March 2-4 Snowstorm Potential Part 2

[REDMK6GLI]

GFS/EURO have been converging on a 10"+ storm for the tristate area.thursday 18z GFS started the trend of a possible phase and coastal enhancement so that could help raise the QPF/snowfall potential yet again if todays model runs continue to put more emphasis on that trend. Mixing issues regardless looks to be confined to S.NJ complements to the cold air mass being introduced to this storm. Wishing all the best and for tons of snow, discuss here folks

[hazwoper]

06Z GFS cut back to the south and in the NYC area. Hoping just a small blip. GFS moved north while NAM way south. Still a ways to go.

[Brian5671]

06Z GFS cut back to the south and in the NYC area. Hoping just a small blip. GFS moved north while NAM way south. Still a ways to go.

verbatim the run gives NYC over 12 inches.   Sharp cutoff about 30-50 miles south of the city

[hazwoper]

verbatim the run gives NYC over 12 inches. Sharp cutoff about 30-50 miles south of the city

True. I should have said city east as those areas have cut back

Meaning LI mostly

[NYStorm]

I'm as much of a weather enthusiast as anyone and want to see a big snowstorm as much as anyone, but I'm reading the 6:41AM update from Upton and to me, it doesn't sound bullish .... it sounds perfectly objective and unsure of the solution at this point in time ... as it probably should be. In fact, they appear to me to be hedging. They talk about multiple possibilities, and say that a full-phase seems less likely. They seem to be indicating 8" area wide, and leaning towards a more suppressed solution with multiple lows, a shorter event, and therefore less accum. Possibly even lower accums than the 8" if the further south trend continues.

[jjvesnow]

SREFS still pretty far north. They haven't budged much yet.

http://mag.ncep.noaa.gov/Image.php?fhr=087ℑ=data%2Fsref%2F09%2Fsref_namer_087_precip_p24.gif&model=sref&area=namer&param=precip_p24&group=Model+Guidance&preselected_formatted_cycle_date=20140228+09+UTC&imageSize=&ps=area

[UlsterCountySnowZ]

Notice how that 14-18" swath has gotten increasingly larger and further east with each gfs run... Someone in the metro area, NNJ, or LHV could jackpot big time

[earthlight]

The trend towards moving the thermal gradient farther north on the GFS is fairly evident over the past 3-4 OP cycles. The ensemble mean and individuals have also trended northward with the thermal gradient over the last day or so. This is a relatively small shift but will have major implications as it also shifts the best lift for heavy precipitation northward...that lift occurs about 50 miles north of the thermal gradient where the best moisture pools over the top of the boundary. So the heavy snowfall band is shifting north as well. 

 

It is hard to say whether this is a solidified trend or not..but I would watch it carefully. 

[UlsterCountySnowZ]

The trend towards moving the thermal gradient farther north on the GFS is fairly evident over the past 3-4 OP cycles. The ensemble mean and individuals have also trended northward with the thermal gradient over the last day or so. This is a relatively small shift but will have major implications as it also shifts the best lift for heavy precipitation northward...that lift occurs about 50 miles north of the thermal gradient where the best moisture pools over the top of the boundary. So the heavy snowfall band is shifting north as well.

It is hard to say whether this is a solidified trend or not..but I would watch it carefully.

I was hoping for a northward shift since I'm about 50 miles north of Manhattan, but I would like to see big snows in the metro area so De Blasio can fumble around again lol

[Rjay]

I'm as much of a weather enthusiast as anyone and want to see a big snowstorm as much as anyone, but I'm reading the 6:41AM update from Upton and to me, it doesn't sound bullish .... it sounds perfectly objective and unsure of the solution at this point in time ... as it probably should be. In fact, they appear to me to be hedging. They talk about multiple possibilities, and say that a full-phase seems less likely. They seem to be indicating 8" area wide, and leaning towards a more suppressed solution with multiple lows, a shorter event, and therefore less accum. Possibly even lower accums than the 8" if the further south trend continues.

