Spring 2023 Medium/Long Range Discussion

[rainsucks]

43 minutes ago, Harry said:

 

Nws has 45 Monday, 50 Tuesday, 49 wednesday, and 53 Thursday with a cold front incoming. 

Normal high 50-51.. 

 

You were saying? 

NWS playing it conservative per usual, and the cold front that you’re referring to isn’t going to affect overall temps that much.

[rainsucks]

1 hour ago, michsnowfreak said:

We going to be well below average on the 18th of the 19th. The map you shared was for the 18th-24th, which will very likely finish colder than average even if the period ends warmer than average.

Depends how Thursday plays out. Some slight concerns that the warm front gets hung up around I-80 or even further south. Should still be on the mild side even if that happens tho.

[Chicago Storm]

On 3/3/2023 at 8:07 PM, Chicago Storm said:

Time for a long awaited update. I previously had thought that I had not mentioned anything regarding the final 1/3rd of February, but apparently I did and had forgotten. In any case, obviously we did see the weather pattern from the middle 1/3rd of February continue through the final 1/3rd of February as well. 

As we are transitioning into March, we are finally seeing some effects of the SPV disruption that has been ongoing since mid-January. We have see a large/significant ridge develop around Europe as we have transitioned from late Feb into early March. This ridge is in the process of retrograding to Greenland, and eventually will back well into Canada, making for a solid -NAO through the early portion of mid-month. At the same time, we are about to see a fairly significant GOA/AK/Aleutian ridge develop (-EPO/-WPO), along with significant ridging in the Arctic (-AO), all of which will continue into the start of mid-month as well.

The-NAO/-AO/-EPO combination will push much the sub-forum into a cooler/colder pattern than we have seen, with the coolest/coldest regime as a whole in comparison to average than we have seen since the late January or the pre-Christmas periods. However, one thing to point out is while it will end up cool/cold compared to average for this upcoming point in March, things to not look favorable at this time for significant/severe cold. This is due to Canada being void of any real significantly cold air leading into this period, likely due in part to the very long process of the SPV being disrupted for nearly a month and a half now, instead of the usually more significant SSW events we have seen in the past.

Another thing to note is that we are also going to be transitioning from the lengthy -PNA/West Coast trough period we have been in, to a more near neutral/+ PNA. This will lead troughs/disturbances will be originating from the Pac NW/SW Canada, instead of rolling into California/the heart of the West Coast like we have been seeing for a while now. With that said, the addition of some cooler/colder temperatures, along with an average pattern in regards to activity, could mean some increased wintry precip chances that include more areas outside of the heavy hit MN/WI/MI corridor (Quality still TBD).

While the evolution of the pattern on the large scale (teleconnections) already started to occur days ago and will continue through the early portion of the middle 1/3rd of March, the effects for us as a whole in the sub-forum will be delayed. We will start seeing more of the effects of this transition at the end of this opening 1/3rd of March, likely continuing through much of the middle 1/3rd of March, even while the pattern on the large scale will likely already have changed once again by then.

Some parting words... This upcoming pattern will decently resemble what you would expect to see with the MJO progression from late February through mid-March (Phase 7-8-1[?] progression). Most recently, for much of the final 1/3rd of February, the MJO has been stalled in low amplitude phase 7. To begin March, and continuing through the next few days, the MJO while transition through high amplitude phase 7. This supports the idea of a delayed transition for effects in our sub-forum from the overall pattern shift. As we head later into this beginning 1/3rd of March and into the middle 1/3rd of March, there is high support for a transition into high amplitude phase 8 and potentially phase 1. This supports the aforementioned relaxation of the PNA, with a mild west/cold east regime. However, on the flip side, phase 8 usually has high correlation of being mild even into the Central US. That may be hindered this go around, due to the significant blocking up north.

The first 1/2 of March pretty much went as expected for the most part. 

