Winter Storm March 2-4, 2018 (snowfall, warm, average, days)

[Cambium]

Pretty interesting setup that might be happening.


1st.. There is the potential for a long duration and big storm around this time frame. GFS been showing it since 4 days ago (11 days before this storm date) but now all other models are showing it so confidence is increasing.


Interestingly what's happening in Europe is the same reason this "slow" storm could happen in Northeast U.S. #AtlanticBlocking


Figure I make it fun with a poll. There will be cold enough air to create snow...and lots of it if this thing is going to stop or slow down.


Who will get the most snow from this storm.. Still 6-7 days away so details will change multiple times a day.

[Cambium]

Poll closes Feb 28th so you have time. But you get extra bragging points if you pick the winner this far out.

[Cambium]

Here is the latest Euro for this storm.. *changing details of results day after day but watch the storm itself.

Comes from the south, slows down, stops, and heads SOUTHEAST. That's because its blocked from moving Northeast

This Euro update has 3-5" of precip for about 40 straight hours in PA and NJ




This is the snowfall total from that update.. That's what happens when you get a big slow storm. But this is the detail you aren't supposed to buy into yet. Will change many times.

[Cambium]

Ok, lets talk about the latest GFS12z today.. You can see these maps and play the loop with this site.


So... Thursday 1am March 1st, the storm comes from Southwest/Texas and heads towards the Great Lakes. A Great Lake Cutter is Never good for snows in the Northeast because you see what it does? It pushes warm air up the Eastern U.S..


At this point its snowing in Western Iowa and Minneapolis Wednesday evening/Thursday night but raining in Eastern Iowa near the storm center...


Take note, below freezing air mass West of the storm.... watch what happens next.. Where does the storm go? It doesn't keep moving Northeast into Canada..





This is 24hrs later...1am Friday March 2nd..


Whether a new storm develops around the coast or that same storm travels EAST remains to be seen but the GFS has the storm over NJ/NYC at this time...(Probably be a new low forming)


Note the cold air aloft at 5000'. It's crashing below freezing behind the storm.. Big push of cold air as the system is moving East..


I put the surface precip map in bottom left corner. It's still all rain for NYC metro, MA and PA. There's a dry slot in PA between the 2 systems as they merge together..


Now watch...





18 hours later.. 7pm Friday March 2nd the storm is STILL off the coast and moving SouthEast! Blocking in North Atlantic preventing it from moving out fast or Northeast...


So.... As the cold air behind it crashes down, the rain changes to snow in NYC and Southern New England and heavy in some areas because the 850mb (5000') temps are below freezing at this point.





It wasn't the most exciting run as far as snow totals but that's good for now.. This is the jist of the pattern and storm situation and that's all we are looking for right now...

Is this storm continuing to show up and where. Details come much later.


One thing that's been consistent is the prolonged period of precip. Some areas might go over 30hrs with it.

[speagles84]

From the run it doesn't look like I'll get any from this storm, you think there's a chance i Will? For now I'll bet on Scranton

[Cambium]

Originally Posted by speagles84

From the run it doesn't look like I'll get any from this storm, you think there's a chance i Will? For now I'll bet on Scranton

I think might be a rain change to snow for many of us. Just have to see how much of it is snow.


What's nice is the long duration of it. Gives a chance for atmosphere to chill down and changeover as opposed to just rain and done.

[Cambium]

Here's Latest Euro12z for Allentown, PA.


2.27" qpf and 60hrs of precip.


Looks light mostly though. Each number in the precip column represents the 6hr total to that hour. For instance. The 0.63" showing for 6z(1am) Friday is what falls Thursday 7pm to 1am.

Euro shows the 850mb temps crashing as I showed before with the GFS.


Looks like this might be a Rain to Snow scenario for many of us. Still 6-8 days away, we'll see.

[Cambium]

With lack of arctic air any moisture from the south will be mostly ........ well... rain.

Just to update...... All overnight models now show mostly rain for PA into Southern New England.


Now 5-6 days away so you can't ignore that.

