Potential Winter Storm March 6-7

[donsutherland1]

KEWR soundings Don?

 

It starts as rain and sleet before going over to wet snow.

[bluewave]

The Gulf Stream SST's are still well above normal, so a cutoff stalling out can produce some

enhanced precip totals where ever the inflow band off the Atlantic sets up. Cutoffs are notorious

for very heavy totals of either rain or snow as we saw with the April Fools storm1997 and December 1992.

Also remember the extreme snowfall rates and liquid totals back on February 9th.

 

[96blizz]

Per soundings, the storm starts as rain then ends as wet snow. Things can still change.

Figured as much. Thx Don. Being far NW in Sussex, I like where I am with this set up...but lots of time and changes coming. To me, models can also underplay the dynamic cooling of a CCB with that look. Like I said, too early but at least the tracking game is on!

[rcad1]

Upton is still going with mainly a heavy rain event for the NYC metro and snow as you get further inland.. They say the city and coast is going to be warm with a e to ene wind they have Wednesday nights low of only 38 and then a high in the low 40.s on thurs..... Hopefully things change but if we were to get e to ene winds the whole time then this is deff a rain storm. That was part of the problem in western nass with the blizzard we had to wait for our winds to come more Northly before we Finally switched from mainly rain to a mix and I think we had more cold air around for the blizzard than what we have now.... hopefully things chanhe for the better as we get closer.........

[bluewave]

Upton is still going with mainly a heavy rain event for the NYC metro and snow as you get further inland.. They say the city and coast is going to be warm with a e to ene wind they have Wednesday nights low of only 38 and then a high in the low 40.s on thurs..... Hopefully things change but if we were to get e to ene winds the whole time then this is deff a rain storm. That was part of the problem in western nass with the blizzard we had to wait for our winds to come more Northly before we Finally switched from mainly rain to a mix and I think we had more cold air around for the blizzard than what we have now.... hopefully things chanhe for the better as we get closer.........

 

Unfortunately, cutoffs over the mid-Atlantic are usually big rain and wind producers at the coast with heavy wet snow inland.

It would have to cutoff SE of the area with a N to NE flow for it to be snow here. So we still have to see what later model runs do.

[earthlight]

Anyone notice that NYC slp stays near normal at 1012mb but surface winds average 25mph and 925-850mb are a whopping 70mph.  Isobars are really bunched in nw quadrant of storm.

 

This could be a potentially huge storm system if the phase comes to fruition with a track near the area similar to the depiction on the 00z Euro. I think that, obviously, snow would be a big threat with a system like this and the guidance is probably not quite there yet as far as catching on to the potential dynamics and the airmass/etc. But very heavy rain and wind along the coast would also be a tremendous concern.

 

It's also worth noting that the models are hinting, already, at the fact that our window is very short with this system for snow and closing rapidly even as the storm happens. Notice how despite a very strong low pressure system near the coast, the models lose the thermal packing to the NW of the surface low and the 850 0c line. The -2 and +2 contours spread out dramatically because the mid and upper level lows cut off and the airmass to the west and north is not cold but modified.

 

I think there is a decent chance that this is a rainstorm along the coast which goes to a paste job just a few miles inland..and the potential for a significant snowfall across the interior. But these are details that we can't really speculate too much on yet..given that the storm is still so far out in the medium range. My main point is that the winds and rain/snow could become a big concern along the coast if these model solutions are correct. But I'm not totally inclined to believe that they are yet.

 

[earthlight]

P.S- The Euro Ensembles were well north and west of yesterdays 12z. But still nowhere near as wrapped up as the OP. But they agree that this could be a significant precipitation maker -- with a fairly widespread precipitation shield especially for the ensembles at 150 hours lead time.

[Weathergun]

Our winds depending position of strong high to north and the storm track.The ECMWF had ENE winds because the low is hugging the coast.  The 6z GFS has storm track far enough east, that winds are mostly out NNE. It also had a deformation band, sitting over during overnight hours Wednesday. We this kind of setup with 11/7/12 Nor'easter. But all these solutions are going to probably change, over the next few days.

[earthlight]

Also, it's worth noting that the Euro has a completely different evolution than what we've been seeing on most of the guidance. It's nothing like the GFS and, if anything, is more similar to the GGEM. What happens this run is that the Pac NW vort becomes a cutoff low of its own over the Northern 1/3 of the Midwest states. There is no big northern stream phase and huge bomb, just a cutoff low that hits the coast and feels some N stream influence and goes negatively tilted.

