Winter wakes up

1-24  Results

We had 2-4" generally in the I84 corridor with 4-5" to the north.  DXR reported .35" of ice. Meriden Airport  reported .57" of ice.  I'd go with .45" for here. Other reports from Upton are here

Started as snow Sat evening, transitioned briefly to sleet, so that we didn't even hear it.  Then around 3am we lost power.  Came back around 4:30.  Then went off again around daybreak.  Generator went on around 8am.  Power came back around 11:30am and went off from 2:30pm Sunday until 5pm Monday.

Temps plummeted to -1 Monday morning and the generator ran longer hours than usual. Winds gusted to 40mph.  Newtown had 25% of customers without power at the peak.

The low pressure actually passed just south of LI, which was only forecast by a few models, NAM3k, WRFARW2 and ICON.  NAM 3k came closest to idea of ice. 

1-19 - Well its here.  NAM abandoned the idea of a southern low, now all models agree.
NWS was a little slow recognizing this but has since lessesed the expected amounts.  These snow amounts are only possible if we get a good front thump of snow sometime between 10pm and 2am (adjust to 8pm and midnight for NJ, etc).  I'm uncomfortable giving up on the idea of ice in the I84 corridor and north.  But snow looks right. Its not all that cold out at 6:30 pm.  32°

1-18  late afternoon

Despite many attempts to draw a snow map, I've given up.  The system coming across the country now has little opportunity to shift. The questions are does it head through the Cumberland gap and out the Delmarva/ACY area, ala the NAM, or does it go through PA/NJ over NYC and inside ACK?

Whichever, we will get some heavy snow to start.  Typically these events stay snow longer than forecast, and the ground temp stays cold longer. Moisture streams in faster than the rise in temps.   Then the NAM has us in CT going to sleet.  GFS/Euro/CMC/UKMet have us turning to rain.

Winter Storm warnings have gone up for most of the area. The NWS office in Upton has the following outlooks

 I think it may be overdone, but only by an inch.  I like this map too.

 Euro is my second favorite, GFS third

12z Euro

12z GFS

Freezing rain remains a threat.  Pay attention to this line as it can cause some serious trouble.  NWS says its more likely sleet than freezing rain though.

1-16 evening

We did see shifts today in the 12z runs and the NAM is starting to come into range and looks to be colder than the GFS.  Actually, the hr 84 of the nam had the temp here at 19 while the GFS was 35.  😲
I can't figure out why the GFS isn't shifting further SE, which is concerning me.   The pieces of the storm are the main storm(A). Energy from the north (B) and energy from the west (C).

 

Parts B&C act to steer the storm.  Should they remain separate from A, as depicted on the NAM run below, then the storm should exit south of the area and bring more in the way of frozen precip.

If either part ends up in the back side of the trough, that may cause the trough to tilt negative and the storm comes up to our west or over us. GFS was advertising this yesterday, but no longer does.  The problem is that it didn't correct enough.

WXDisco comment on this


1-16  Tomorrow is the day to really start taking model runs seriously.  Yesterday morning started out with a shift NW of the GFS, Euro, Navy and GEM.  Then in the afternoon, the UKMET, usually the furthest west, jumped to an off shore solution.  Slowly the GFS and Euro have followed with the shift evident in the images below.   The energy for this storm is hitting the coast on the 17th.  Currently there is no data other than from satellite so models have less to go on.  This is why through the day Thursday and into Friday, there could be some major changes.

Wednesday morning Euro snowfall forecast

Tuesday afternoon Euro snowfall forecast

0z Wednesday Euro ensemble members

12z Tuesday Euro ens members

The GFS snowfall GIF shows the retreat NW yesterday then a jump to the coast today.

The Experimental GFS Replacement FV3 also shows the advancing southeast of the snow line

GEM shifted SE too

Timing and track are not the only open questions.  We have to contend with two different scenarios with type of storm as well.  GFS is more strung out like a frontal passage.  Two lows develop and as the trough approaches, they ride up in front of it.  The other low is by the yellow convection

While the GEM, Euro, JMA, UKMET all have a single low.

CMC single low as example

The timing portion is do they ride up before, after or during the cold front passage. The track depends where the trough is - the track is pretty certain to be between midway to the 40/70 benchmark and Albany.  Closer the benchmark means all snow, Albany means snow to rain.  In between may result in snow-ice-rain-ice-snow.  We're only talking 200 miles difference here 4 days out.


1-13  Winter woke up today in the Mid Atlantic with 2-6" of snow reported in the VA/DC/MD area.  But as alluded to in the last post, a more meaningful storm is brewing for MLK weekend.

This will grab attention!

0z Canadian

6z FV3

18z FV3

18z GFS

Well you laugh and say, thats the GFS or FV3 - what about the Euro

 

We're a week out or so.  Don't be surprised to see this move out of our area the next two days.  But if that happens, check back in on day 3 or 4.   

Details as to what causes this storm when I have time to look at it more, along with a what can go wrong analysis.  Sadly with work and a wake tomorrow, Tuesday might be the earliest I can spend some time.