Storm is happening, now we're finding out the details and it might not be a snow lovers storm.

[Cambium]

Quick discussions from NWS regarding this storm..

Eastern Ridge slides east allowing the storm to move in. Blocking in North Atlantic will slow things down

National Weather Service New York NY
717 AM EST Sun Feb 25 2018

The models are in good agreement that the deep layered ridge axis
slides to the east on Thursday allowing a cutoff low to track into
the Great Lakes Thursday then into the northeastern States Thursday
night and Friday. The models then differ on how fast this cutoff low
exits to the east for the remainder of the week. This will
ultimately be dependent on the location/strength of blocking
downstream over the N Atlantic. As a result, while there is good
agreement that rain develops over the area by late Thursday, there
is not good agreement over when the precipitation ends (solutions
vary from Friday night through late Saturday at this point). There
also is not good agreement over how much, if any, wintry
precipitation the area sees with this system, with the best chance
over interior areas to the N/W of NYC and Long Island Sound

Technicals from NWS Boston and a Snowmeggadeon 2010 reminder?? . lmao! That's when we had crazy blocking too.

NAO deeply negative! They are thinking this storm goes south from where models are showing it now. That would imply snow into the picture north of Philly I think.

National Weather Service Taunton MA
648 AM EST Sun Feb 25 2018

Overview...

Blocky N Atlantic pattern associated with an anomalous -NAO of 4 to
5 standard deviations (SD) below average, associated +3 SD H5 high
retrograding W into SE Canada, parent 1040+ surface high, pressing
the thermal wind axis S thru which N/S stream impulses merge having
dug through a prevailing W CONUS H5 trof before ejecting, stretching
E. Energy piling up, slowed, pressed S by high pressure building N,
favorable storm development emerges off the E CONUS coast. Airmass
juxtaposition key as to outcomes towards the end of the week after a
quiet start. Only confidence is persistent NE winds of significant
duration during high astro-tides, coastal flooding concerns. Lower
confidence otherwise, consensus forecast guidance heavily weighted
with ensemble means continues. Hit targets of opportunity below.

Thursday into the weekend...

Battle of airmasses between an ejecting low out of the Central CONUS
up against building high pressure into Canada. Slowed pattern, each
building their own weight, juxtaposition between the two ultimately
determining outcomes.


Strong -NAO, -4 to -5 SD, would expect a cool,
dry setup for NE CONUS, storm track lying further S per block. Mid-
Atlantic getting crushed. Interrogating Washington DC top 10 snows
versus the NAO time series after 1948, 5 out of 7 storms, 3 prior to
1948, were associated with a -NAO around -3. Recall February 2010?
Washington DC "snowmageddon" of 17.8"? Monthly NAO averaged near -2.
Cherry picking data? Perhaps. CIPS analogs? Interrogating where NAO
indices <= -1, noting trend of sliding low S of New England, further
so with a stronger -NAO.

Ensemble members clustering off the Delmarva Peninsula while model
deterministic solutions are hugging further N close to Long Island.
Believe S trend is emerging per 25.0z EC. Echoing prior forecaster,
strong -NAO, subsequent block, storms forced E, slowed, evolving
into coastal storms, but storms could get suppressed S. It is all
about timing. Simply wait and see with later forecasts. But per
climatology, prefer ensemble clustering / 25.0z EC which are further
S compared to all other guidance.

Warm-core system, absent Arctic air, precip-type issues
mainly as rain / snow first glance. Confident of persistent NE winds
during high astro-tides, coastal flooding concerns.

[Cambium]

New Euro is out and its stronger with the storm and a tad colder. But still rain for NYC.

Here's the snowfall total from this new update.

Concord and Boston have 48hrs of precip totalling over 3 inches and have rain go to snow but get over an inch liquid that falls as all snow. That would be wild. Flooding will have to be a concern if this continues to be shown.

Need storm to keep trending south for NYC to be in. Right now, Mid Atlantic looks to get spared from any snow except for the mountains. Still 5 days away.