 

In the image below you can see the Euro at H5 from last nights 00z run valid at 144 and 168 hours. Notice how even at 144 hours, the Pac NW is already cutoff and moving southeast underneath the big block which had formed over Eastern Canada. The block is important, because it pushed out the ULL which was providing tremendous confluence over the Northeast on previous runs. But watch how even at 168 hours, the Northern stream entity never totally phases. The Pac NW shortwave, as its own entity, produces this storm system on this run specifically.

 

So although we got the result we wanted out of this run, the medium range guidance is still waffling around dramatically with these solutions. I wouldn't hang my hat on any one scenario just yet.

 

[SnoSki14]

Coastal flooding could be a major concern then if the storm really bombs out considering the pressure gradient. 

[Neblizzard]

This storm would certainly generate powerful winds along the coast for an extended period of time. I believe we are in between the full and new moon at that time, but a fetch like that would still generate serious coastal flooding. The airmass overall is quite stale so we are going to need a bombing low to generate its own cold air. Long ways away but definitely intriguing signs on the guidance .

[bluewave]

This storm would certainly generate powerful winds along the coast for an extended period of time. I believe we are in between the full and new moon at that time, but a fetch like that would still generate serious coastal flooding. The airmass overall is quite stale so we are going to need a bombing low to generate its own cold air. Long ways away but definitely intriguing signs on the guidance .

 

Should something like the Euro verify, we could see surges in the 4-5 foot range similar to March 2010. We got lucky

with that storm as the peak surge coincided with low tide. It would be bad news here if a Euro stall in that position

played out with peaking winds near the higher of the daily tides.

[uncle W]

in March 1962 there was a big cut off stalled low south of NYC...It never made it up far enough for a big snowstorm but the shore took a beating...But that year had record breaking cold and a very negative AO at the time...This time around we will have marginal cold air similar to 2001...

[jm1220]

This storm would certainly generate powerful winds along the coast for an extended period of time. I believe we are in between the full and new moon at that time, but a fetch like that would still generate serious coastal flooding. The airmass overall is quite stale so we are going to need a bombing low to generate its own cold air. Long ways away but definitely intriguing signs on the guidance .

Still a very long way out with this, so there are likely to be many shifts. But verbatim, a storm like that could be devastating to many of the areas impacted by Sandy. Our beaches just can't take days of pounding waves and another tidal surge. Our beach in particular lost 5 feet of elevation and although it is mostly being replaced, the dunes and other barriers are nowhere near ready for this kind of storm.

 

And for those along the coast who think this will be snow if it does hit, we again have to walk a very tight rope between no/light precip and mostly rain due to the occlusion/cutting off of the storm and stale airmass in early March. Inland would have a better shot. So this is another storm I probably wouldn't want to deal with-more flooding and probable power outages for likely just a windswept rain. Can there be a lot of snow? Sure, but at this juncture I would weigh more toward a lot of rain and slop for coastal areas if this is a major hit.

[nzucker]

I think the models might be warming us up too much...they have -8C 850s in here Sunday/Monday and then all of a sudden we warm to 0C with a major storm system to our southeast. If anything, thicknesses should be crashing with the bombing low, but the 0z ECM cuts it off so much that it loses its cold air feed. It would be preferable for there to be more of a northern stream influence so we get a fresher supply of cold. 

[Zir0b]

I think the models might be warming us up too much...they have -8C 850s in here Sunday/Monday and then all of a sudden we warm to 0C with a major storm system to our southeast. If anything, thicknesses should be crashing with the bombing low, but the 0z ECM cuts it off so much that it loses its cold air feed. It would be preferable for there to be more of a northern stream influence so we get a fresher supply of cold. 

Prior runs of the Euro were colder because it phased in the northern branch, overnight the models trended toward having a stronger stand alone pacific s/w. We definitely need to hope for more northern stream interaction otherwise the coast is going to have big problems, even with heavy precip rates. 

[earthlight]

I think the models might be warming us up too much...they have -8C 850s in here Sunday/Monday and then all of a sudden we warm to 0C with a major storm system to our southeast. If anything, thicknesses should be crashing with the bombing low, but the 0z ECM cuts it off so much that it loses its cold air feed. It would be preferable for there to be more of a northern stream influence so we get a fresher supply of cold. 

 

It's the lack of northern stream interaction that I detailed above and zirob alluded to as well. The airmass back to the west isn't ideal and the ridge is pressing down on the pattern pretty fast after Tuesday-Wednesday. So the lack of northern stream interaction means the Pacific shortwave is cutting off on its own. Once it cuts off we start to get flooded with milder air.

 

But I think during the heavy precipitation, most interests away from the coast would be fine if these solutions came to fruition.

[nzucker]

It's the lack of northern stream interaction that I detailed above and zirob alluded to as well. The airmass back to the west isn't ideal and the ridge is pressing down on the pattern pretty fast after Tuesday-Wednesday. So the lack of northern stream interaction means the Pacific shortwave is cutting off on its own. Once it cuts off we start to get flooded with milder air.

