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February Medium/Long Range Discussion Thread


North Balti Zen

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1 hour ago, mappy said:

quoting this as a reminder: this stuff belongs in banter. This thread is already a cluttered mess of some really good discussion followed by crap posts. Keep the crap to banter. 

 

Thanks, from the semi, sorta, have power, but not really, "staff"

I feel like pointing out the trends are unfavorable and reasons why is fine and adds to the discussion. Discussing why the guidance continually shifts for the worse is also legit.  But it gets annoying when you have to wade through 20 posts of "this sucks" or "the models suck" or silliest of all "long range is a waste" as if we don't know how low probability it is. 

If you think talking about long range is a waste why are you in the long range thread spending time talking about how talking about it is a waste of time. Seems your just venting that it hasn't snowed more then anything. 

It's fine to discuss the model errors and bias but add something of value besides a one liner. I am just as frustrated but we shouldn't turn this thread into a dumpster fire. We have the panic room for that.  Just my 2 cents. Carry on with jumping off the ledge now. 

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7 minutes ago, psuhoffman said:

I feel like pointing out the trends are unfavorable and reasons why is fine and adds to the discussion. Discussing why the guidance continually shifts for the worse is also legit.  But it gets annoying when you have to wade through 20 posts of "this sucks" or "the models suck" or silliest of all "long range is a waste" as if we don't know how low probability it is. 

If you think talking about long range is a waste why are you in the long range thread spending time talking about how talking about it is a waste of time. Seems your just venting that it hasn't snowed more then anything. 

It's fine to discuss the model errors and bias but add something of value besides a one liner. I am just as frustrated but we shouldn't turn this thread into a dumpster fire. We have the panic room for that.  Just my 2 cents. Carry on with jumping off the ledge now. 

Notice which comment she responded to.

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Long time lurker here... it seems that we need the southern SW from the first system to become the dominant LP, as otherwise the front never comes through and the later week storm easily cuts. If the southern shortwave from the Monday system were to develop more as we saw in earlier runs, then the later system has to dig more. Unfortunately, models have been trending away from that idea :(

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27 minutes ago, flsch22 said:

"Our old friend the WAR is back." 

 

What is the WAR? And thanks for this interesting discussion!

Western Atlantic Ridge

WAR.png

We want lower heights (blue) right where that ridge (red) is.  There are some things to like about the look, the ridge in the west, the higher heights up in greenland, but that WAR is an absolute killer.  The reason we need the lower heights there is simply to create the conditions we need leading into a storm.  With ridging there the flow ahead of any approaching trough/storm will be out of the south with no resistance or mechanism to hold in cold.  Any storm that amplifies or deepends will probably cut to our west and even if it didn't it would be hard to hold in cold.  Keep in mind one of the major causes of the lift that creates our precip is the warm air advection (WAA) or warm air being lifted up and over the denser cold air.  So any storm that comes at us is naturally going to try to push the temperature gradient (baroclinic zone) north as it comes up.  Without a mechanism to offer resistance our temperature will warm and we rain.  Put a low up there where the WAR is and the counter clockwise flow around it does two things.  THe flow is out of the north behind it offering resistance to the warmth coming from the south.  That the confluence created by the coming together of the streams of air between the approaching trough and the lower heights up near 50 lat 50 long (often called the 50/50 low) encourages higher pressure to be to our north.  Confluence creates high pressure.  That is what we need.  

Below is the composite h5 for our 7 biggest area wide snowfalls of the last 30 years.  The first is 2 days before the storm, the second is the day of.   Feb 83, Jan 96, Jan 2000, Feb 03, Dec 09, Feb 10, and Jan 16.  Notice the big take aways.  The ridging up top centered over Greenland and the 50/50 low or those blues to our northeast.  Those are by far the biggest factors, but honestly, looking at all our big snows the 50/50 low is even more consistently a component then even the Greenland ridging (-nao).  Having a WAR there just about kills us.  Notice also, the ambiguous look over the CONUS leading into those events.  And the day of the lower heights over AK.  Also notice the center of the h5 lower heights over the CONUS builds in the tennessee valley and goes under us as a trough digs in under all the ridging in Canada.  One problem lately is even when we get a trough its centered to our north with the best height falls.  We actually have a pretty close look to that setup on some of the long range stuff, especially the GEFS, but we have got to lose that WAR.   The look long range is actually better for us, with more ridging up top and the trough developing under us.  Get some lower heights into the western atlantic northeast of us and the pattern goes from meh to oh yea real fast.  The good news is that isnt a huge adjustment and would put us into a pretty darn good look. 

