Texas Fall-2015

[Ntxw]

One thing that's weird right now is that the Midwest and Great lakes Region is in a pattern that's more like a La Nina while the Southern U.S is in more of a Nino Pattern, what could be attributed to this?

-PNA most likely aided by the MJO in the IO. For the southern US the subtropical jet is strong and controlling much of the weather. Is a warm November La Nina like up there? Many stations are running 4-6F above normal

[TheProfessor]

One thing that's weird right now is that the Midwest and Great lakes Region is in a pattern that's more like a La Nina while the Southern U.S is in more of a Nino Pattern, what could be attributed to this?

-PNA most likely. For the southern US the subtropical jet is strong and controlling much of the weather. Is a warm November La Nina like up there? Many stations are running 4-6F above normal

I'm not sure, someone on a different forum pointed it out, I think La Nina Novembers are a bit rainier and we've been getting a quite a bit of rain for the area, and right now it's below normal in Central Ohio, we are sitting at 46 degrees and might not make it to 50 if the fog doesn't clear out. It's been sitting around 50-55 for the past few days. Average is about 52 for this time of year.

[Ntxw]

I'm not sure, someone on a different forum pointed it out, I think La Nina Novembers are a bit rainier and we've been getting a quite a bit of rain for the area, and right now it's below normal in Central Ohio, we are sitting at 46 degrees and might not make it to 50 if the fog doesn't clear out. It's been sitting around 50-55 for the past few days. Average is about 52 for this time of year.

I wouldn't call it La Nina forcing just yet. It is a long term signal, if your averages and rainfall totals for the whole month fits La Nina criteria I would then do a re-analysis to see what caused it. There's not always going to be El Nino or La Nina weather patterns at all times it's ebb and flow and the dominant one overall shows up. But yeah the IO MJO isn't very Nino like atm since usually that focuses over the Pacific.

To note with such a strong STJ i wouldn't be surprised if at times this winter it poked it's nose up your way

[Ntxw]

Speaking of STJ take a look at it via 250mb winds very strong blowing in from our southwest. It's the one on the southern end, when the northern and subtropical jet merges=storm.

http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=us&pkg=uv250&runtime=2015111012&fh=90&xpos=0&ypos=295

[TeamPlayersBlue]

What may be causing the blow torch where Professor is would be the constant ULL spinning over Alaska. The Stratosphere is VERY cold there apparently. Readings colder than they have seen in a while for this time of year. This is helping to pump Pacific air into Canada keeping any trough from dipping into the GReat Lakes region.

One effect from this low is sending lows down the Cali coast which then dig into the SW desert area of the US and head our direction. High pressure seems to be building in the Pac to pull these Lows down the Cali coast and REALLY helping them dig.

The STJ is very impressive. With the latest reading of El nino being as strong as it is, no surprise in the strength of the winds. It will continue or get even stronger through the winter. You can see in that loop, when they merge/phase, the Low gains strength immediately. So cool watching everything play out.

[Ralph's Weather]

Not wanting to work so I took a look at some 09/10 data and it is as we have been saying. EPO was up and down but only a couple crashes those did seem to coincide with cold outbreaks. PNA was mostly negative, but we know that is not a big driver here. NAO was mostly strongly negative which is what drove our cold. Our snowiest day is recent history or for some in recorded history featured a NAO of-405 and an EPO of 101.

[TeamPlayersBlue]

Nice work! Yeah, hoping the cool pool south of greenland helps with the -NAO

[Ntxw]

One effect from this low is sending lows down the Cali coast which then dig into the SW desert area of the US and head our direction. High pressure seems to be building in the Pac to pull these Lows down the Cali coast and REALLY helping them dig.

Maybe effects of the TPB warm waters west of Mexico? Thank goodness for the Hudson block though, it keeps the digging systems further south. In a month or two they won't be cutting up to the central plains, likely transferring to the coast and into the gulf/SE US. Your 1972-1973 analog may bode well. That kind of storm suppression is possible.

[Ralph's Weather]

The biggest difference in this season from 09/10 is the PDO is positive now and was neutral then (also the El Nino was more centrally based than this one and obviously weaker). The Atlantic is pretty similar as far as I can tell.
To me this adds up to a very wet SW flow and likely periodic blocking over the Atlantic. We may not see so many 1045 mb highs, but we will see many bowling ball 500mb lows.

