12/29 - New Years Storm Threat Discussion

[IsentropicLift]

Right here, maybe if we can get that perfect ejection of the energy from the cut off low in the SW to phase with that energy coming down from Central Canada and phase over the Southeast we might be in business. Instead that northern stream system is probably just going to swing through as a clipper and we end up with a positive tilt trough.

[readingaccount1]

What did the European model show liquid wise at 12z? .25 or .15?

[readingaccount1]

Mt Holly snow graphs show 4.4 inches of snow in parts of NJ.

[IsentropicLift]

Mt Holly snow graphs show 4.4 inches of snow in parts of NJ.

Where did you see that? I just checked Mt. Holly and Upton and neither one of them have been updated yet for the next storm.

[readingaccount1]

Where did you see that? I just checked Mt. Holly and Upton and neither one of them have been updated yet for the next storm.

It is from the local forecast:

http://forecast.weather.gov/MapClick.php?lat=40.57964&lon=-74.384491525424&unit=0&lg=english&FcstType=graphical

[Edge Weather]

What did the European model show liquid wise at 12z? .25 or .15?

.23 at Andover, .19 at Caldwell, .18 at Morristown, .21 at NYC

[TwcMan]

Doesn't Euro usually lessen the precip in this range? Just a question, not a wishcast

[Edge Weather]

Doesn't Euro usually lessen the precip in this range? Just a question, not a wishcast

Sometimes yes, sometimes no. Honestly though recently I have seen it show absolutely no precipitation at all and we end up getting up to .20 with some of the recent storms, only 2 days out. So, it is possible, but not highly likely.

[IsentropicLift]

Just about every 12z GFS ensemble member gives areas North and West of the City several inches of snow. Nothing for Long Island.

http://raleighwx.americanwx.com/models/gfsensemble/members/12zsnowf078.html

[Edge Weather]

Back to my question about ratios though. Anyone who is knowledgeable here, maybe earthlight or a met, should we use 10:1 for this or something higher?

[earthlight]

Just about every 12z GFS ensemble member gives areas North and West of the City several inches of snow. Nothing for Long Island.

http://raleighwx.ame...2zsnowf078.html

Using those for snowfall totals is about the worst possible thing you could ever do as a forecaster.

[readingaccount1]

Mt Holly seems to have removed the Hazardous Weather Outlook. I would presume either an update or a watch to follow?

[Stormlover74]

10:1 maybe 12:1 in colder locales but in general we're not in an arctic airmass where it would be 15 or 20:1

Back to my question about ratios though. Anyone who is knowledgeable here, maybe earthlight or a met, should we use 10:1 for this or something higher?

[Stormlover74]

Watches seem highly unlikely with virtually all models showing <6" event.

Mt Holly seems to have removed the Hazardous Weather Outlook. I would presume either an update or a watch to follow?

[nzucker]

10:1 maybe 12:1 in colder locales but in general we're not in an arctic airmass where it would be 15 or 20:1

I could see 12:1 here....high is supposed to be 31F here in Dobbs Ferry.

[green tube]

Mt Holly seems to have removed the Hazardous Weather Outlook. I would presume either an update or a watch to follow?

a watch??

you make snow88 look like a pessimist.

[IsentropicLift]

Using those for snowfall totals is about the worst possible thing you could ever do as a forecaster.

Well my reasoning for posting them was the consistency more than anything else.

[RUNNAWAYICEBERG]

I could see 12:1 here....high is supposed to be 31F here in Dobbs Ferry.

not to mention the mountain your house sits..... your backyard is another 1F degree cooler. your ratios could spike to 15:1. down in the valleys of westchester your looking at 2-3in storm while your mountain peak picks up an extra inch. huge differences between mt zucker and the rest of dobbs ferry.

[IsentropicLift]

Back to my question about ratios though. Anyone who is knowledgeable here, maybe earthlight or a met, should we use 10:1 for this or something higher?

Per the 12z GFS bukfit tool I have the highest ratio would be 14:1 at KMMU which is the closest station I have to your location. But then the ratios quickly drop after that.