The second 1/2 of March, which we have already moved into, will feature a very rollercoaster March-like weather pattern across the CONUS. As mentioned in the previous post at the start of March, the pattern was already expected to be once again transitioning by now, which it has done so. The period of significant -EPO/-AO/-NAO has quickly relaxed, giving way to an EPO/AO/NAO that is in flux, and will continue to be through the end of the month. What this means is we will see periods of AO/NAO ridging, pretty much transient or meandering nature, but nonetheless still there. With an EPO bouncing around the +/- sides of neutral and a significant/lengthy -PNA period expected, this will support constant troughs dropping in from the Alaska vicinity, down into the West Coast, and then moving across the CONUS below the transient AO/NAO ridging.

This will all lead to an active, but steadily moving weather pattern across the CONUS. Best snow chances will be across the northern half of the sub-forum, namely the heavy hit corridor of the winter (MN/WI/MI), with severe weather opportunities possible across the southern half of the sub-forum. This will also be a pattern with temperatures that bounce around quite rollercoaster like as well, with mild temps ahead of storm systems and cool temps behind them. Once again, all in all what I would consider to be a typical March-like pattern.

Looking ahead towards getting into the beginning of April, it looks quite likely a similar pattern will continue.

[Harry]

43 minutes ago, rainsucks said:

NWS playing it conservative per usual, and the cold front that you’re referring to isn’t going to affect overall temps that much.

 

They could be over compensating for the lake effect expected later tonight into Saturday night. May take a few days to melt off depending on how much falls. 

[mississaugasnow]

29 minutes ago, Harry said:

 

They could be over compensating for the lake effect expected later tonight into Saturday night. May take a few days to melt off depending on how much falls. 

wow you guys already average in the low 50s now? We dont get that in Toronto until early April 

[michsnowfreak]

22 minutes ago, mississaugasnow said:

wow you guys already average in the low 50s now? We dont get that in Toronto until early April 

I doubt Harry averages low 50s yet. Avg high for Detroit today is 47, warming to 52 March 31st.

[Harry]

35 minutes ago, michsnowfreak said:

I doubt Harry averages low 50s yet. Avg high for Detroit today is 47, warming to 52 March 31st.

 

Yeah I am not sure wtf I was looking at but your right the normal high is 46.

[Stebo]

12 hours ago, RCNYILWX said:

Next Thursday checks pattern recognition boxes for a legit severe/tornado threat in the region given a juicy air mass (55-60+ Td) surging northward with a sharpening warm front, 70-90 kt flow at h5, and forecast steep mid-level lapse rates.

The forecast lower amplitude 500 mb pattern results in a more favorable wind profile with height, WSW or SW at h5, vs. meridional south or SSW with a negatively tilted trough. In addition, there would be a chance for right moving storms to have residence time near the warm front as opposed to immediately surging north of the boundary.

All the usual caveats apply, including meaningful shifts in the currently favorable looking setup, but at this lead time, one of the better late March synoptic patterns in recent years. March 28, 2020 comes to mind and that event not performing to its potential exemplifies the caveats for March setups.

Signal is there for a flooding threat as well if the boundary can stay convectively active through the night.

At least it's something to monitor and more interesting than the brutal CAD to start this weekend.


 

Agreed, the first thing I thought when I looked at the 500mb pattern was it had some similarities to 3/27/91, albeit timing is not right locally. It is definitely something to watch tho through the week.

[Stebo]

6 hours ago, Chicago Storm said:

The first 1/2 of March pretty much went as expected for the most part. 

The second 1/2 of March, which we have already moved into, will feature a very rollercoaster March-like weather pattern across the CONUS. As mentioned in the previous post at the start of March, the pattern was already expected to be once again transitioning by now, which it has done so. The period of significant -EPO/-AO/-NAO has quickly relaxed, giving way to an EPO/AO/NAO that is in flux, and will continue to be through the end of the month. What this means is we will see periods of AO/NAO ridging, pretty much transient or meandering nature, but nonetheless still there. With an EPO bouncing around the +/- sides of neutral and a significant/lengthy -PNA period expected, this will support constant troughs dropping in from the Alaska vicinity, down into the West Coast, and then moving across the CONUS below the transient AO/NAO ridging.

