North East and Mid Atlantic Weather

Mid Atlantic Monday Storm, Watching Wednesday and beyond.

By: Pcroton, 12:30 PM GMT on January 31, 2014

Good Morning.

Monday has become a threat to dump a moderate to even heavy snowfall on the region from Virginia through New Jersey.

We are still about one day too far out to discuss snowfall totals as the system still spans beyond the tail end of the NAM and SREF runs.

Hopefully by Saturday afternoon we can have a high confidence in the forecast...and can begin to look at snowfall totals.

Over the past couple of days the system was either modeled to be very far north or very far south of the region. Guidance began shifting north yesterday with the Euro/GFS reaching the central Middle Atlantic and the Canadian the upper Middle Atlantic region.

Here are your model maps this morning:

0Z 1/13:


SREF: Just entered the picture for Washington DC and this shows how the system could be a significant threat to the region.


GFS: This model is still struggling in various ways. I think it's a southern outlier for this event.


Our Wednesday event is still evolving in the model guidance and the system is still being handled poorly. It appears we will have a primary low coming up through the Appalachians that will then transfer it's energy to the coastline. At this time it is illogical to expect the primary low to continue tracking west of the region and up into Canada - as it'd be attempting to plow through the Polar Vortex which is not a possible scenario.

What this means is an energy transfer to the coast must take place. We have been down that road before and we know all too well that an earlier transfer means more cold air and a more widespread snowfall - whereas a later transfer means warm marine air will flood into the coastlines and inland to I95 thus changing everyone south and east of I95 to ice, sleet, and eventually rain.

Here is today's 0Z GFS showing the energy transfer idea. Do not focus on the exact details of the placement of the low centers on this map as this run is still not yet trustworthy. It's about the pattern, system, and idea. The thought still is that the GFS is too warm and too far inland.

Here's the 0Z Euro which takes a path that would hit us all with a significant snowfall threat. Unfortunately we are only offered the low resolution 1 frame per 24 hours and that results in the large jump:

Here is the 0Z Canadian Model, storm just enters the picture on it's final frame:

This model also shows the energy transfer to the coast but it is late and weak with it. I think we will have a further east primary low, a quicker and stronger transfer to the coast.


I must caution that the models have been mishandling this system and will continue to do so through at least Saturday's model runs. Until the disturbances are within our sampling network the models aren't getting fed the proper data and are just trying to resolve the energy the best they can.

I think they are phasing the energy too quickly leading to the further inland track leaving us at the mercy of a difficult coastal energy transfer. I assume the models will gravitate towards a later phase and furth east solution as we near Sunday.

Remember the timing of our phasing is very important and at this moment the models don't have the proper data regarding strength and speed of our disturbances so they are guessing. Here's a small graphic to illustrate the significance and fragility of timing.

Don't get too attached to any one scenario. Just know that a significant storm system will be impacting the region from late Tuesday through Wednesday. We can draw our rain/snow lines probably later on Sunday but more likely for the real close border zones it will be a Monday call.

Here is a small graphic illustrating the ramifications of an early and late energy transfer to the coasts.

When the primary low is stubborn and maintains it's strength it acts as a conveyor belt for the warm air. Once the primary releases it's grip that conveyor ceases and cold air rushes into the newly formed coastal low. It is very important for this transition to occur early and rapidly. The longer the primary holds on the less likely the coasts see significant snowfall.


Looking even further ahead there is a chance at a followup system in the Feb 9-10 time frame. I continue to feel that if this system is there and it's close enough on the heels of the Wednesday storm, that we could see a further East storm track leading towards a more widespread snowfall threat. If the storm holds off too long then the pattern rebounds enough to where the follow storm may just follow the previous one. All about timing.

Euro: Showing a strong 500mb disturbance and negative tilt in the region.

GFS: Given our pattern this solution is way too far inland at this time. The Euro above is far more reasonable. That said it does appear there will be another storm system in the region.


A look deeper into our temperature/precip profiles for the 8-14 day range.


When Wednesday's details become clearer we will open a new blog entry to focus on the threat.

Updated: 12:35 PM GMT on January 31, 2014


Feb 5-15th, multiple hits?