MONITORING CUTOFF LOW CURRENTLY APPROACHING SOUTHERN CALIFORNIA COAST. THIS SYSTEM OPENS UP AS IT MOVES INTO THE DESERT SOUTHWEST SATURDAY...THEN TRACKS EASTWARD EARLY NEXT WEEK. THE QUESTION BECOMES HOW MUCH DOES IT PHASE WITH A SOUTHWARD EXTENSION OF A NORTHERN STREAM TROUGH...AND HOW STRONG IS THE EASTWARD ARM OF THE ARCTIC HIGH BUILDING TO OUR N SUNDAY NIGHT THROUGH MONDAY NIGHT. THE LESS PHASING AND/OR THE STRONGER THE HIGH THE MORE LIKELY THE LOW WILL BE SUPPRESSED WELL TO OUR SOUTH...AND REDUCING THE POTENTIAL IMPACT OF THE STORM. THE STRONGER THE PHASING AND/OR THE WEAKER THE HIGH...THE CLOSER THE LOW WILL COME TO THE REGION...AND THE GREATER THE IMPACT OF THE STORM. CURRENT TRENDS ARE FAVOR LESS PHASING...BUT ARE UNCLEAR ABOUT THE STRENGTH OF THE HIGH. TAKING THESE TRENDS...THERE IS THE POTENTIAL THAT WE COULD SEE MULTIPLE WAVES OF LOW PRESSURE TRACK TO OUR SE INSTEAD OF ONE COHERENT STRONGER STORM. THE FIRST LOW SHOULD TRACK NEAR THE BENCH MARK MONDAY MORNING...AND THE SECOND WELL TO THE SOUTHEAST OF THE BENCH MARK LATE MONDAY...WITH A THIRD LOW TRACKING EVEN FARTHER TO THE SE MONDAY NIGHT. BASED ON THIS...STILL EXPECT SNOW TO DEVELOP FROM SW TO NE SUNDAY EVENING...AND WITH THE LOW TRACKING FARTHER TO THE SE MONDAY NIGHT...NOW EXPECT SNOW TO END FROM NW TO SE FAIRLY EARLY MONDAY EVENING. GIVEN THAT THE SOLUTION IS NOW FAVORING MULTIPLE WEAKER LOWS...VICE ONE MAIN LOW...SHOULD NOT DRAW AS MOISTURE AS A WHOLE INTO THE REGION. BASED ON THIS...HAVE REDUCED THE AMOUNT OF PRECIPITATION EXPECTED...ESPECIALLY ACROSS NORTHERN ZONES. SEE THE HYDRO SECTION OF THE AFD FOR DETAILS. ONE THING THE FARTHER OFFSHORE TRACK FOR THE LOWS DOES THOUGH...COUPLED WITH THE EXTENSION OF THE ARCTIC HIGH BUILDING IN TO THE N...IS THAT ANY LOW LEVEL WARM AIR WILL STAY TO OUR SOUTH...SO THE AREA SHOULD ONLY EXPERIENCE ALL SNOW. THE STRENGTH OF THE HIGH WILL ULTIMATELY DETERMINE HOW COLD IT GETS...BUT FOR NOW WOULD EXPECT MORE OF A FLUFFY SNOW THAN A WET SNOW...ESPECIALLY ACROSS THE INTERIOR. SO THE HIGHER SNOW RATIOS ACROSS THE N COULD VERY WELL OFFSET THE LOWER QPF. AS A RESULT...THERE IS CURRENTLY NO REASON TO DEPART FROM PREVIOUS FORECAST OF AT LEAST 8 INCHES OF SNOW ACROSS THE TRI-STATE FROM SUNDAY NIGHT INTO MONDAY NIGHT. HOWEVER...IF THE TREND CONTINUES TOWARDS A MORE SUPPRESSED TO THE S SOLUTION...THEN LOWER AMOUNTS ARE POSSIBLE...IT IS STILL CONCEIVABLE THAT THE ENTIRE REGION COULD END UP GETTING NO SNOW AT ALL - THOUGH HIGHLY UNLIKELY. ANOTHER POSSIBILITY THAT WOULD LOWER SNOW AMOUNTS OVER SOUTHERN ZONES IS THAT A WEAKER HIGH BUILDS TO THE N THAN CURRENTLY EXPECTED...THIS WOULD ALLOW FOR A WINTRY MIX OVER SOUTHERN ZONES...REDUCING AMOUNTS THERE. THIS ALSO APPEARS UNLIKELY AT THIS TIME. ANOTHER SOLUTION STILL POSSIBLE IS THAT THERE IS MORE PHASING THAN CURRENTLY FORECAST...THIS WOULD BRING THE LOWS...OR MORE LIKELY A SINGLE LOW TRACKING CLOSER TO THE BENCH MARK...THIS WOULD INCREASE QPF AND SNOWFALL...BUT COULD ALSO BRING THE LOW LEVEL WARM TONGUE OVER SOUTHERN PORTIONS OF THE AREA...DEPENDING ON THE STRENGTH OF THE HIGH. THIS IS A MORE REALISTIC POSSIBILITY. GIVEN ALL THE UNCERTAINTY WILL CONTINUE THE HWO AS IS...EXCEPT FOR WILL MENTION THE SNOW SHOULD END BY EARLY MONDAY EVENING.

