January 25th-26th Storm Observations

BLOG

http://epawablogs.com/significant-east-coast-storm-brewing/

EURO Ensembles look like OP.

This is game on!

This is getting exciting!

What does OP mean?

Frank_Wx wrote:BLOG

http://epawablogs.com/significant-east-coast-storm-brewing/

Excellent. At least we'll get something out of this, maybe substantial.

He was saying the euro ensembles looked like the operational run of the Euro

This storm warrants a chat tomorrow night at 9pm. Spread the word.

If the EURO trends a bit north with a stronger storm things will look great, 18z GFS looked pretty good for CNJ through NYC

Looks like the NAM has adjusted south

ill be here! No classes for me wednesday and thursday!

The latest 00z GFS model comes out with a different solution for the Friday storm. First thing is first, it is SLOWER this run, meaning instead of starting Friday morning it starts late Friday afternoon. It is also weaker and faster. GFS only brought about 2-4 inches of snow this run, as opposed to the 5-10 inches it had earlier today. From my understanding, it sheared out the energy to our west too much and it brought less precipitation along with it, thus leading to a less ampe'd storm. One thing to note is the GEFS (GFS Ensembles) have remained consistent on a stronger storm while the GFS Operational keeps spitting out different solutions from run to run. This run looked suspect to me but it is still a possible solution. Look for my morning update where I will then show what the 00z EURO model has to say about this storm. I'm sure it will be different from the GFS...but we'll see.

Dude id post images of the other models from tn but they r a joke. All have different solutions. From suppressed to a storm that cuts to our west. I still like outlr chances as of now. But i see this as a fast moving, relatively weak storm that drops 3-6 inches with locally 8" somewhere.

Euro has around .90 precip for NYC. That's a 6-12 inch storm for many. It takes a classic nor-easter track.

0z Euro Snowfall

http://www.americanwx.com/bb/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=85939

Ill take it

If Euro of .90 precip came to fruition with temps in low 20's in many areas through the brunt of the storm someone would see 12-15 inches.

I doubt it's that juicy, but I'll take close.

Accuweather showing 1.2 inches for NYC now on Friday which would be a huge disappointment. No idea what model they're going with there. I guess the GFS.

Poorly sampled data due to the distance of the energies we need to develop this storm is the biggest reason why we are seeing these varying solutions. My advice to you all is to just observe that data that comes in today, but not truly begin analyzing until tomorrow. You're just going to drive yourself insane trying to determine which model is right. It can be a non-event to an extreme event to something in the middle. I will say that with the cut-off confluence to our northeast and psuedo ridge in the west, I do favor the non-american models right now. But time will tell.

The good old "only time will tell" adage!! Was it doc or sroc that said they are going to wait until Thursday - some sound advice. Frank , thanks for the advice.

Yeah Mugs by Thurs morning IMO we should have it locked in whether or not this will be a minor, mod, or major event. I just dont like how the ridge in the west gets broken down right as the northern stream energy is diving into the plains.

I doubt its even locked as of thursday morning...especially when the hi res models come into play showing everything from nada to a foot of snow . Im sticking with my original call of a relatively weak, fast moving system that drops 3-6". Ill take it lol

In no way what I am about to discuss is this what I am 100% sold on as what will happen for Friday into Sat, but I am a little concerned. What Im concerned with, and what the past 12-24hr trends for the many of the major models have shown is a less amplified ridge in the west, which in turns prevents a more amplified trough in the east, which in turn leads to a weaker storm, most of which slides to our south leaving us with a light snow event for the 25th-26th. Ill explain in more detail.
Here are a series of images taken from todays 18z NAM ( not because I think this is the end all be all in solns but because it illustrates my concerns regarding the trend in many of the models in the last 12-24hrs.
https://2img.net/r/ihimizer/img689/7899/jan26th2013500mbhr60.gif
This first image shows the two pieces of energy as they move past the Rockies. Notice that the southern energy is lagging behind the northern energy at this point. Pay attention also to the western ridge axis (depicted in blue) tilted towards the east, as well as the amplitude, or steepness of the down slope on the east side of the axis. At this point its still pretty decent. Its the combination of the steepness of the western ridge combined with the driving North/Northwest winds of the Polar Vortex (PV) that will dictate just how deep the trough can dig in as it makes its way east.
https://2img.net/r/ihimizer/img833/8987/jan26th500mbhr72.gif
Now here is 12 hrs later at hr72. Notice how the Southern energy is now out ahead of, or east of the northern energy. Also notice the ridge is flattening out in the west. Not good. This slows the progress of the northern energy or holds it back some delaying its interaction with the southern stream, as well as a less intense interaction with the southern stream. To better visualize what I am saying picture rolling a marble down a 25degree slope into another marble, now picture rolling the same marble down a 60 degree slope. The steeper the slope, the faster the velocity. The faster the velocity, the more intense the collision. Now in this weather scenario we need the northern stream energy to slide down a steeper slope which in turn would lead to a more intense interaction (aka phase) and stronger system as it approaches the coast. In addition since objects in motion tend to stay in motion if the ridge in the west stays more amplified the interactions of the northern energy would dig the trough further south. As the phasing system rounds the more amplified and further south trough it would allow for it to tap into more gulf moisture, and as it comes up the east side of the trough a more SW to NE track along the coast would allow more interaction with the Atlantic. This was shown not more than 24hrs ago esp by the euro.
Unfortunately the trend has been in the last 24hrs a less amplified ridge in the west as the two pieces of energy begin to interact which leads to the northern energy to lag behind and stay on a more northerly track west to east, and the southern energy escapes to the south, and therefore out ahead of the northern energy delaying the phase until its too late. By the time the primary forms off the coast the southern energy is to far out in front of the northern energy for the phase to occur in time.
Hr 84 500mb
https://2img.net/r/ihimizer/img46/1200/jan26th2013500mbhr84.gif
Hr84 surface map
https://2img.net/r/ihimizer/img845/6167/jan26th2013surface.gif
Keep in mind the pices to this puzzle have not come ashore in the west as of yet.

Scott.......Lee Goldberg just said something similar to what you just said here, yet my local station in CT said possible 8-10" of snow.

I guess both are right this stage of the game. I really believe that it will take until thurs morning to sort it all out.

Just checked in today and wow trends were bad, oh well, still time to change.

By now, we are aware that the American models are showing sheared out energy coming through the northern tier of the country (our northern stream) with a flat psuedo ridge, while the non-american models are a little more bullish but develop a later phase. The NAM tonight came in more amp'd with the ridge out west, but it still tracked the northern stream energy due east into the lakes. Based on synoptics, that should not happen and the northern stream energy should have dug into the trough...even if it did not penetrate that much. Now, the only thing I can think of is the NAM is completely mishandling the strength of the northern stream energy as weak, very weak, and a weak s/w will follow path of least resistance and track toward the GL, even though the PV is situated up north. But seeing a pretty amp'd southern stream means that if that northern stream dug as I think it should have, we would have our storm. If GFS shows a NAM-like solution tonight I would start getting concerned, and if it continues at 12z tomorrow I think that's all she wrote.

The NAM said hello sunshine...unreal

Scott, just read the writeup. Good stuff. But if you look at the h5 maps, there is a lot of energy on the backside of the trough. The split-flow pattern being modeled on the American models seems way too extreme and that is disrupting the western ridge. The non-american models still have a western ridge and maintain somewhat of a storm. So we will see what happens...