By: Pcroton, 4:06 PM GMT on January 29, 2014

It would appear there are signs that our coastal pipeline may be awakening. With an increase in sub-tropical jet stream energy and an endless supply of arctic disturbances and outbreaks the models are jumping on the idea of a major multi-storm winter event.

First, for the weekend, not much to talk about here. On again and off again rain/snow shower chances.


Perhaps something a little more organized comes through later on Monday:


If you recall February 6-10, 2010 you may be seeing a repeat if the models were to have their way.

42" in 3 days time here in central NJ.


European Model snowfall output through February 9th (I believe) From Joe Bastardi, WX Bell:

That is a 10:1 ratio mind you.


1/29 0Z GFS showing 3 storms in the time frame: From Levi Cowan, Tropical Tidbits.


1/29 12Z GFS For Feb 9th:


Environment Canada Feb 6-13th Temp Anomalies (Blue - below, Purples - Average, Reds - above)

CPC 8-14Day Precip:

Updated: 1:53 PM GMT on January 30, 2014


SE Snow Storm / NE Quiet

By: Pcroton, 8:59 PM GMT on January 26, 2014

SE Snowfall looks pretty darn good to me here... NE Weather will be addressed in the comments section.



Bufkit Warehouse
College of DuPage Models
Tropical Tidbits
Earl Barker Model Page
NCEP SREF Data Plumes
HPC Winter Weather




HPC 4" is over 40% probability. When you're over 40% you usually meet that threshold.





Updated: 9:33 PM GMT on January 26, 2014


Snow squalls, Cold, Super Bowl Storm

By: Pcroton, 12:21 PM GMT on January 25, 2014

Good Morning. First off we'd like to wish a fellow blogger well in health.

Quoting 49. originalLT:
5years ago this month I had quintuple by-pass open heart

surgery, Now I'm feeling some discomfort in my left side of my chest, gonna have it checked out. If I don't post for a while it's because I've been

admitted to the hospital to be checked out. Hope that does't happen, wish me luck, LT

Good Luck, LT. Hope things turn out minor.


Today in the Middle Atlantic and North East we have snow squalls on the way. I'm looking for 1-2" at the coasts and 2-4" inland. I realize this is more than the modeling shows but I think more of these heavy squalls will survive the mountains than advertised.

Current Radar:

NAM Simulated Radar:


Looking ahead to the rest of the week we have bitter cold and an out to sea storm track. Further to our North West it appears significant Lake Effect Snows are setting up.

Newark, NJ Bufkit Data:

Washington, DC Bufkit Data:

144hr Regional Snowfall Totals: Today

For some time there it appeared that Eastern NC could see several inches of snow, and this is still a possibility, but latest model runs are further
out to sea with a string of less organized disturbances.

GFS off the coast:

GFS rendering Yesterday:

144hr Snowfall showing NC Potential: Yesterday


Further ahead it looks like we will finally see our Sub-Tropical Jet Stream come alive and give us a couple of disturbances in a row timed with, you guessed it, the outdoors Super Bowl event in the Meadowlands.


Shortly after on February 4th a secondary storm is forming in the South East headed for our region. At this time, and you can never pinpoint finer details, the systems are modeled to take a slightly inland track which would bring a whole array of nasty weather from snow, to sleet, to rain. It is entirely possible we see a few classic I-95 boundary events of which was the case earlier in the year.


Supportive of I95 boundary events is the very warm waters just off shore. If these are tapped by strong Easterly surface winds then yes we will see the classic setups of everyone starting as snow and then the usual Eastern and coastal areas changing to sleet and then rain.


At this time we merely see a pattern of increasing southern stream disturbances combining with arctic air from the north. Attempting to nail down timing, amounts, and rain/snow lines is a fools errand. I think the disturbances will be there to be had but in what nature is unforseen. They could be I95 mixes but it also wouldn't take much to make them widespread regional snowfalls, either. Stay tuned.

8-14 Day Temperature Outlooks, Feb 2-9. Placement of this anomaly would favor east coast storms but...inland tracking as far as the DC-NYC corridor is concerned. Coastal NJ, DE, MD, etc...could find themselves on the short end of the snow stick with this setup. We're still too early for that determination but going with what we have it does look like your classic snow-sleet-to rain setup for the I95 corridor and points south and east. Could this be the setup Pennsylvania and interior NY has been lacking for years? Could be.

