Official Long Range Thread 5.0

[Frank_Wx]

All eyes turn to next weekend...

00z EURO







Read latest blog for details of this storm

[CPcantmeasuresnow]

You would think I would get this by now but,,,,

The dark blue 32 line is surface temps? The 540 line is freezing at 850's? If so what is the 0 I'm guessing centigrade line for? Freezing at what level? Looking at this with my limited understanding the mid levels look to warm for snow or am I way off base.

Inquiring minds would like to know. Any of the professorial types awake out there, Frank, Sroc, mugs, Ace, Al, RB, NJ, isotherm or any others please feel free to answer and thanks in advance.

[docstox12]

I guess my statement here CP is the blind leading the blind but the 32 line is that dark purple one.It looks like we are right on it or just a little north of it, so we are ok up here but S and E of us are not.As Frank said, not much cold air in Canada at this juncture so the storm has to crank up and dynamic cooling to occur.The 540 line I'm still not clear with. Of course you realize, this far out in time, these models are about as useful as a fart in a spacesuit so don't get too ramped up yet.

[algae888]

You would think I would get this by now but,,,,

The dark blue 32 line is surface temps? The 540 line is freezing at 850's? If so what is the 0 I'm guessing centigrade line for? Freezing at what level? Looking at this with my limited understanding the mid levels look to warm for snow or am I way off base.  

Inquiring minds would like to know. Any of the professorial types awake out there, Frank, Sroc, mugs, Ace, Al, RB, NJ, isotherm or any others please feel free to answer and thanks in advance.

cp I believe as you stated the 32* line is the surface. the 0* line is the 850's  and the 540 line that you are inquiring about is the 500mb temps. on models it's the 1000-500 thickness. in winter we can get snow with a 546 thickness and surface and 850 temps a little above freezing but ideally we want them all below freezing.

[algae888]

here is a little more detail with respect to temperature levels. 2 meter temps is the surface. 925mb is about 2500 feet above, 850mb is 5000 feet, next is 700mb is about 10,000', 500mb is 18,000' and 300mb is 30,000' above sea level. these are the standard heights used in determining temps as we go up in the atmosphere. there are many good sights to learn about this. just enter 500 or 850 temp heights in your search engine and you will find them.

[sroc4]

Al actually the 540 line and the 500mb temps are not quite one in the same. Here a link that explains it really well. http://www.theweatherprediction.com/habyhints/97/

[sroc4]

The 0*c line is the freezing line for the 850mb level and the 32 is the surface. As a general rule look for the R/S line to set up near the 850mb freezing line.

[rb924119]

Sroc, you beat me to the punch.....the 540 line represents a thickness, which I'm sure this article explains. If not, feel free to inquire further lol

[CPcantmeasuresnow]

The 0*c line is the freezing line for the 850mb level and the 32 is the surface. As a general rule look for the R/S line to set up near the 850mb freezing line.

Then the 540 line is freezing at what level, feet, in the atmosphere?

[amugs]

The 540 line is in reference to a 5,400 geopotential meter thickness between 1000 and 500 millibars. Thickness is a primary function of the temperature of the air and a secondary function of the moisture content of the air

CP - as Scott stated this is the line where the r/s line sets up in the atmosphere - now could it be north or west of there and we get freezing line you did sure when you cold air damming or low level cold air (LLC) that gets trapped at the surface . This is what even Alex has referred to from his scholars up at the great Lyndon State College meteorological department.

Looking at the CMC and GFS past xmass and my god the 32* goes all the way down the GOM - showing New Orleans getting snow and ice near the end of the runs.

The powder keg is going to be delivered next weekend and you will all join me in a online taping of this bad boy and celebration imaginary style - sht my wife might kill me since we have our annual xmass party next Saturday night and if I am in the Chat room I am sleeping with the dog - not bad she is cute and warm and loves her master!!

GFS is lost in this pattern and really has been struggling these last couple of months - scoring 3rd in verification

[Snow88]

Upton for next weekend

A DEVELOPING LOW OVER TEXAS AND ITS PROGRESSION INTO THE WEEKEND IS STILL UNCERTAIN. 00Z GFS HAS TRACKED THE LOW FURTHER SOUTH OF THE LOCAL AREA SATURDAY. P-TYPE IS ALSO UNCERTAIN...AND A LOT WILL DEPEND ON WHETHER THE DEPARTING HIGH HANGS IN LONG ENOUGH TO KEEP PROVIDING COLD AIR DURING THE EVENT. AT THIS EARLY JUNCTURE HAVE FCST EITHER RAIN OR SNOW SAT AFTERNOON CHANGING TO ALL SNOW.

[algae888]

Al actually the 540 line and the 500mb temps are not quite one in the same. Here a link that explains it really well. http://www.theweatherprediction.com/habyhints/97/

thanks for clarifying that scott. always thought it reflected temps further up in the atmosphere. It does to some degree but it is much more complicated than that. always learning on here.

[sroc4]

The 0*c line is the freezing line for the 850mb level and the 32 is the surface. As a general rule look for the R/S line to set up near the 850mb freezing line.

Then the 540 line is freezing at what level, feet, in the atmosphere?

