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.