DISCUSSION ONLY: Snow/rain/slopfest potential Tuesday 11/27/2012

[famartin]

why wouldnt you just drive there? Its not like its a 5 hr drive.

2" of snow and it could be. This is metro Philly, remember?

[tombo82685]

you want to talk about isothermal, this is the skew t from the camden area. Freezing level is around 950, this is hr 24

[Ralph Wiggum]

The definition of a "bullseye". Just outside of it myself.

My area DYL.

Not impressed with this system. Sloppy 1-2". Better than nothing I suppose.

[Bobby EPAWA]

* SNOW ACCUMULATIONS...UP TO TWO OR THREE INCHES

Seems a little light to me for Northern Bucks, Northern Montco, Northern Berks, Lehigh and Northampton... unless this is dismissing the hi res models that are consistently showing more QPF, heavier rates. Curious as to why the lower numbers for those areas specifically - probably something I am overlooking, but not seeing a rain mix here with heavier rates.

[tombo82685]

Seems a little light to me for Northern Bucks, Northern Montco, Northern Berks, Lehigh and Northampton... unless this is dismissing the hi res models that are consistently showing more QPF, heavier rates. Curious as to why the lower numbers for those areas specifically - probably something I am overlooking, but not seeing a rain mix here with heavier rates.

my guess, because it wont stick initially until you get that heavy rate. So .1-.2 may be blown in qpf till the heavy banding comes in? Also, you probably just can't go 100 meso models. I would think you would have to take into consideration the globals to. Which are no where near as wet.

[Quakertown needs snow]

why wouldnt you just drive there? Its not like its a 5 hr drive.

did you miss the word "nutjob"?

are we thinking start time is still before dawn? or after?

[phlwx]

meso models are good to show where precip is falling at a projected time but not necessarily an accurate indicator of qpf.

[Sunny and Warm]

Seems a little light to me for Northern Bucks, Northern Montco, Northern Berks, Lehigh and Northampton... unless this is dismissing the hi res models that are consistently showing more QPF, heavier rates. Curious as to why the lower numbers for those areas specifically - probably something I am overlooking, but not seeing a rain mix here with heavier rates.

I have learned to never doubt the appropriateness of a conservative NWS forecast. Much more right than wrong with a lot more meteorology behind it than you and I can muster. Besides, no one gets shot if you start conservative and ramp up as required. In reverse, people get testy for having been panicked unnecessarily into buying eggs, milk, bread.

[anthonyweather]

Hope you get a lot of work this winter!

Congratulations! If you get down to Perkiomen Woods in Collegeville, don't run over the guy cross-country skiing, becuase it will most likely be me!

Very nice! Hopefully you will have some pics to share with us through the winter.

cool!

how much to plow my driveway? shhhhhh

Congrats!

Hey guys hopefully ill be of some use to ya's this winter! I got hired as a plow operator for penndot, I'll be out of the schnecksville area shed

Congrats! Interview and hire on the same day!

Hey thanks everyone!!! 3 guys were in front of me were in their 40's and didnt get the job, but me (20years old) did (:

Quakertown : not sure how youd feel about a beginner pulling a mack with a 12 foot wide plow into your driveway

noticed some road brining on I 78 this afternoon around the Allentown area

Boss man told me they were gonna brine to make sure all the trucks and equipment were ready for the winter

[Bobby EPAWA]

I have learned to never doubt the appropriateness of a conservative NWS forecast. Much more right than wrong with a lot more meteorology behind it than you and I can muster. Besides, no one gets shot if you start conservative and ramp up as required. In reverse, people get testy for having been panicked unnecessarily into buying eggs, milk, bread.

Not challenging or even insinuating conservativeness - just trying to get some reasoning ideas. Believe me, I have been conservative on this nuisance train for days...

[famartin]

Seems a little light to me for Northern Bucks, Northern Montco, Northern Berks, Lehigh and Northampton... unless this is dismissing the hi res models that are consistently showing more QPF, heavier rates. Curious as to why the lower numbers for those areas specifically - probably something I am overlooking, but not seeing a rain mix here with heavier rates.

NYC area was mostly snow on 11/7 but still only had 5:1 ratios. Or less.

[Boch23]

So I guess penndot is putting brine down. There is brine on 291 down by the airport. What's funny is they didn't put anything down the last storm where we were predicted to get a good amount but put it down where we are expected to get little if any snow. I guess it's better to be safe than sorry?

[Parsley]

did you miss the word "nutjob"?

are we thinking start time is still before dawn? or after?

Well, the wetter/faster NAM(18z) has it snowing before 12z. Starting a little before daybreak. The less juicy models like the Euro/GFS are a little slower with its arrival with no appreciable snow til after 12z. I guess these events often begin faster than expected, but who knows.

[Sunny and Warm]

Not challenging or even insinuating conservativeness - just trying to get some reasoning ideas. Believe me, I have been conservative on this nuisance train for days...

I wasn't insinuating you were either. Just making a statement about my own observations over the years. Since abnormal weather of any kind is abnormal, it is always a safe play to stay within the boundries of normal in any situation unless the parameters scream otherwise. I would imagine that Mets have seen dozens and dozens of these type of scenarios over the years and have a pretty good feel for what the QPF and snow production was from many of them.

