Friday, March 18, 2016

Friday Morning Storm Update: Hes Cut!

Good morning everyone. I tell you when it comes to tracking storms there is never a dull moment even within 50 hours of an event. The best way I can describe last night model runs is with the image below..

Let me explain the metaphor here. For you Rocky fans, pretend the European model is Ivan Drago and the GFS is Rocky. As unstoppable as the European model seemed all week, the GFS has just come in with a huge right hook last night knocking it off its axis. Translation: Last nights European model run has shifted east towards the GFS! Now when we try to forecast you can not be impulsive but you need to try to stay realistic. We all know how Rocky IV ends and I will discuss my updated view on the fate of this storm below. 

Here is a quick summary of my updated thoughts. I also have an accumulation map below. Warning, confidence levels are not high at this time. You can see why I wanted to wait till this morning to make the map.  

  • Winter storm targets the northeast Sunday into early Monday
  • There is a chance of snow for all areas extending from Baltimore/Washington up into Boston. 
    • The intensity of this snow is still a big question mark and will all depend on the track of this storm
  • At this time most major models are folding towards the GFS models more east solution
    • This could be a red flag and we need to take this seriously
  • The more east solution means a lighter snow event and less impacts further inland into PA and Update NY, VT, NH
    • However today model runs should tell the tale
  • My map below is my best efforts at accumulations 

I am taking the middle ground here with snowfall. I will hone in and tweak this to a final forecast this weekend. At this time the darker blue is where the heaviest accumulations could be. This is not just based on precipitation intensity but also surface temps. The 1-3 inch area will have a warmer surface so snow will not accumulate as easy. 

So lets take a look at modeling. The European model overnight caved to the GFS. I will admit I am very surprised at this...

Here was the GFS..

The Canadian is still very aggressive but did shift east..

This is all due to the energy in the upper atmosphere being flatter and not as amplified. I talked about this yesterday. 

So here is the bottom line. The models are obviously picking up on something here which is causing the east shift. Kudos to the GFS for picking this up the earliest. One of two things will happen from here. One, the models continue jog east and this is a very minor event (bust) or two, there is a little bit of a jog back west and this is more significant. My map above is based on a slight jog back west. 

We will see what the data looks like today. I will update around 5pm.


  1. HEY WILLY, what about NAM? It took a big shift east between 0Z and 6Z. Remember what happened when everyone ignored the NAM back in January. Then again, NAM was staying consistent back then, whereas it too is being very loosey-goosey this time. Just like the big bad Champ Euro (I liked those Rocky films too). Seems like GFS has come closest so far in taking a stand and sticking with it (like Rocky -- didn't Drago say during the fight "he's made of iron"?). Oh yea, the overnite Canadian seems to have gone to a classic "phase at 40-70 and hold for northern blocking" scenario, dumping around a foot on us. But it wasn't doing that yesterday or the day before. This one looks like it's going to the final round. Jim G

    1. Yeah the Nam and the sref ensembles all east not a good sign at all. Haha I thought people would like that rocky analogy. So basically this is boom or bust many ens members are still west but if at 12z this stays east we might be looking at the knockout blow. The final countdown is underway!