[PB GFI]

This is goin to be a major winter to storm for this entire board unless you are in southern nj. Everyone else from Philly into CNJ to KNYC to long island and into NNJ should expect a 10 to as much as 15 inch snowstorm. The gfs 850s are a tick warmer at hour 72 but the euro has trended colder in its it's last 2 runs.

Don't confuse the expansion of snow on the northern side with a chance of a change or mix

The gfs is just picking up on a more robust precip field. This is going to be a cold snow. IMO

[REDMK6GLI]

This is goin to be a major winter to storm for this entire board unless you are in southern nj. Everyone else from Philly into CNJ to KNYC to long island and into NNJ should expect a 10 to as much as 15 inch snowstorm. The gfs 850s are a tick warmer at hour 72 but the euro has trended colder in its it's last 2 runs.

Don't confuse the expansion of snow on the northern side with a chance of a change or mix

The gfs is just picking up on a more robust precip field. This is going to be a cold snow. IMO

Currently the axis of heaviest snow blending the GFS/EURO is from w.PA, C/N.NJ, NYC onto LI and. LHV looks like

[IsentropicLift]

verbatim the run gives NYC over 12 inches.   Sharp cutoff about 30-50 miles south of the city

If you take back the window washing and allow for a slight correct north the heaviest hit area should be right a long interstate 80 from the mid-west all the way to the coast.

[RockawayRowdies]

FWIW: Upton has updated point n click hourly forecasts with the snow predictions. Here's what's predicted for Mahwah, NJ in Bergen County..

[jm1220]

The trend towards moving the thermal gradient farther north on the GFS is fairly evident over the past 3-4 OP cycles. The ensemble mean and individuals have also trended northward with the thermal gradient over the last day or so. This is a relatively small shift but will have major implications as it also shifts the best lift for heavy precipitation northward...that lift occurs about 50 miles north of the thermal gradient where the best moisture pools over the top of the boundary. So the heavy snowfall band is shifting north as well. 

 

It is hard to say whether this is a solidified trend or not..but I would watch it carefully. 

Agree, this is definitely far from a settled down situation. Still a lot of ways we can get relatively shafted, or have tons of mixing. The PV has to be strong so this is kept as far south as possible. The possibility of mixing cutting down on totals or the best lift overshooting us is significantly higher IMO than suppression.

 

This phasing possibility worries me also, if it happens too soon the whole storm will be pushed north and the only people it will benefit will be the New England crew and way north and west. It could help us too but we need perfect timing.

[jm1220]

True. I should have said city east as those areas have cut back

Meaning LI mostly

I think pretty much anything is still on the table, from a major snowstorm everywhere to lots of slop to suppression (by far the least likely of these three possibilities).

[earthlight]

Agree, this is definitely far from a settled down situation. Still a lot of ways we can get relatively shafted, or have tons of mixing. The PV has to be strong so this is kept as far south as possible. The possibility of mixing cutting down on totals or the best lift overshooting us is significantly higher IMO than suppression.

 

This phasing possibility worries me also, if it happens too soon the whole storm will be pushed north and the only people it will benefit will be the New England crew and way north and west. It could help us too but we need perfect timing.

 

The phasing doesn't really have me too concerned. If you really take a look at it, it's just an elongated shortwave over the Great Lakes that is interacting with our disturbance. While this might pull it a bit north over time, there really is no amplitude to that feature and the phase itself won't be anything big that would give us a more wound up solution (unless things really change). 

 

I would be more concerned about the shortwave trending more consolidated and amplified while the PV trends less suppressive. That will initially allow for more WAA. 

[SnoSki14]

Yeah it's possible we could be screwed in central nj so I'm very worried. Any north shift and it could be a wrap.

