Update at 530pm

Totals going up.

Friday Morning: An Updated Look at the Weekend Storm

Good morning everyone. Most areas saw a nice white coating last night which does remind us it is in fact winter. Latest trends for our weekend storm have been to bring it more west which means there will be some impacts for areas near the coast on Saturday. As you all know I have been talking about this storm since Saturday so at least we will have something to show for it when its all said and done. To start off here is my snowfall forecast for Saturday..

Most areas do not see more than up to an inch, but close to the coast things get interesting. Extreme southern coastal NJ, DE, MD and especially the cape can see a nice moderate snowfall Saturday as this storm brushes by.

To show the shift, here was the model projection from yesterday morning..

And now 24 hrs later (current run)..

You can see a very big shift west and most models are all following this trend. It does not mean a big snowstorm for the I-95 but it does mean there now will be impacts near the coast.  

The reason this has come back west is due to the energy in the southern jet stream being sharper and stronger than originally modeled..

Thats all for now lets see what last second trends evolve and I will have an update out tonight. For now I feel good with the snow map I have as it is a compromise between many different models.

Thursday Night Snow Discussion: Flakes Fly Tonight, Weekend Storm Trending West

Video below gives my updated thoughts on tonight's light snow and the storm that develops over the weekend. A few westward trends developed today, we will see if they hold. If they do, then coastal areas are in play for more snow Saturday. More tomorrow morning.

Thursday Morning: Light Snow Tonight, Wide Right This Weekend with a Suprise

Good morning. The arctic front has arrived and much colder temperatures have come along with it this morning. This cold air will hold for at least the next 5 days with temperatures only reaching the upper 20's to low 30's for highs and teens for lows. Bundle up!

Summary:

• Light snow moves in late tonight for most areas
• 1-2 inches with the higher amounts closer to the coast
• Locally 3 near Long Island and Boston
• Snow ends by day break south to north
• Weekend storm misses to our east and scrapes the coast with light snow
• Areas near Boston need to watch out for enhanced snowfall Saturday night due to something called an inverted trough
• Still a little room for the weekend storm to trend west but not enough for major impacts inland

Light snow moves in later tonight as a wave develops along this arctic front. Snow should start a few hours before midnight in many areas..

By day break it is moving out and focusing on the Boston area..

Since it will be very cold there will be high snow ratios. This means only a 10th of an inch of liquid can produce 1.5" of snow. 

Right now I like this ratio adjusted snow projection for amounts...

General 1-2 inches with locally 3 near the coastal areas especially near the cape.

There should be some travel impacts due to the timing of this system.


We then move on to my whiff of a weekend storm. Believe it or not, the models have trended back west a little due to enhanced blocking but it is too little too late. However, an interesting situation is developing where something called an inverted trough can develop as this time passes by. This means a small area of heavy snow mostly likely near Boston. Lets take a look..

As is most major models now show a close miss for Saturday..

This can still trend about 50 miles west so coastal areas and the southern Mid Atlantic say around DE, VA, E MD, and NC need to keep an eye on this.

Heres where things get interesting. As this storm scrapes by with light snow in coastal areas an inverted trough can develop somewhere near Boston shown below..

Inverted troughs are small scale features that can produce a small localized area of heavy precipitation or snow. They are extremely hard to predict but models have been hinting on this feature to develop somewhere in that red circle on late Saturday night. If this occurs there will be moderate snowfall amounts associated with it. 

For example look at the GFS snowfall projections because of this inverted trough..

We are going to have to watch this closely due to the difficult nature of nailing this feature down. Just know its possible. 

Thats all for now, I will have an update on the light snow and the weekend situation later tonight around 8pm.

Wednesday Morning: Loosing Confidence for Weekend Storm, Light Snow Friday

Good morning everyone. As you are aware by now I am/was tracking the potential for a coastal storm this weekend. From the weekend I told everyone that this is pure speculation until we saw the "players" come on the field. Well today is Wednesday and those players (upper air disturbances) are getting close to the field and I do not see the overall trend I am looking for. The towel is in my hand but I will wait till tonight until I throw it in. 

To start off, it looks like we can see some light snow on the arctic front Friday morning This is better than nothing and most models are trying to show this below..

Expect 1 possibly 2 inches of accumulation as this will be a very high ratio snow because of the arctic air. *It will be very cold tomorrow through the weekend.*

Then the main target period approaches and right now I only have one model (the European and its ensembles) trying to support my storm idea for Saturday, although it even still has some work to do.

