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There is a pattern that makes this outcome more likely. When there is little blocking ( we lose confluence, 50/50, pv location, etc and also taking into account the trough axis location ) you can actually have repeated episodes of very cold and then transition to warmer/mild and wet. Happened many times last year in the winter and so far this year when storms have cut. Granted you might go the route of snow>ice to rain as well if there is CAD set-up and if the air mass is very cold. You might also get re-development in cases such as the primary weakening to our NW, and then a new center develops closer to the coast, but with out latitude the moisture usually ends before the real cold moves in and we can transition back to all snow. Areas to our NE benefit the most.

Don S update from a few minutes ago in the NYC forum. I like it ! <<< Quick pattern evolution thoughts... The base case as per historical data has been that the MJO would progress into Phases 7 and then 8. More of the guidance is showing a move into Phase 7 in the extended range. The GEFS and bias-corrected GEFS show the MJO moving into Phase 7 at an amplitude > 2.000. Passage of the MJO into and through Phase 7 and very high amplitudes during the second half of January have typically seen trough development in the East and a snowy February. These developments suggest that the potential for a pattern change away from the much above normal warmth (with short breaks) for the first half of January are increasing for the second half of the month. The closing week has the potential to see the onset of a sustained colder pattern. >>>

Another thing to keep in mind is whether we get a surprise transient NAO block as previously it was in a couple Euro Control runs.

Here is an IOD update. Keep in mind the influence continues from this record setting event and it is still a pattern driver to a degree, but is gradually losing its effect.

As others have mentioned here regarding the MJO, overall change to colder might have legs into Feb .

Most interested what happens after the cutter, near the 21 st to 24 th time period.

Brilliant, because too many times in the past we have had the rug pulled form under us. Also, I am in it for a sustainable period of cold, along with snow as well please. Too many transient cold periods, I hope we lock into a longer period of cold and storm potential.

@bluewave simply in terms of modeling do you have stats or a personal favorite when it comes to predicting the MJO. What model tends to do best? As, I know there are many.

Good post, and you might enjoy this read I brought from Tip over in the NE forum regarding the coming - EPO .... see bold section From Tip : < Not sure who's said what over the last page or so ... so all credit where it is due, but the 00z GFS operational run ( and few priors that I can recall ) have been more aggressive with -EPO than it's ensemble means, but now the mean "might" be catching on just looking at the individual GEF members. As rumor has it the EPS has been showing changes in the Pacific in the extended for a few days now.. . The 00z Euro is hitting at a middling robust blocking ridge over Alaska. Given that these more sophisticated operational versions of disparate model types are nodding over that index switching modes, these are not altogether bad operational indicators for cold. I'm interested in ESRL's EPO progs from 00z because just eye-balling the GEF members individually, it does appear to be more of them situated blocking nodes and or ridge axis at higher latitudes of N-NE Pacific arc. The take away there/mean is that they actually have it, not so much any given particulars that are unlikely to be correct. We'll cross the orientation bridge when the time comes. But, from D4.5 right out to the end of the D13 ..that entire period is now rather robustly -EPO in the operational 00z, and 06z GFS, so those rumors of the EPS Pacific are not 'entirely' alone. In the dailies, the GFS has been signaling a whopper cold whack out there around ( now ) 204 or so hours.. but total smear time is probably a 3.5 day stint at < 520 dm thickness.. with some nadir temps that are dropping steam plumes. Yet the robuster ridge(ings) over the Alaskan sector are still out there in the la-la range of that model. I like it when 564 dm centers over Fairbanks! There's likely to be a few renditions of mass loading into the Canadian shield, with on and off disturbance orientations/existence but, the dearth of bona fide winter patterning is apparently on a shortened lease here. >

Of note, the GFS has the Jan 22 threat, and while taking a quick look this morning the Euro Control has a snow event for the Eastern areas for Jan 20th . There is potential between Jan 20 th and the 24 th. and probably beyond as well. At least the option to track versus getting a tan. Also, some indications we may be trending to a + PNA look way out in fantasy land.

Will be interesting to track the continued changes moving forward.

It appears now that the TPV takes up home on our side, maybe in the vicinity of Hudson Bay. So, a readily available cold air source. Maybe this potential set-up creates a more conducive environment regarding the NAM state , as mentioned previously, anything closer to neutral would be a lot better than right now. I will ride any improvements in AO and the PNA states, would love to get some favorable indices later in the month. If we do, that in itself will lend a lot more confidence that we can track a legitimate threat for the coastal areas, my area and your area included. psu already got his 5 inches

Fits the Euro seasonal model forecast released on 1/1/2020, encouraging so far .