bigstorms1.gifBigstorms2.gif

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4 minutes ago, psuhoffman said:

Western Atlantic Ridge

WAR.png

We want lower heights (blue) right where that ridge (red) is.  There are some things to like about the look, the ridge in the west, the higher heights up in greenland, but that WAR is an absolute killer.  The reason we need the lower heights there is simply to create the conditions we need leading into a storm.  With ridging there the flow ahead of any approaching trough/storm will be out of the south with no resistance or mechanism to hold in cold.  Any storm that amplifies or deepends will probably cut to our west and even if it didn't it would be hard to hold in cold.  Keep in mind one of the major causes of the lift that creates our precip is the warm air advection (WAA) or warm air being lifted up and over the denser cold air.  So any storm that comes at us is naturally going to try to push the temperature gradient (baroclinic zone) north as it comes up.  Without a mechanism to offer resistance our temperature will warm and we rain.  Put a low up there where the WAR is and the counter clockwise flow around it does two things.  THe flow is out of the north behind it offering resistance to the warmth coming from the south.  That the confluence created by the coming together of the streams of air between the approaching trough and the lower heights up near 50 lat 50 long (often called the 50/50 low) encourages higher pressure to be to our north.  Confluence creates high pressure.  That is what we need.  

Below is the composite h5 for our 7 biggest area wide snowfalls of the last 30 years.  The first is 2 days before the storm, the second is the day of.   Feb 83, Jan 96, Jan 2000, Feb 03, Dec 09, Feb 10, and Jan 16.  Notice the big take aways.  The ridging up top centered over Greenland and the 50/50 low or those blues to our northeast.  Those are by far the biggest factors, but honestly, looking at all our big snows the 50/50 low is even more consistently a component then even the Greenland ridging (-nao).  Having a WAR there just about kills us.  Notice also, the ambiguous look over the CONUS leading into those events.  And the day of the lower heights over AK.  Also notice the center of the h5 lower heights over the CONUS builds in the tennessee valley and goes under us as a trough digs in under all the ridging in Canada.  One problem lately is even when we get a trough its centered to our north with the best height falls.  We actually have a pretty close look to that setup on some of the long range stuff, especially the GEFS, but we have got to lose that WAR.   The look long range is actually better for us, with more ridging up top and the trough developing under us.  Get some lower heights into the western atlantic northeast of us and the pattern goes from meh to oh yea real fast.  The good news is that isnt a huge adjustment and would put us into a pretty darn good look. 

bigstorms1.gifBigstorms2.gif

Excellent analysis!

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37 minutes ago, tstate21 said:

Long time lurker here... it seems that we need the southern SW from the first system to become the dominant LP, as otherwise the front never comes through and the later week storm easily cuts. If the southern shortwave from the Monday system were to develop more as we saw in earlier runs, then the later system has to dig more. Unfortunately, models have been trending away from that idea :(

yes, the key is getting the southern energy to be the dominant player.   Earlier some brought up how models often lose a threat and then bring it back.  More typically that is because of issues resolving disturbances within the overall flow.  Especially in phasing the models can struggle from range on properly identifying timing and interaction between these vorts.  However, our issue now is that the guidance is shifting the overall pattern away from what we need every run.  That said, could the STJ system trend stronger and perhaps get us back towards something in future runs sure, but its a bigger problem then just the model having issues within the flow, the issue now is the flow.  

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1 minute ago, psuhoffman said:

Yea sometimes I forget that without context clues things can be taken the wrong way on here.  

All good. Going to clean up the thread, so don't freak when posts go poof. 

 

Keeping my original warning, and your post though. 

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Just now, Eskimo Joe said:

I'd be happy to trade the rest of the winter for a fast spring that yields a hot summer with a couple of good flooding and severe weather episodes.  We've been starved on the severe side since 2012.

Move to Oklahoma then.....

 

Sorry, just not needing to hear this junk at that end of January.  Yes it sucks.  Just take a break from the forum. 

Perfect banter for panic room thread.  No tags needed and all are welcome.