Lastly, I have given up on the NAO. I had no opinion on what it may do as that is above my knowledge level, but many folks really had high hopes this would go strongly negative around Mid-January and play a crucial role in a blocking pattern that would give us a high risk of blockbuster snow events. It's been positive, remains positive, and will continue positive. We're starting to get late here with this.

As a final note we have been seeing the models in the long range continuously trying to revive winter going all the way back to January 16th. As we know we had five systems lined up, one for the 16th, one for the 18th, one for the 21st, the 27th, and the 30th. Only the third system panned out thus far. Given the high level of recent long range failures I would remain on the cautious side yet there are signs we will return to stormy weather one way or another in early February.

Updated: 1:51 PM GMT on January 25, 2014


Stormy Weather returning to the Middle Atlantic

By: Pcroton, 2:40 AM GMT on January 23, 2014

As we discussed two blog entries ago it became clear that the final week of January could become quite stormy. It appears we have gotten our wish.

We still have a couple of tricky systems to get through before we return to some more familiar coastal low development late in the period.

Before we dive in I want to speak about forecasting and the recent problems we have had with spotting systems early enough to prepare for them. The majority of our recent winter weather has been all northern stream energy shoved into the area by the polar jet and polar vortex.

These disturbances originate near Alaska, ride up and over the large western ridge of high pressure, and dive down from the Yukon Territories through Canada and into the upper plains. We then know the story of a couple of these clippers sliding to the East coast and undergoing significant deepening leading to several very impressive snow storms.

We have all witnessed the models poorly handle these systems outside of 24 hours and especially outside of 48 hours prior to the onset of the storm system.

The problem lies in where these disturbances are coming from. We have a very sparce gathering network in Canada and especially isolated or non-existent into the Yukon and Alaska. Model performace and 90% data input and these disturbances are so poorly sampled or not at all that the data that is input into the models is not indicitive of the true strength and nature of these systems. As a result they are poorly modeled over our area as weak and disorganized and of little impact. Once these disturbances enter the denser sounding network the models get a spike in useable data and suddenly produce stormy solutions.

This accounts for "surprise storm" and "models came out of nowhere with this one". Models function off of data. Data must be input to run a model. Sparse data yields poor results. You may notice once we had the disturbances in the upper plains is when the models suddenly take off with the Middle Atlantic storms solutions. Unfortunately this places us in a 24-36 hour time frame, 48 hours max, prior to event have a viable modeling solution of which to derive a forecast.

Another significant player which I believe gets no air time has been the timing of these very strong arctic fronts plunging due south from Quebec into the North East. These frontal systems have been responsible for many surprise totals so far this winter. They have provided energy, a focus for lift, a tracking mechanism for the lows themselves, and very strong arctic air which leads to strong temperature gradients along the coast which helps these lows intensify rapidly. It appears at this time we could be looking at yet another arctic front involved with an Ohio Valley clipper system teaming up to give us another significant snowfall surprise.

Given all of these issues I would continue to expect more modeling errors and forecasting challenges ahead.

Here are the notable storm threats over the next two weeks.

On Thursday we have a decaying clipper that looks to cross the region. At this time it appears it will lose most of it's moisture over the mountains and once it hits the Mid Atlantic region it won't be much more than a nuisance. Looking at up to an inch in isolated heavier snow showers.

On Saturday a more vigorous low moves through the Great Lakes and southern Canada trailing a stronger frontal system which looks like it will produce some moderate to heavy bursts of snow in the form of snow squalls. While these are short lived they can add up quickly. Perhaps expect 2" but don't be surprised to get 3" in some cases. Further south in DE/MD and beyond there is some question as to how strong this event could be. Perhaps 0-1" is a safe bet for now.

Then we turn our attention to Monday. This system is eerily similar to January 2nd, and January 21st, in respect to potential development, and moreso, last minute notice that we're going from snow showers to a significant storm system. This is just another case of the disturbance in question being in the Yukon Territories and we are unable to sample it and provide the models with the necessary data to yield a strong east coast solution at this time. We are going to be held hostage yet again as a result and I don't think we find resolution until Saturday once the system begins to get sampled better.

