Legitimate Snow Potential

[AfewUniversesBelowNormal]

The first piece is the real threat... 2nd piece, while stronger, will be too warm. 

If the Day 4 storm trends NW like it often does, it has the potential to be a 3-6" snowfall NW of I95

18z GFS is really close to a phase, it could be like 1 model run to make up the difference and give the area precip (3-4 runs for 3"+ storm)

 

It's kind of strange that in 2005 I would look at a Day 4 map and know if the same dry/unphased biased as 12 years later. But it's 80% true. 

[showmethesnow]

18 minutes ago, Ralph Wiggum said:

I went thru all 50 individual eps members and while I agree that there has been some better trends with the mean, there isnt a single eps member that shows this as a significant coastal storm unless you live out over the ocean, and even those couple of members have a rather stretched out slp. One thing I am seeing on most members is the speed of the kicker headed out of the N Plains. The N jet, while showing some amplification, just seems too progressive. Could one of the N vorts catch the S Jet and change the game as we get closer? Sure. If the Southern energy wasnt so far South/amplified into the GOM I would be more enthused because the -nao, even given the fast flow in the N Jet, is helping to amplify the N Jet but because the vorts are so far apart in each respective jet they dont have a chance to phase. This is actually a case of the SW Ridge being too strong imo and causing too much amplification in the S Jet. There is still alot of energy moving around around the N Jet and one of these could resolve and trend more favorably. My point is the euro suite isnt pointing toward a widespread Thanksgiving coastal storm unless you live in the SE or out in the open water.....for now.

Okay, I see what you are saying. I haven't dug deep into the individual members and am going by mean alone at this point. I am not sure I would trust so much what the Eps is throwing out at this point with the NS though when I look at all the changes we have seen just in two days.

[Ralph Wiggum]

2 hours ago, showmethesnow said:

Okay, I see what you are saying. I haven't dug deep into the individual members and am going by mean alone at this point. I am not sure I would trust so much what the Eps is throwing out at this point with the NS though when I look at all the changes we have seen just in two days.

Yes....and as Chuck noted, lots of shortwaves racing thru the flow under the -nao/pv configuration. I would assume the models are having *some* challenges handling this 100% correctly yet, so yeah, some uncertainly still looms. 

[AfewUniversesBelowNormal]

Super cold air in PA and good moisture right off the coast, bring the two together a bit (phase) and you have a legitimate storm. Best case scenario is a 6-12" event, maybe 15% possible. 

[Cobalt]

0z GFS kicks the storm out to sea, which probably explains why the 850s/ground temps are a tad colder to. 

[Cobalt]

0z EPS actually has a mean of .1-.5 inches of snow right down 95

[showmethesnow]

The GEFS has deteriorated quite a bit overnight for the possible storm roughly centered on Friday. We see the northern portion of the western ridging now being sheared eastward along with the higher heights which is undercutting the pv and breaking down its associated trough that is extending southward. This is the look that the Eps was throwing out just a couple of days ago and had since moved away from. This look will not come close to getting it done as it presents a flat flow through our region and cuts off any NS energy being able to interact during any possible spin up off the SE coast (which would most likely be weak and head OTS). It does continue to show a second surge of the pv/trough southward along with very cold air for the Sunday/Monday time frame which may need to be watched depending on how things evolve earlier during the Fri/Sat period.

After 2/3 days of seeing somewhat large changes on the EPS it has now strung together 2 runs that closely match each other for the short and mid term period. We see some minor changes for both the good and the bad in regards to the possible Friday/Saturday coastal compared to the prior run. The biggest takeaway from the run though is that it continues to hold firm on not shearing the northern portion of the ridging westward that it was during on prior runs and of which the GEFS is now showing. But status quo will not cut it at this point for a possible coastal impacting our region with time running out. The Eps also has a second surge of the pv southward along with some very cold air during the Sunday/Mon time frame. 

