10/25 - 10/31 Hurricane Norma and a series of storms bring heavy rainfall and possible snow to the central US

[Clinton]

Looks like the middle of the country could enjoy a good soaker and could the northern plains enjoy their first snowfall?  Lots of questions ahead to see if any of the energy coming out of the SW can phase with hurricane Norma as the remnants potentially move into the central US.  The GFS shows the energy phasing as a storm system rounds a deep western trough.  The Euro keeps Norma and it energy kinda staled of the Mexico coast however both models still deliver nice rains.

GFS

Euro

Finally a 3rd piece of energy will dive in from the Pacific NW bringing massive temperature change and our first taste of Winter.  This could lead to the first significant snowstorm of the season for the Dakotas and Minn and more rains for the drought stricken areas in the plains .  Could the snow make it further south, lots of time to figure that out as models digest what looks to be an exciting week of the new LRC.

Total precip:

GFS 

Euros take

Ensemble Means

The Wintery side:

 

[Clinton]

Forgot to mention the Canadian shows a more suppressed solution with a more stretched out 3rd piece of energy that brings little moisture to Nebraska, South Dakota and western Iowa.   

[Tom]

Thanks for firing up the thread Clinton!  It's finally exciting to see a long duration SW Flow pattern that will pretty much encompass our entire Sub Forum. Been waiting for this week of weather to see how it would evolve.  The models are still not quite on board as you mentioned there are many variables at play here.  I'd like to see 1 or 2 wound up storms out of this pattern for the central CONUS.  The teleconnections appear to signal a decent chance to wind up a storm but the DEEP -EPO is always a culprit for a storm to get cutoff in the SW.

Look at that "Omega Block" near Alaska...this new LRC pattern setting up is going to be a year well known for the year of Omega Blocks.  We've had several instances already of these atmospheric phenomenon's setting up across various locations across  North America.

 

[Clinton]

7 minutes ago, Tom said:

Thanks for firing up the thread Clinton!  It's finally exciting to see a long duration SW Flow pattern that will pretty much encompass our entire Sub Forum. Been waiting for this week of weather to see how it would evolve.  The models are still not quite on board as you mentioned there are many variables at play here.  I'd like to see 1 or 2 wound up storms out of this pattern for the central CONUS.  The teleconnections appear to signal a decent chance to wind up a storm but the DEEP -EPO is always a culprit for a storm to get cutoff in the SW.

Look at that "Omega Block" near Alaska...this new LRC pattern setting up is going to be a year well known for the year of Omega Blocks.  We've had several instances already of these atmospheric phenomenon's setting up across various locations across  North America.

 

I agree and on the heels of next week's storms the pattern looks ripe for another one to dig in with some cold air in place. Both the GFS and Euro have been hinting at that as looks to reload quickly. 

[hawkstwelve]

Really hope the GFS ends up right with how it phases all three pieces of energy together next week. Makes it much more interesting than the Euro/Canadian solution of keeping everything separate. There are extremely large differences in the 500mb pattern just six days out (maps below). I have a feeling the Euro solution will end up correct just based on it's overall better accuracy. But the GFS could still pull out the surprise and end up winning this battle.

It will be interesting to see where the models stand by the end of the weekend. By then, the pieces will be starting to move into place within the upper level pattern. That should allow the models to start getting a better initialization and by extension, a better handle on how things will ultimately play out.

[mlgamer]

Not to be a Negative Nellie, but I don't have confidence in any of the global model solutions so far. For example, latest GEM (12z) has only around 0.30" QPF for me over the next seven days. That's not gonna cut it. I keep thinking of the old adage "never forecast rain in a drought".  Still, plenty of time for more twists and turns...

[Hawkeye]

I'm not liking the trend of some of the models.  The GFS suddenly lost the western trough (the one behind the southwest cutoff) a couple days ago, but it is back now.  However, the Canadian has no trough at all over the west, instead showing a fast wnw flow over the northern US, which does not allow the southwest cutoff low to lift northeast and totally screws the big rain event around here.  Unfortunately, the UK has now also shifted from a western trough to garbage, just like the Canadian.  Last night's Euro showed a hint of this as well, but did not go all the way.  It's quite possible the big event could vanish.

[hawkstwelve]

You can see a northward jump of the main heavy snow band to the NNW on the latest 12z GEFS run vs the previous four runs. Looks closer to the Euro solution of keeping the snow mainly in Canada. Might mark a move that the deterministic GFS may make in the near future.

 

[Clinton]

1 hour ago, mlgamer said:

Not to be a Negative Nellie, but I don't have confidence in any of the global model solutions so far. For example, latest GEM (12z) has only around 0.30" QPF for me over the next seven days. That's not gonna cut it. I keep thinking of the old adage "never forecast rain in a drought".  Still, plenty of time for more twists and turns...