After that we seem to be looking at the Sub-Tropical jet stream becoming more involved in the pattern. The models have been focusing a potentially major event along the Middle Atlantic coastlines in the Jan 30-31st time frames - for what seems like an eternity. The pattern does seem to suggest this and those who are well educated in the field all seem to believe this is coming. After that a followup system looks possible on Super Bowl Sunday, and if the first sytem pans out - it will head to the maritimes and provide some very strong blocking for the Feb 2nd storm.

That's it on the highlights, now let's get into some maps for Saturday and Monday in the comments section below.


Strong Winter Storm to affect Middle Atlantic, SE New England

By: Pcroton, 11:29 AM GMT on January 20, 2014

Well, I really crapped the bed on this one folks....and so did just about everyone else.

How fragile is out storm track in the Middle Atlantic region? Apparently enough to go from a nuisance inch or two... to a full blown winter storm... in about 12 hours of modeling time.

Tuesday looks to now be a major event for the Middle Atlantic States and SE New England.


This disturbance will lead to coastal cyclogenesis on Tuesday: 6AM 1/20:


ALL Maps updated 1/21, 6AM:


Current Advisores: 6AM 1/21


Euro 0Z 1/21:

CMC 0Z 1/21:

GFS 0Z 1/21

NAM 0Z 1/21


HPC 4"+ Probabilities: If you are within the 40% contour you will likely see 4" plus. 1/21

HPC 8"+ Probabilities: If you are within the 40% contour you will likely see 8" plus. 1/21

HPC Maximum Storm Potential: 1/21

GFS Snowfall: 0Z 1/21

NAM Snowfall: 0Z 1/21

Updated: 11:40 AM GMT on January 21, 2014


Winter's Return: Last week of January?

By: Pcroton, 1:36 PM GMT on January 14, 2014

In my last blog entry I covered why I felt this present week and into the next would be seasonal and relatively quiet. Since that topic has been covered I figured we should open a new blog entry to look forward and discuss the upcoming threats.

I know everyone was hoping for and even expecting a quick return to arctic outbreaks and coastal storms due to the widespread thinking bouncing around the web but it was not going to happen that quickly. We continue to target the last week of January for this potential.

Ok, so here we go, as I anticipated this week will come to a close with just a few small disturbances unlikely to amount to anything significant for the greater cities of the middle atlantic or north east. Clipper after clipper dancing through starved of moisture..some disturbances reaching the water and developing but due to a fast progressive flow, too many disturbances chewing up the available energy, and a lack of blocking...they end up shooting harmlessly out of the area.


Here is the current NAO forecast:


Wednesday into Thursday we have our incoming Clipper #1. It immediate wanes and heads back up into Canada..with the next Clipper #2dropping in.


Late Wednesday into Thursday Clipper #2 follows Clipper #1 up into Canada and wanes...missing a phase with a coastal development that won't affect us. You can see Clipper #3 enter the picture.


Late Saturday into Sunday Clipper #3 dives through the region while waning and then hits the water and develops while Clipper #4 enters the picture. Due to the speed of the flow and lack of blocking #3 just harmlessly heads out to sea. Now this is one of those instances you want to keep an eye on because sometimes (rarely) these can develop a little quicker and catch the coastal regions with a light to moderate snowfall before departing. At this time that doesn't appear to be the case.


Then on Monday Clipper #4 stays north and heads out of the picture.

As we can see there is a lot of activity but there's nothing of actual concern here. Snow/Rain showers perhaps with each passing disturbance. At this time nothing promising looming over the next 7 days.


Now we get into the more distinct threat timing. Our first threat, January 22-23 time frame, could yield a potential storm. So far as it has been modeled it is not coming together in a favorable position to deliver a blow to the middle atlantic. It's too late and too sloppy. I would caution we're too far away to call the timing on phasing at this time. I think we can't really do that for at least another 4 days. It's nice to see the system there and the new pattern coming into sight which would lead to this type of storm development. That being said we can't just jump on the hype. As we learned this week that's the wrong way to forecast. Those pessimistic about a dramatic return to winter this week were in a tiny camp of thinking. Now they're not just the majority they're the authority. It's the weather, folks, and while it's tough to not get caught up in the computer generated versions of it, you got to add a little smarts to it when you can and say "Ok, nice solution, but are the components there to support it?" And this time around I felt there wasn't, which led to the last blog entry.