Cp I'll try to explain this later unless someone else can. It's not quite an easy answer. I'm currently hung over from a Xmas party last night and walking out the door to have my 6 year olds birthday party wih 20 crazy kids running around. Should be fun. Lol

[Dunnzoo]

The powder keg is going to be delivered next weekend and you will all join me in a online taping of this bad boy and celebration imaginary style - sht my wife might kill me since we have our annual xmass party next Saturday night and if I am in the Chat room I am sleeping with the dog - not bad she is cute and warm and loves her master!!

Woohoo! Party at mugs house! Then the wife won't know he's talking shop!

[Frank_Wx]

The 0*c line is the freezing line for the 850mb level and the 32 is the surface. As a general rule look for the R/S line to set up near the 850mb freezing line.

Then the 540 line is freezing at what level, feet, in the atmosphere?

Like others have said, 850 mb line (below 0*C) is a much better indicator of the rain/snow line. 540 thickness is used between 1000 and 500 millibars. There are several factors that go into determining rain or snow, which is why sometimes we have to use soundings to get an idea if a model really is showing rain or snow, but the 540 line means there is at least a 50% chance that the precip. falling will be snow. Obviously if you have cold 850's as well, that percentage shoots way up. 

Read here to see what I mean

http://www.theweatherprediction.com/habyhints/97/

[Frank_Wx]

The 0*c line is the freezing line for the 850mb level and the 32 is the surface. As a general rule look for the R/S line to set up near the 850mb freezing line.

Then the 540 line is freezing at what level, feet, in the atmosphere?

Cp I'll try to explain this later unless someone else can. It's not quite an easy answer. I'm currently hung over from a Xmas party last night and walking out the door to have my 6 year olds birthday party wih 20 crazy kids running around. Should be fun. Lol

Oh lord. Good luck

[jmanley32]

12z Euro is beautiful for 21st, storm deepens to 984 mb inside the benchmark but that hopefully will move a bit east but everyone gets in on something from that run wow (some get crushed). GFS and CMC still not enthused, but as I said I am going with the Euro until (and I hope it doesn't) lose the storm.

[nutleyblizzard]

12z Euro is beautiful for 21st, storm deepens to 984 mb inside the benchmark but that hopefully will move a bit east but everyone gets in on something from that run wow (some get crushed).  GFS and CMC still not enthused, but as I said I am going with the Euro until (and I hope it doesn't) lose the storm.

Yep. 50 miles further east, and its a MECS even for the coast. Way too early to worry about precip type… just as long as the EURO shows the storm. I don't trust the GFS long range. I think it will catch on in a few days.

[jmanley32]

nutley I agree totally, its about 168 hours out till its over us on Euro, so GFS should catch on maybe around 120 hrs or so, who knows maybe less, as mugs said its third in line, and well CMC is just a crummy model. Have to admit I am a bit stoked, Even a 6+ inche storm which it shows still ofr NYC area I will be thrilled.

[jmanley32]

Euro also shows the beginnings of what looks to be our possible xmas storm (and it looks strong even way down there. Man imagine if we get SECS, MECS and maybe even a HECS every 10 days or so like the systems have been happening the area will be buried and many of us will be right on the high end of the snowfall contest.

[nutleyblizzard]

The storm around xmas will have the most potential between the two. If the storm on the 21st also produces, that will be a bonus.

[jmanley32]

Yeah, so far looking ok for this far out on Euro ensembles for next weekend. About 20 have a storm with any snow and about 15 have significant snow. If the one for xmas comes I just hope its not on the 26-27th because I have to travel to CT to see family for a late holiday. Not saying I do not want the storm but that would greatly mess up plans as I doubt very much it could easily be rescheduled.

[amugs]

Guys just saw teh euro and holy smokes it is barking at this storm - just hope that 17th storm does it work and gives us the 50/50 low that we need for this to produce - part of the step down process - may start as a mix then we all change to snow and the ensembles are honking too. The GooFuS has been just awful lately - god dam american models - I can't wait for that darn upgrade coming in March and April - we go with the euro it is hot and has a much better track record in this time range - #1 verification score and the set up is not jiving in my mind.

Miller A's all the ways!!!!!!!!!!!!

[docstox12]

NWS starting to pick up on that Euro, now a 30% chance of snow here sat night-sunday.Nothing was mentioned this morning.Very early but it's a positive.

Happy days!!!

[rb924119]

We have to be very, very cautious with the 21st storm since those rex block situations always play havoc on the models because there is so much uncertainty in the progression of the cutoff low beneath the ridge. Does it remain disconnected from the flow, or does it begin to open up as the pattern progresses? This can be clearly seen in all of the ensembles, and how the spaghettis are everywhere. It's just too uncertain for me at this time to get too excited. Do I think there will be a storm? Absolutely. Do I think that there is a solid chance that it comes up the east coast? Absolutely. The times of pattern changes are extremely volatile for the atmosphere, and that is when you get your biggest storms because of all of the instability associated with the changing atmosphere. Couple that with the cold-shift in the pattern, and I think there is certainly cause for excitement. I'm trying to remain as calm as possible, though, because so many things can change. If this is still being shown on Wednesday, I'm punching my ticket and boarding the train. To have the EURO keyed in this far out says something, as we all know how well it's been doing so far this season at picking up on storms in the long range (knock on wood), but I'm just trying to demonstrate the caution that must be taken when looking at this particular situation.

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