March 7-8 possible snow threat

[The Iceman]

the HRRR is late range looks cooler than even the 3k for tn...another good sign hopefully

[hazwoper]

10 minutes ago, The Iceman said:

here is my 2nd call...possibly final call as I am not anticipating many more significant changes that would alter this map. If a final call map is warranted it will be after 18z tonight. sorry for the amateur level map  this is philly centric btw so new york area and baltimore areas I could be off.

Not a bad map.  I'd probably move the 5-10" line a tad NW to start at the fall line, but aside from that pretty much mirrors my thoughts as well.

[DiehardFF]

RGEM is a great hit.

[Albedoman]

I have not look at the soundings for our area but is their a chance of thundersnow in the cards, especially where the heavier banding occurs? 

[The Iceman]

i really don't care what the rain/snow maps say...this is whiteout heavy wet snow for SE PA and parts of jersey on the rgem...great great run

 

[The Iceman]

Just now, Albedoman said:

I have not look at the soundings for our area but is their a chance of thundersnow in the cards, especially where the heavier banding occurs? 

absolutely...i'd almost say it's a certainty someone sees thundersnow tomorrow sometime between 15-21z.

[The Iceman]

mt holly disco updated at 930 this morning...seems that they are leaning towards all of PA being mostly snow at the moment. A+ disco though as always.

 

Quote

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
The next nor`easter makes its presence felt beginning in the
short term. Its worst effects will be after this however. The
low across the Ohio Valley will send its attached front across
the area this evening. Moisture will pool along it while the
nor`easter begins to deepen over the Tidewater area of VA late
tonight. Pops increase from SW to NE is association with the
front. P-type will be mostly rain at first, but change to snow
N/W during the evening. A light accumulation (1-2 inches) is
expected by dawn Wednesday in much of NJ (except the extreme
south), our ern PA counties, Cecil county MD and and New Castle
county, De. Lows tonight will range from the mid/upper 20s north
to mid 30s across srn Delaware. Winds will be mostly E/SE
around 10 mph.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Complex nor`easter to impact the region on Wednesday.

As primary low tracks from the Ohio Valley into western NY and
western PA, a secondary low over the Southeast U.S. lifts into
the Mid-Atlantic coast Wednesday morning, and then rapidly
intensifies along the New Jersey coast as H5 trough with strong
shortwaves dig into the East Coast, and is strengthened by a
120-130 kt jet streak.

Although models are coming into agreement for parts of the
region, there is still uncertainty as to where the rain/snow
line will set up. As a result, there is still uncertainty as to
snow totals, mainly in parts of New Jersey.

The 00Z/06 NAM/operational GFS/Canadian are closer to the coast
than the 00Z/06 ECMWF, the ECMWF is not much farther east. As a
result, have generally increased QPF amounts, and are expecting
up to inch of QPF for most of the region, and as from 1.25-1.5"
across much of NJ and into southeast PA.

What makes this forecast difficult is that there is no arctic
airmass in place ahead of the storm. As mentioned in the short
term discussion, precip starts out as rain, and does not change
over until the colder air filters south. As a result, as the low
lifts along the coast, the onshore flow will take over, and
temperatures will be able to rise into the 40s for much of the
Delmarva and southeast NJ, and even along the NJ coast. The
problem will be how far inland will that warmer air get? For
now, the highest confidence is that areas north and west of the
Fall Line, generally the Lehigh Valley, Poconos, and northern
NJ, will be the coldest with temperatures generally in the low
30s. Between 8-14 inches of snow will fall, with the highest
amounts in higher elevations, and slightly lower amounts
approaching I-95. The I-95 corridor looks to be the dividing
line between mostly snow, and a wintry mix that will keep
snowfall accumulations down.

