Mar 1 & 2

3-1

Woke up to a half inch of light snow this morning.  A little surprised at the timing, but otherwise expected it.

The below scenario has substantially evolved since the 25th and I haven't had time to update.
Instead of one storm, we've had three.  This morning an upper level disturbance moved through, a little further north than expected, bringing snow all the way to CT.

Its going to be followed by a more organized low pressure system which now is forecast to bomb off the NJ coast, especially as it moves by SE Mass.   Using the NAM for sanity sake.

This is unfortunate as I'm leading a church retreat on Saturday that we've been preparing for since last June.  The R/S line for this is going to be fun to watch.  Long Island and Central NJ seem to be the battle area.  Also fun to watch are the various snow maps.  GFS sniffed this out first, followed by the NAM and Euro. 

Euro

GFS

NAM

To be honest, the GFS seems overdone.  I think 4-7" is more likely than 10", but the way this has been developing/trending, maybe we see a foot. 



2-26
From the 3-1 thread at wxdisco, I thought I was opening, but Shaulov beat me

Sometimes size doesn't matter.
Upper level disturbance coming through on the first, separate from the system hitting the NE on the 28th and from the following coastal or cutter on the 2nd.  
500mb and 700mb show the upward motion.


700 RH is moist

Results in this surface

And this snow

   




2-25
Another forecasting nightmare.  I blog to show and remember how difficult it is to predict the weather.
Saturday's storm has looked to be a rainstorm for most of the area as a low cuts through the lakes.  However, this isn't set in stone.  And the models at 5 days out are all over the place. The two models that are the most different are....the GFS and European.  So lets look at he 500mb maps and see why.

Both start off fairly similar on thursday. System over Canada, ULL entering WA/OR




In less than a day the differences begin. The GFS unwinds the energy in the PACNW and sends it into a ULL coming down from Canada.  The Euro holds the energy back (a known bias), but more importantly, doesn't send the ULL down into the CONUS, but keeps moving it east in Canada.


The GFS has the pacnw energy start to build a ridge which influences the ULL in Canada, which it has held back, causing the ULL to dig down a little as the energies interact.  The Euro keeps them separate.

Then you end up with a strong storm on the GFS, but just strung out energy on the Euro.


Resulting in this surface map.  GFS with low going toward lakes.  Euro with some weak energy seen over GA/SC on the 500mb map triggers a weak low off the coast grazing the mid atlantic


Other model solutions - UKMET looks to completely ignore all of this.

CMC hits us with a southern system

And JMA and WPC have what is probably the right scenario - its whats happened all season. A low to the lakes, but a second low forming.  This solution puts us into that snow/sleet/ice type of storm we've had all year.  If the secondary is stronger, its colder.  If its weaker, then we are more likely to get rain until you get north of MA.

Feb 28th.

2-28  Only a dusting from this. 

2-25
First, lets look at Thursdays event. Its a shortwave coming down from Canada over the lakes.  Should hit overnight and believe it or not, may be ALL snow.  First all snow event for us.  Now it depends on the track of course.  GFS and Euro are similar, so I'll show the GFS. Note on the GFS how that LP comes up from the south and meets up with our event.  That phase was forecast by the Euro days ago, but right over us resulting in a huge blizzard.

 NAM is a little further north which is typical.  But as I type the new run is coming in.

We should be in for a 1-3 or 2-4" event over NNJ, NY, CT, RI.  If it trends further south, perhaps even Philly sees some snow.

2-18 Hudson Valley, CT, MA, RI special

Results

2-18  1-3" in Albany area including Litchfield.  2-4 rest of N CT and RI.  3-5" in MA
Radar image shows basically what happened. Precip split N and S of us.  We did get some showery type of snow later and some sleet mixed in over night.

2-17
Been watching the 2/18 and 2/10 period for a week now.  Two systems, both weak and not much to be excited about.  The first will come through tonite.  For areas north of the Merritt I think should remain mostly snow and 2-4".  From I 80 south, ice/rain.  In between 1-3" snow with some mix. 

The 12z model runs were fairly diverse with the ICON having 1" and the RGEM having 6".

Icon

 

RGEM

Euro is right in the middle.  GFS is lighter and warmer.

Euro

GFS

Should note the GFS map may include sleet and ice, so it really should look like the Pivotal map

NWS has a winter weather advisory out for the northern suburbs.

After the heavier stuff falls overnight, Monday should be dreary with either some light snow, freezing mist or rain.   Nothing to accumulate unless you're further east in RI/MA

The 18z Nam threw out some pretty impressive precip for some reason.  Could be that it sees the -8c line as collapsing in some heavier precip and during the upward motion at 10,000 feet.

That resulted in this snow map, which is less likely, but still possible.  This type of snow would required a winter storm warning.  18z GFS came in a bit heavier too, though more along the CT/MA line

So look for 1-2" in NNJ, LI, CT coast.  2-4" from the Merritt to I84 (with some potential for 6") and 3-5" for 84 to the MA/VT/NH line (with some potential for 8")