End of March

3-19  Trended west from yesterday.  No real reason. Looking like mostly rain and from 1.5" to 2.5" of it with 30-35mph winds at the coast and gusts inland to 40mph. Just a nasty spring noreaster.

 

 

GFS and Fv3 on board with it being a coastal hugger too. This would still have brought us rain in January.

CMC is off on its own with a 966 low off NJ and hurricane force winds.

 

 I really don't see how much further back it can go.  Wouldn't surprise to see if bump east a bit.
Noting how the GFS starts it later.  Still need to watch when this thing starts to deepen.  I think the NAM is weird in that with the cold air coming in, as well as the upper level vorticity and negative tilt that it doesn't deepen the low, at least in the 18z run. It goes from 1010 to 1003 in 6 hrs (45-51) then as the upper energy hits it, to 1001,999,995,992,992,990 every three hrs.  Or from 1010 to 990 in 24 hrs.  Should be more.

As of now, it s 80% chance rain, 20% chance of any snow for the tristate. 

Then there's the 26th

3/18

All hands on deck - as the day progressed, so did the development of this storm.  Just as it should with an upper low coming down.  The saving grace for snow haters is that it will be pretty warm ahead of it.  Also, its trending further west.

Todays Euro runs.

The problem with the Euro is that while the 1000-500 thickness shows snow for us, its the boundary layer that's warm (thickness is a description of the temperature from surface to 18,000 ft).  If the storm develops faster then there's a chance CT and RI get some snow out of this.

 GFS just came on board...

FV3 had backed off the snow idea





UKIE was still farther east.  Usually it overdoes phasing, this time it misses it. It really should be further west by the upper low.

A bunch of things can happen -it can keep drifting west, which I'm skeptical of based on where the upper low is coming in.  It can form quicker or further south as the NAM is indicating, which might result in a rain to snow situation.  It can bump out to sea and graze us, which might also bring some rain to snow. But I like today's maps.  I think if the upper levels arrive when and where they do as depicted today, then the low forms closer into them.  If those upper levels flatten out or are slower, then maybe more west, but if its too slow, not at all.  If they push faster or further east, then it goes out to sea.

NAVGEM is furthest east by the UKMET which is a red flag for the UKIE.  Otherwise models look lined up nicely.

3/17
We had two events to watch this week.  The first was a light clipper that comes through on the 18th.  Moisture is limited, but could put a dusting to an inch down in places anywhere from Baltimore to Hartford.  Lately its been more focused south towards Baltimore.

The second one is more interesting.  The evolution on the models is a textbook demonstration as to how hard being a meteorologist is.   I started looking at this one when the long range EPS (euro ensemble) put forth this forecast run on the 10th.  Upper low coming into the midwest with a storm coming up the coast .

It further developed it to the strongest storm of the season

 

It then muddled around in different forms...

Then it simply disappeared for a few days until this run on the euro operational brought it back yesterday

 What happens when a trough enters the US in the Great Lakes and pushes down is that a storm usually forms just in advance of it.  As depecited above.  Now timing and placement would still need to be ironed out, but it should happen.   But then there's this mornings Euro run which is just a frontal passage with no storm at all.

Meanwhile the old GFS went from frontal passage to storm.  Now note the storm is offshore, but the trough axis is pretty far back which doesn't seem right.  Below is the trend showing how its developed in the last day.

Then there's the new GFS-FV3 which buries us.  Its trended to the strongest storm of the season.

Leading to this result

Being 5 days out, what do you forecast.....  right now snow showers is a good bet with frontal passage.  But the GFS and CMC have a storm off the coast which is out of touch with the trough. NAVGEM is furthest east where it belongs.

Mar 4

Results
We had 12" in Newtown, with some getting 14" in CT.  All snow!

2-28  The time frame has split into thirds.  3/1 light snow, 3/2 storm, 3/4 storm.  This may NOT be the last of the snow either before it warms up for St Patricks day (hopefully).

Much of this was mixed in with the 3-2 post, which has now developed into its own nor'reaster. 

This is from my post at  WX Disco

Storm moves fast.  Enters south of San Fran on Saturday.   Its a pretty zonal flow ahead and confluent to the north.  Argues for it to move W-E

24 hrs the Upper Low (in Red) is halfway across, slightly south of entry.  Surface low forms in Blue over AL.  No ridge in front.
Normally you'd look for energy behind it to form a deeper trough, forcing it to move north.  But that energy is strung out and not diving down. There's not much forcing the storm north.

By the end of the run the surface low is off NJ.  The Upper low is barely recognizable over KY.  Its just a bit north of the latitude it entered.  Something has moved it a bit  north, I just cant see what.
Surface low in blue is over SNJ.  The troughs aren't lined up and while the NWS in Upton says that there is phasing, to me it seems that the energy in the northern stream stays separate.
The green lines are various trough axis.  The northern trough is positively tilted. The middle trough more neutral, but this is more of an opinion than fact.
You can argue there is some negative tilt in the middle trough, but my point is more that they aren't aligned very well.  This may change.  But I wonder if you play this out a few more frames does that energy in the upper midwest push the storm further east, or does it dive further down and bring the storm further north.  It looks to me with the trough orientation that it pushes it out.

Things that can go wrong:  Our main energy hits CA in 40 hrs.  How accurate is that without sampling? 
The energy on the SE side of the green line by the lakes is actually over Canada now.  The energy behind the green line over MN/ND and Canada isn't sampled yet. How much influence does that have if its not correctly modeled. 
The adage that the latitude a storm enters it exits is appropriate due to the zonal flow.  In this case its a little off at the 500mb level.  Ideally it would be exiting over the DelMarVa.  
Lastly does the Saturday system muck things up ahead of this.  If that develops further, what happens?  There's also two shortwaves at hr 45 - one near Idaho the other over the lakes that can throw things off a bit.