NYC CWA Feb 1-2 Storm Discussion

[earthlight]

Through 60 hours 0.75-1.00" QPF for N NJ/NYC/SE NY/SW CT

The surface hasn't yet risen above freezing with the 32 F line off the south shore of LI at that exact hour. The precipitation is still falling..so it probably ends as rain..but you still have 0.75-1.00" liquid falling with the surface a good bit below freezing.

[IsentropicLift]

EC never pops a secondary I'm assuming?

[earthlight]

Just a brief example...at KEWR

At 12z Wednesday surface temp is -1.6 F...H85 temp is 1.7 C already about 0.50" liquid accumulated.

We're going to have to wait for 925mb temp maps to gander at the depth of the warm layer.

[SACRUS]

Just a brief example...at KEWR

At 12z Wednesday surface temp is -1.6 F...H85 temp is 1.7 C already about 0.50" liquid accumulated.

We're going to have to wait for 925mb temp maps to gander at the depth of the warm layer.

sounding like ugly commutes tue am/pm /wed am

[CooL]

Huge cutoff 500mb low in northern Mexico at hr 96

[earthlight]

sounding like ugly commutes tue am/pm /wed am

Yeah..although I do think the icing potential is being hit a bit too hard right now. You really need light precipitation rates and a perfect setup for freezing rain..once the warm layer gets too deep it more often than not turns to rain even if your temperature is below freezing. The exception is far N&W..Passaic/Bergen/Morris whereabouts.

[Snowlover11]

Ouch looking like a pretty big icing problem here.

[earthlight]

Here's my thoughts on the event, I think the ice threat is real and could be serious for some.

http://www.lightinthestorm.com/

Good stuff, bud. I'm not totally sold on the big icing event, yet...but we shall see

[Isotherm]

Yeah..although I do think the icing potential is being hit a bit too hard right now. You really need light precipitation rates and a perfect setup for freezing rain..once the warm layer gets too deep it more often than not turns to rain even if your temperature is below freezing. The exception is far N&W..Passaic/Bergen/Morris whereabouts.

John -- I'd agree if there were no low level cold air drainage from the northeast (latent heat release would allow temps to approach 32F fairly rapidly, rendering the ice accural rather mino). But we've got a 1030-32mb sfc high sitting in an almost classic position - SE Quebec, which would keep the NE flow going. I can see temps in the 26-30 degree range during much of the icing.

[Isotherm]

Nice analysis iso. I agree with the ice threat especially in n-nj (near i-78)/nyc and expect surface progs still under done. Another interseting week, maybe central park can squeeze in an inch ust prior to midnight.

Thanks Tony, we've certainly had plenty of storms to track this winter. Never a dull moment.

[Wxoutlooksblog]

Yeah..although I do think the icing potential is being hit a bit too hard right now. You really need light precipitation rates and a perfect setup for freezing rain..once the warm layer gets too deep it more often than not turns to rain even if your temperature is below freezing. The exception is far N&W..Passaic/Bergen/Morris whereabouts.

If the temperatures is below freezing, it's freezing rain!! Geez!

WX/PT

[SACRUS]

Yeah..although I do think the icing potential is being hit a bit too hard right now. You really need light precipitation rates and a perfect setup for freezing rain..once the warm layer gets too deep it more often than not turns to rain even if your temperature is below freezing. The exception is far N&W..Passaic/Bergen/Morris whereabouts.

John, rare indeed as you travel down the turnpike south of i80 and i78 but the ecm tends too be warm (as is most guidance) with surface progs in these situations. I think this run is more a red flag than the nam...

[A-L-E-X]

Good stuff, bud. I'm not totally sold on the big icing event, yet...but we shall see

If it ends up like Jan 1994 you could have a big icing event-- most of that storm it was heavy freezing rain and we ended up with 2" of the stuff.

[Isotherm]

Good stuff, bud. I'm not totally sold on the big icing event, yet...but we shall see

Thanks man, and I do agree about it being difficult to get an ice storm down here, but I think this threat has high potential.