I feel like mother nature needs to treat us nicely on this one and get us some good rainfall.  I would hate to be 0-2 in the new pattern, GFS and GEFS both looking pretty good this afternoon.  However I do have the same skepticism when it comes to drought.  Mother Nature will have to show me! 

[Hawkeye]

The reason for the widening model differences is how each handles the northeast Pacific.  The models (mostly just the GFS now) that dig the second trough into the west have a Gulf of Alaska ridge that separates the diving sw Canada energy from a big system out in the Pacific.  What more models are trending to now, though, is the ridge gets pinched off, so the diving sw Canada energy and the Pacific energy connect and interact.  This interaction prevents the sw Canada energy from digging further.

[OttumwaSnomow]

5 hours ago, Hawkeye said:

I'm not liking the trend of some of the models.  The GFS suddenly lost the western trough (the one behind the southwest cutoff) a couple days ago, but it is back now.  However, the Canadian has no trough at all over the west, instead showing a fast wnw flow over the northern US, which does not allow the southwest cutoff low to lift northeast and totally screws the big rain event around here.  Unfortunately, the UK has now also shifted from a western trough to garbage, just like the Canadian.  Last night's Euro showed a hint of this as well, but did not go all the way.  It's quite possible the big event could vanish.

Like the last big event did for my part of Iowa. Puff the magic dragon its gone! Models giveth  and models taketh away.  Ridiculous. 

[Black Hole]

The trough digging down from the NW, the trough over the desert southwest, and Norma are all tied together. It seems that if the trough over the NW stretches out instead of digging the trough over the southwest doesn't eject properly and it really limits the rain potential of this event. That is the most probable outcome too. 

[Clinton]

The Euro wants to bring the remnants of Norma right over mby and also holds the main energy in the Pacific NW back and bring it out with a deep trough over the middle of the country.  Long story short the 0z Euro was awesome run if you want some moisture over the next 10 days.  Further more the way it handles the energy out of the NW would lead to a major winter storm and artic outbreak in future cycles.  However with the 3 major models we still have 3 completely different solutions.

Euro at hr 138 and hr 216

  

GFS same hrs

Canadian is want different 

[Clinton]

0z EPS

GEFS

[Hawkeye]

The 12z Canadian and UK have trended back toward the western trough scenario.

[Hawkeye]

2 hours ago, Hawkeye said:

The 12z Canadian and UK have trended back toward the western trough scenario.

The 12z Euro also trended back toward the GFS.

[Hawkeye]

Recent EPS runs ticked down with rain totals across the region, but this morning's run is the wettest so far.

[Clinton]

5 minutes ago, Hawkeye said:

Recent EPS runs ticked down with rain totals across the region, but this morning's run is the wettest so far.

That would put a little dent in the drought down my way.  I just feel if I can break the ice things may open up.

[Andie]

Originating from the Comet IP/Halley, also known as Halley's Comet, the Orionid meteor shower peaks across the Northern Hemisphere every October. This year, the peak activity happens on Oct. 21, offering the best chance to see the meteors in action. 

[OttumwaSnomow]

If this system and trough dont give me a decent  rain I will just cry.   Just look at these factual numbers at the Ottumwa  airport.  And Jan and Feb were actually  wet and above average precip!!  What is shocking is the Bloomfield  Iowa area was the wettest  part of Iowa sept 2022 until April 2023.  And in the entirety  of 2023 Ottumwa  and Bloomfield  are the driest sites in Iowa.  April 20th until now this area is a complete  desert with exception  of a couple spots that got a heavy pop-up  thunderstorm.  Seem like this area is first into drought and last out. If someone  could  research  amounts  of weeks in drought  here since  June 2012 it will blow your minds compared to other midwest locations. And my land was one that caught  popups, I am right at 21" for 2023. 5" more than other spots near me. Its rained over 1"  just 2 times!!! And one was in Feb.

[Clinton]

There're miner differences between the GFS and it ensembles and the Euro and it's with where the remints of Norma will track.  The Euro and EPS showing 1-2 inches for mby with the GFS and GEFS being further west leaving me with a trace to a 1/4 of an inch.  Hopefully the Euro holds since we are at hr 90 but the drier GFS has been what I've seen for the last 365 days.

Edit:  The latest NAM came out in my favor.

Edited October 22, 2023 by Clinton

[hawkstwelve]

GFS has definitely trended slower and weaker with the second system. 

[hawkstwelve]

What kind of sick joke is the GFS trying to play... 

[hawkstwelve]

First Euro run that puts down some white gold over Sioux Falls. 

[Clinton]

Edited the date to the thread to include pre Halloween snow and rainfall.