Most models continue keep the 2nd and larger storm threat out to sea..

The European and its ensembles are more impressed and bring this closer to the coast..

Why the difference? Well like I have talked about it all comes down to the upper air energy guiding the storm at the surface..

The below image taken from the GFS explains it again..

You can see how the approaching disturbance in the northern jet stream must be very sharp and dive into the lakes hard. If that happened then the 2nd disturbance associated with the southern jet stream would respond and hug the coast closer. Right now, the gfs is not sharp enough with the northern disturbance and it allows the 2nd disturbance to round the bend wide right resulting in an offshore storm at the surface.

It would not take much to change this but regardless I do not like the lack of trending on the major models. A few European ensemble members have a big storm but that is not nearly enough to make a case. It is for this reason that the towel is in my hand and I will likely throw it in by tonight or tomorrow morning once I get a little more data.

Stay tuned. 

Tuesday Morning: Waiting and Seeing

Good morning. There is not really to much I can add from yesterday's post. The period to watch is this weekend as a small disturbance might effect the region Friday with a larger storm threat on its heals. At this time, there is no real support from models to make any bold predictions. Most guidance takes the storm systems south our our area as the upper level energy does not amplify properly. The key will be to wait till about Wednesday to see if any of this changes. Thus, we are just speculating at this time.

You can see how models are south over the weekend..

This is due to the flow too flat and unorganized. If you want a stronger storm that at least has a chance of moving more north, you need to change a few things..

For one, the southern piece of energy circled needs to be sharper and less flat. That northern piece also has to dive in sharp enough to help turn a developing storm north. Right now no models show that. The only reason I am not calling this threat off is the fact that these "players" are not on the field yet meaning the energy is not property sampled by the models (it is way off the country). By the time we get to Wednesday, I should be able to say if this has any merit as those disturbances will be in better sampling range for the models. 

So we will see what happens. I always want to show you guys what can happen as opposed to what the models just project will happen. That makes things more interesting.

More to come. 

Monday Morning Weather Discussion: Still Eyeing Late This Week

Happy New Year everyone! Will the first week of 2017 feature snow? Still too soon to know for sure, but as I discussed in my last video I am watching the evolution of the weather pattern at the end of this week for a chance. 

Here is a summary:

• Peroids of cold rain today and tomorrow with temperatures in the low 40's
• Weather clears out by Wednesday with cooler conditions
• Very cold air moves in for Thursday into the weekend with highs in the 20's for many areas and lows in the teens
• We then have to watch for potential winter storm development over the weekend
• This is still speculation as many factors need to come together
• Over the next few days we should start to get more clarity on if this becomes a real threat
• No sustained warm ups on the horizon, winter is here

Rain today and tomorrow as low pressure moves through the area. The track of this low allows some warm air to filter in..

We see clearing on Wednesday as very cold air approaches from the northwest towards the end of the week..

This is ingredient # 1 for storm development- cold air in place. 

We then have a few pieces of energy to track which would need to come together properly for storm development. These pieces are labeled below..

A storm developing will depend on if that northern energy can dive sharp enough into that pacific energy ejecting from the west. If these two pieces come together perfectly then we can see a big storm. However, if that northern energy comes in too flat or that pacific energy ejects slower then we have nothing. The models right now are wobbling all over the place on how all these ingredients come together. These rapid swings should continue for the next 48 hours at least.

The one thing that has been more consistent in this set up is the -NAO (high pressure over Greenland) and a vortex of low pressure in eastern Canada as seen labled above. This is a major factor in helping that cold air stay locked in ahead of the storm and this alone makes it worth discussing this threat.

So lets get to surface projections. Right now most models show a storm developing offshore due to a flatter interaction between the northern and southern energy..

There have been a few model runs however that have blown up a storm due to the factors being in sync. The next image shows the GFS model from last night valid for Saturday night..

You can see the aggressive output here with a major winter storm. I show this as an example of what can happen of all the factors come together property. There is absolutely potential on the table here.

So where do we go from here? It will be critical to study model trends over the next 48 hours and see what direction they go. If by say Wednesday we still see the hint that the bigger storm can develop then you will start to see me take things more seriously and start to forecast.   At this time however all we can do is just sit back and watch. There is simply just too much margin for error in the models this far out to make a prediction. 

More to come.