[MJO812]

Through 60 hours 0.75-1.00" QPF for N NJ/NYC/SE NY/SW CT

The surface hasn't yet risen above freezing with the 32 F line off the south shore of LI at that exact hour. The precipitation is still falling..so it probably ends as rain..but you still have 0.75-1.00" liquid falling with the surface a good bit below freezing.

How are the 850's?

[eduggs]

Yeah..although I do think the icing potential is being hit a bit too hard right now. You really need light precipitation rates and a perfect setup for freezing rain..once the warm layer gets too deep it more often than not turns to rain even if your temperature is below freezing. The exception is far N&W..Passaic/Bergen/Morris whereabouts.

Is this true? I've always thought freezing rain was a property of the surface temperature only. How much of the rain freezes on contact always seems to be a function of the intensity and the temperature. At 10F almost all of it freezes on everything whereas at 32F it freezes only on some surfaces and there's a lot of wet runoff. But freezing rain feels the same as rain when you reach out to feel it with your palm. Because it is rain.

[TwcMan]

The fact the EURO, which usually has a warm bias, is this cold should raise some red flags IMO.

[earthlight]

Is this true? I've always thought freezing rain was a property of the surface temperature only. How much of the rain freezes on contact always seems to be a function of the intensity and the temperature. At 10F almost all of it freezes on everything whereas at 32F it freezes only on some surfaces and there's a lot of wet runoff. But freezing rain feels the same as rain when you reach out to feel it with your palm. Because it is rain.

By "the exception" I meant the exception for where a more significant wintry weather event could occur...meaning more snow/sleet/etc. Should have clarified.

[Wxoutlooksblog]

Thanks man, and I do agree about it being difficult to get an ice storm down here, but I think this threat has high potential.

Potential for ice at this time is very high, about as high as you'd ever see in the NYC area. That doesn't mean it's going to happen, but we are one step closer to it.

WX/PT

[Dsnowx53]

Is this true? I've always thought freezing rain was a property of the surface temperature only. How much of the rain freezes on contact always seems to be a function of the intensity and the temperature. At 10F almost all of it freezes on everything whereas at 32F it freezes only on some surfaces and there's a lot of wet runoff. But freezing rain feels the same as rain when you reach out to feel it with your palm. Because it is rain.

Yeah, this is what I thought, too.

[A-L-E-X]

Potential for ice at this time is very high, about as high as you'd ever see in the NYC area. That doesn't mean it's going to happen, but we are one step closer to it.

WX/PT

I always look at Jan 1994 as the poster child for big ice storms around here..... if this is anything like that (and the pattern is very similar) then it could be an exceptional event.

[SACRUS]

Potential for ice at this time is very high, about as high as you'd ever see in the NYC area. That doesn't mean it's going to happen, but we are one step closer to it.

WX/PT

Yeah, I agree and kudos to those who were adamant with the threat nyc south into NJ. Lets see ho temps perform tomorrow vs guidance.

[eduggs]

By "the exception" I meant the exception for where a more significant wintry weather event could occur...meaning more snow/sleet/etc. Should have clarified.

Gotcha... just thought the depth of the warm layer had more to do with sleet vs. freezing rain and the severity of freezing rain had to do with surface temp. Agreed on locations where ww threat is greatest.

[SACRUS]

I always look at Jan 1994 as the poster child for big ice storms around here..... if this is anything like that (and the pattern is very similar) then it could be an exceptional event.

If I recall temps then were in the teens or lower prior to the storms. Which date, id like to check the data.

[A-L-E-X]

If I recall temps then were in the teens or lower prior to the storms. Which date, id like to check the data.

They were, but I think they rose into the mid and upper 20s (and a high of 31 here towards the end of the storm.) Ended up with close to 2 inches of ice basically covering everything! I forget what day it was, but it was somewhere in the 2nd week of the month, Tony.