Overall the overnight runs were not what you wanted to see for a coastal impacting our region around Friday. The GEFS was a flat NO and the Eps was a very low probability set up. That being said the GEFS suddenly flipping on what it wants to do with the ridging in the west, after showing great continuity with many prior runs, leaves doubt in my mind. Also the Eps stringing 2 runs together does not constitute continuity after watching the prior 2 to 3 days be all over the board. If the Eps can string together another couple of runs that match fairly closely then it will be a whole different story.

The GEFS and to a lesser extent the Eps have both been showing for quite some time a window of opportunity from Thanksgiving onward (roughly 4 days or so). As I see the models evolve I am beginning to question if we may be keying on the wrong time period within this window. The look during the second pv surge (Sun/Mon) continues to improve. After a very brief surge of warm air Saturday we see it quickly scoured out by very anomalous cold temps (Sunday/Monday) that continue to deepen over subsequent runs. Now how that time period actually plays out (potential or not) will be highly dependent on what we see occur prior with the potential first event. 

[showmethesnow]

The 06z GEFS is in close agreement with the 00z. Still shearing the northern portion of the ridge in the west screwing up our chances for a coastal. But as far as the secondary surge of the pv and possible potential (sun/mon) we see continued improvement. Really no use in breaking down that period of time until we actually have a resolution for the possible Friday event. But I will say that if the GEFS is correct and there is some energy still off the southeast coast during the secondary surge it could possibly get interesting.

[Wonderdog]

1 hour ago, showmethesnow said:

The 06z GEFS is in close agreement with the 00z. Still shearing the northern portion of the ridge in the west screwing up our chances for a coastal. But as far as the secondary surge of the pv and possible potential (sun/mon) we see continued improvement. Really no use in breaking down that period of time until we actually have a resolution for the possible Friday event. But I will say that if the GEFS is correct and there is some energy still off the southeast coast during the secondary surge it could possibly get interesting.

Love your write-ups and Analysis but ever since you started this thread, this window of opportunity has narrowed greatly. LOL

[showmethesnow]

1 hour ago, Wonderdog said:

Love your write-ups and Analysis but ever since you started this thread, this window of opportunity has narrowed greatly. LOL

Funny how that works, isn't it. Guess I jinxed it.  

Have figured the Friday deal was a low probability event for quite awhile now but there was some interest by others to follow it, me included, so I thought I would pull the discussion out of the long range thread so as to not clutter it up and bother others who have moved on. Been following this period since day 15 on the GEFS and I thought I would see it through to the bitter end. And who knows, Sunday/Monday has been improving. But even if this window throws us a big fat 0 it is rather enjoyable following short/mid range threats as opposed to what we dealt with last winter with everything being at least 10 days out if not 15+. Might even glean some habits/trends of the models for the short/mid term periods for this winter.

[BristowWx]

11 minutes ago, losetoa6 said:

Interesting thst the UK wants blow a low up off SC coast day 5...still a miss it looks like  but a sharper trough then Gfs and much stronger verbatim.

I still have a sliver of hope that something forms..or something happens to change the typical upper 40s and mostly sunny forecast..just a sliver

[showmethesnow]

Looking at the GEFS and we do see some marginal improvements but not near enough to bring Friday into play. Will have to see what the Eps has to say on the matter but we are quickly running out of time. Give it another day without substantial improvements and then it may be time to call it DOA. BUT the Sun/Mon period is quickly gaining my interest. We once again see improvements on the GEFS to where we are starting to get a good look at 500 mb. I will continue to follow the Friday time period but now it won't be so much for the potential for Friday but more so for what it could possible setup for Sun/Mon (leaving some energy off the coast).

[AfewUniversesBelowNormal]

Was expecting the threat to be completely gone, but GFS is close to a phase. There may even be some drizzle as the cold moves in. It could literally be 1 model run to trend into a snowstorm threat (1-3"), then maybe more... 

[mattie g]

To be honest...I’m completely ambivalent regarding a storm that impacts our region around Thanksgiving. I’m more interested in just seeing southern-stream energy at this point in time.

[Cobalt]

If you squint, the GFS is about 10 miles further West than it's 12z run

[Wonderdog]

12 hours ago, Cobalt said:

If you squint, the GFS is about 10 miles further West than it's 12z run

You don't have to squint to see that the storm is now closer to the coast after looking at the 6z GFS. But we're running out of time and this storm looks like a Tuesday evening storm.

