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wdrag

Monday Feb 15 - midday Feb 16, 2021 Significant Winter Ice Event interior

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859AM/14:  The GGEM/RGEM are going to win this Monday battle of no precip vs freezing precip occurring. The 06z EC and lesser so GFS, are capitulating to a two part event beginning Monday morning.  The 06Z EC gets this going pretty fast before dawn Monday.  

I'll get the OBS thread going around 9PM tonight... and to keep it simple, will combine both the front end Monday morning with the primary Monday afternoon-Tuesday morning event.  Problems for us will be developing.  Added NWS 09z/14 ensembles for .10 glaze and .25" glaze (threshold to begin power outages, the grow much larger when 0.50 glaze ) and added the 5AM view of NWS snowfall expected by Tuesday evening.  

 

513 AM/14 placeholder- will fully update by 915A today. It's Valentines Day. Hope all is going well. Rain LI for this event- some of it heavy. Topic headline changed a bit to further add some detail. 

Otherwise, Certainly an Advisory event coming inside of I-95 Monday-Tuesday morning. There is a low probability of Watch-Warning verification ne PA/nwNJ/se NYS and N CT part of the forum for ice but questionalbe we can get to 1/2" damaging ice qualifying for a warning.  I suspect there will be some damage and power outages if the furnace (borrowed from others on the forum) RGEM continues this cold but possibly below warning criteria.  The GFS is warm tho its 06z version looks slightly colder. The GFSV16 is colder than it's soon outgoing GFS op and it holds to the 0.2-0.4" FRAM ice accretion for the event, which begins sometime Monday and ends midday Tuesday.  I still don't have a good feel for Monday but modeling is trending to agree with prior versions(from at least back to 00z/13) of the GGEM/RGEM that our untreated surfaces problems begin Monday during the day, especially afternoon.  Need more time to assess.    My feeling is the leftover advisory from this morning complicated multiple confusing headlines for the NWS and the idea, take one event at a time.  More later with graphics. 

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745AM Saturday the 13th update:  

Good Saturday morning everyone - Feb 13.  Adjusted topic headline slightly to include potential for an ice storm across the high terrain, and timing, tho w uncertainty. This will more easily allow an eventual OBS thread bridge back to Monday afternoon, if needed that early. 
 
The GGEM/RGEM for Monday: I dont have an answer.  Some modeling yes, others NO.  Something to watch. Right now am advising friends its okay to travel midday Monday along I84 due to milder temps near freezing but this 00z-06z/13 GGEM/RGEM is a concern. 
 
Late Monday the 15th-Tue the 16th: a significant advisable-warnable extensive ice event coming to the I84 corridor where it may transition to snow. This is mostly ice and I foresee-expect extensive delays Tuesday morning, and some cancels. Unsure whether this is mostly sleet or combined sleet-freezing rain. Might even have a bit of snow with this, just north of I84 where I could see several inches in this mix. Just too much uncertainty for me to know.
 
For NYC-I95 so problematic am not going to attempt to detail... it varies by the modeling and cycle but looks like a transition to rain LI and NJ coast for sure on the 16th.  BUT... stay tuned if wind stays mostly NNE.  
 
What I think I'm seeing is the GGEM-G=RGEM  drift colder early this coming week.  
 
All yours... will be back around 5P to this thread.  
 
Added one NWS 09z/13 NWS ensemble graphic: the risk of icing Monday, especially at night.  This tells me a problem is coming.
 
 

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854AM Friday the 12th: Have no changes to the Thursday 11th updated post.  Added the WPC overnight prob for 3"+ of snow which favors north of Li and lots of zr/ip/r for LI and the NJ coast. 

 

830AM Thursday the 11th:  Have not added ice storm for the 18th and extended the thread into the 19th, but will probably do that tomorrow morning the 12th after 1 more day of cycles. I think ice storm warning is a possibility for the 18th-19th in parts of the higher terrain I84 corridor but far too early to highlight, since it's also possible that the modeling is too warm-allowing for more sleet/snow - future modeling to determine.  Right now it's complex with predominant ice (ice to rain LI) but may end as snow everywhere?  So far no sign of a closed low slowing things any further so have to go with what we see.  NAEFS turns interestingly cold in the 1000-500MBthickness to wrap this event up on the 19th.

