnow]

Last nights 0Z CMC, fantasy stuff, but fun to look at, unless you live in eastern LI or Cape Cod and Boston.

[White Gorilla]

22 minutes ago, CPcantmeasuresnow said:

Last nights 0Z CMC, fantasy stuff, but fun to look at, unless you live in eastern LI or Cape Cod and Boston.

 

Fun to dream 

[wdrag]

12Z/22 EPS and GEFS for you to decide.  Just so you know the NAEFS continues colder and suggests a light to moderate snowfall for I84.  I don't have time for all the graphics but here's the difference between the 12z/22 EPS and GEFS.  Your call and you are welcome to professionally critique here any possible flaw-bias in my thinking.  Right now, all options are on the board. I am doubtful of a big windup low in the Great Lakes on the 28th. Instead a weaker low,  near L Erie with redevelopment s of LI, then a merger into a deepening low near the New England Coast on the afternoon of the 29th. If I am wrong, it will have been over reliance on the NAEFS 52 member ensemble vs the generally more highly regarded EPS , vs the sometimes maligned GEFS.  I'd like another 00z/23 cycle to show me that I've incorrectly relied upon a GGEM-GFS ensemble blend.  Blocking i realize is good but not ideal.  Again, you decide what is best in your own mind. 

[wdrag]

December 29 probably won't happen as snow I84, even though the EC EPS is coming around to the GEFS digging trough. Probably a little too late to prevent rain, instead of snow for I84-though I haven't given up hope for slower and further south on the digging short wave but for now,  this first date option of the 29th has less chance of working out as snow. Also, for now, the less digging scenario now generally advertised means the event is faster, more likely occurring mainly on Monday the 28th. 

1/1/21  An event is coming late NY Eve or NY Day.  It too may be rain but for now has a little greater chance of snow, especially interior. No time to assess as 12/24-25 is my primary consideration. 

[NEG NAO]

3 hours ago, wdrag said:

December 29 probably won't happen as snow I84, even though the EC EPS is coming around to the GEFS digging trough. Probably a little too late to prevent rain, instead of snow for I84-though I haven't given up hope for slower and further south on the digging short wave but for now,  this first date option of the 29th has less chance of working out as snow. Also, for now, the less digging scenario now generally advertised means the event is faster, more likely occurring mainly on Monday the 28th. 

1/1/21  An event is coming late NY Eve or NY Day.  It too may be rain but for now has a little greater chance of snow, especially interior. No time to assess as 12/24-25 is my primary consideration. 

Does this reinforce the idea of not trusting some models past a certain number of days ?? even though the AO, NAO and PNA  were and still are favorable for winter weather around these parts next week BUT how about the EPO ? Can't seem to find anymore graphics to show the EPO since I heard the NWS took them away ??? Also some  in the weather community were so certain that the early next week system would not be able to cut because of the block setting up and would be forced to redevelop south of us . What contributed to the system  being able to cut and not redevelop ???? Or is this still a possibility at some point next week ???? 

[wdrag]

1 hour ago, NEG NAO said:

Does this reinforce the idea of not trusting some models past a certain number of days ?? even though the AO, NAO and PNA  were and still are favorable for winter weather around these parts next week BUT how about the EPO ? Can't seem to find anymore graphics to show the EPO since I heard the NWS took them away ??? Also some  in the weather community were so certain that the early next week system would not be able to cut because of the block setting up and would be forced to redevelop south of us . What contributed to the system  being able to cut and not redevelop ???? Or is this still a possibility at some point next week ???? 

Don't have an easy answer...  I trust models to 5 or 6 days except marginal or minor situations where there is a lot of variability. I trust patterns to as much as 11 days, especially if high amplitude stability.  

My hope for 12/29 is 20% or 30% at this time based on the modeling through 06z/23.  Pattern favorable but not the 50/50 LOW lock!  Other factors probably come into play--- some for which i'm not well skilled.  Without a firm confluence zone in the St Lawrence Valley to northern NYS, or a 50/50 low,  cutters are always possible. If the waa into the Great Lakes weakens and heads more east in future runs, then I84 comes back on the board.  For now, letting it rest This is 5-6 days off and short wave interactions might force a somewhat different scenario. 

[wdrag]

This thread is modeled as a loser per modeling through 00z/24. The 29th is probably coming through as a cold front with a few showers on the 28th with possibly a little useless slight wet snow highest I84 terrain before wash away by a shower.  The first of January is still on the boards, though it looks too warm, at least initially. That one is looking more robust qpf wise and surprisingly WPC has a halfway decent chance of freezing rain or snow down toward Allentown late NY eve. I won't add the D7 graphic here - time constraints, but will revisit Christmas morning. 

We just need separation of northern-southern streams on both dates and a more southern latitude track of the southern stream short wave, which for now, does not look promising. 536A/24 

 

[wdrag]

Merry Christmas 2020! I will revisit this topic either late this afternoon or Saturday morning for a change in title featuring Jan 1--- but only if the EC is consistent at 55 + MPH gusts.  Anything less, becomes our routine event.  Something is coming Dec 31-Jan 2 and it may be more complex than what we see right now ranging from some sort of wind-flood event to a system with a very low prob of some wet snow.  I kind of want to be careful about a topic adjustment, if any.  For now consider the significant snow threat non existent though the GEFS,maybe by climo or whatever, has something for at least I84 on the first. 

[hudsonvalley21]

3 hours ago, wdrag said:

Merry Christmas 2020! I will revisit this topic either late this afternoon or Saturday morning for a change in title featuring Jan 1--- but only if the EC is consistent at 55 + MPH gusts.  Anything less, becomes our routine event.  Something is coming Dec 31-Jan 2 and it may be more complex than what we see right now ranging from some sort of wind-flood event to a system with a very low prob of some wet snow.  I kind of want to be careful about a topic adjustment, if any.  For now consider the significant snow threat non existent though the GEFS,maybe by climo or whatever, has something for at least I84 on the first. 

Merry Christmas to you and yours.

[wdrag]

Hi everyone,

FFG will be down quite a bit for the 12/31-1/2/21 event.  Wind guidance currently favors 5 MPH less than what we experienced this morning. Want to see 00z/26 model cycle, in particular if any separation between the northern and possibly dragging southern stream short wave, which then would make things considerably more interesting for wintry precip.  As of now, continue the warmer wetter windy idea with no model support for my wintry concern. So, tomorrow morning, if it looks solidly wet,  I'll work on changing this thread (preserving the original poor 12/29, 1/1 wintry impressions). 

Happy Holidays!

Walt