[earthlight]

Gotcha... just thought the depth of the warm layer had more to do with sleet vs. freezing rain and the severity of freezing rain had to do with surface temp. Agreed on locations where ww threat is greatest.

You're absolutely correct. Speaking of which, when was the last legit freezing rain event in this area? Wasn't there on in Dec '08 or '09? I can't really remember too well..but I know it wasn't too long ago.

[MJO812]

The last Ice storm warning for NYC was on February 14.2007.

[SACRUS]

They were, but I think they rose into the mid and upper 20s (and a high of 31 here towards the end of the storm.) Ended up with close to 2 inches of ice basically covering everything! I forget what day it was, but it was somewhere in the 2nd week of the month, Tony.

EWR Jan '94

       HI   LO  AVG     HI   LO  AVG   DEPT     AMNT   SNOW SNCVR   HDD
1      43   22   33     39   26   33     +0     0.29    0.0    1     32
2      51   32   42     39   26   32    +10     0.00    0.0    0     23
3      35   29   32     39   25   32     +0     0.15    1.2    1     33
4      34   24   29     38   25   32     -3     0.48    1.6    1     36
5      33   20   27     38   25   32     -5     0.00    0.0    0     38
6      25   18   22     38   25   32    -10     0.01    0.0    0     43
7      27   21   24     38   25   32     -8     0.71    2.4    2     41
8      33   14   24     38   25   32     -8     0.15    1.2    3     41
9      27   12   20     38   25   31    -11     0.00    0.0    3     45
10      28   15   22     38   25   31     -9     0.00    0.0    3     43
11      34   17   26     38   24   31     -5     0.00    0.0    3     39
12      34   29   32     38   24   31     +1     0.54    2.8    6     33
13      39   32   36     38   24   31     +5     0.00    0.0    5     29
14      38   19   29     38   24   31     -2     0.01    0.0    4     36
15      19    5   12     38   24   31    -19     0.00    0.0    4     53
16      15    2    9     38   24   31    -22     0.00    0.0    4     56
17      44   11   28     38   24   31     -3     1.49    2.4    2     37
18      36    3   20     38   24   31    -11     0.20    2.0    3     45
19       8   -2    3     38   24   31    -28     0.00    0.0    3     62
20      16    0    8     38   24   31    -23     0.00    0.0    3     57
21      23    5   14     38   24   31    -17     0.00    0.0    3     51
22      33   14   24     38   24   31     -7     0.00    0.0    3     41
23      31   20   26     38   24   31     -5     0.00    0.0    3     39
24      48   26   37     38   24   31     +6     0.00    0.0    2     28
25      40   23   32     38   24   31     +1     0.01    0.0    2     33
26      32    2   17     38   24   31    -14     0.52    5.1    7     48
27      32   -2   15     38   24   31    -16     0.08    0.0    7     50
28      55   17   36     38   24   31     +5     1.72    0.0    1     29
29      43   35   39     38   24   31     +8     0.00    0.0    0     26
30      36   24   30     38   24   31     -1     0.00    0.0    0     35
31      33   19   26     38   24   31     -5     0.00    0.0    0     39

[eduggs]

You're absolutely correct. Speaking of which, when was the last legit freezing rain event in this area? Wasn't there on in Dec '08 or '09? I can't really remember too well..but I know it wasn't too long ago.

By memory it sure seems pretty rare in the metro area. And in places like Manhattan where most of the paved surfaces are warm and/or treated, it has to be very cold for serious accretion. Like you suggested it's much more common in the NW burbs. I know the hudson highlands got some pretty good icing earlier this year.

[RutgersWx92]

They were, but I think they rose into the mid and upper 20s (and a high of 31 here towards the end of the storm.) Ended up with close to 2 inches of ice basically covering everything! I forget what day it was, but it was somewhere in the 2nd week of the month, Tony.

I'm pretty sure that January 7-8, 1994 is generally regarded as the worst ice storm on record for this area (at least for central NJ). I'm guessing that's what you're referring to.