Late 15-early 17... i like a colder solution than generally modeled tho not necessarily buying into the 06z GFS op.  I think NYC will see some snow acc but ice could eventually get involved NJ/LI. Modeling is pretty cold at the surface. This will be a moderate event. Advisory event or possibly even a warning event for some of the subforum. 

Added NWS overnight prob of 3+" of snow Tuesday the 16th..favoring I84. Also the 06z/11 GEFS with the blue line the op run and the black the mean. You see ther spread in membership.  Includes qpf, 850T, 2meter T and snowfall. I'd play the snowfall low key right now, so much spread mainly due to ptype.  Definitely warmer on the 18th-19th. 

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255 PM Wednesday (10th update):  No overall change.  Think the 14th is probably all snow or just a touch of rain extreme southeast? By 6PM Valentines night, I think the Feb totals in NYC will have increased 1.5-4" from this mornings 19.9 value...to place the Feb NYC ranking near  #11.  No guarantees but I think the Valentines (late 13th-14th) event is mostly snow and generally light. I still like 1-4" as a basic starting point. Did see the GFS trying to split NYC with nothing, but  relying a little more on the GGEM and ensembles for this assessment.

Tuesday the 16th: I know there is potential for ice all the way up to I84... but the front end thump of snow should be decent and I could see this event remaining all snow far nw NJ to nw CT and 6+ continues to be what I'm thinking, at least along and north of I84. Axis of heaviest snow ice is debatable as is northward ice encroachment but overall this looks to be a fairly cold event.  

Thursday the 18th into early 19th:  Challenging... at first glance looks warm, but if you look at the GEFS and some previous operational runs, one can envision a closed 500MB low developing in TN/MO/ARK and then from there??? slower, so that we have a somewhat colder subdued event the 18th and may have to wait for a big qpf event til late 19th or 20th (outside this thread), instead of as progressive as now generally modeled.  One question i would have... would that closed low be able to translate newd the eastern Great Lakes or... across the Mid Atlantic?  Lots of speculation on my part, and maybe it just comes out bodily as now implied (18-19)? Just bringing up the complexities I can see. No matter, more ice/snow/rain...take your pick and for now I would have to favor rain LI/coastal NJ or brief snow-ice to rain there while, interior?? maybe lots of ice?

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808A Wednesday (10th) update:  No overall change. This is the thread that dove tails with the 11th-13th thread. The 13th event, however it evolves will probably end up with a decent amount of snow on the morning of the 14th and so am continuing the widespread 1-4" idea (even LI-NAEFS rather cold there). Modeling has trended a little colder (blocking) but not necessarily a big coastal, but some WAA snow.  16th: looking more significant than the 14th.  I think it's still cold enough for a front end thump of snow. Ice/rain may eventually get involved NJ/LI but where all snow, seems like a decent chance of 6+, probably I84 corridor, but even LI has a chance of at least a light snowfall prior to a phase change.  18th: may be the biggest qpf event of all 3 with a more southerly track of the trough and a GMEX scoop of RH (18th-early 19th?)BUT, that one seems somewhat warmer... so more problematic for maintaining entire wintry elements, but possible.  The good news: IFFFFF this one is pretty big and more of a southern streamer,  there is a "chance" it will re-energize the block near 50-50 for subsequent events after the 21st. ?????? Cross that bridge after the joy of tracking too many small-moderate events that offer snow/ice to the forum.  A lot to track and maintain an unwavering perspective of what may happen (minimizing big changes to thinking as the models sort it all out).  Added the WPC ensemble chance of 3"+ of snow for the 16th. Small chance we'll be #10 ranked Feb snowfall in NYC CP by the end of the 16th. Depends on amounts 11th, 14 leading up the 16th.

 

547A Tuesday the 9th: Complex and seems to be trending a little warmer so that LI and s of I78 are problematic on much snowfall, with snow/ice mostly nw of I95.  Could even have events change briefly to rain over the interior of the subforum.  How they evolve...uncertainty.  I still think something on Valentines Day and then 1 or two events 16th-18th.  Ensembles favor mostly the 16th-18th and give the subforum snowfall especially nw NJ but the trend on amounts is somewhat less. Am cautious since some of the blocking may be relaxing.  CFS is comparatively warm and wet and that's bothersome but am unsure how accurate CFS is. For now considering it another member and have to mention this option. All could turn out a little snowier close to NYC but for now, that is not a lock. 

