--Oct 6th--pattern change coming

Well folks here we are on the precipice of a new winter weather season(my favorite).  BUT we have to go through the transitional phase that we call fall.  During this time we start to see hints and or glimpses on how the winter pattern MAY set up.  Because the days are still long (relative to the winter months), and the sea surface temps (SST) are still very warm, etc this time of year it is not uncommon to see patterns flip back and forth until a more definitive winter pattern locks into place as we enter Dec and Jan.  Remember there are many factors that go into governing the major weather pattern drivers.  The global SST are a HUGE factor and will play a major role in determining how things play out.  The Pacific SST's will dictate the phases of the current El NINO in the tropical pacific, the PDO in the Northern Pacific, the MJO, the PNA off our west coast, the EPO South of the Aleutians and gulf of Alaska(GOA); whereas, the Atlantic SST will dictate the phases of the AMO, NAO and so on.  We will not touch much on these different teleconnections in this write up.  Instead I am going to show you where our pattern is currently, and how a much colder pattern is on the horizon.  Now when I say much colder I mean relative to averages.  We ARE NOT in winter yet, but some areas might think so.

As has been already discussed some in the LR thread change she is a coming.  You may have seen some maps of the northern hemisphere (NH) over there and thought..."what the heck am I looking at? And why are they getting so worked up over it.  To understand that lets take a look at where the current pattern sits.  To illustrate my points I am going to use the GFS ensemble maps(GEFS) and the Euro Ensemble maps(EPS).  They are the 500mb(about18,000ft in the atmosphere) anomaly maps.  Remember the ensemble maps I am going to show you is the average of all the individual members of that particular model.  I believe the GEFS has 25members and the EPS has 51.  So that means when looking at the Euro ens map what you see is the avg of all 51 members individual runs.  Ok enough of that lets get going.  

When viewing these maps keep in mind red colors = ridging = high pressure = clockwise wind direction; whereas, Blue = trough = low pressure = counterclockwise wind direction.

Here are the NH 500mb anomaly maps at time 00 from this evenings 00z runs for both GFS and European ensemble respectively.

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Now same maps but Ive drawn in the general wind flow.  Take note that the source of the air that is over most if not all of the CONUS originates from the warm waters of the Pacific Ocean as well as the gulf of mexico indicated by the yellow X's.  As you can also see the cold air over the arctic is locked up to the north.

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Now beginning around the 28th/29th and going through about the 4th/5th a major transition in the pattern is taking place on the models leading to a colder and stormier pattern in the east.  The next maps are 00z Oct 6th where the pattern seems to have finished the transition and locks itself in.  I believe the most important aspect of this pattern change is in the west.  Take particular note of the ridging that develops into Alaska and the trough that backs up south of the Aleutian islands.  The two compliment each other.  The trough actually aids in pumping the ridge. Again GEFS first followed by the EPS

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This is basically the pattern that has dictated the outcomes of the last two winters.  That Alaskan ridge leads to a cross polar flow.  What that means is that now instead of the warm pacific as the source region for the air in the east the air now originates in Siberia, crosses over the frozen ice pack that is the arctic (that Mugsy has been showing how rapidly as of late has been expanding), and spilling through Canada into the trough that is in the east.  Now keep in mind because of the time of year by the time that air filters into the Lower 48 it will modify, but it will absolutely lead to colder than avg temps for many in the east.  If this pattern shows up again this winter expect colder than normal temps and wet(snowy) conditions along the eastern third of the CONUS for sure.  

So to reiterate we go from this:  
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TO this by Oct 6th:

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Now I stress this may change as we approach OCT 6th, but the signal on multiple models and their Ensembles to the ridge up into Alaska should lead to the pattern I described above as we head into Oct.  I would expect 1-2 decent storm systems affecting the east coast between Oct4th-8th time frame.  The details of where, how much, etc is not important this far out.  

With that Happy Football Sunday.  

Nice write-up!! And I definitely agree with the pattern change around this time-frame. Should be an interesting ten days ahead of us

Great wrote up sroc easy to understand

If this was only January/February. PLEASE PLEASE PLEASE TELL ME WE WILL SEE MAPS WITH SIMILAR SET UPS DURING WINTER> So beautiful I wanna cry.

Happy Sunday!

Please click on the link to read my latest blog regarding the direction our upper air pattern is headed in. We are likely to see increased rain chances in October compared to this month. Also, we should begin feeling more like Fall relatively soon. There is also some El Nino discussion.

http://njstrongweather.blogspot.com/2015/09/expect-complete-360-pattern-change-in.html

Congratulations to the Mets on clinching the NL East. It looks like the Yankees will get in via Wild Card. October baseball in NYC is back!

Best,

Frank

Excellent job, Frank.So good to see that pattern change to more Fall-like weather and rain chances.Lot's of interesting things to look at the next few weeks.

Glad to see the chances for precip is increasing, but not on the 4th! I have tickets for the last regular season Met game!

I just realized my headline should read 180 instead of 360. Ha

We should consolidate our write ups. I'm mobile.

Holy crap didn't even see yours. Yea I'll do that.

Looks like Doc and I both did a write up on the upcoming pattern change so I just merged the two threads together. Docs is posted here...mine is linked to my blog.

@doc - nice detail to what could be coming. Thanks for taking the time to do the write up and breaking it down in language everyone can understand.

Just got a chance to read yours. Looks like we are on the same page for Oct. It's funny how we both decided to do a write up at the same time.