[showmethesnow]

43 minutes ago, Wonderdog said:

You don't have to squint to see that the storm is now closer to the coast after looking at the 6z GFS. But we're running out of time and this storm looks like a Tuesday evening storm.

Yeah, now seeing the models wanting to bring up some energy in the late Tuesday/Wed time frame. Flow in front of the incoming trough would probably allow moisture to get into the region especially on the shore. Temps are warm at this point and cold would filter in after the fact (at least with what the models show now).

Though you should never say never I think Friday we can pretty much stick a fork in it. After 2 days of watching the models we never saw the changes we needed for a coastal in our region and in fact the whole setup at this point looks like crap. Probably end up with a weak low off the southeast coast moving out to sea. Not to mention we once again see the EPS breaking down the northern portion of the western ridging sending higher heights and warm temps eastward.

Sunday/Monday is still of interest. The general setup has potential. Depending on the placement of the pv and associated trough we could possibly see our first realistic chance of at least snow in the air. 

 

[BristowWx]

It never fails to surprise me that for all the model gyrations and interesting scenarios presented what we end up with is usually warmer and less impactful.  I have been watching Thanksgiving weekend for the last two weeks and we went from these crazy winter like negative departures on temperature to something that is just on the cool side of normal.  Totally unremarkable and completely boring.  With full sun it’ll feel like spring.  Just the nature of where we live.  Long range predictions are just fish wrap.  

[mattie g]

21 minutes ago, BristowWx said:

It never fails to surprise me that for all the model gyrations and interesting scenarios presented what we end up with is usually warmer and less impactful.  I have been watching Thanksgiving weekend for the last two weeks and we went from these crazy winter like negative departures on temperature to something that is just on the cool side of normal.  Totally unremarkable and completely boring.  With full sun it’ll feel like spring.  Just the nature of where we live.  Long range predictions are just fish wrap.  

It's November.

[BristowWx]

9 minutes ago, mattie g said:

It's November.

But the 500 mb colors on the models were in all the right places for something exceptional.  I was wishcasting a silly turkey day pattern that we would talk about for years to come.  Something mythical.   

[CAPE]

5 minutes ago, BristowWx said:

But the 500 mb colors on the models were in all the right places for something exceptional.  I was wishcasting a silly turkey day pattern that we would talk about for years to come.  Something mythical.   

It's preseason. Just hope those pretty colors on the models are in all the right places a month from now.

[BristowWx]

3 minutes ago, C.A.P.E. said:

It's preseason. Just hope those pretty colors on the models are in all the right places a month from now.

Yeah I know.  Just being stupid.  Although I did have a little higher expectation for this long wave pattern.  Not snow really for my location but just stormy.  I like all weather situations except partly to mostly sunny.  Figured the trough and block would yield something interesting.  

[WinterWxLuvr]

2 hours ago, BristowWx said:

It never fails to surprise me that for all the model gyrations and interesting scenarios presented what we end up with is usually warmer and less impactful.  I have been watching Thanksgiving weekend for the last two weeks and we went from these crazy winter like negative departures on temperature to something that is just on the cool side of normal.  Totally unremarkable and completely boring.  With full sun it’ll feel like spring.  Just the nature of where we live.  Long range predictions are just fish wrap.  

The models have biases which are magnified the further out in time you go.  You have to learn what those biases are.

For example, the first time the GFS shows a northern stream vort cruising down and running through North Carolina about 5 days out, watch and you'll see it end up in Pennsylvania by game time.

[Cobalt]

I always notice these costal storms typically head NW on the model runs within 3 days of the storm. If this does happen, it still won't be enough for more than 1 or 2 wet snowflakes. There just isn't enough cold air whatsoever.

