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January Medium/Long Range Discussion


WinterWxLuvr
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1 hour ago, Ralph Wiggum said:

Dare I say....I kinda miss TWC circa 1987-1995ish. Actual mets, some extremely extremely advanced mets (Stu Ostro, John Hope, Paul Kocin, Dave Schwartz, etc etc). Actually delved into atmospheric sciences and taught and took time to explain and weren't just on camera celebs. I know that outlet tends to get ripped by weenies near and far....but that was a much simpler time and we were at the mercy of the long range forecast they did once or twice an hour. Good stuff. The coverage of the 93 and 96 storms on there....epic.....just epic.  

 

Spent many an hour staring at TWC, longgggg before it succumbed to the scourge of BS that is modern TV.  

Hold onto those memories. Nostalgia is a wonderful thing, even if it means a power mullet, 80s stash, and awkward TV persona!  Good times indeed.  

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3 minutes ago, WxUSAF said:

Ok, wanted to make a post showing the impact of the ocean storm on ~Friday to the environment afterward and hence the possibility of a Sunday/MLK day storm.  Helpfully, the 3 big globals provided a very nice contrast in this with their 12z runs.  Obviously there are other differences that impact the result as well, but I think the ocean storm is a pretty big player to help define the storm track and whether it gives room to the next shortwave/s to amplify.  

 

First is the 12z GFS.  It produced a very strong ocean storm that was close to shore.  For reference across all 3 models, the shortwave that could produce a late weekend storm is near the US/Canadian border over ND/MN in the northern stream.  There's also southern stream energy over the intermountain West and southern CA.  gfs_z500a_namer_21.thumb.png.045fa352f64a3ec7028e0275869bc4b5.png

 

Next is the GGEM.  It's ocean storm is weaker and farther SE over the ocean.  It's nearly a cutoff low and just meanders out to sea.  gem_z500a_namer_21.thumb.png.1f7e327aa78bb2b98b7bdb3944c7667f.png

 

Lastly is the Euro.  It produces a storm, but it's moving offshore and is "just right" in terms of storm strength.  Strong enough to suppress the flow, but not too strong to swamp everything else.  Helpfully, also note how the northern stream and southern stream energy already is somewhat "phased" here (all the shortwaves are in line from Los Angeles all the way up to Manitoba).  ecmwf_z500a_namer_6.thumb.png.3ba39ec18a31a969df3e1ffcee2e8b50.png

 

So what happens after?  Watch the dark green color, which in this case is the 552 dm height contour, and the light blue (534 dm height).  

GFS:  Look how close the ocean storm is to the surface reflection of our shortwave of interest (the L near Cleveland).  Light blue height level right through the Great Lakes.  The ocean storm hangs around and is very strong.  It suppresses the flow and gives our shortwave no room to amplify.  So we end up with a weak frontal passage.  

gfs_z500_mslp_namer_25.thumb.png.39048c118d0ec1f95b4dfb274ac1c136.png  

 

GGEM:  The storms have more spacing, the ocean low is weaker, and there's TOO MUCH room for our shortwave/storm to amplify.  Dark green height contour is well up into OH/PA/NYC. Result?  Cutter.  

gem_z500_mslp_namer_25.thumb.png.2185aa4ce73b23b60b8f494a6a6c5350.png

 

Euro:  Now it's JUST RIGHT.  The ocean storm is nearly as strong as on the GFS, but it's farther OTS.  So it's suppressing the flow just enough (dark green contour is through VA), but not TOO MUCH.  Hence, our storm tracks farther south and it's bombs away.  And yes, the Euro is also good because it phases the northern and southern stream energy. But the storm track is important.  Phase the energy on the Euro, but have an ocean storm like on the GGEM and the thing cuts to Hudson Bay and we get warm rain.  ecmwf_z500_mslp_namer_7.thumb.png.c50231148fe98715c8b01459b97f267e.png

 

I think the GFS solution of a strong ocean storm that's close to shore is probably the last likely?  18z GFS was a small step toward a more Euro like outcome.  GGEM and Euro like outcomes for the ocean storm are more likely IMO, but that doesn't mean we get a big snowy coastal because that's also contingent on how and if the energy out west phases.  

Great right up and explanation with illustrations!

You put it much more eloquently than I did earlier this afternoon.

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13 minutes ago, WinterWxLuvr said:

18z gefs members leave a lot of interesting possibilities on the table for next weekend.