This will all lead to an active, but steadily moving weather pattern across the CONUS. Best snow chances will be across the northern half of the sub-forum, namely the heavy hit corridor of the winter (MN/WI/MI), with severe weather opportunities possible across the southern half of the sub-forum. This will also be a pattern with temperatures that bounce around quite rollercoaster like as well, with mild temps ahead of storm systems and cool temps behind them. Once again, all in all what I would consider to be a typical March-like pattern.

Looking ahead towards getting into the beginning of April, it looks quite likely a similar pattern will continue.

Keep the rollercoaster going, I'll take the active weather no matter what form.

[A-L-E-K]

Will be better when wf get strong enough to regularly clear i80 tho

[Stevo6899]

Models hinting at a decent snow next weekend....

[CheeselandSkies]

SPC has put in an area for next Thursday, but it's for the Southern Plains.

[andyhb]

Going to mention this here to start, but while the shorter-term attention is on the trough coming through around 3/23-24 for appreciable severe potential, something bigger may be lurking right in behind if the following system amplifies more in the west. This has been a trend in the ensemble guidance for the last several runs.

The lead system never really makes much of a dent in the Gulf as far as frontal intrusions go. What's left behind is a very moist air mass waiting to be pulled north. The 500 mb setup around 3/26-27 on all of the 12z models except the GFS (lol) would indicate the possibility of a rather large scale severe weather event should a couple of tweaks occur. It probably does need to amplify a bit more to get an earlier low-level response for pulling moisture north, but the signal is generally for a broad-based trough with a very intense jet max and strong flow overspreading a large area. All will depend on track/initial amplification and the timing/magnitude of the low-level response and surface cyclogenesis.

Below is the run-to-run 500 mb mean shift in the last few runs of the EPS. Can see how it's shifting slower (more wave spacing) and deeper, both of which would allow for more modification following the 3/23-24 system.

[CheeselandSkies]

2 hours ago, andyhb said:

Going to mention this here to start, but while the shorter-term attention is on the trough coming through around 3/23-24 for appreciable severe potential, something bigger may be lurking right in behind if the following system amplifies more in the west. This has been a trend in the ensemble guidance for the last several runs.

The lead system never really makes much of a dent in the Gulf as far as frontal intrusions go. What's left behind is a very moist air mass waiting to be pulled north. The 500 mb setup around 3/26-27 on all of the 12z models except the GFS (lol) would indicate the possibility of a rather large scale severe weather event should a couple of tweaks occur. It probably does need to amplify a bit more to get an earlier low-level response for pulling moisture north, but the signal is generally for a broad-based trough with a very intense jet max and strong flow overspreading a large area. All will depend on track/initial amplification and the timing/magnitude of the low-level response and surface cyclogenesis.

Below is the run-to-run 500 mb mean shift in the last few runs of the EPS. Can see how it's shifting slower (more wave spacing) and deeper, both of which would allow for more modification following the 3/23-24 system.

Been watching, although with the GFS bouncing around so much it's hard to get too excited. Do appreciate your thoughts, Andy.

[Harry]

3 hours ago, andyhb said:

Going to mention this here to start, but while the shorter-term attention is on the trough coming through around 3/23-24 for appreciable severe potential, something bigger may be lurking right in behind if the following system amplifies more in the west. This has been a trend in the ensemble guidance for the last several runs.

The lead system never really makes much of a dent in the Gulf as far as frontal intrusions go. What's left behind is a very moist air mass waiting to be pulled north. The 500 mb setup around 3/26-27 on all of the 12z models except the GFS (lol) would indicate the possibility of a rather large scale severe weather event should a couple of tweaks occur. It probably does need to amplify a bit more to get an earlier low-level response for pulling moisture north, but the signal is generally for a broad-based trough with a very intense jet max and strong flow overspreading a large area. All will depend on track/initial amplification and the timing/magnitude of the low-level response and surface cyclogenesis.

Below is the run-to-run 500 mb mean shift in the last few runs of the EPS. Can see how it's shifting slower (more wave spacing) and deeper, both of which would allow for more modification following the 3/23-24 system.

 

I could do without that stronger looking-nao signal and thus note the stronger ridging up towards Greenland. Can also see the building heights in the far top left and thus a more pronounced -EPO. 

