February/March 2021 - Frigid or Flop? Pattern/Longterm Forecast Thread.

[Carvers Gap]

Just now getting back in pocket.  Couple of things:

1. Pattern looks REALLY good if you live in west and middle TN during the next 10 days.

2.  The MJO for the EMON and EURO is a BIG improvement...let's hope we don't go with US modeling.  If modeling trends towards the Euro, there are some big changes in store for modeling still yet to come.

 

[Carvers Gap]

Just looking at the CMC, GFS and Euro for 12z...looks like this sub-forum is going to be an active place.  Though details are not nailed down...sure seems like the intersection of precip and cold is in this area.  Right now, I favor middle and west areas first with the threat gradually pushing east.  The 12z Euro IMHO would be a massive ice storm for pretty much everyone.  I know it had rain in the East, but doubt that cold is going to get scoured that quickly with two highs sitting over the top.    

[Carvers Gap]

12z suite is loaded for bear....Looks like 3-4 windows for winter weather.   Pretty much every system is going to have to be watched as each one has a winter component on the west and NW side.  

[codgator]

Just need to get that Cold moving East faster 

[AMZ8990]

14 minutes ago, Carvers Gap said:

Just now getting back in pocket.  Couple of things:

1. Pattern looks REALLY good if you live in west and middle TN during the next 10 days.

2.  The MJO for the EMON and EURO is a BIG improvement...let's hope we don't go with US modeling.  If modeling trends towards the Euro, there are some big changes in store for modeling still yet to come.

 

I agree carver!  Right now storm tracks are hammering the the dakotas, Nebraska, Iowa, northern Missouri, etc.  it’s only a matter of time before that track moves south a bit, (hopefully).  If and when it does, it could be a big time event for somewhere in our forum area.  They were getting hammered day after day in Des Moines while I was up there, and central Missouri got pounded yesterday as I was on my way home, it was a very difficult drive to say the least.  I say all that just to reiterate how much energy is flying around the lower 48 right now.  Given the cold air in place to our north, we have a lot of variables in are favor to produce a good storm over the next 5-10 days.  

 

[WestTennWX]

Memphis Disco...looks like an Ice Storm Warning may be in our future

 

National Weather Service Memphis TN
1148 AM CST Tue Feb 9 2021

.UPDATE...
A quasi-stationary front lies across the Mid-South at this time,
separating cold, arctic air from a mild air mass to the south.
Temperatures in northeast AR and the Bootheel are currently in the
upper 20s and lower 30s while readings are approaching 60F at
Tupelo. The flow aloft is quasi-zonal at this time with no strong
shortwave trough approaching in the very near term. This will keep
PoPs limited today. A few light showers or perhaps some drizzle, is
possible north of the front and we`re seeing visibility reduced
to 3-5SM from Jonesboro into northwest TN. Temperatures aren`t
expected to improve much today given the cold advection and cloud
cover across the region.

Isentropic ascent will increase tonight as a strong upper-level
jet propagates across the Great Lakes. This will enhance rain
chances tonight, especially late. QPF will likely be slightly
higher than last night, but temperatures will be below freezing in
the northwest portion of the CWA. This may result in some light
freezing rain/drizzle and could result in some travel problems
overnight. Rather than issue a Winter Weather Advisory on top of
the Winter Storm Watch, the better option may be to begin an Ice
Storm Warning (continuing through the "main event" Wednesday night
into Thursday) earlier for some areas to encompass both events.
Will have more on that this afternoon, but wanted to get the
current thinking out in the open.

[Carvers Gap]

4 minutes ago, WestTennWX said:

Memphis Disco...looks like an Ice Storm Warning may be in our future

 

National Weather Service Memphis TN
1148 AM CST Tue Feb 9 2021

.UPDATE...
A quasi-stationary front lies across the Mid-South at this time,
separating cold, arctic air from a mild air mass to the south.
Temperatures in northeast AR and the Bootheel are currently in the
upper 20s and lower 30s while readings are approaching 60F at
Tupelo. The flow aloft is quasi-zonal at this time with no strong
shortwave trough approaching in the very near term. This will keep
PoPs limited today. A few light showers or perhaps some drizzle, is
possible north of the front and we`re seeing visibility reduced
to 3-5SM from Jonesboro into northwest TN. Temperatures aren`t
expected to improve much today given the cold advection and cloud
cover across the region.

Isentropic ascent will increase tonight as a strong upper-level
jet propagates across the Great Lakes. This will enhance rain
chances tonight, especially late. QPF will likely be slightly
higher than last night, but temperatures will be below freezing in
the northwest portion of the CWA. This may result in some light
freezing rain/drizzle and could result in some travel problems
overnight. Rather than issue a Winter Weather Advisory on top of
the Winter Storm Watch, the better option may be to begin an Ice
Storm Warning (continuing through the "main event" Wednesday night
into Thursday) earlier for some areas to encompass both events.
Will have more on that this afternoon, but wanted to get the
current thinking out in the open.

You all feel free to fire-up a thread.  Been a while since that area of the forum has had a thread for an event.  

[Carvers Gap]

This is the 12z EPS.  This is the look that brings winter wx to the forum area.