[tombo82685]

weenie map from 18z

one with ratios

[famartin]

So I guess penndot is putting brine down. There is brine on 291 down by the airport. What's funny is they didn't put anything down the last storm where we were predicted to get a good amount but put it down where we are expected to get little if any snow. I guess it's better to be safe than sorry?

Last storm started midday with solar insolation, roads were gonna start wet no matter what and then possibly get snowy. Brine would get washed off before it could do any good.

This storm will start predawn across most of PA and thus road surfaces will be colder with no insolation. Probably starts as snow most places except maybe PHL proper. A lot will depend on just what temps do tonight, especially after clouds move in. They may spike above freezing, but regardless, its a smarter move to prepare for a possibly snowy morning rush.

[Bobby EPAWA]

NYC area was mostly snow on 11/7 but still only had 5:1 ratios. Or less.

Good point... but use ABE as a point of reference here for example - 5:1 ratios there?

Also, wouldn't you ditch the globals and use meso models to try to determine meso banding areas?

[tombo82685]

Good point... but use ABE as a point of reference here for example - 5:1 ratios there?

Also, wouldn't you ditch the globals and use meso models to try to determine meso banding areas?

not ray, but im pretty sure the euro has a better skill in terms of qpf accuracy than the nam.

[famartin]

Good point... but use ABE as a point of reference here for example - 5:1 ratios there?

Also, wouldn't you ditch the globals and use meso models to try to determine meso banding areas?

Yes, though like others have said, take their QPF with a big grain (pound) of salt. I think there was a NAM run before 11/7 that showed over 1.5" around NYC. That was about 1.5 times reality.

[famartin]

not ray, but im pretty sure the euro has a better skill in terms of qpf accuracy than the nam.

It does. Rainshadow has looked into it more than I have, though. (I think).

[famartin]

Good point... but use ABE as a point of reference here for example - 5:1 ratios there?

Also, wouldn't you ditch the globals and use meso models to try to determine meso banding areas?

ABE may be better off, but they look like they may end up on the QPF gradient. That's always scary since it may mean the best meso banding will stay south and you don't actually get into the good rates. You may just stare at them as they set up 5-10 miles south of you.

[tombo82685]

Last storm started midday with solar insolation, roads were gonna start wet no matter what and then possibly get snowy. Brine would get washed off before it could do any good.

This storm will start predawn across most of PA and thus road surfaces will be colder with no insolation. Probably starts as snow most places except maybe PHL proper. A lot will depend on just what temps do tonight, especially after clouds move in. They may spike above freezing, but regardless, its a smarter move to prepare for a possibly snowy morning rush.

i think that could be a good wild card for those areas on the edge. If they radiate well tonight, and clouds hold off till 2-3am and allow temps to get down to freezing or below it could help out. Also, the temp will drop to once precip starts. The nam never gets phl below 36-37 tonight, while the gfs gets it to freezing the rises to 37 once clouds move in im assuming.

[Parsley]

18z RGEM a little juicier as well. Looks like 10mm-15mm (0.40"-0.60") regionwide.

[Bobby EPAWA]

It may mean the best meso banding will stay south and you don't actually get into the good rates. You may just stare at them as they set up 5-10 miles south of you.

Story of my life

Thanks guys

[Parsley]

ABE may be better off, but they look like they may end up on the QPF gradient. That's always scary since it may mean the best meso banding will stay south and you don't actually get into the good rates. You may just stare at them as they set up 5-10 miles south of you.

Going to be a close call as always. That I-78 corridor from PA into NJ may be the best location (with no drastic changes in the models) in terms of amont of moisture + a cold enough column for all snow.

[tombo82685]

best word of advice is to expect nothing and if you get some accum be happy. A lot can go wrong for the good and better with this event. It will all come down to if any hvy banding takes place. If it happens like the 18z gfs is showing many places wont get much at all. On the other hand if the nam is correct and those heavy areas break out places in the path of that could be very surprised.

[tombo82685]

Going to be a close call as always. That I-78 corridor from PA into NJ may be the best location (with no drastic changes in the models) in terms of amont of moisture + a cold enough column for all snow.

i wouldn't even say that far north..i would say the ptw-ukt-dyl-lansdale to downingtown area, if models are right looks to be the best.

[Parsley]

best word of advice is to expect nothing and if you get some accum be happy. A lot can go wrong for the good and better with this event. It will all come down to if any hvy banding takes place. If it happens like the 18z gfs is showing many places wont get much at all. On the other hand if the nam is correct and those heavy areas break out places in the path of that could be very surprised.

True.

Atleast the GFS shows the potential for a few hour period (I won't call it a "thump") of snow in the morning hours before things fizzle out. That alone isn't too shabby.

[tombo82685]

True.

Atleast the GFS shows the potential for a few hour period (I want call it a "thump") of snow in the morning hours before things fizzle out. That alone isn't too shabby.

the gfs though is a heck of a lot warmer in the lower levels and would deff have rain from dyl to lansdale to downingtown area south. Its all mute right now. You just gotta now cast and watch your temps and esp from surface to 925mb, that is the problem area. It will snow where it wants to snow tomorrow. For sure though, their will definitely be surprises for the good or bad like their always is for storms.

[Parsley]

i wouldn't even say that far north..i would say the ptw-ukt-dyl-lansdale to downingtown area, if models are right looks to be the best.

Meh, we're talking 10 miles or so across eastern PA.....all in all, the same general area. Maybe a smidge south.

Like the last storm, it will probably be 50 miles in a different direction