[cut]

Is that Update/discussion posted by RJay from the overnight?  It certainly doesn't correlate with what Earthlight said about the thermal gradient migrating north in the last few op cycles.

[Zelocita Weather]

Both the GFS/Euro (and in a different way the GGEM) have been in great agreement overall on the snow/non-snow line for the past 3 days. Subtle shifts from warm to cold to warm to cold have occured differing by model and run, but one thing is consistent. If you take the 'spray' of all models there has not been one run of either the GFS/EURO over the past 3 days that has not produced a mjor snowstorm from TTN-LI (NW). I think we are positioned well. 

[heavy_wx]

The phasing doesn't really have me too concerned. If you really take a look at it, it's just an elongated shortwave over the Great Lakes that is interacting with our disturbance. While this might pull it a bit north over time, there really is no amplitude to that feature and the phase itself won't be anything big that would give us a more wound up solution (unless things really change). 

 

I would be more concerned about the shortwave trending more consolidated and amplified while the PV trends less suppressive. That will initially allow for more WAA. 

 

Yeah there's no well defined northern stream shortwave that could phase with the Pacific disturbance. That's not to say the disturbance can't slow down its deamplification due to enhanced convection over the the southeast. That mechanism would allow for a relatively stronger surface low and greater WAA, perhaps resulting in a northward shift of the best mesoscale forcing.

[earthlight]

Yeah there's no well defined northern stream shortwave that could phase with the Pacific disturbance. That's not to say the disturbance can't slow down its deamplification due to enhanced convection over the the southeast. That mechanism would allow for a relatively stronger surface low and greater WAA, perhaps resulting in a northward shift of the best mesoscale forcing.

 

Agreed. Other than that, I guess my main concern would be that the shortwave over the Great Lakes trends slightly more amplified (not sure really how much room there is for that anyway), which takes the thermal gradient and elongates it more at a SW to NE direction over the Northern Mid Atlantic and New England. This would also be unfavorable for our area, similarly to the increased WAA as a result of a more consolidated Pacific shortwave ejecting northeastward. 

 

But in terms of a major shift north/west or warmer...we would need to see the orientation of the PV and upper level flow change fairly dramatically to our north. The models have been pretty consistent with the pattern surrounding the system, so although its still 84 hours out I would be pretty shocked if we saw that change at this point. 

[jm1220]

Both the GFS/Euro (and in a different way the GGEM) have been in great agreement overall on the snow/non-snow line for the past 3 days. Subtle shifts from warm to cold to warm to cold have occured differing by model and run, but one thing is consistent. If you take the 'spray' of all models there has not been one run of either the GFS/EURO over the past 3 days that has not produced a mjor snowstorm from TTN-LI (NW). I think we are positioned well. 

48 hours before the Feb 4th event, the entire tri-state area was expected to be cold enough on multiple models (the Euro especially if I remember right) for mostly snow. Then there was a last minute north lurch and mixing made it all the way through CT. 07-08 had multiple such outcomes as well, where the storm verified 100 miles north of where models had them at this range. I think the Feb 4th outcome is quite possible in this case, hopefully I'm wrong. Like I said days ago, warm advection driven storms never sit well with me for coastal/city areas. I think we need more to go right for major snow for us than people think, and a lobe or two of the PV being off by a little right now can make this end up with a lot more mixing.

[Heisy]

Looks like NAM not going to back off the warm first part

[IsentropicLift]

I agree with what most are saying here, it's not a phase that's occurring, but more of just the two streams interacting. In this case it's working to our advantage. If you go back a day or so ago the models were nearly completely shearing out the southern vort while it was still well southwest of the area. I'm encouraged by the continued trend of a more organized and stronger southern vort. If it does get sheared out, hopefully it's after it's well offshore.

[IsentropicLift]

Looks like NAM not going to back off the warm first part

I only have it out to hour 36 on SV, what are you seeing?

[SnoSki14]

The threat on the 4th had a primary in like western PA so you can't compare this to that.

[Heisy]

I only have it out to hour 36 on SV, what are you seeing?

 

Been looking at models my entire life brotha, I can tell already. 2nd part will come a tad north though

[IsentropicLift]

Been looking at models my entire life, I can tell already. 2nd part will come a tad north though

Got it, regardless it's still the long range NAM until tomorrow.

[SnoSki14]

The Nam is garbage unless inside 36 hrs.