121229/1500Z 51 07003KT 29.2F SNOW 14:1| 1.4|| 0.00|| 0.00|| 0.096 14:1| 1.4|| 0.00|| 0.00|| 0.10 100| 0| 0

121229/1800Z 54 05003KT 31.2F SNOW 10:1| 1.5|| 0.00|| 0.00|| 0.148 12:1| 2.9|| 0.00|| 0.00|| 0.24 100| 0| 0

121229/2100Z 57 01006KT 31.7F SNOW 8:1| 0.4|| 0.00|| 0.00|| 0.048 11:1| 3.3|| 0.00|| 0.00|| 0.29 100| 0| 0

121230/0000Z 60 35006KT 28.7F SNOW 7:1| 0.1|| 0.00|| 0.00|| 0.016 11:1| 3.5|| 0.00|| 0.00|| 0.31 100| 0| 0

[Storm At Sea]

South Jersey has lower criteria for warnings. It wouldn't be unreasonable for some areas to be in a watch for 2-5 in. for the event.

a watch??

you make snow88 look like a pessimist.

[Edge Weather]

Per the 12z GFS bukfit tool I have the highest ratio would be 14:1 at KMMU which is the closest station I have to your location. But then the ratios quickly drop after that.

121229/1500Z 51 07003KT 29.2F SNOW 14:1| 1.4|| 0.00|| 0.00|| 0.096 14:1| 1.4|| 0.00|| 0.00|| 0.10 100| 0| 0

121229/1800Z 54 05003KT 31.2F SNOW 10:1| 1.5|| 0.00|| 0.00|| 0.148 12:1| 2.9|| 0.00|| 0.00|| 0.24 100| 0| 0

121229/2100Z 57 01006KT 31.7F SNOW 8:1| 0.4|| 0.00|| 0.00|| 0.048 11:1| 3.3|| 0.00|| 0.00|| 0.29 100| 0| 0

121230/0000Z 60 35006KT 28.7F SNOW 7:1| 0.1|| 0.00|| 0.00|| 0.016 11:1| 3.5|| 0.00|| 0.00|| 0.31 100| 0| 0

Thank you

[IsentropicLift]

Thank you

No problem, I also checked the 12z NAM for you. Higher ratios but less precip so a little less accumulation.

121229/1400Z 50 11003KT 29.7F SNOW 6:1| 0.1|| 0.00|| 0.00|| 0.023 6:1| 0.1|| 0.00|| 0.00|| 0.02 100| 0| 0

121229/1500Z 51 10003KT 29.9F SNOW 6:1| 0.1|| 0.00|| 0.00|| 0.024 6:1| 0.3|| 0.00|| 0.00|| 0.05 100| 0| 0

121229/1600Z 52 VRB02KT 30.8F SNOW 13:1| 0.2|| 0.00|| 0.00|| 0.018 8:1| 0.5|| 0.00|| 0.00|| 0.07 100| 0| 0

121229/1700Z 53 VRB00KT 30.8F SNOW 16:1| 0.6|| 0.00|| 0.00|| 0.039 11:1| 1.1|| 0.00|| 0.00|| 0.10 100| 0| 0

121229/1800Z 54 VRB01KT 31.0F SNOW 21:1| 0.7|| 0.00|| 0.00|| 0.033 13:1| 1.8|| 0.00|| 0.00|| 0.14 100| 0| 0

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

121229/1900Z 55 VRB01KT 31.0F SNOW 18:1| 0.4|| 0.00|| 0.00|| 0.024 14:1| 2.2|| 0.00|| 0.00|| 0.16 100| 0| 0

121229/2000Z 56 VRB02KT 31.7F SNOW 10:1| 0.0|| 0.00|| 0.00|| 0.004 14:1| 2.3|| 0.00|| 0.00|| 0.16 100| 0| 0

[IsentropicLift]

South Jersey has lower criteria for warnings. It wouldn't be unreasonable for some areas to be in a watch for 2-5 in. for the event.

12 hr Warning criteria snowfall

and 24 hr

[earthlight]

The 15z SREFs definitely ticked south and east...probably lost some of the more amplifier members.

[TWCCraig]

The 15z SREFs definitely ticked south and east...probably lost some of the more amplifier members.

[allgame830]

I guess a minor event it is...

[Rjay]

Prior to an event, when do the SREFs become reliable? The NAM used to be inside 48 hrs but the past couple of years its been awful for the most part.

[jm1220]

I'm thinking a 2-4" type event for most of the area, maybe a 5" here and there. Hopefully the coastal low development doesn't rob too much of the initial snow. The big bomb idea was always farfetched given the progressive, little-blocking pattern. Advisory-criteria event, enough to remind people it's winter.

[nzucker]

Euro Ensembles are still looking decent according to the SNE thread.

[Snow_Miser]

Through hour 24, the NAM is definitely digging the vort associated with the system more compared to the 12z NAM at hour 30. It's also stronger with the vort overall, and has higher heights along the east coast. We'll see.