 

815A Monday the 8th: I think we're going to have to see some snow here on Valentines Day I see the warm GFS but for now think its too warm). Amounts uncertain but its pretty clear to me that WAA and short wave coming into the area, then shoots off to the northeast own the 15th, but leaves behind maybe?? the coldest of the season here on Monday morning the 15th. Either wind chill near 15 below I84 corridor or widespread temps down to zero or colder I84 corridor (not that cold urban centers). 

Tue-Thu 16th-18th: more snow and ice coming I80 region northward. Model uncertainty is large. I'm thinking colder with the precarious balancing of southeastern USA warmth trying to heave northward at times against the generally blocked colder pattern across the northern USA. Rain could be invoked with this. 
---

Initial post from 2/7 midday. Have included rain in the tags, because we're close to having rain ,at times, within the overall cold enough pattern for snow and Ice, mainly along and northwest of I95. QPF this 5 day period should  be in the range of a general 0.5" minimum,  to possibly a maximum ~1.5". How much falls as snow, ice, rain is unknown and debatable. Multiple ensembles offer plenty of snow in and to the west and north of our subforum.  Favorable blocking for northeast snowfall appears to remain through this period, and well beyond. Am witnessing via modeling and reality,  a balancing of the cold core from southwest Canada to the northern Plains and Great Lakes shooting off pieces into the northeast USA,  then on into the north Atlantic. These reestablish-reinforce the blocking -NAO  from northern Canada to Greenland, and, following each pulse of CAA that moves through our subforum, there is WAA ahead of the next short wave.  So far, the cold core has not broken off in total,  to change the pattern and so, the snow opportunities continue on and on.  February is already off to a special start and we may be heading for a top 10 snowiest February (see attached February Central Park ranking and year). 

Will narrow the goal posts on these possibilities for this 5 day period as we draw closer.  My most confident period of something significant-substantial is the 16th-17th, but I have to consider some of the modeling that likes Valentines Day for an event and also the 16th-17th, delayed a day til the 18th.  

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7 hours ago, wdrag said:

Have included rain in the tags, because we're close to having rain ,at times, within the overall cold enough pattern for snow and Ice, mainly along and northwest of I95. QPF this 5 day period should  be in the range of a general 0.5" minimum,  to possibly a maximum ~1.5". How much falls as snow, ice, rain is unknown and debatable. Multiple ensembles offer plenty of snow in and to the west and north of our subforum.  Favorable blocking for northeast snowfall appears to remain through this period, and well beyond. Am witnessing via modeling and reality,  a balancing of the cold core from southwest Canada to the northern Plains and Great Lakes shooting off pieces into the northeast USA,  then on into the north Atlantic. These reestablish-reinforce the blocking -NAO  from northern Canada to Greenland, and, following each pulse of CAA that moves through our subforum, there is WAA ahead of the next short wave.  So far, the cold core has not broken off in total,  to change the pattern and so, the snow opportunities continue on and on.  February is already off to a special start and we may be heading for a top 10 snowiest February (see attached February Central Park ranking and year). 

Will narrow the goal posts on these possibilities for this 5 day period as we draw closer.  My most confident period of something significant-substantial is the 16th-17th, but I have to consider some of the modeling that likes Valentines Day for an event and also the 16th-17th, delayed a day til the 18th.  

Screen Shot 2021-02-07 at 10.38.08 AM.png

 

4D683F83-4B21-48B5-9226-6ACD84B8E10F.jpeg

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3 minutes ago, wdrag said:

Yes... will not be surprised at widespread 10-20" with isolated 35 BUT... we'll need all 4-5 events (9, 11, 14, 16-17) and ~80% snow. Do think we're on our way to at least a top 10 February for NYC snowfall. Already #16 as of 4PM.

2010 took the prize for Feb IIRC....even though the bulk of the storms and snow were south of us that year....