[Carvers Gap]

Just looking at the ensembles....looks like an outside thread at a light mixed precip event Sunday, a bigger event around the 16th, and then the overrunning pattern just holds.  We are going to have to work for it in eastern areas, but man....middle and west TN are looking good.  Honestly, if the 12z EPS is correct in the depiction of the gradient....it is going to be a wild couple of weeks.  And we haven't really pushed back the pattern.  The boundary for the cold air has been moved, but the overrunning pattern is still appears legit.  

[Carvers Gap]

Been a while since we have seen a 384 mean for the entire sub-forum that looked like this.

[WestTennWX]

18 minutes ago, Carvers Gap said:

You all feel free to fire-up a thread.  Been a while since that area of the forum has had a thread for an event.  

Thanks Carver, went ahead and started one.  I'm on the fence with Ice Storms, it's a love/hate thing.  Memories of 09 are still pretty fresh, we were without power for a week here in Obion County.

[Carvers Gap]

2 minutes ago, WestTennWX said:

Thanks Carver, went ahead and started one.  I'm on the fence with Ice Storms, it's a love/hate thing.  Memories of 09 are still pretty fresh, we were without power for a week here in Obion County.

Yeah, the thread doesn't mean anyone likes it!  Totally agree.  However, if they are talking ice storm warnings...it is newsworthy and worth discussing IMO.

[Holston_River_Rambler]

Yet another one of the options on the table for next week's system:

[Holston_River_Rambler]

Annnddddd at our hour of dire need, the GFS v16 has returned:

 

a gif of all three systems we've been talking about, since it has been so long since we've had access to its data. 

[BNAwx]

16 minutes ago, Holston_River_Rambler said:

Annnddddd at our hour of dire need, the GFS v16 has returned:

 

a gif of all three systems we've been talking about, since it has been so long since we've had access to its data. 

[Mrwolf1972]

18z gfs  ice storms back on the 16th

[Carvers Gap]

Like clockwork, when we begin to see even one model exit the MJO 6/7 loop...seems like we see the front press on all models.  I know I sound like a broken record, but this boundary "should" press eastward with each piece of energy.  Have to think the Tuesday system is looking like a significant event, but I am going to remain guarded with that.  Also, beware of systems that cut directly into big highs.  They may attack them as the enter or exit the area, but if they are over the Lakes, easter Plains, or central Plains....that system is likely to be forced southeast.

[John1122]

Just now, Carvers Gap said:

Like clockwork, when we begin to see even one model exit the MJO 6/7 loop...seems like we see the front press on all models.  I know I sound like a broken record, but this boundary "should" press eastward with each piece of energy.  Have to think the Tuesday system is looking like a significant event, but I am going to remain guarded with that.  Also, beware of systems that cut directly into big highs.  They may attack them as the enter or exit the area, but if they are over the Lakes, easter Plains, or central Plains....that system is likely to be forced southeast.

Modeling has tried to cut straight into banana highs at times all winter and it's yet to happen.  I have to assume there is something in the underlying physics that causes that. 

[Carvers Gap]

53 minutes ago, John1122 said:

Modeling has tried to cut straight into banana highs at times all winter and it's yet to happen.  I have to assume there is something in the underlying physics that causes that. 

JB mentioned the same error. I have seen systems cut between just a sliver daylight between two big highs.  I also have seen big highs exit quickly.  But some of the stuff shown lately just seems so counterintuitive.  A great example is how far south the ice line has trended.  It was just north of the Ohio River.  Now it is running though sought KY.  My suspicion is that this cold finds its way to the Plateau and then banks west of the Apps.  Might take several storms for this to occur, but I like that option.  I like this pattern.  Maybe I won't in the end...but truly being near the boundary between cold and precip is interesting to follow.  Also, modeling is VERY prone to big shifts even in the medium range right now.  So, I think any solution that appears locked-ed at d5...might not be.   

And yeah, sometimes it is like modeling doesn't see the NAO block and then it is like....whoa, better fix that solution once it finally "sees" it.

[John1122]

The ICON is all in on a big winter event for at least the western 2/3rds of the state. Possibly ice on the east side but not sure yet. 

[John1122]

Yep, Plateau west sees snow and the eastern valley is freezing rain most likely. The ICON on TT only shows rain or snow. But the temp is sub 32 basically everywhere but the eastern mountains. Over 1 inch of QPF with Temps in the upper 20s to near 30 in the east. 

Temps as precip arrives.  During. Then as it exits. 

Precip panels. 

 

[John1122]

GFS has a monster winter storm in Texas. Used to be money in the bank here. We will see where it goes. 

[John1122]

[John1122]

20s under the ZR. Teens and high singles to the west. 

[Mrwolf1972]

We just can't get the cold air past the plateau. 

[John1122]

Warm nose from hades. Much harder to actually raise temps with precip falling than is likely being modeled here. 

[John1122]

Basically after tomorrow the western 2/3rds of the state stays near to well below freezing. Nashville west spends about a week in the deep freeze with snow, sleet and ZR.  

[John1122]

V16

 

[dwagner88]

I have a feeling this one is going to be very frustrating to watch for those of us East of the Plateau. That SE ridge just isn’t going to allow the cold air into the valley.  

[John1122]

The Canadian has a completely different take and only gives a glancing blow but it's snow. All models have the ice over the next few days. All have the big storm early next week. All are slightly different for it.