Late Weekend Storm Threat

[yankeex777]

The run was certainly colder than 6z.  Very odd long duration event.

[IsentropicLift]

The GGEM is more amped up than 00z. So far on Monday night there is a surface low over West Virginia and signs of a weak transfer towards the coast. 

[IsentropicLift]

The run was certainly colder than 6z.  Very odd long duration event.

We've moved onto the GGEM.

[IsentropicLift]

Weak coastal East of the benchmark, misses everyone, but it's really digging the trailing energy so it's probably going to try and develop another low.

[WaPo]

Lmao people arguing over 12z gfs 5days out smh

Really?

Personally I'm frustrated by the different

interpretations of one model run. I know it's a discussion board, but pbp should be done by well revered posters or mets. Too much hyperbole and not enough analysis.

The trends seem to be indicating a weaker overrunning event right now. Coastal is too far south and east at the moment.

[IsentropicLift]

The 00z GGEM did this and it spun up a strong coastal for Tuesday.

[SnoSki14]

We're going to get snow one way or another with this pattern. I'm not so focused on every single model and every single run because all the little details will drive you crazy. 

[IsentropicLift]

We get nailed by the coastal but it has precip type issues for pretty much everyone. 850's are cold this run but somehow the surface torches. Doesn't make much sense.

[snowblind]

We need to sit back and relax a little. I think by fri 12z we should know a bit more. I wouldnt trust any model to specific at this point in time

[wkd]

can someone put up a snow map?

[SnowGoose69]

We get nailed by the coastal but it has precip type issues for pretty much everyone. 850's are cold this run but somehow the surface torches. Doesn't make much sense.

The CMC is notorious for doing that

[SnowGoose69]

If I had to put money on it I would bet this evolves like that event in 2011, the overrunning will end up missing us to the north and we will be sent into another dimension by the coastal, I think the event I'm thinking of the NWS busted severely and all the overrunning snow fell 30-50 miles north of NYC

[pstar3182]

gfs_asnow_us_25.png

[IsentropicLift]

The CMC is notorious for doing that

Yeah, I'm going to call BS here.

 

The GGEM has 2-4" LE from the two events, highest amounts over NE PA and NW NJ.

[Brian5671]

If I had to put money on it I would bet this evolves like that event in 2011, the overrunning will end up missing us to the north and we will be sent into another dimension by the coastal, I think the event I'm thinking of the NWS busted severely and all the overrunning snow fell 30-50 miles north of NYC

was that the 1/27/11 event?   We had about 5-7 inches overrunning that morning (largely unforecast) and then got destroyed by the coastal that evening/overnight.

[IsentropicLift]

 

 

 

 

 

 

 

 

 

[SnowGoose69]

was that the 1/27/11 event? We had about 5-7 inches overrunning that morning (largely unforecast) and then got destroyed by the coastal that evening/overnight.

No there was an event 2 weeks later maybe where all the overrunning ended up over CT and the Hudson valley but models had it over NYC up until maybe 36 hours before then moved it north

[Zir0b]

12z navgem looks good with the lead overruning wave, miss with the coastal

[mob1]

was that the 1/27/11 event? We had about 5-7 inches overrunning that morning (largely unforecast) and then got destroyed by the coastal that evening/overnight.

I believe you're talking about Feb 2010, NYC got 20 inches from that after a day of rain that turned to wet snow and didn't start sticking till it got very heavy that night. There was an insane west to east cutoff with the Catskills getting 4-6 feet of snow and heavy rain east of that.

[IsentropicLift]

 

 

[IsentropicLift]

The GGEM just keeps going and going and going until eventually we dry slot before the coastal moves in.

[Brian5671]

The GGEM just keeps going and going and going until eventually we dry slot before the coastal moves in.

GGEM dumps 3 feet of snow N and W of NYC lol

[PB GFI]

GGEM dumps 3 feet of snow N and W of NYC lol

4FT HV and NEPA 

[NEG NAO]

12Z GFS Text Output at Newark - Continuous Light Snow From Just After Midnight Sunday Till about Noon Tuesday - 60 hours - yielding just under an inch qpf. Temperatures below freezing from late 2/5 through 2/20 with additional snow chances during that period .

 

http://wxweb.meteostar.com/sample/sample.shtml?text=kewr

[IsentropicLift]

12z GFS for KLGA, not a foot + like some people were saying.