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19 minutes ago, wdrag said:

Yes... will not be surprised at widespread 10-20" with isolated 35 BUT... we'll need all 4-5 events (9, 11, 14, 16-17) and ~80% snow. Do think we're on our way to at least a top 10 February for NYC snowfall. Already #16 as of 4PM.

A little over 3 on Tuesday and we’d be top 10

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3 hours ago, wdrag said:

Yes... will not be surprised at widespread 10-20" with isolated 35 BUT... we'll need all 4-5 events (9, 11, 14, 16-17) and ~80% snow. Do think we're on our way to at least a top 10 February for NYC snowfall. Already #16 as of 4PM.

keep in mind that some of these areas have already seen 30 inches this month lol

Can you find a list of top snowiest months, Walt?  Maybe NYC can break 40 inches this month!

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3 hours ago, weatherpruf said:

2010 took the prize for Feb IIRC....even though the bulk of the storms and snow were south of us that year....

if we were at the latitude of Toms River we would've had 50 inches that month.  It was Jan 2011 and Feb 2010 that are my top 2

 

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12 hours ago, wdrag said:

Have included rain in the tags, because we're close to having rain ,at times, within the overall cold enough pattern for snow and Ice, mainly along and northwest of I95. QPF this 5 day period should  be in the range of a general 0.5" minimum,  to possibly a maximum ~1.5". How much falls as snow, ice, rain is unknown and debatable. Multiple ensembles offer plenty of snow in and to the west and north of our subforum.  Favorable blocking for northeast snowfall appears to remain through this period, and well beyond. Am witnessing via modeling and reality,  a balancing of the cold core from southwest Canada to the northern Plains and Great Lakes shooting off pieces into the northeast USA,  then on into the north Atlantic. These reestablish-reinforce the blocking -NAO  from northern Canada to Greenland, and, following each pulse of CAA that moves through our subforum, there is WAA ahead of the next short wave.  So far, the cold core has not broken off in total,  to change the pattern and so, the snow opportunities continue on and on.  February is already off to a special start and we may be heading for a top 10 snowiest February (see attached February Central Park ranking and year). 

Will narrow the goal posts on these possibilities for this 5 day period as we draw closer.  My most confident period of something significant-substantial is the 16th-17th, but I have to consider some of the modeling that likes Valentines Day for an event and also the 16th-17th, delayed a day til the 18th.  

Screen Shot 2021-02-07 at 10.38.08 AM.png

Walt....those are yearly snowfall totals not seasonal ones....I saw 1996 in there and saw the 61.3 figure and knew it was wrong lol.  They are including December from the following season in there instead of December 1995

 

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I have nearly 24 in of snow depth already with another 12 by the weekend for us not counting any potential storm after the 15th here in Macungie. Walt is spot on- entire snow season in snow depth for the LV is unreal and will lead to major flooding worse than 96 if we do not get a slow melt

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12 minutes ago, Albedoman said:

I have nearly 24 in of snow depth already with another 12 by the weekend for us not counting any potential storm after the 15th here in Macungie. Walt is spot on- entire snow season in snow depth for the LV is unreal and will lead to major flooding worse than 96 if we do not get a slow melt

you're just south of my other home, I cant imagine how bad it will be in Jim Thorpe this spring.

Our only hope is it never melts and just keeps snowing the entire year lol

 

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7 hours ago, LibertyBell said:

Walt....those are yearly snowfall totals not seasonal ones....I saw 1996 in there and saw the 61.3 figure and knew it was wrong lol.  They are including December from the following season in there instead of December 1995

 

The purpose of the data was to look only at FEB ranking of snowfalls. There was probably a better way for me to focus on Feb, but that was simplest-fastest for me. This is valid for FEB only. 

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7 hours ago, LibertyBell said:

keep in mind that some of these areas have already seen 30 inches this month lol

Can you find a list of top snowiest months, Walt?  Maybe NYC can break 40 inches this month!

Just need to take one at a time. Modeling has depressed a bit the past overnight cycle, and then the GFS op went warm and wet 16th-17th.  This will iron out.  

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25 minutes ago, wdrag said:

Just need to take one at a time. Modeling has depressed a bit the past overnight cycle, and then the GFS op went warm and wet 16th-17th.  This will iron out.  

Yes it'll take a while to get everything in order. 

