730 am Update: Final Forecast, Made Some Changes

12pm Video Supplement: Warm Air Winning

**Don't forget brutal arctic air rushes in Sunday night. Monday morning will be in the single digits**<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Good morning. A few changes to discuss this morning. The current data is coming in  warmer than originally projected and that will have forecast implications today. It is time to get ahead of this and update things.

Summary:

• Storm is trending warmer than thought based on current observations
• This means rain will be more of a factor vs some initial ice and snow for many in the tri-state
• Ice and snow line now will be pushed more northwest on my new map
• NW NJ to southern New England can see high ice impacts (freezing rain)
• I circled region in yellow on my new map.
• Lower snow accumulations for some compared to yesterday
• Storm starts roughly around 5-7pm today.
• snow to start for many, changing over to ice and rain (see new map)
• Still bitter cold on Monday

So lets get to this:

The Final Forecast:

Although it may seem cold out now, the models are now insisting a warmer surge moves in by this afternoon. Image below shows the model trend in surface temperatures (warmer)...

My whole concern about today was that the dense cold air would hang in tough as the storm approached. However, as recent modeling trends show above, more warm air looks to move in as storm gets underway. Notice how the air may warm above freezing even up to northern NJ. We will have to see if this actually happens.

Here is an updated model projection of the storm starting at 5 pm today ending tomorrow morning...

Heavy snowfall for the interior with that ice zone more northwest than originally thought.

Here is current model consensus for the ice zone...

A narrow but potentially high impact band of freezing rain. That spells trouble.

Stay safe out there, I will have another update this evening as storm is underway. 

6:30 Update: Winter Storm Hits Tomorrow

No changes to this mornings forecast guys. I like what I have. Strong front end thump of snow later tomorrow afternoon followed by sleet and freezing rain for many in NNJ. To the south it does change to plain rain. Storm over by late Sunday morning with bitter cold air to follow (close to 0). More details in my latest video. Final update out in the morning.

Friday: Updated Winter Storm Forecast

Good morning. The new data is in, and it is time to make a few tweaks to my original forecast. A major winter storm will be impacting most of the region Saturday into Sunday.As the story goes every single time no forecast is easy. In this case, my biggest concern is trying to nail down a narrow 20 mile band of freezing rain that I think will occur with this storm and cause big impacts. Also, trying to nail down where the heavy snow accumulations cutoff is the next challenge. Combining model data with experience I have come up with this as my updated forecast map.

The timing is Saturday afternoon through Sunday Morning...

Looking at this map the critical areas are the light and dark pink. Somewhere in this area should see signifigant icing. At this time I think its in the form of freezing rain for the light pink area. Just to the NW in the dark pink I expect more sleet than freezing rain. Some models are warmer than what I have and would shift this whole map NW but I think those models are under doing the cold air as I have discussed all week.

So lets get to the play by play of how this may evolve...

Very cold air settles into the region by Saturday morning...

A low pressure system loaded with moisture then begins to approach this cold air from the southwest...

By the time we get to mid afternoon Saturday or just past mid afternoon (3-7pm) Saturday, snow will start to break out for many areas in our region...

For areas in CNJ northward, I think the initial few hours later on Saturday is a pretty good front end thump of snow where even areas like CNJ can see a few inches pile up with several more to the NW.

By the time we approach midnight below, warm air starts to work in aloft and the snow changes to sleet and freezing rain for many s...

This is the critical forecast point as models are mixed on how far north the mixing and rain line goes. Some have it more north than what you see above. I am going on the colder side here based on experience which is why I am showing this model.

Regardless, if I am right, surface temps stay cold for many during this critical period...

This is where my iceing concerns come into play for areas in the light pink zone as there is a chance a good amount of freezing rain can occur.

As an example, this high resolution model at 4 am Sunday shows that freezing rain band. It is prob a little too far south in this model projection but you get my point...

The pink to the north is a sleet storm. Again the placement of these features is still pretty uncertain but my forecast map tries to make a prediction.

By daybreak Sunday morning the back end of the storm approaches and the narrow freezing rain band and sleet continue with heavy heavy snow to the NW. 

There is a chance that just after daybreak things can change back to snow for areas seeing ice seen below...

The storm is over for many by late morning and by mid afternoon in New England.

Then comes a major major cold shot Sunday night which will cause any liquid areas to flash freeze by Monday morning...

Although this may be a little overdone you can see how serious this cold air is. Sub zero temps possibly all the way down to the NJ boarder...

Snow and ice removal will be key Sunday ahead of this brutal air mass.

Stay tuned for my next update at 6pm tonight. I will be making the final tweaks if necessary to this forecast.

830 Video: Taking a Look at This Weekend's Storm

No major changes from this morning. I will be updating my forecast in the morning based on the new data tonight. Regardless, I think this storm has big impacts for areas in the dark pink zone to the NW. The video goes into further detail.

Thursday: Major Winter Storm This Weekend, Major Ice NW of I-95 Possible

Good morning. As our weekend storm threat continues to close in on us, we can now try to sort out additional details. My post yesterday really broke down the setup for this storm and why I thought the cold air at the surface would put of a fight. I suggest you check out that post if you missed it.

Today I want to focus on some more detail behind what the major impacts will be. As I continue to look at updated models, one word keeps coming to mind, ice. Also, who ever does see more rain, temperatures are going to plumet Monday morning and cause a flash freeze. A lot going on!