[hawkstwelve]

 

[Black Hole]

It's definitely going to be raining a lot this week in Oklahoma. PWATs will be near the 99th percentile for much of the next few days as Norma's moisture gets pulled into the trough with deep southwest flow. Could easily see several inches if all goes well. 

[Clinton]

We haven't seen this much widespread rainfall in a very long time. Very excited!

[Clinton]

6 hours ago, hawkstwelve said:

 

Are you buying what the GFS is trying to sell?

[Hawkeye]

This week may end up being much drier than expected around here.   Today's wave missed north, the tropical remnants should mostly miss south, the Tuesday night front flare-up misses north, then the main low mostly misses north.  The overrunning event late in the weekend is our best hope for anything decent.

[hawkstwelve]

2 hours ago, Clinton said:

Are you buying what the GFS is trying to sell?

Not buying it to that degree. I'm thinking we have a decent shot of at least seeing some flakes in the air some time between Friday and Halloween. If all lines up right, maybe an outside shot at 1-3 inches like the Euro is showing. The almost foot of snow the latest GFS is showing? Yeah, don't see that happening. I think that's just the GFS doing GFS things. 

Speaking of GFS things... Latest run shows us topping out in the 20s for a few days with a low temp in the single digits. Euro a little more realistic with highs in the 30s/lows in the 20s. Either way you slice it, gonna be cold! 

[Tom]

4 hours ago, Clinton said:

We haven't seen this much widespread rainfall in a very long time. Very excited!

Mother Nature's blessings for the central CONUS...

[OttumwaSnomow]

@Tom @Clinton Im usually  not this pessimistic  but I can see a coming bust for my part of SE Iowa.  Just like last week it was model  mania,  the warm front wimped out here.  The low went north  and  i tiny spoke with a little  daytime heating brought us here a 20 min thundershower of half inch. I dont like the way this  system  is inicializing or the track of the low. Even less than last weeks half inch WILL NOT SUPRISE ME HERE!. And unfortunately  drier winter months are knocking at the door. Horrible  place here for weather!!!!

[Clinton]

21 minutes ago, OttumwaSnomow said:

@Tom @Clinton Im usually  not this pessimistic  but I can see a coming bust for my part of SE Iowa.  Just like last week it was model  mania,  the warm front wimped out here.  The low went north  and  i tiny spoke with a little  daytime heating brought us here a 20 min thundershower of half inch. I dont like the way this  system  is inicializing or the track of the low. Even less than last weeks half inch WILL NOT SUPRISE ME HERE!. And unfortunately  drier winter months are knocking at the door. Horrible  place here for weather!!!!

SW Flow with hurricane moisture plus a strong cold front with an upper level low.  It's going to be hars to miss. I understand your pessimism though with what we've endured over the last year.

[mlgamer]

24 minutes ago, Clinton said:

SW Flow with hurricane moisture plus a strong cold front with an upper level low.  It's going to be hars to miss. I understand your pessimism though with what we've endured over the last year.

Believe it or not, I'm actually up to cautiously optimistic that we may get a much needed, beneficial rain out of this. Certainly we won't get missed this time...right??!!

[Tom]

59 minutes ago, OttumwaSnomow said:

@Tom @Clinton Im usually  not this pessimistic  but I can see a coming bust for my part of SE Iowa.  Just like last week it was model  mania,  the warm front wimped out here.  The low went north  and  i tiny spoke with a little  daytime heating brought us here a 20 min thundershower of half inch. I dont like the way this  system  is inicializing or the track of the low. Even less than last weeks half inch WILL NOT SUPRISE ME HERE!. And unfortunately  drier winter months are knocking at the door. Horrible  place here for weather!!!!

As @Clintonmentioned, this SW Flow pattern and the tight temp gradient is prime for widespread precip to break out along the frontal boundary.  You might not get bulls-eyed but the bigger picture is clear to me that the MW is in a good spot.  My call is for at least 1.00" of rain to fall in your area.

[hawkstwelve]

A little taste of what could be coming our way for some folks...

 

[Clinton]

24 minutes ago, mlgamer said:

Believe it or not, I'm actually up to cautiously optimistic that we may get a much needed, beneficial rain out of this. Certainly we won't get missed this time...right??!!

Even a blind squirrel can find a nut right! Lol

[jaster220]

5 hours ago, Tom said:

Mother Nature's blessings for the central CONUS...

But clearly a miss for EIA

[Hawkeye]

Ugh!!!  This week of widespread heavy rain is going down the toilet.  Round #1, today, missed north.  Round #2, the tropical remnants, will mostly miss south.  Round #3, the frontal flare-up, will miss well north.  Round #4, the main low, will likely drop the best rain nw.  Thank God Cedar Rapids got hit good by the last wet system, because this week is trending more like the rest of 2023.