February Medium/Long Range Thread

[psuhoffman]

7 minutes ago, Stormchaserchuck1 said:

Back in the day, I made a daily index of all the strongest N. Hemisphere 500mb areas: 1. south NAO (north-central Atlantic) 2. North NAO- Greenland. 3. AO (arctic circle, although this one was rare), 4. EPO. 5. Gulf of Alaska. 6. PNA (Aleutian Islands). 7. WPO Bering Strait. 

I found that [1] the south-NAO had +temperature correlation in the Mid Atlantic and Southeast, and neutral to positive 500mb heights. AO was negative temps and heights, but moreso north, so a combination of those two is close to neutral for the Mid Atlantic.. average high temperature now is 40, so that's saying low 30s is probably the best case scenario.  We know how those borderline events, with +NAO (south-based) or more recently -pna, we know how they trend from the medium to short range when a N. Hemisphere major index area is in a constant. They don't trend toward more snow... 

I'm a believer of the AO, but it's a short wavelength pattern, where we have some unfavorable things stacked directly underneath. 

Thanks for the info. I’d be curious to see what this rare combo of that extreme a -AO block encroaching into the north nao domain over top a south +nao would do. I guess we’re about to find out. 

[CAPE]

3 minutes ago, stormtracker said:

Kinda hard to tell what the 18z Euro is gonna do...but thermals are precarious 

Not the best look up top at the surface. Not horrible, but with HP off the NE coast its hard to imagine we don't mix or go to rain beyond the end of that run.

[psuhoffman]

6 minutes ago, stormtracker said:

Kinda hard to tell what the 18z Euro is gonna do...but thermals are precarious 

Slightly colder press, better CAD but slightly more amplified wave. Likely a wash and similar to 12z in the end. 

[aldie 22]

3 minutes ago, CAPE said:

Not the best look up top at the surface. Not horrible, but with HP off the NE coast its hard to imagine we don't mix or go to rain beyond the end of that run.

You're on a mission...rough week at work? 

[psuhoffman]

2 minutes ago, CAPE said:

Not the best look up top at the surface. Not horrible, but with HP off the NE coast its hard to imagine we don't mix or go to rain beyond the end of that run.

South of PA definitely mixes but it’s not the worst look. Yea there is a weakness in the high where we don’t want it but still generally higher pressure all across to our north. If we can get the pressure directly over us about 5mb higher we have a chance. This isn’t that far from a snowier outcome imo. 

[psuhoffman]

2 minutes ago, aldie 22 said:

You're on a mission...rough week at work? 

Would it be funny if cape, bob and I all came in here one day with a mission of driving all the weenies off a cliff just to see what happens?  
 

Don’t worry I would NEVER do such a thing. 

[stormtracker]

6 minutes ago, CAPE said:

Not the best look up top at the surface. Not horrible, but with HP off the NE coast its hard to imagine we don't mix or go to rain beyond the end of that run.

Ugh...I would be ecstatic if the Euro had moved even a little bit toward the GFS

[mitchnick]

1 minute ago, psuhoffman said:

Would it be funny if cape, bob and I all came in here one day with to a mission of driving all the weenies off a cliff just to see what happens?  
 

Don’t worry I would NEVER do such a thing. 

Why do you think you need a mission to drive weenies off the cliff? Lol

[psuhoffman]

2 minutes ago, stormtracker said:

Ugh...I would be ecstatic if the Euro had moved even a little bit toward the GFS

It did. Slightly. You’re welcome. 

[Terpeast]

Euro is getting better for us. It shifted bigly north earlier today, and now it came back south almost halfway.

[NorthArlington101]

Just now, Terpeast said:

Euro is getting better for us. It shifted bigly north earlier today, and now it came back south almost halfway.

probably foolish but I'd sign the dotted line on this right now. I still haven't seen more than ~1" fall since I missed the jan. 6 storm. hopefully this is about worst-case

[psuhoffman]

5 minutes ago, Terpeast said:

Euro is getting better for us. It shifted bigly north earlier today, and now it came back south almost halfway.

Way too many act like each run at day 7 is going to be the final solution v just another clue. Until we get within a few days I treat each run like one card being dealt in a long night at the poker table. Some act like every run is the last card of the night and they have their entire life savings riding on it. 