Nice write up guys, big changes coming possibly some pretty stormy wx, look at banter latest GFS rain totals up to 168, sheesh if its true we in trouble, at least its not all in one day (again if it happens).

Excellent write up SROC and Frank, easy to understand and yes she is going to change to a  fall like pattern and people are going to be say what?/ Where is the dry sunny weather - Mama ain't playin' that game na more!!

Doc and Frank...thanks for the tutorial on the upcoming pattern changes for October.Clear, concise and full of excellent information.Hoping that scenario Doc points out that could give us a cold, snowy winter happens.After reading these dissertations, i was inspired to go out and mark a fencepost with 6 inch, 12 inch,18,24,30 and 36 inch markings for snow measurement.I can look out my office window and see it,LOL!

Hey CP, let the low temperature and snow measurement war in the LHV begin,LOL!

Anybody worried about what this pattern resembles from a few Octobers ago? Granted, there are some variations, but it's eerily similar. I think we might REALLY need to pay attention to this, especially for coastal sections. Inland areas will likely see flooding, but I'm very concerned about the coast; they've had sustained onshore fetch for weeks now, add to that this week's deluge and then a tropical system possibly going through an ET as it interacts with the Mid-latitude jet and gets drawn westward toward the coast. This is not good fellas.

RB are you mentioning the infamous "S" storm in 2012? That would be one heck of a thing, 1:100 years I guess not if it comes to fruition. Yes I am concerned it is earily similar and NYC and jersey all way to cape will be under the gun, forget about tomorrow through wed nights rain that's least of our concerns. Your the met, what do you think? Are hwrf and GFDL that far off? I posted in tropics section but would it be safe to say I'd be okay to post on this even in one of the more looked upon threads, and if so which one since this appears to be a formidable threat? BTW yopu are not the only one online saying the setup similar to 2012.

Do you think the models are underplaying the interaction of to be TS Joquin, only models show a huge hit on area just east into CT are GFDL and HWRF, Interested to see the 12z Euro, its still 6-7 days out I think the Euro showed the first bomb at day 8 for 2012, so maybe we not seen the full force of whats to come. It may take passing this first batch to see whats coming which doesn't give much time to prepare after Wed.

rb924119 wrote:Anybody worried about what this pattern resembles from a few Octobers ago? Granted, there are some variations, but it's eerily similar. I think we might REALLY need to pay attention to this, especially for coastal sections. Inland areas will likely see flooding, but I'm very concerned about the coast; they've had sustained onshore fetch for weeks now, add to that this week's deluge and then a tropical system possibly going through an ET as it interacts with the Mid-latitude jet and gets drawn westward toward the coast. This is not good fellas.

I think warm air transport/conveyor belt is going to be a MAJOR player. Busts high and low are possible depending on where you live. I think LI might have a tough time with this.

I have many concerns biggest being the coast this weekend the water was all the way up the beach

sroc4 wrote:

rb924119 wrote:Anybody worried about what this pattern resembles from a few Octobers ago? Granted, there are some variations, but it's eerily similar. I think we might REALLY need to pay attention to this, especially for coastal sections. Inland areas will likely see flooding, but I'm very concerned about the coast; they've had sustained onshore fetch for weeks now, add to that this week's deluge and then a tropical system possibly going through an ET as it interacts with the Mid-latitude jet and gets drawn westward toward the coast. This is not good fellas.

I think warm air transport/conveyor belt is going to be a MAJOR player.  Busts high and low are possible depending on where you live.  I think LI might have a tough time with this.  

Flooding going be a big issue all over, CMC came in just insane, taking that as a bit high 8-12 inches, from 36-156 hrs. sroc you think NYC area is still possibly in play? I see LI is the main hit area on current projections but once HH come back, which they are out there now and we get a named storm the tracks often change drastically. AND models can have huge changes. Not a lot of time to work with here we should know if a few days.

skinsfan1177 wrote:I have many concerns biggest being the coast this weekend the water was all the way up the beach

Yeah jersey coast def does not need a big storm surge.

I agree, sroc.

Jman, I am referring to Sandy, but I'm not going to hype this yet. Granted, it has shown up a few times already as a possible solution, but even at this juncture, it is a very delicate setup. I was just doing some fast analysis, and right now, it would appear that a system 10,000 miles away may be the determining factor, and the unfortunate thing is, the way in which it will determine the outcome can only be **parameterized** by models. Instead of being able to take measurements that then go into the millions of calculations and permutations in the models when they run, the data is only assumed to behave in whatever particular way the programmers designed it to within the mathematical core of the model. As was the same with Sandy, the parameterization of the current GFS is allowing it to produce a similar outcome right now. The EURO may be entirely different. The key right now is not to try to figure out whether this could over or under achieve; those possibilities always exist regardless of what the data says, as we saw quite often last winter. The key here is to figure out whether or not the solution, and inherently, the parameterization(s) of the model(s) are leading to plausible outcomes.

To answer your other question, I honestly don't know much of anything about those other models. I've never really used them.

Wow 10,000 miles away no wonder the models are kinda all over, but yet are still kinda on the same page at this juncture. Euro will be interesting as it nailed Sandy. I understand its delicate and could go either way but as you said it makes me uneasy.

In my honest opinion, the latest CMC run is garbage. Throw it out. It's impossible to maintain a binary mid-level system, let alone a tri(ary?). GT* outta here CMC, you're drunk. Go home lmfao