 

But I think during the heavy precipitation, most interests away from the coast would be fine if these solutions came to fruition.

Are we going to see the coldest weather of this March a bit later, say March 15-20, when the PNA rebuilds after a mild period in the second week of the month?

 

I know we'll have some modest negative departures Sunday, Monday, and Tuesday with highs in the upper 30s to around 40, but we we get any real cold after that? Models have been hinting at a cold March but when?

[jm1220]

Prior runs of the Euro were colder because it phased in the northern branch, overnight the models trended toward having a stronger stand alone pacific s/w. We definitely need to hope for more northern stream interaction otherwise the coast is going to have big problems, even with heavy precip rates. 

It's early March-the coast is heavily favored to be rain if there isn't a good cold air source, in this case it's cut off completely from anything but stale air. Maybe enough dynamics could make it snow but that's always iffy even 24-48 hrs out. Good luck inland-this would be a storm that the coast absolutely doesn't want.

[Zir0b]

It's early March-the coast is heavily favored to be rain if there isn't a good cold air source, in this case it's cut off completely from anything but stale air. Maybe enough dynamics could make it snow but that's always iffy even 24-48 hrs out. Good luck inland-this would be a storm that the coast absolutely doesn't want.

Well it did snow all the way to the coastal plain on November 7 so anything is possible. Does anyone remember what the thermal profiles looked like for that storm a few days out? 

[nyblizz44]

It's early March-the coast is heavily favored to be rain if there isn't a good cold air source, in this case it's cut off completely from anything but stale air. Maybe enough dynamics could make it snow but that's always iffy even 24-48 hrs out. Good luck inland-this would be a storm that the coast absolutely doesn't want.

Lets be smart about this PLEASE .what time of March it is has little to NO bearing. Track, thermal profiles & intensity rates do. sit back and watch and in 72 hours it will be far clearer. If the Euro holds serve we could be trending towards something large & white!

[jm1220]

Well it did snow all the way to the coastal plain on November 7 so anything is possible. Does anyone remember what the thermal profiles looked like for that storm a few days out? 

It hooked up with the northern stream, so cold air was available. It also was forecasted to track directly over the coastal plain, so inland would have received the heavy snow. Instead it jogged east at the last minute and the coast got in on the snow as well. It actually was a huge break for the coast because a more west track would have meant another period of perhaps 60-70mph easterly winds immediately after Sandy. We instead had the snow, but lighter offshore winds. There almost certainly would have been a lot more flooding if that storm had gone more west.

[MJO812]

Match 1888 had rain to heavy snow and March 2001 had rain to snow for many.

[Zir0b]

Lets be smart about this PLEASE .what time of March it is has little to NO bearing. Track, thermal profiles & intensity rates do. sit back and watch and in 72 hours it will be far clearer. If the Euro holds serve we could be trending towards something large & white!

It certainly does have bearing. The March 13-14, 2010 Nor'easter was rain for everybody even though it had a good track and heavy precip. But we're definitely going to have more cold air around for this one, even if it's marginal. So I'd think most people would get SOME snow

http://nws.met.psu.edu/severe/2010/13Mar2010.pdf

[Weathergun]

The 0z Euro 500mb pattern does have some similarities what occurred during the December 1992 Nor'easter:

 

 

[uncle W]

there have been many snowfalls in the past with marginal cold air...During the March 58 storm the coldest temperature was 31 the morning of 21st...It was above freezing before and after that in the city...On march 21st-22nd 1964 NYC got 5" of wet snow that started as rain with a minimum temp of 32 at the storms end...March 18-19th 1992's 6" storm had a temperature range of 33/31...March 1965 had snow on St. patrick's day with a minimum of 34...

[Neblizzard]

The 0z Euro 500mb pattern does have some similarities what occurred during the December 1992 Nor'easter:

December 1992 Nor'easter 500mb.gif

00zeuro500mbHeightAnomalyNH144.gif

Wow very similar, looks like the 92 storm had a -NAO as well displaced over Southern Canada. It's hard to get a fast moving coastal storm with a 500mb setup like that. That's why this storm could be a major problem if the models are right.

[Zelocita Weather]

GFS Looks like it is going to be a pretty good QPF producer...not sure on temps yet though...Pretty classic look with some blocking, highs draped to the north and west, low on the outerbanks with precip shield expanding and some room for amplification

 

 

 

GFS = SNOW BOMB

[andyhb]

12z GFS is bombing out at 126, phasing still not complete with the northern stream anomaly.

[yl715]

Northern stream dipping in at 120. This may be a bit warm at coastal regions. But it's gonna be a bomb.