For now, upgraded areas west of the Fall Line, and farther
south, areas west of I-95 to a Winter Storm Warning. Kept
portions of NJ, generally on the eastern side of I-95 and the
eastern side of the Delaware River south of Trenton in a Watch.
Some locations in the Watch area could get up to 7 inches, and
some locations may be upgraded to a Warning later today. The
Watch may also be converted to an Advisory if it appears that
lesser snow amounts will fall.

The issue with this storm is that the snow will be a heavy, wet
snow that could result in tree and power line damage that
results in power outages once snow starts to accumulate on
limbs and branches.

For winds, the strongest winds will be right along the NJ
coast, where mostly rain will fall. Keep in mind that the ground
is already saturated, so it will not take much for additional
trees and power lines to be brought down as well, but these
areas are not expecting heavy accumulating snow.

Snow tapers off Wednesday night

 

[hazwoper]

For
now, the highest confidence is that areas north and west of the
Fall Line, generally the Lehigh Valley, Poconos, and northern
NJ, will be the coldest with temperatures generally in the low
30s. Between 8-14 inches of snow will fall, with the highest
amounts in higher elevations, and slightly lower amounts
approaching I-95. The I-95 corridor looks to be the dividing
line between mostly snow, and a wintry mix that will keep
snowfall accumulations down.

 

They seem to be mirroring my thoughts on this system for last day or so.  I like it.

[ChescoWx]

12z NAM looks like a KMQS to KABE  to KFWN special - NW Chester County still over a foot but mix line is getting close into SE Chesco. Also, watch out for bigger early hit tonight with 1st wave. Seeing HRRR showing near 6" in spots of Chester County by tomorrow's AM rush

[The Iceman]

GFS continues to be west and warm concerning but I trust 3k nams thermals of the gfs any day.

[tcutter]

10 minutes ago, ChescoPaWxman said:

12z NAM looks like a KMQS to KABE  to KFWN special - NW Chester County still over a foot but mix line is getting close into SE Chesco. Also, watch out for bigger early hit tonight with 1st wave. Seeing HRRR showing near 6" in spots of Chester County by tomorrow's AM rush

If the HRRR is right then we could end up with a foot and a half of snow??

[The Iceman]

The fact that the HRRR is much cooler than both the 3k nam and the hi res RGEM is encouraging. Also makes me think the gfs is entirely too warm as the low is similar on all the models at that point.

[RedSky]

It is certainly taking on the classic I95 climo storm look from Philly to NYC, there is a whole generation of people now that are use to these big storms snowing to the coast 

 

[RedSky]

1 minute ago, The Iceman said:

The fact that the HRRR is much cooler than both the 3k nam and the hi res RGEM is encouraging. Also makes me think the gfs is entirely too warm as the low is similar on all the models at that point.

We don't have to be worried about the GFS the last storm proves that it's obviously too warm in SEPA

 

[The Iceman]

the hi res rgem has 3-4 inches in mercer co and central/lower buck county by 12z tomorrow morning. interesting the hi res models are keying in on the front end tonight possibly over performing. something to watch as it will be occurring during prime accumulation hours. I wouldn't be surprised at all if that is the case.

[ChescoWx]

Even warmer GFS still shows near a foot of snow for many areas from KMQS to KFWN...

[The Iceman]

the hi res rgem is still running and still has hours of heavy snow to go but looks like the best run yet for all of the area...this is through 18z...we have at least 5 hours of heavy snow panels left...

 

[gakmsg]

4 minutes ago, RedSky said:

It is certainly taking on the classic I95 climo storm look from Philly to NYC, there is a whole generation of people now that are use to these big storms snowing to the coast 

 

You are correct -I lived in Delco for 50 years - and always coveted the snow in the mystical "Northern and Western suburbs".  When I moved to Northwest Montco ten years ago - it seemed Delco became ground zero to spite my departure.  This definitely has that "old school" look to it. 

[Jsdphilly]

It is still looking like everyone north and west of 95/the river/center city is going to get a good hit. The thermos are starting to show colder temps and I am more and more confident that the mixing will be minimal, even in to downtown. 