 

Nut

 

 

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1 hour ago, BTRWx said:

Let's not be too down on the pattern.  The MJO has and continues to show one of the best signals we can ask for the second to third weeks in Feb. ;)

 

ECMF_mjo Jan 31_2017.gif

The suddenly emergence of the mjo as a player again but in the hostile phases may be partially responsible for the sudden less favorable shift in guidance.  Of course that would argue it could help us when it does get into 8. The key to me is getting there with a workable pattern. We wasted the last mjo trip through 8-2 because the pattern was so god awful with the whole continent void of cold that all it did was set up some blocking and a better storm track (but it still rained with a coastal perfect track) and mute the torch a bit. The mjo isn't a magic bullet. If the pattern is closer next go around maybe it can give the final push we need though. 

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4 minutes ago, Eskimo Joe said:

I'd be happy to trade the rest of the winter for a fast spring that yields a hot summer with a couple of good flooding and severe weather episodes.  We've been starved on the severe side since 2012.

Yeah, who doesn't hope for people to lose their homes and lives.  I'm with you.

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I think a lot of the frustration in here doesn't come from looking at the longer range, but the fact that the long range has looked good numerous times and then literally never materializes. If you had a good look in the long range and then it came to fruition once or twice, at least there would be some hope/confidence that other long range looks could be right, therefore making it more interesting to track. Right now, it's just comical how nothing at the 8-10 day period seems to ever get closer in time.

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6 minutes ago, psuhoffman said:

The suddenly emergence of the mjo as a player again but in the hostile phases may be partially responsible for the sudden less favorable shift in guidance.  Of course that would argue it could help us when it does get into 8. The key to me is getting there with a workable pattern. We wasted the last mjo trip through 8-2 because the pattern was so god awful with the whole continent void of cold that all it did was set up some blocking and a better storm track (but it still rained with a coastal perfect track) and mute the torch a bit. The mjo isn't a magic bullet. If the pattern is closer next go around maybe it can give the final push we need though. 

On that thought, teleconnections seem to be showing some improvement for that period too. I at least like the stronger amplitude through phases 8 and 1 being modeled. ftp://ftp.cdc.noaa.gov/Public/gbates/reforecast2/teleconn/4indices.png

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5 minutes ago, WinterWxLuvr said:

I only looked quickly, but I honestly thought the gfs looked better for the weekend than it did yesterday afternoon.

Sorry but keep looking.  534 countour is now 540.  Noticeable tick north w/ R/S line as it was in SW WVA, and now is almost int KPIT.

Not good, but not commenting beyond, as the fish will continue to flop beyone 5-7 days.

Nut

 

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18 minutes ago, Eskimo Joe said:

I'd be happy to trade the rest of the winter for a fast spring that yields a hot summer with a couple of good flooding and severe weather episodes.  We've been starved on the severe side since 2012.

Something tells me you are going to get your wish. That Bermuda high showing up on the long range would mercifully end this debacle of a winter.

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6 minutes ago, osfan24 said:

I think a lot of the frustration in here doesn't come from looking at the longer range, but the fact that the long range has looked good numerous times and then literally never materializes. If you had a good look in the long range and then it came to fruition once or twice, at least there would be some hope/confidence that other long range looks could be right, therefore making it more interesting to track. Right now, it's just comical how nothing at the 8-10 day period seems to ever get closer in time.

I am going to play devils advocate here.  The guidance has not been as awful as these posts seem to imply.  They have shown general looks that were better from range.  Then when we got closer the "warts" on the face of the pattern showed up and the details were not supportive of a snowstorm.  But the general better look wasnt that far off.  Look at these two plots.  One is 24 hours ago and the other is right now.  They are not that far off from the look 10 days ago for right now that had us thinking "better pattern"  And that look is a better pattern.  There is a lot to like here.  Eastern trough.  Ridge bridge over the top.  Displaced PV in Canada.  But the trough yesterday just didnt amplify quite enough, and this week nothing ejects across the CONUS with enough energy to develop a storm.  We waste a 7 day window basically.  Then the WAR pops up just in time for the next actual storm system.  But the pattern came to fruition the way the guidance suggested, but we didnt get the snow.  I know the snow is all we actually care about, but specific storm tracks and such is NOT what we can look at day 10-15 stuff for.  Saying the models failed because the runs that showed snow at day 10 didnt pan out is misusing the long range guidance. 

That said I am NOT arguing they have been great.  The small details they have missed have all trended in the wrong direction consistently such that the result was no snow each time.  They have overdone the NAO and AO all winter.  We are finally getting some help up there, but a bit less then suggested and other hostile factors are offsetting it.  I guess I am a bit in the middle on the performance of the long range guidance this year.  I feel like they have done well picking up on general trends and pattern shifts but crappy with specifics and snow chances. 

24hoursago.pngrightnow.png

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