Winter storm 12/8-9 model discussion part II

[WVclimo]

Interesting

 

 

 

http://www.hpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=qpfpfd

 

That's a very nice, well-written discussion, and really a fun read for early December.  Thanks for sharing it, Yoda.

And they keep the watch for now for everyone else?

LWX has been very solid for the event.  Unlike past seasons, where they might have broad brushed some warnings, they have been careful trying to get this forecast right.  I guess being a Sunday, they have less pressure to pull any triggers.

[snowdude]

I am very happy that I live well east of those mountains. They can enjoy all that ice on the roads. With a 45 degree road we should only have wet roads, and an inch of snow on a warm road is no prob.

 

I for one do NOT want to get ''Dallas'ed''.

Dallas had temps in the 70s before the storm. We will still have icy and slick roads in spots. Ground temps are misleading I think. But yes mid 40s is better than subfreezing which means mainly wet to start.

[mitchnick]

Don't know if this is what you guys call a southern stream, but this stuff definitely has a southern and tropical connection.

here's another wv shot

http://www.ssd.noaa.gov/PS/PCPN/DATA/RT/na-wv-loop.html

[mappy]

I'm expecting an WWA for me. York county is under one, can't imagine LWX would give me a warning while CTP gave them an advisory.

[WxMan1]

Does appear odd -- it's certainly showing up on NDFD and correlates well with the point-and-click forecasts (which it should given that the formatter pulls in these ice accum grids); however, it does not jive with the wording in the current watch area (.25+ ice) nor the advisory area east of I95 (up to .2" of ice).

Still think this ice map is horrible. 

 

[mappy]

30/26 here

[TerpWeather]

For anyone interested: MD's major roads and their temperatures. Down to the 30s mostly
http://www.chart.state.md.us/travinfo/weatherStationData.asp

[yoda]

I'm expecting an WWA for me. York county is under one, can't imagine LWX would give me a warning while CTP gave them an advisory.

I imagine that everyone still under a watch will go to warning IMO... but we shall see

[DCAlexandria]

Dew point 21 now here in Alexandria. Temp 37

[aldie 22]

Dew point 21 now here in Alexandria. Temp 37

DP 29 here

[snowdude]

Why are they waiting for Charlottesville and those areas. That's a warning I would think no question

[Grothar of Herndon]

Temp 36

DP 24

[snow.]

18z GFS is likely too far south with the precip shield and thus too dry.  I'd expect to verify wetter by 0z tomorrow

[BristowWx]

18z GFS is likely too far south with the precip shield and thus too dry.  I'd expect to verify wetter by 0z tomorrow

Why? Just curious and trying to learn. It seems that high is keeping things suppressed.

[aldie 22]

Why....what are you cooking?

It's what JYO is reporting

[Bob Chill]

18z GFS is likely too far south with the precip shield and thus too dry.  I'd expect to verify wetter by 0z tomorrow

I just clicked the imaginary like button 40 times. And I agree. We've seen it happen many times. If the storm was originating from canada then I would be more concerned about precip totals. :Let's get busy during our brief window. 

[Bob Chill]

Why? Just curious and trying to learn. It seems that high is keeping things suppressed.

 

Warm air advection precip has a much easier time overcoming low level cold and dry. There will be some good lift for a time and should press against the high. We all need to pray the front wave is moisture laden though. 

[WVclimo]

DP 29 here

31/18.  30.54in

[yoda]

Why are they waiting for Charlottesville and those areas. That's a warning I would think no question

I guess LWX is waiting for the early 00z suite (aka 21z SREFs and 00z NAM) before pulling the trigger?

[wxmeddler]

For anyone interested: MD's major roads and their temperatures. Down to the 30s mostly

http://www.chart.state.md.us/travinfo/weatherStationData.asp

 

My to do list is to make a python script to make a GR placefile out of that.

[I-83 BLIZZARD]

I'm expecting an WWA for me. York county is under one, can't imagine LWX would give me a warning while CTP gave them an advisory.

They are very conservative with their advisories and warnings up here. I have had 6 inch events with warnings to my south and no advisory here ever.

[snow.]

Why? Just curious and trying to learn. It seems that high is keeping things suppressed.

 

It is an outlier meaning it is inconsistent with all other guidance, including its own previous runs.  (I am mainly talking about that 1st wave through 21z.  The one we care about for snow)

 

It is the 18z GFS which tends to be a goofy run. It ran dry yesterday too.

 

It is inconsistent with its own ensembles as far as the precip shield and axis.

 

If it shows the same thing at 0z, then maybe it is onto something, but I expect it will come in wetter through 21z on the next run.  Even so, it give me 0.20" through 21z which would be all snow/sleet and probably give me my inch, and I care most about my backyard when I am in the game.  When I am out of the game, I take more interest in other parts of the CWA.  I'm sure later in the day I will be more interested in those getting tattooed with ice.  Until late afternoon all I'll care about is my backyard, football and sleep deprivation

[mitchnick]

I guess LWX is waiting for the early 00z suite (aka 21z SREFs and 00z NAM) before pulling the trigger?

that or Dave's final call

[Ian]

that or Dave's final call

Is he still calling for 3x what everyone else is?

[BristowWx]

It is an outlier meaning it is inconsistent with all other guidance, including its own previous runs.  (I am mainly talking about that 1st wave through 21z.  The one we care about for snow)

 

It is the 18z GFS which tends to be a goofy run. It ran dry yesterday too.

 

It is inconsistent with its own ensembles as far as the precip shield and axis.

 

If it shows the same thing at 0z, then maybe it is onto something, but I expect it will come in wetter through 21z on the next run.  Even so, it give me 0.20" through 21z which would be all snow/sleet and probably give me my inch, and I care most about my backyard when I am in the game.  When I am out of the game, I take more interest in other parts of the CWA.  I'm sure later in the day I will be more interested in those getting tattooed with ice.  Until late afternoon all I'll care about is my backyard, football and sleep deprivation

Thanks. Appreciate the insight. I was just thinking it was the HP being strong and keeping the shield south.

[yoda]

[snow.]

Thanks. Appreciate the insight. I was just thinking it was the HP being strong and keeping the shield south.

 

that's happening, but shouldn't happen to the extent that run is showing

[Bob Chill]

Thanks. Appreciate the insight. I was just thinking it was the HP being strong and keeping the shield south.

The high is doing that as a whole. Roll back in time a few days and look at the model runs. The initial wave of snow was prog to make it into new England. It has proved to be quite a beast. It's a very sharp cutoff on the northern edge. This is a bit unusual with a low track to the west.

Precip streams north later after the hp loses its grip. But it's all rain for the most part. Being in the snow jackpot (even tho it's small) down here with this type of storm is not common.

[87storms]

i'd rather the hp be strong and roll the dice on precip.

[PhineasC]

At least it is plenty cold before the storm. Seems like lately we are 50 degrees the day of the storm and praying for all sorts of crazy rates and frontal passages.