[mitchnick]

Looking at the 18z Gfs and all the threats it had and then looking at the 18z Euro, I'd bet that if that went out further we would be seeing more threats like the Gfs. Where the boundary would set up nobody knows. Don't believe me, look at this 700mb RH map at 144hrs on the Euro and Gfs.

[Ralph Wiggum]

1 hour ago, snowmagnet said:

Phew. It’s been a stressful day on the page. This would have made everyone happy if we hadn’t been seeing all the crazy ensemble runs for at least 5 days. Total roller coaster ride. 

I don't understand how a hobby like this is stressful? I guess people make it stressful on themselves. The weather is what it is. We just take it or leave it....there is no changing it

[JenkinsJinkies]

8 minutes ago, psuhoffman said:

Way too many act like each run at day 7 is going to be the final solution v just another clue. Until we get within a few days I treat each run like one card being dealt in a long night at the poker table. Some act like every run is the last card of the night and they have their entire life savings riding on it. 

8 years of constant rug pulls does that to people.

[CAPE]

29 minutes ago, aldie 22 said:

You're on a mission...rough week at work? 

Not as much time to fuck off on here for sure.

Just calling it as I see it. It's but another op run and quite possibly does not represent the actual outcome. Hopefully we can do better.

[CAPE]

Btw, PDIII potential here.

 

[Stormchaserchuck1]

11 minutes ago, CAPE said:

Btw, PDIII potential here.

That Atlantic trough is far enough south where it's no longer a +NAO. Is that the frame where it goes furthest south, or does it sustain? (I know GEFS has been consistently showing +NAO in the long range.. but EPS has been leading the way in the Pacific). 

^Nice 4 wave trough pattern around a -AO..

[psuhoffman]

8 minutes ago, Stormchaserchuck1 said:

That Atlantic trough is far enough south where it's no longer a +NAO. Is that the frame where it goes furthest south, or does it sustain? (I know GEFS has been consistently showing +NAO in the long range.. but EPS has been leading the way in the Pacific). 

^Nice 4 wave trough pattern around a -AO..

It’s pretty stable after to when the run ends here, then if you believe the extended it peaks a few days after with that image I posted an hour ago you got excited about. I think that’s our best window of opportunity for a real MECS event. 

[osfan24]

2 hours ago, CAPE said:

HH clown map through mid month

Meh

[Stormchaserchuck1]

5 minutes ago, psuhoffman said:

It’s pretty stable after to when the run ends here, then if you believe the extended it peaks a few days after with that image I posted an hour ago you got excited about. I think that’s our best window of opportunity for a real MECS event. 

I've been noticing our Springs have been warming up fast in the decadal trend period.. that's why I kind of cringe when I hear of excitement Feb 20 - March 15.. I think something about the sun angle has been associated with -PNA conditions in the late Winter (my theory). 

I think our best chance is actually days 4-7, when we have -EPO.. then the block lifts out and stays at 90N. the 18z GEFS still has south-based +NAO, which could flare up somewhat of a SE ridge at 500mb. 

[CAPE]

6 minutes ago, psuhoffman said:

It’s pretty stable after to when the run ends here, then if you believe the extended it peaks a few days after with that image I posted an hour ago you got excited about. I think that’s our best window of opportunity for a real MECS event. 

Absolutely, but a little too late for a PDIII potential storm.

[mitchnick]

18z AI looks close to identical for Tuesday. Snow starts Tuesday morning around 12z and last flakes don't stop until around 12z Wednesday. 

Next Friday starts as snow and then turns to rain.

Next Wednesday, 2/19, is much better as I  said at 12z it had a chance . Pretty close to Tuesday's event.

[Terpeast]

5 minutes ago, mitchnick said:

18z AI looks close to identical for Tuesday. Snow starts Tuesday morning around 12z and last flakes don't stop until around 12z Wednesday. 

Next Friday starts as snow and then turns to rain.

Next Wednesday, 2/19, is much better as I  said at 12z it had a chance . Pretty close to Tuesday's event.

The 2/19 might be the wave associated with a better pattern as psu was saying. If it holds

[psuhoffman]

26 minutes ago, Stormchaserchuck1 said:

I've been noticing our Springs have been warming up fast in the decadal trend period.. that's why I kind of cringe when I hear of excitement Feb 20 - March 15.. I think something about the sun angle has been associated with -PNA conditions in the late Winter (my theory). 