Before I get to that, do not forget we have light snow coming in late tonight till daybreak. Expect 1-3 inches for many CNJ  northward with locally 4 inch amounts by tomorrow morning.

Back to our weekend storm...


What will start for many as a front end thump of several inches of snow later on Saturday afternoon into Saturday night, will then transition to sleet then freezing rain. This is going to happen as precipitation rates really pick up. That means we can end up seeing signifigant ice accumulations by Sunday. My updated map below illustrates my point...

First off for areas in dark blue, this is an all out snowstorm with well over a foot of snow for many. The region I want to focus on however is the dark pink where after several inches of snow fall, we can see over a half inch of ice accumulate. That would not be a good situation and we need to monitor closely. Remember just because you many only see 4 inches of snow, that does not mean impacts are low. The ice to follow will be a much bigger threat.

Lets take a look at model projections. I am using the NAM model because I think it looks correct...

What starts as a front end thump of snow Saturday afternoon...

Changes over to ice as warm air works its way in aloft...

Due to the deep arctic air mass ahead of this storm...

Temperatures at the surface are not looking to budge seen blow, despite the fact warm air will work in aloft....

This spells ice storm and I am concerned there will be big impacts.

To make matters worse, bitter cold air moves in on Monday morning with temps in single digits and teens causing a flash freeze...

We still are 2.5 days away from this event. Things can change to warmer/colder as always. However, I think its important folks know whats on the table here. If it trends warmer, the map will shift NW if it trends colder, snow amounts will increase and the map shifts SE. I do think what I have looks good however.

There will be a video tonight around 830 pm to break all of this down.

Wednesday: Significant Weekend Storm, Colder Solution Prevailing

Good morning. We have a lot to talk about today as I am getting some more clarity on what will be a major weekend winter storm for many Saturday into Sunday. After a few days of evaluating the weather pattern ahead of the storm and the updated model guidance, one thing is standing out to me, we can not fight the dense cold air that will be out ahead of this storm. Models are now catching on to this idea and are not eroding away that cold air as quickly as originally thought. Translation, there is a good chance we are in for a heavy interior snowfall, and a potential high impact snow/ice storm for areas I-95 NW Saturday into Sunday. I have updated my winter storm outlook index! Our pattern change is here folks.

Real quick, before we get there, we will have a light snowfall event on Friday morning for all areas in CNJ north...

Expect a general 1-2 inches for many but higher amounts (2-4) in the higher elevations of NW NJ and into New England with this. More of a nuisance but it could cause some travel headaches Friday morning. Snowfall rates should not be too heavy however. It is over by 10am Friday.

Now, this minor storm sets the stage for the bigger storm for the weekend. Remember how in my Monday post I went into detail how the cold air this minor storm drapes down will set up a natural boundary between warm and cold air for the weekend storm to ride along.

Well, the cold air will be very cold, very dense, and very impressive by Saturday morning...

Sub zero in northern New England with temps in low to mid 20s for I-95.

The approaching storm is going to have to run into this dense cold air and try to fight it off...

Here is where things have been changing over last 24 hours on the models and the more I look at it the more it makes sense to me. It is not easy to just wipe out cold air like this. What normally happens is the cold air is under modeled. This means that although the warm air may with aloft, the temps hold firmer at the surface. This means only one thing- snow to ice/freezing rain. That outcome now is looking more likely for folks along the I-95 NW.

The big trend to really show this has been at 18,000ft where the models now are suggesting the northern jet stream does not try to phase early with the southern jet stream. This phase would have aided in warmer air moving into the region. The fact that that may not happen as early now means the cold air has a better chance of putting up a fight. The animation below shows the trend away from the phase as seen by energy in Canada retreating...

I noticed this start yesterday and the trend has continue overnight. Major forecast implication if this stays true. 

So what does this mean for impacts?

A front end thump of heavy snow now look like it can happen for many on Saturday afternoon/evening..

This would mean a several inches could pile up quickly later on Saturday night for many areas seen in blue above.

Then the warm air aloft should start to influence this storm and a changeover to ice occurs by early Sunday morning...

This will be a mix of snow, sleet and freezing rain for areas in the pink and eventually could change to all freezing rain for some. With surface temps holding steady near freezing, we can see big ice issues with this for many.

There then are indications we see a changeover back to some snow at the end of the storm Sunday afternoon/night. This detail still remains unclear...

When it is all said and done here are my initial thoughts on what impacts may be. Remember this can change considering it is only Wednesday..

Stay tuned, I will likely have a video tonight around 7pm. Lets see if the colder trend verifies.

Tuesday: Interior Snow Threat for Weekend, Light Snow Friday

Good morning. In a time crunch this morning but I want to give an update on my post from yesterday. I laid out the factors for the weekends storm and mentioned why I thought it was more of an interior snow threat. Those thoughts have not changed and the models are also suggesting that is the outcome at this time. This means all areas to the SE of New England see snow changing to ice and rain Saturday night into Sunday.

Beforehand however, we will have a nice light snow event for areas Thursday night into Friday morning...

This looks like a 1-3 incher for many and 2-4 incher for the higher elevations of NW NJ and PA into New England. Again timing is Thursday night into early Friday morning. I will have more details on this tomorrow. 

Then the main storm Saturday night...

What starts as snow early...

Changes over...

For the interior we are going to likely see well over a foot of snow fall with this. Ski areas will be happy. 

Things can still change but I think the projection above makes sense given the setup I described yesterday.

I will have more details coming by tomorrow. Need to head to the day job.