Gfs has way less separation because it’s digging the NS into the Ohio valley v the Midwest on the euro and the Gfs is mostly leaving the southern stream behind.  Euro has a very good synoptic setup for the weekend the Gfs not so much. Real model war in the not crazy long range going on. 

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32 minutes ago, WxUSAF said:

Ok, wanted to make a post showing the impact of the ocean storm on ~Friday to the environment afterward and hence the possibility of a Sunday/MLK day storm.  Helpfully, the 3 big globals provided a very nice contrast in this with their 12z runs.  Obviously there are other differences that impact the result as well, but I think the ocean storm is a pretty big player to help define the storm track and whether it gives room to the next shortwave/s to amplify.  

 

First is the 12z GFS.  It produced a very strong ocean storm that was close to shore.  For reference across all 3 models, the shortwave that could produce a late weekend storm is near the US/Canadian border over ND/MN in the northern stream.  There's also southern stream energy over the intermountain West and southern CA.  gfs_z500a_namer_21.thumb.png.045fa352f64a3ec7028e0275869bc4b5.png

 

Next is the GGEM.  It's ocean storm is weaker and farther SE over the ocean.  It's nearly a cutoff low and just meanders out to sea.  gem_z500a_namer_21.thumb.png.1f7e327aa78bb2b98b7bdb3944c7667f.png

 

Lastly is the Euro.  It produces a storm, but it's moving offshore and is "just right" in terms of storm strength.  Strong enough to suppress the flow, but not too strong to swamp everything else.  Helpfully, also note how the northern stream and southern stream energy already is somewhat "phased" here (all the shortwaves are in line from Los Angeles all the way up to Manitoba).  ecmwf_z500a_namer_6.thumb.png.3ba39ec18a31a969df3e1ffcee2e8b50.png

 

So what happens after?  Watch the dark green color, which in this case is the 552 dm height contour, and the light blue (534 dm height).  

GFS:  Look how close the ocean storm is to the surface reflection of our shortwave of interest (the L near Cleveland).  Light blue height level right through the Great Lakes.  The ocean storm hangs around and is very strong.  It suppresses the flow and gives our shortwave no room to amplify.  So we end up with a weak frontal passage.  

gfs_z500_mslp_namer_25.thumb.png.39048c118d0ec1f95b4dfb274ac1c136.png  

 

GGEM:  The storms have more spacing, the ocean low is weaker, and there's TOO MUCH room for our shortwave/storm to amplify.  Dark green height contour is well up into OH/PA/NYC. Result?  Cutter.  

gem_z500_mslp_namer_25.thumb.png.2185aa4ce73b23b60b8f494a6a6c5350.png

 

Euro:  Now it's JUST RIGHT.  The ocean storm is nearly as strong as on the GFS, but it's farther OTS.  So it's suppressing the flow just enough (dark green contour is through VA), but not TOO MUCH.  Hence, our storm tracks farther south and it's bombs away.  And yes, the Euro is also good because it phases the northern and southern stream energy. But the storm track is important.  Phase the energy on the Euro, but have an ocean storm like on the GGEM and the thing cuts to Hudson Bay and we get warm rain.  ecmwf_z500_mslp_namer_7.thumb.png.c50231148fe98715c8b01459b97f267e.png

 

I think the GFS solution of a strong ocean storm that's close to shore is probably the last likely?  18z GFS was a small step toward a more Euro like outcome.  GGEM and Euro like outcomes for the ocean storm are more likely IMO, but that doesn't mean we get a big snowy coastal because that's also contingent on how and if the energy out west phases.  

Are you like, a met or something? This was good reading.

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1 hour ago, WxUSAF said:

Ok, wanted to make a post showing the impact of the ocean storm on ~Friday to the environment afterward and hence the possibility of a Sunday/MLK day storm.  Helpfully, the 3 big globals provided a very nice contrast in this with their 12z runs.  Obviously there are other differences that impact the result as well, but I think the ocean storm is a pretty big player to help define the storm track and whether it gives room to the next shortwave/s to amplify.  