[showmethesnow]

10 hours ago, losetoa6 said:

If flurries and snow showers don't fly Sunday /Monday it's going to miss a great opportunity.  700mb and 850mb moisture looks good. (18z Gfs)

 

 

The overnight GFS actually rotates a shortwave/vort max through MD midday Sunday. Surface doesn't reflect it at this point but that isn't surprising considering it is 5 days out and the GFS normally doesn't pick up well on that until we are closer in range. Last few runs on the GFS have been hit or miss with this feature. Euro hints at the possibility. Will be a good deal of energy rotating through so it would not be a shocker to see someone (better chances north) get a decent burst of snow though the surface temps may make any stickage prohibitive unless rates are there. This all of course is based on the models being correct for 5 days out. Which after watching the models with this 4 day window is not a sure thing whatsoever.

After watching this 4 day window of potential I hope we are not seeing a common theme with how the blocking verifies compared to what the models show. Time and again they have presented a decent look with strong west based blocking (-NAO) extending south into Canada. This was forcing the pieces of pv rotating through Canada farther south and west as well as the respective troughs associated with them. But what we are actually seeing is that the blocking is further east and pole-ward so we are not seeing the penetration of the the pv/troughs southward/westward that were giving us our somewhat good looks at that given time. Been a firm believer that we will need to see this blocking south and west to give us our chances otherwise the potential will move NEward as we have seen occur with this current window. Another negative is that with these features farther east/north it is allowing easier access for the higher heights and warmth to move eastward into our region between surges of the trough into the east. At that point we are then talking timing issues with whether the warmth can be scoured out quickly enough for any potential storm. 

 

[showmethesnow]

29 minutes ago, losetoa6 said:

Here's 0z. A little further south and would be even better. Still worth tracking ..though 6z not as good. Yesterday had a couple ensembles dig pretty nice but 0z seemed to have lost those few for now .

It's definitely worth watching that time period for some NS energy diving down and sliding underneath. Just have to hope we don't see a continuation of the adjustment of the pv and trough northward. We are on the southern edge of chances as it is now.

[WinterWxLuvr]

3 hours ago, showmethesnow said:

The overnight GFS actually rotates a shortwave/vort max through MD midday Sunday. Surface doesn't reflect it at this point but that isn't surprising considering it is 5 days out and the GFS normally doesn't pick up well on that until we are closer in range. Last few runs on the GFS have been hit or miss with this feature. Euro hints at the possibility. Will be a good deal of energy rotating through so it would not be a shocker to see someone (better chances north) get a decent burst of snow though the surface temps may make any stickage prohibitive unless rates are there. This all of course is based on the models being correct for 5 days out. Which after watching the models with this 4 day window is not a sure thing whatsoever.

After watching this 4 day window of potential I hope we are not seeing a common theme with how the blocking verifies compared to what the models show. Time and again they have presented a decent look with strong west based blocking (-NAO) extending south into Canada. This was forcing the pieces of pv rotating through Canada farther south and west as well as the respective troughs associated with them. But what we are actually seeing is that the blocking is further east and pole-ward so we are not seeing the penetration of the the pv/troughs southward/westward that were giving us our somewhat good looks at that given time. Been a firm believer that we will need to see this blocking south and west to give us our chances otherwise the potential will move NEward as we have seen occur with this current window. Another negative is that with these features farther east/north it is allowing easier access for the higher heights and warmth to move eastward into our region between surges of the trough into the east. At that point we are then talking timing issues with whether the warmth can be scoured out quickly enough for any potential storm. 

 

This was that bias with the GFS and northern stream energy that I mentioned yesterday.  They very often end up modeled too far south and west than actually verifies..

[showmethesnow]

42 minutes ago, WinterWxLuvr said:

This was that bias with the GFS and northern stream energy that I mentioned yesterday.  They very often end up modeled too far south and west than actually verifies..

We were seeing this with the Euro as well. Not so sure about the CMC but from what little I saw it probably had the same issue as well.

[mitchnick]

This thread needs to be renamed "Bast@rd Snow Potential" since there was nothing legitimate about it. 

[Amped]

4 hours ago, mitchnick said:

This thread needs to be renamed "Bast@rd Snow Potential" since there was nothing legitimate about it. 

And locked  there is no snow close enough to be worth discussing. Might as well discuss the CFS PDIII storm.