Downtown is looking like 20-25mm of H20

My area is looking around 30mm

Further NW looks solidly in the 30's.

If we don't look at the snow maps...its pretty clear what is going to happen. West of the mixing, lots of snow...in the mixing, not so much. Where the mixing stops...i am not sure anyone is really gonna know until were in it.

 

 

[RedSky]

10 minutes ago, gakmsg said:

You are correct -I lived in Delco for 50 years - and always coveted the snow in the mystical "Northern and Western suburbs".  When I moved to Northwest Montco ten years ago - it seemed Delco became ground zero to spite my departure.  This definitely has that "old school" look to it. 

Yes the same exact thing happened to me I moved to Quakertown ten years ago and in an uncanny way the climate norms shifted. Now that I likely will be leaving the area the climate is shifting back to normal.

Ironically I may be staying in Monmouth County for a time, sorry Monmouth peeps there goes your snow lol

 

 

[The Iceman]

hi res rgem... still snowing. this model has done better than the rgem this winter imo and definitely did much better last storm

 

 

 

[The Iceman]

for sh*ts and giggles the old 12z eta(what is now the nam but at 32km resolution) is further east like the euro...the true EE rule in effect?

[DiehardFF]

CMC has a lot of QPF, but does not translate it to snow. 1.7 QPF for most of bucks.

[Jsdphilly]

1 minute ago, DiehardFF said:

CMC has a lot of QPF, but does not translate it to snow. 1.7 QPF for most of bucks.

This is the kind of stuff I just don't understand about the snow maps! They are fun to look at, but that is just nuts. Do you know how bad the ratios would need to be for you to not get slammed? Same thing with most of the region. Just a matter of mixing at this point!

[Newman]

Even though it seems I locked in for 10+", I'm still really really hesitant. So many things could go wrong.

[DiehardFF]

1 minute ago, Jsdphilly said:

This is the kind of stuff I just don't understand about the snow maps! They are fun to look at, but that is just nuts. Do you know how bad the ratios would need to be for you to not get slammed? Same thing with most of the region. Just a matter of mixing at this point!

Ya and its not like 850mb temps are -1, or 0. They are -2 through -5 throughout the storm. 1.7 QPF to about 6" per WxBell clown map in lower bucks.

[RedSky]

2 minutes ago, Newman said:

Even though it seems I locked in for 10+", I'm still really really hesitant. So many things could go wrong.

Miller B southwest flank we been there and done that which is why i'm done buying into these 100%

 

[The Iceman]

1 minute ago, DiehardFF said:

Ya and its not like 850mb temps are -1, or 0. They are -2 through -5 throughout the storm. 1.7 QPF to about 6" per WxBell clown map in lower bucks.

cmc doesn't have the resoluition for thermals... look at the rgem and hi res rgem... same track as cmc but better thermals thus we get slammed. this was the case last storm. in these borderline temp situations the lower resolution models cannot depict the rain snow line accurately. 

[DiehardFF]

1 minute ago, The Iceman said:

cmc doesn't have the resoluition for thermals... look at the rgem and hi res rgem... same track as cmc but better thermals thus we get slammed. this was the case last storm. in these borderline temp situations the lower resolution models cannot depict the rain snow line accurately. 

Ya but we get more QPF with the CMC ha ha. Who knows. Its amazing the amount of snow difference from KDYL to KTTN area.

[ChescoWx]

1 minute ago, The Iceman said:

cmc doesn't have the resoluition for thermals... look at the rgem and hi res rgem... same track as cmc but better thermals thus we get slammed. this was the case last storm. in these borderline temp situations the lower resolution models cannot depict the rain snow line accurately. 

Without a doubt when 850's are below 0c but QPF is not matching snow map totals it is due to topographic influences. This is why the NWS mentioned spots with elevation especially over 500 ft ASL will do better. A 200 foot difference could be the difference between S+ and 32.5 (with plenty of melting) vs S+ and 31.7 (with less melting)