 

First is the 12z GFS.  It produced a very strong ocean storm that was close to shore.  For reference across all 3 models, the shortwave that could produce a late weekend storm is near the US/Canadian border over ND/MN in the northern stream.  There's also southern stream energy over the intermountain West and southern CA.  gfs_z500a_namer_21.thumb.png.045fa352f64a3ec7028e0275869bc4b5.png

 

Next is the GGEM.  It's ocean storm is weaker and farther SE over the ocean.  It's nearly a cutoff low and just meanders out to sea.  gem_z500a_namer_21.thumb.png.1f7e327aa78bb2b98b7bdb3944c7667f.png

 

Lastly is the Euro.  It produces a storm, but it's moving offshore and is "just right" in terms of storm strength.  Strong enough to suppress the flow, but not too strong to swamp everything else.  Helpfully, also note how the northern stream and southern stream energy already is somewhat "phased" here (all the shortwaves are in line from Los Angeles all the way up to Manitoba).  ecmwf_z500a_namer_6.thumb.png.3ba39ec18a31a969df3e1ffcee2e8b50.png

 

So what happens after?  Watch the dark green color, which in this case is the 552 dm height contour, and the light blue (534 dm height).  

GFS:  Look how close the ocean storm is to the surface reflection of our shortwave of interest (the L near Cleveland).  Light blue height level right through the Great Lakes.  The ocean storm hangs around and is very strong.  It suppresses the flow and gives our shortwave no room to amplify.  So we end up with a weak frontal passage.  

gfs_z500_mslp_namer_25.thumb.png.39048c118d0ec1f95b4dfb274ac1c136.png  

 

GGEM:  The storms have more spacing, the ocean low is weaker, and there's TOO MUCH room for our shortwave/storm to amplify.  Dark green height contour is well up into OH/PA/NYC. Result?  Cutter.  

gem_z500_mslp_namer_25.thumb.png.2185aa4ce73b23b60b8f494a6a6c5350.png

 

Euro:  Now it's JUST RIGHT.  The ocean storm is nearly as strong as on the GFS, but it's farther OTS.  So it's suppressing the flow just enough (dark green contour is through VA), but not TOO MUCH.  Hence, our storm tracks farther south and it's bombs away.  And yes, the Euro is also good because it phases the northern and southern stream energy. But the storm track is important.  Phase the energy on the Euro, but have an ocean storm like on the GGEM and the thing cuts to Hudson Bay and we get warm rain.  ecmwf_z500_mslp_namer_7.thumb.png.c50231148fe98715c8b01459b97f267e.png

 

I think the GFS solution of a strong ocean storm that's close to shore is probably the last likely?  18z GFS was a small step toward a more Euro like outcome.  GGEM and Euro like outcomes for the ocean storm are more likely IMO, but that doesn't mean we get a big snowy coastal because that's also contingent on how and if the energy out west phases.  

Thank you…fine write up

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15 minutes ago, clskinsfan said:

Was a pretty common thing with the GFS before the upgrade. We are going to find out if that has been fixed or not over the next couple of weeks. 

did you just put together an WTF QB Draft package video lol?

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11 minutes ago, psuhoffman said:

Just to drive home the luck factor…that loop is beautiful. Absolutely perfect pattern. But look at the result of that run on the ground. 
9C6CEC36-3EF4-44D1-AC7F-DEFD46C1012C.thumb.png.31ee123679d6f73e5ccaf44918849c58.png

know that would be a hell of a guest post by Steve. Thanks for doing that btw!

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13 minutes ago, psuhoffman said:

Just to drive home the luck factor…that loop is beautiful. Absolutely perfect pattern. But look at the result of that run on the ground. 

That is funny. I guess luck needs to be listed first in order of importance above a  - AO , -NAO or a + PNA in the Mid Atlantic. 

Hopefully we get some great luck to go with our upcoming favorable pattern.  

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51 minutes ago, frd said:

That is funny. I guess luck needs to be listed first in order of importance above a  - AO , -NAO or a + PNA in the Mid Atlantic. 

Hopefully we get some great luck to go with our upcoming favorable pattern.  

Your point is correct but those other things (the ways we quantify the pattern) are pre-requisites before luck even matters.  We can luck our way to some minor marginal events without any pattern help but we’re not getting a MECS or HECS or some heater of successive SECS’s without any pattern help no matter what. Sometimes we can score with “less” help but if the NAO, AO, PNA, EPO are all bad luck won’t save us.  The pattern puts us in the game then we need luck to win. 
 

On a related note, there were a handful of warning snows in my case study (BWI warning snows since 1950) without any discernible pattern help in the indexes but they all had a Hudson Bay ridge. That’s a weird feature that doesn’t always show up on any of the numerical indexes yet it’s a more regional feature that can turn an otherwise bad pattern into a workable one. 

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