 

150208/0600Z  90  VRB02KT  28.1F  SNOW   11:1| 0.2|| 0.00|| 0.00|| 0.019   11:1|  0.2|| 0.00|| 0.00|| 0.02  100|  0|  0
150208/0900Z  93  06003KT  29.2F  SNOW    7:1| 0.4|| 0.00|| 0.00|| 0.057    8:1|  0.6|| 0.00|| 0.00|| 0.08  100|  0|  0
150208/1200Z  96  04008KT  28.1F  SNOW    8:1| 0.7|| 0.00|| 0.00|| 0.084    8:1|  1.3|| 0.00|| 0.00|| 0.16  100|  0|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
150208/1500Z  99  05012KT  25.4F  SNOW    5:1| 0.3|| 0.00|| 0.00|| 0.056    7:1|  1.6|| 0.00|| 0.00|| 0.21  100|  0|  0
150208/1800Z 102  05011KT  23.1F  SNOW    4:1| 0.1|| 0.00|| 0.00|| 0.035    7:1|  1.7|| 0.00|| 0.00|| 0.25  100|  0|  0
150208/2100Z 105  05011KT  20.6F  SNOW    9:1| 0.3|| 0.00|| 0.00|| 0.037    7:1|  2.1|| 0.00|| 0.00|| 0.29  100|  0|  0
150209/0000Z 108  05012KT  17.3F  SNOW   15:1| 0.7|| 0.00|| 0.00|| 0.044    8:1|  2.7|| 0.00|| 0.00|| 0.33  100|  0|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
150209/0300Z 111  05012KT  15.5F  SNOW    6:1| 0.3|| 0.00|| 0.00|| 0.051    8:1|  3.0|| 0.00|| 0.00|| 0.38  100|  0|  0
150209/0600Z 114  05012KT  15.0F  SNOW    5:1| 0.1|| 0.00|| 0.00|| 0.025    8:1|  3.1|| 0.00|| 0.00|| 0.41  100|  0|  0
150209/0900Z 117  05012KT  15.3F  SNOW    6:1| 0.2|| 0.00|| 0.00|| 0.042    8:1|  3.4|| 0.00|| 0.00|| 0.45  100|  0|  0
150209/1200Z 120  05011KT  16.2F  SNOW    8:1| 0.3|| 0.00|| 0.00|| 0.033    8:1|  3.6|| 0.00|| 0.00|| 0.48  100|  0|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
150209/1500Z 123  05012KT  19.3F  SNOW    7:1| 0.3|| 0.00|| 0.00|| 0.036    8:1|  3.9|| 0.00|| 0.00|| 0.52  100|  0|  0
150209/1800Z 126  05013KT  22.0F  SNOW    9:1| 0.4|| 0.00|| 0.00|| 0.044    8:1|  4.3|| 0.00|| 0.00|| 0.56  100|  0|  0
150209/2100Z 129  04014KT  23.6F  SNOW   14:1| 0.3|| 0.00|| 0.00|| 0.025    8:1|  4.6|| 0.00|| 0.00|| 0.59  100|  0|  0
150210/0000Z 132  04013KT  24.9F  SNOW   11:1| 0.8|| 0.00|| 0.00|| 0.077    8:1|  5.5|| 0.00|| 0.00|| 0.66  100|  0|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
150210/0300Z 135  04014KT  25.1F  SNOW   12:1| 1.0|| 0.00|| 0.00|| 0.080    9:1|  6.4|| 0.00|| 0.00|| 0.74  100|  0|  0
150210/0600Z 138  03014KT  23.1F  SNOW    6:1| 0.4|| 0.00|| 0.00|| 0.062    8:1|  6.8|| 0.00|| 0.00|| 0.81  100|  0|  0
150210/0900Z 141  03014KT  22.7F  SNOW    5:1| 0.2|| 0.00|| 0.00|| 0.035    8:1|  7.0|| 0.00|| 0.00|| 0.84  100|  0|  0
150210/1200Z 144  03013KT  24.2F  SNOW    6:1| 0.3|| 0.00|| 0.00|| 0.050    8:1|  7.3|| 0.00|| 0.00|| 0.89  100|  0|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
150210/1500Z 147  02014KT  26.3F  SNOW   10:1| 0.2|| 0.00|| 0.00|| 0.024    8:1|  7.5|| 0.00|| 0.00|| 0.91  100|  0|  0
 

[rsteff]

A few reasons...

 

1) Those weenie WxBell maps assume a 10:1 ratio which is not always correct, in fact most of the time it's wrong.

 

2) The WxBell maps count sleet as snow.

 

3) In general snowfall amounts are nearly impossible to forecast more than a day in advance, and sometimes even hours in advance as slight changes in temperature profiles and mesoscale features can have large implications.

[SR Airglow]

12z GFS for KLGA, not a foot + like some people were saying.