As far as all those telecons go they all will be negative by the weekend with the PNA falling off into.the unknown. Can't recall to often seeing it with all of them ( AO, NAO, EPO, PNA ) negative and PNA so negative. Something I think will have to give. With the MJO crashing into the COD ( phase 3 ) it leaves alot more questions going forward beyond the weekend? Basically gonna be no forcing to help things move along but for how long is the question? 

 

[andyhb]

Lol, now the ensembles back away from the more amplified 3/26 idea. Naturally.

Initial troughing isn't amplified enough in the west and there's too much vorticity leaking eastward early + the PV lobe near Hudson Bay is creating confluence that shears the trough out with eastward extent.

Looks like it's 3/24 or bust right now.

[CheeselandSkies]

3 hours ago, andyhb said:

Lol, now the ensembles back away from the more amplified 3/26 idea. Naturally.

Initial troughing isn't amplified enough in the west and there's too much vorticity leaking eastward early + the PV lobe near Hudson Bay is creating confluence that shears the trough out with eastward extent.

Looks like it's 3/24 or bust right now.

What else is new? lol

[RCNYILWX]

Lol, now the ensembles back away from the more amplified 3/26 idea. Naturally.
Initial troughing isn't amplified enough in the west and there's too much vorticity leaking eastward early + the PV lobe near Hudson Bay is creating confluence that shears the trough out with eastward extent.
Looks like it's 3/24 or bust right now.

-NAO ftl.

Sent from my SM-G998U using Tapatalk

[Harry]

21 minutes ago, RCNYILWX said:

-NAO ftl.

Sent from my SM-G998U using Tapatalk
 

 

Thus what keeps me from jumping on any nw trend type discussion. Ofcourse most of the models did go that route today with the weekend event. See if it holds or was a blip. 

I just know I really don't care for another 6+ cement snow. Hoping the nw route holds. 

[bowtie`]

On 3/14/2023 at 8:08 PM, Cary67 said:

^ Most years when do you mow the lawn for the first time? April 18th last Spring

 

 

On 3/14/2023 at 8:36 PM, chuckster2012 said:

A guy down here in southern IN. just mowed his grass today after 1/2" snow last night.

 

On 3/14/2023 at 9:29 PM, bowtie` said:

 

I had to look this up. Last year I mowed for the first time April 3rd. And seeing how I am right between the both of you, it even looks right.

I just mowed this afternoon. The forecast of six days of rain kind of forced my hand. The south and west side grass needed to be cut and if I tried to wait out the rain it would have been a jungle.

[michsnowfreak]

Just now, bowtie` said:

 

 

I just mowed this afternoon. The forecast of six days of rain kind of forced my hand. The south and west side grass needed to be cut and if I tried to wait out the rain it would have been a jungle.

When did you start greening up? All dormant here 

[bowtie`]

46 minutes ago, michsnowfreak said:

When did you start greening up? All dormant here 

I tried something different this year. Some aggressive winter feeding. The green has been vaguely around most of the year. The serious green started about two weeks ago.

[A-L-E-K]

green shoots all over now, just need some prolonged warmth to get things really popping

[OrdIowPitMsp]

I’m sure there is some green stuff under the blanket of snow imby just waiting for it’s opportunity. 

[A-L-E-K]

looks wet, not really warm or exciting tho 

[A-L-E-K]

eps starting to look mild/warmish...hype?

[buckeye]

On 3/21/2023 at 10:39 PM, michsnowfreak said:

"When did you start greening up? .... "

...he nervously asked as beads of sweat formed on his brow...

[buckeye]

7 hours ago, A-L-E-K said:

eps starting to look mild/warmish...hype?

I'm in

[Harry]

8 hours ago, A-L-E-K said:

eps starting to look mild/warmish...hype?

 

Could be. MJO has strengthened again. Get that into 4 and we should start seeing a warming trend. 

[TheClimateChanger]

This just blew my mind.  Shared this in the Ohio thread, but thought this was a statistic worthy of sharing to the entire subforum. Warmest start to the year at Akron-Canton Regional Airport, but more shockingly 8 of the 14 warmest years on record have occurred in the last nine years, dating back to 1887. Just absolutely astounding.