[Ntxw]

The positive AO is currently peaking and will lower. There's slight warming at 10mb in Asia, not yet enough to disturb the PV but the Siberian high shows signs of strengthening. We will need that warmth to explode northward towards the pole from Siberia. I think it's possible we see a neutral/-AO for final third of November.



And who doesn't like seeing lists of analogs?

[TeamPlayersBlue]

Is the below normal 10 mb temps a result of the high amount of snow they have received in Siberia? Pooling the cold dense air over the region? If so, then yeah its possible it can create a SSW event.

And yes! My warm pool is starting to show its effect. It seems, or maybe i just didnt know this before, that the high pressure in the region west of the US or Mex is helping the systems dig just right for us in Tx. 1050+ highs crossing the border like last couple years may not occur as often, youre right but i think there may be moments where a large high comes down we get enough blocking up there.

Be honest, there is a combination of things that seem to be playing out really well for us winter lovers here.
Its all starting to click! Lol, learn so much from you guys. Thanks again.

[TheProfessor]

What may be causing the blow torch where Professor is would be the constant ULL spinning over Alaska. The Stratosphere is VERY cold there apparently. Readings colder than they have seen in a while for this time of year. This is helping to pump Pacific air into Canada keeping any trough from dipping into the GReat Lakes region.

One effect from this low is sending lows down the Cali coast which then dig into the SW desert area of the US and head our direction. High pressure seems to be building in the Pac to pull these Lows down the Cali coast and REALLY helping them dig.

The STJ is very impressive. With the latest reading of El nino being as strong as it is, no surprise in the strength of the winds. It will continue or get even stronger through the winter. You can see in that loop, when they merge/phase, the Low gains strength immediately. So cool watching everything play out.

There's no blow torch here right now, has been near to below normal the past few days, it didn't reach 50 today, the blow torch was affecting more of the people west of me in Illinois and Nebraska, it was reaching low 80s there while we had a few days in the low 70s, but that was a week ago.

[Ntxw]

Is the below normal 10 mb temps a result of the high amount of snow they have received in Siberia? Pooling the cold dense air over the region? If so, then yeah its possible it can create a SSW event. .

It's a natural progression of the season as the northern hemisphere cools and the Polar Vortex in the stratosphere sets up shop. I think one of the biggest factors Asia is so important is because of it's size and the Himalayas. Mountain torque off those chains can kickstart warming and then the strength/size of the semi permanent Siberian high (over vast snowfields) can really warm up the stratosphere more so than anywhere else. The southern hemisphere lacks land mass and mountain set ups like we have Asia thus SSW down there rarely occurs, nothing disturbs the Antarctic PV (of course I say this and post below one of the rare events for them). I choose to look at 10mb because 30-40k ft straddles the tropopause, separating the troposphere from the stratosphere. So events that occur or start here generally can effect both.

I'll have to reread Judah Cohen's paper but he illustrates it very well.

Here is one I dug up from early Nov last before, the events up there just before the Nuri blast that set up the -AO after the first week of November

[gatorcane]

Hmmm



Zoomed in:

[Ralph's Weather]

Man the 18Z GFS goes cold and dry after next week's storm. Lows in the 20s and highs in the 40s with maybe a flurry. Can't go with any particular solution right now as the models are all over the place, but what is certain is that the pattern is becoming more winter like starting next week.

[Brent]

22 at DFW... highs barely above freezing a couple of days. 519 thickness!

[TeamPlayersBlue]

Do you have a link to Judah Cohen's article? I cant find one

[Ntxw]

Here you go, his paper linked from NOAA

http://www.nws.noaa.gov/ost/climate/STIP/FY11CTBSeminars/jcohen_062211.pdf

[TeamPlayersBlue]

Thanks! Look what you started, now im going to be busy tonight lol

[Ntxw]

Lots of wind advisories for the plains. Not surprising given the strong 130kt+ STJ screaming overhead, though that's not directly the cause.



Cool to think right below that mass of convection near the bottom wall to wall is El Nino, engine of it all