Your analysis is solid for the next several events. The Tuesday event will probably be too far north for NYC but it could always trend a bit south.

Best chance will be Friday and then we'll see what late weekend brings. Large rise in the AO & flip to +PNA could indicate something bigger than a nuisance event. 

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56 minutes ago, SnoSki14 said:

Yes it'll take a while to get everything in order. 

Your analysis is solid for the next several events. The Tuesday event will probably be too far north for NYC but it could always trend a bit south.

Best chance will be Friday and then we'll see what late weekend brings. Large rise in the AO & flip to +PNA could indicate something bigger than a nuisance event. 

Agreed.

Overall multi model as I interpret: AO/NAO negative for the next 2 weeks at least I think and so the EPO going positive to me indicates bigger clashes of warm air trying to get into our area, eventually... not immediately upon the EPO change to +.  That could be after the 18th but am not considering anything beyond the 18th till we get through this week. 

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Laughable differences with the GFS from 06z to 12z today lol

Now showing potential ice storm for NYC east.. it's much better than what it was showing at 06z tho :snowwindow:

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8 minutes ago, patrick05 said:

Laughable differences with the GFS from 06z to 12z today lol

Now showing potential ice storm for NYC east.. it's much better than what it was showing at 06z tho :snowwindow:

Don’t look at the GFS thermals. With that track it’s a big snowstorm for all taken verbatim of course.

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1 hour ago, patrick05 said:

Laughable differences with the GFS from 06z to 12z today lol

Now showing potential ice storm for NYC east.. it's much better than what it was showing at 06z tho :snowwindow:

The GFS was an apps runner yesterday, I don't think it has much of a clue on this storm.

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3 minutes ago, LibertyBell said:

another very long duration storm over 24 hours?

I would take same totals under 24 hours as well.

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547A Tuesday the 9th: Complex and seems to be trending a little warmer so that LI and s of I78 are problematic on much snowfall, with snow/ice mostly nw of I95.  Could even have events change briefly to rain over the interior of the subforum.  How they evolve...uncertainty.  I still think something on Valentines Day and then 1 or two events 16th-18th.  Ensembles favor mostly the 16th-18th and give the subforum snowfall especially nw NJ but the trend on amounts is somewhat less. Am cautious since some of the blocking may be relaxing.  CFS is comparatively warm and wet and that's bothersome but am unsure how accurate CFS is. For now considering it another member and have to mention this option. All could turn out a little snowier close to NYC but for now, that is not a lock. 

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1 hour ago, wdrag said:

547A Tuesday the 9th: Complex and seems to be trending a little warmer so that LI and s of I78 are problematic on much snowfall, with snow/ice mostly nw of I95.  Could even have events change briefly to rain over the interior of the subforum.  How they evolve...uncertainty.  I still think something on Valentines Day and then 1 or two events 16th-18th.  Ensembles favor mostly the 16th-18th and give the subforum snowfall especially nw NJ but the trend on amounts is somewhat less. Am cautious since some of the blocking may be relaxing.  CFS is comparatively warm and wet and that's bothersome but am unsure how accurate CFS is. For now considering it another member and have to mention this option. All could turn out a little snowier close to NYC but for now, that is not a lock. 

Thanks Walt. I would have to believe that it's relatively rare to "escape" the break down of an extreme blocking period without at least a moderate snowstorm. Would have to think the EPO going positive is to blame.

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Will rereview late today. A +EPO i dont think is instant change?  Is it?  I think it suggests a trend. Butting up against a -block might be favorable for events.  I don't know the details of the oscillations. I just use tham as considerations on impacts. I do agree with you on at least one moderate event in the subforum (not counting todays along I84).  I think the one on-going up here will be underestimated in CT/MA.  Just when the next?  and is it cold enough for I78-LI south.  I sort of think so but have to blend the models.  NO QUESTION: A lot of opportunities through the 18th.  What sticks?  Ensembles have accumulations even LI. 

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The 12z GFS is running now. It seems to take the precipitation for thurs-Friday south as a HP air mass invades the region. Also showing rain on Sunday and Monday with the low that tracks to the Gulf of Maine. I was hoping to see the plows come out once in the next week or so near me but I’m beginning to have some doubts. 

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