 

150208/0600Z  90  VRB02KT  28.1F  SNOW   11:1| 0.2|| 0.00|| 0.00|| 0.019   11:1|  0.2|| 0.00|| 0.00|| 0.02  100|  0|  0

150208/0900Z  93  06003KT  29.2F  SNOW    7:1| 0.4|| 0.00|| 0.00|| 0.057    8:1|  0.6|| 0.00|| 0.00|| 0.08  100|  0|  0

150208/1200Z  96  04008KT  28.1F  SNOW    8:1| 0.7|| 0.00|| 0.00|| 0.084    8:1|  1.3|| 0.00|| 0.00|| 0.16  100|  0|  0

----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---

150208/1500Z  99  05012KT  25.4F  SNOW    5:1| 0.3|| 0.00|| 0.00|| 0.056    7:1|  1.6|| 0.00|| 0.00|| 0.21  100|  0|  0

150208/1800Z 102  05011KT  23.1F  SNOW    4:1| 0.1|| 0.00|| 0.00|| 0.035    7:1|  1.7|| 0.00|| 0.00|| 0.25  100|  0|  0

150208/2100Z 105  05011KT  20.6F  SNOW    9:1| 0.3|| 0.00|| 0.00|| 0.037    7:1|  2.1|| 0.00|| 0.00|| 0.29  100|  0|  0

150209/0000Z 108  05012KT  17.3F  SNOW   15:1| 0.7|| 0.00|| 0.00|| 0.044    8:1|  2.7|| 0.00|| 0.00|| 0.33  100|  0|  0

----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---

150209/0300Z 111  05012KT  15.5F  SNOW    6:1| 0.3|| 0.00|| 0.00|| 0.051    8:1|  3.0|| 0.00|| 0.00|| 0.38  100|  0|  0

150209/0600Z 114  05012KT  15.0F  SNOW    5:1| 0.1|| 0.00|| 0.00|| 0.025    8:1|  3.1|| 0.00|| 0.00|| 0.41  100|  0|  0

150209/0900Z 117  05012KT  15.3F  SNOW    6:1| 0.2|| 0.00|| 0.00|| 0.042    8:1|  3.4|| 0.00|| 0.00|| 0.45  100|  0|  0

150209/1200Z 120  05011KT  16.2F  SNOW    8:1| 0.3|| 0.00|| 0.00|| 0.033    8:1|  3.6|| 0.00|| 0.00|| 0.48  100|  0|  0

----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---

150209/1500Z 123  05012KT  19.3F  SNOW    7:1| 0.3|| 0.00|| 0.00|| 0.036    8:1|  3.9|| 0.00|| 0.00|| 0.52  100|  0|  0

150209/1800Z 126  05013KT  22.0F  SNOW    9:1| 0.4|| 0.00|| 0.00|| 0.044    8:1|  4.3|| 0.00|| 0.00|| 0.56  100|  0|  0

150209/2100Z 129  04014KT  23.6F  SNOW   14:1| 0.3|| 0.00|| 0.00|| 0.025    8:1|  4.6|| 0.00|| 0.00|| 0.59  100|  0|  0

150210/0000Z 132  04013KT  24.9F  SNOW   11:1| 0.8|| 0.00|| 0.00|| 0.077    8:1|  5.5|| 0.00|| 0.00|| 0.66  100|  0|  0

----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---

150210/0300Z 135  04014KT  25.1F  SNOW   12:1| 1.0|| 0.00|| 0.00|| 0.080    9:1|  6.4|| 0.00|| 0.00|| 0.74  100|  0|  0

150210/0600Z 138  03014KT  23.1F  SNOW    6:1| 0.4|| 0.00|| 0.00|| 0.062    8:1|  6.8|| 0.00|| 0.00|| 0.81  100|  0|  0

150210/0900Z 141  03014KT  22.7F  SNOW    5:1| 0.2|| 0.00|| 0.00|| 0.035    8:1|  7.0|| 0.00|| 0.00|| 0.84  100|  0|  0

150210/1200Z 144  03013KT  24.2F  SNOW    6:1| 0.3|| 0.00|| 0.00|| 0.050    8:1|  7.3|| 0.00|| 0.00|| 0.89  100|  0|  0

----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---

150210/1500Z 147  02014KT  26.3F  SNOW   10:1| 0.2|| 0.00|| 0.00|| 0.024    8:1|  7.5|| 0.00|| 0.00|| 0.91  100|  0|  0

 

Probably because for some reason it's assuming 5:1 ratios for a lot of it which is completely unrealistic considering 850s and surface.

[IsentropicLift]

Probably because for some reason it's assuming 5:1 ratios for a lot of it which is completely unrealistic considering 850s and surface.

850's aren't that cold, 8:1 is just the average ratio.

[CIK62]

GFSx is 18" around here but refers to precipitation type with a 'Z' throughout.   What does this mean?

[IsentropicLift]

GFSx is 18" around here but refers to precipitation type with a 'Z' throughout.   What does this mean?

ZR would be freezing rain.