Here is the evolution disturbance. Nice polar energy, nice sub tropical energy, and a phase. Poor/Late timing for us, but details aren't to be laid out this far in advance:


Here are the temperatures associated with the peak system potential for the region.


Here is the upper level dynamic..a negatively tilting trough but it may just happen too late. Again now we're talking details that you cannot iron out this far in advance. By the time we get to this point maybe we have an earlier phase and earlier tilt and the region finds itself under the gun. However, again, there isn't blocking with this system, and if that remains the case then you don't get earlier tilts or phases because everything is moving too fast.


One nice piece to the 22-23 storm puzzle is this piece of cold air rocketing south east towards the US.


At the very end you can see it goes into the Canadian Maritimes and if this system sticks around - we finally have a blocking mechanism.

Perhaps the follow up storm can utilize this and we FINALLY get our big one? It is what we will be watching.


If we wanted any of our storms to produce this year this is what we want to see a day or two before the next storm enters the picture. We haven't seen this so far this year. However don't get your hopes up quite yet...because if the system doesn't hang around up there in the maritimes to provide blocking and instead moves along - we're looking at more of the same. We need to see this happen in 10 days, need to see it stick there, and need to see the next storm come in on it's heels. Then we have our blocking and we could have our blockbuster.

Unfortunately....the answer in the models is no to that. Again we're way out here now to be trusting things. Yesterday's runs showed a 2nd storm on the heels of the first around the 27th. That is gone now and replaced with one on the 30th. By the time the 30th rolls around the nice blocking provided by the Jan 22-23 system is gone and retrograded far east into Canada. While there are some positive signs here that the final week of January may produce - nothing is locked in.


January 27th: Nice Blocking.


January 30th: Much less blocking...late storm.


Stay tuned...the final week of January looks like it will produce. Two good threats there for a moderate to heavy snow event. The only unsolved question is that of proper lead to a blockbuster or maybe two. That's something we just cannot see this far in advance. However pattern wise it appears we will have the threats to deal with.

Updated: 1:45 PM GMT on January 14, 2014


A return to winter or just seasonable? NE/Mdl Atl

By: Pcroton, 1:09 AM GMT on January 12, 2014

A return to winter or just seasonable?

Middle Atlantic, Jan 12.

It seems there has a been a lot of buzz about winter returning in a powerful manner later this week. From the data I have looked at over the past seven days leading up to now I have gone against this thinking and will continue to do so.

I feel like it is over stated and although it may seem sound in theory, a cold air intrusion aiding in northern and southern streams interacting to cause coastal cyclogenesis, there has been no support of such a system taking shape thus far.

While models have been known to push one solution, then finally sample an important disturbance, and suddenly flip their solutions...I just don't see that occurring this time. If that were to happen it would start with the 0Z Monday models as the disturbance leading to our late week storm system should be better sampled by Sunday afternoon and that data should make the 0Z model runs.

I also believe the idea that we're returning to arctic weather is over stated. After a cold weekend we will moderate and continue with our zonal flow and our seasonably moderate temperatures followed by the occasional frontal system and next 1-2 day cool down.

Here is the GFS on a potential weak system later in the week: I think the surface temperatures are going to be warm enough where some may only get a mix of rain and some snow and no real accumulations. You can see at 500mb there is no Candian Maritime blocking. The stage is set for this disturbance to be a weak mix and fly out to sea.

Here is the Euro on the same potential system:

As you can see these are two weak zonal solutions with no blocking and limited cold air available. I think this is much ado about nothing. Given this is the only system in town there is no data to support the idea of a coastal storm coupled with an arctic air intrusion for later this week. I just don't see it happening. These solutions are not unlike the modeling leading up to our most recent Thursday night into Friday morning storm. What was once seen as a potential 1-3" snow threat turned into a Friday morning icy nightmare and then rain.

Here is the NAO, which was rumored to go quite negative, and in fact after a little negative blip later this week which appears to be incorrect (ref the 500mb chartsshowing riding in the Canadian Maritimes), will apparently head quite positive. I would discount the negative blip, especially the ensembles doing a 1 day huge drop prior to returning positive. It just doesn't fit with the 500mb pattern.

We have seen through the season that the positive trips for the NAO seem to last 2+ weeks. So if this next positive period comes to fruition we're not looking at a change for at least 2 weeks in my opinion and the modeling seems to support that. Of course all if this is based on whether or not you trust the modeling.