I think our best chance is actually days 4-7, when we have -EPO.. then the block lifts out and stays at 90N. the 18z GEFS still has south-based +NAO, which could flare up somewhat of a SE ridge at 500mb. 

Fair point but to play devils advocate, the last 8 years most of the time was a torch earlier in winter also. It’s not like January and February were cold either.  An already warm continent doesn’t lend itself to cold March. But we did get a snowstorm March 20 in 2018 from blocking in a late season cold enso. Some similarities and only 7 years ago. 2015 and 2014 aren’t that long ago either. Have things really changed that much or was the warm spring a function of the crazy -PDO cycle we were in?  This years PDO does not seem as hostile. I think we might be in the midst of a transition in the pacific out of that long term cycle. 

[MDScienceTeacher]

1 hour ago, Stormchaserchuck1 said:

Was excited until I saw hr456

Yeah I dont care if it is upper air/ long wave/ ensemble mean .. I just dont take anything serious outside of 180 hours... I just dont have the knowledge to take what the computer model is spitting out seriously.  I am sure @psuhoffman does, so I will trust him.  My kids watch a lot of weather youtube and there are guys who will literally step through every frame of the CFS out to six weeks and talk about it as if it is a forecast. Its a real disservice and not the intended use of those models.

 

[clskinsfan]

Last spring was cold. My plants had to go in the ground 2 weeks later than usual. 

[mitchnick]

14 minutes ago, Terpeast said:

The 2/19 might be the wave associated with a better pattern as psu was saying. If it holds

Here are the 850's and 500mb at the start of the event.

https://charts.ecmwf.int/products/aifs_medium-z500-t850?base_time=202502051800&projection=opencharts_north_america&valid_time=202502190600

Here's the surface. It looks like the storm starts warm and then temps crash but there decent precip we'll after the cold. Not your typical precip chasing cold.

https://charts.ecmwf.int/products/aifs_medium-mslp-rain?base_time=202502051800&interval=6&projection=opencharts_north_america&valid_time=202502190600

[psuhoffman]

11 minutes ago, Terpeast said:

The 2/19 might be the wave associated with a better pattern as psu was saying. If it holds

Might be the first threat of “that” window. I foresee multiple waves while the block decays and the trough is centered in the east. Not sure how extended. March 2018 we had a solid month with chance after chance and frankly it took incredible back luck to only get that one big snowfall.   Don’t know if this has that same staying power. But I’d guess even if the block decays quickly we get at least a week which would be time for 2 waves before the pattern breaks down. 
 

I’m not out on next week. The EPO is going to want the front to press. The AO is going negative. It’s not the best MECS look for a classic coastal but we’ve scored in fluke atypical setups before. I noted a decent number of “how did that happen” snows when I did that case study of all mid Atlantic snowstorms.  Maybe we get lucky again. I just think the pattern after might require less luck that’s all. 

[Stormchaserchuck1]

9 minutes ago, psuhoffman said:

Fair point but to play devils advocate, the last 8 years most of the time was a torch earlier in winter also. It’s not like January and February were cold either.  An already warm continent doesn’t lend itself to cold March. But we did get a snowstorm March 20 in 2018 from blocking in a late season cold enso. Some similarities and only 7 years ago. 2015 and 2014 aren’t that long ago either. Have things really changed that much or was the warm spring a function of the crazy -PDO cycle we were in?  This years PDO does not seem as hostile. I think we might be in the midst of a transition in the pacific out of that long term cycle. 

The monthly composites page is down, or I would show you I'm referring to the -PNA, it's anomaly from Feb-March 2018-2024 has been record breaking by like 150%. Even if we neutralize that this year.. we need cold 500mb to get snow going into March. Actually in the last 8 years... last January we had snow in +PNA/-NAO, this early Jan we got snow in +PNA/-NAO.. when the indexes have been super favorable is the only time we're getting >4". Otherwise it's been a near shutout. I'll post the Feb 2018-2024 map when the CDC page comes back online.  It seems like after our coldest day of the year, Jan 27th, something flips a switch and we amplify -PNA... this year it might be closer to neutral, but I don't think we're going to reverse the pattern anytime soon.