He needs to go out to lunch with Webb, it is not all HL, but wondering whether the implications from the improving Pac will make the high latitudes more receptive to influences from certain players. Isotherm as always mentions not just the attacks on the pv during a typical winter season, but whether the environment is favorable for certain things to proceed in a cooperative manner. Everything from AAM, Glamm, waves 1 and 2, etc. I like the trends today. The period near Jan 20 to 24 is very interesting but more so is what happens from there to effect Feb and March as well.

I can't believe you got 5.1 inches of snow from yesterday's event. I measured a semi dusting last night, your location is great! And, I loved your photo yesterday with the kids and the the trees in the background , I just saw it moments ago. Congrats on the snow !

Nice to see the EPS get some support from the GEFS. As @WxUSAF noted Webb really likes this wave to continue to progress. Some folks I follow whom specialize in tropical forcing and the West Pac weather patterns think this wave has a chance to get to phase 8.

Me as well. If you knew that answer you could make a lot of money in the energy markets. I for one believe we will see changes, but they will be gradual and hopefully these "positive" changes appear closer and closer to real time as we near February. It has been another challenging Pacific to forecast, two years in a row. I realize there are other factors besides the Pac, way too many to name, you know them all. Just when you think you have a handle on one , an unforeseen pattern driver or player rears its ugly head. This year the IOD has been a pain just to name one.

Don't forget we may even get some help from the high amp MJO to encourage HL influence, as Matt mentions here, and also as mentioned previously last week by Don S and Bluewave .

Given previous powerful and even record breaking North Atlantic storms, the past several months, this is not really that far fetched an idea/outcome. This is also around the noted time period of Jan 17 to 22 nd.

As a follow up to the previous post from Matt Hugo re the GFS and the PV Simon points out the CFS also has the same time period ( Jan 17 to the 22 rd ) with a decrease as well, but afterwards while the GFS continues the downtrend the CFS rebounds. I could speculate that what happens during this time frame, and shortly thereafter, along with the latest QBO numbers may have a pretty significant impact on what occurs in our weather during February , well at least in regards to the HL and the NAM state.

I hardly ever look at the Euro Control but way out in fantasy lands it develops a West based NAO / Davis Straights block. Not sure the mechanism to how it achieved this, possibly the Scand retro and or wave breaking etc. Anyway, Webb mentioned this possibility today, ironic it shows up on the Control, and we know what a well timed and placed West based NAO block can do via some of the recent updates psu posted about ( re how the Atlantic can help us when we have a crap Pacific )

It raining here so thinking about the future. Great Update from @donsutherland1 courtesy 33andrain I really thought the part about the EPS was an eye opener. I am hopeful though that the pv weakens later in Jan and Feb. But, I am still unsure whether we see sustained and significant weakening or whether any weakening is simply based on passing peak strength pv climatology. Here it is : < Some quick thoughts on the long-range pattern evolution... 1. The GEFS remains stuck with essentially the western trough-eastern ridge pattern. 2. The EPS appears to have accelerated the onset of a colder pattern. Both ideas are actually problematic. First, the base case from historical data is that the MJO will likely progress into Phases 7 and 8 in the extended range. The GEFS idea seems not to reflect that development. The shift in the MJO, even with lags, should start manifesting itself in some hemispheric changes. Second, in past cases where strong AO+/PNA- regimes rapidly collapsed, the period of troughing in the East was often short-lived (late January 2000 followed by February 2000 provide an illustration). Also worrisome is that strong polar vortex that is shown on the extended range of the EPS. There would be a risk that its persistence would lead to a scenario where above normal 500 mb heights are elongated and eventually stretch across the CONUS with the coldest air being bottled up mainly in Canada (with only some transient shots). Overall, I still think a slower pattern evolution still makes more sense, especially if the MJO progresses as typically is the case following very high amplitude passage through Phase 4 during the January 5-20 period. Colder shots would be transient until perhaps the closing week of January and then more sustained cold could develop. Interestingly enough, some of the recent CFSv2 weekly forecasts show such a situation. >

Judah is silly........... One minute winter is coming .... then it is over .... no its back.............I have heard this before from .............hmmmm.......... DT ........LOL he cancelled and then un-cancelled and then cancelled the un-cancelled....... Sorry got distracted back to topic . Webb thinks otherwise. Here you go -

Of note, of course the implications are uncertain, but some changes are most likely going to happen., maybe a reshuffle up top and a weakening to a degree. Hugo suggesting the GFS versus the GEFS is more believable. We know that the GEFS does have a bias, so maybe this time the GFS has a clue. Look at the date on the image below , Jan 23 rd, and then check out the post form HM further down......, funny things seem to happen near the 20th

EPS not budging. If anything, it appears to achieve a more favorable outcome quicker. Buy your tickets now, EPS versus the GEFS .