Here are some regional temperature bufkits for the temporary weekend cooldown:

LaGuardia Airport, Queens NY Bufkit:

Philadelphia, PA Bufkit:

Here is the longer range peek at the GFS at the 500mb level. I don't see any significant arctic outbreaks. Just your more run of the mill zonal flow mixed in with some short lived cooler days after the passages of weak cold fronts associated with northern stream disturbances in southern Canada. Honestly it resembles more fall like weather in this case. Here are a few select panes to illustrate the outbreaks and the zonal periods. With the dips in the east the west is zonal. When the eastern dips move on the western zonal flow moves in.

Things can and do change but I would at this time be quite tempered in enthusiasm if you were expecting a return to the severe arctic weather we had just gotten through and were hoping to couple that with a coastal pipeline of storms. At this time it just does not appear to exist.

Here is a look at the 500mb pattern from above, you are looking down on the north pole, with the US in the bottom portion of the image. Note that throughout the Northern Hemisphere there is no noteworthy pattern amplification.

Here is another component to our early season storms, the sub-tropical jet stream, which is extremely weak and in fact the weakest I've seen it so far this fall/winter season. You can also see on the windstreams picture the very narrow and short lived 500mb polar intrusions. These will be a feature of the next two weeks it would appear. Short lived 1-2 day cool downs and 5-6 day zonal seasonable weather.

To make a note some folks who did believe in a "return to deep winter" were looking more towards the very end of January and even the first week of February. While winter is not over time does move quickly and if we find ourselves in early February and the next 16 days continue to show more of the same....well we do know that Valentines day frequently is a good bench mark to see winter begin to transition around the Middle we could indeed be coming to a close. It does pay to keep in mind we've all seen big snow storms in late February, and even March, and in the northern Middle Atlantic every few years early April yields a surprise. Winter is not over until the grass is green and the plants are awakening. Yet as we learned late last year in March, twice in fact, if you don't have blocking you don't have a snow storm and instead you get some messy teases that disappoint.

That said there has been a lot of focus on winter returning in a severe manner this week. I think the bigger question at this time is whether or not the severe part of winter has passed and we are looking at a more seasonable second half to winter - or does the second half of winter also feature another round of arctic temps.

With the NAO modeled to go positive and the 500mb level appearing to be progressive and zonal with only minimal and short lived dips I don't think we get our answer any time over the next two weeks.

As always the models do not drive the weather. The GFS is not a train schedule and the storms are not trains. We go with what we can see and what we can see right now does not fall in line with the desires to see a big return of winter at this time.

Updated: 1:16 AM GMT on January 12, 2014


Temperature Rollercoaster + 2 Storms: NorthEast US

By: Pcroton, 9:14 PM GMT on January 03, 2014

On the heels of our most recent storm system that wrapped up off of the NJ Coastline we have a temperature roller coaster and two storm threats to deal with.

A disorganized system will cross through our western region Sunday into Monday. It does not appear it will wind up until it reaches Canada. There are some light snow threats within the region as a result but heavier snows seem confined out west and north.




After that the next system for Thursday into Friday appears to be somewhat similar to what we just experienced...a central US low pressure area traveling eastward to the NJ/DE coastline...meeting up with arctic air. While it is too far out for any particular details the models have done well putting disturbances within the region in specific time frames and being correct about their existence.

It is important to just know the threat exists and not take the shape or strength of the system on the long term model run in faith. We just learned with this past storm how poorly the models pick up on such a system and how a multitude of scenarios get spat out. They aren't to be taken literally that is for sure...but this most recent storm we had was seen on the GFS at 16 days you trust a disturbance will be in the region. Plenty of time to watch it evolve. I'd say Tuesday is a good day to start model watching this one.

Lastly we have the bitter cold to deal with and a rollercoaster of temperatures. This should be taken seriously.

Stamford CT:

Rutgers, East Brunswick, NJ:

Wilmington, DE:

Jacksonville, FL:

Updates will of course run through the blog....and if Thursday-Friday looks to become a more serious event a new blog entry will be out.

Updated: 9:15 PM GMT on January 03, 2014


About Pcroton

Located in Monmouth County in central NJ. Watching the weather from North Carolina to Maine.

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