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Lets Talk January...Pretty Please?

40/70 Benchmark

By 40/70 Benchmark,
in New England

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Ginx snewx

Ginx snewx

Posted
Posted

well time to run the analogs for the D+8 D+ 11 time frame.The Dec 18 the analog look in Dec worked out very well as this week was highlighted as stormy and colder. Running a composite of all the dates possible on the analogs yields an upcoming Colder than Normal East with a possible Arctic blast. Running days forward yields cold until around the 8th then a thaw for a few days as heights rise mid month. Farther out in time yields a reload but that is really beyond the skill set. So looks like a pretty good 8-11 day period of solid winter then a thaw before reload. At least that is what the analog days say. Analog dates 1964 0102,1952 1222,1986 0102,1975 1218,1999 0112, 1961 0102, 1962 0101, 1986 0108, 1992 0118 , 1956 1231, 1955 0112, 1961 1230

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Isotherm

Isotherm

Posted
Posted

Posted in the main thread. My thoughts for Jan; first half at least is likely to be wintry.

I think an important point to make is that US temperatures so far this winter have been negatively correlated to the AO and NAO, which is contrary to the majority of years, and why December ended up being quite a bit warmer than what most of us expected a month ago. Generally a -AO/NAO couplet produces some sustained cold periods in the CONUS and Eastern US, but that has not transpired through the 20th. The last week of December will average below normal in the East, but won't be enough to erase the strong positive temp departures of Dec 1-20.

The H5 height anomaly orientation we saw for Dec 1-20 that produced the CONUS warmth has already reversed, and going forward is likely to be much different than the regime we saw so far. The positive EPO with low heights in the Western Arctic down through AK and NW Canada was largely responsible for the lack of cold air getting into the lower 48. The strongly negative PNA didn't help matters, as there was no mechanism to transport the polar air in Western Canada southwestward due to the troughiness off the West Coast.

Now, the EPO has neutralized and we're seeing major height rises in the regions we've seen low heights so far this winter. Additionally, the PNA is positive, though that pulse is probable to last only a couple weeks before neutralizing again, due to the -PDO regime. The EPO will be an important forecast tool as we progress through the coming weeks. Concerning the AO, statistics strongly favor a renewed period of blocking after our current/upcoming neutralization period. I don't anticipate the AO to remain very positive for a long duration (or reach strongly positive levels).

Most evidence points to the first half of January being cold to very cold in most of the US given the height anomaly flip noted above. The second half of January will probably feature moderation after the PNA relaxes and the AO is not strongly negative. However, I think the build-up of negative departures that we're likely to see the first 10-15 days of January will be more than enough to ensure a cold finish to the month for the East.

byhbp.jpg

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QVectorman

QVectorman

Posted
Posted

With the MJO going into phase 1 and the 5-7 day lag for MJO induced waves to traverse the eastern US it would set us up for a wave to arrive in the east between Dec. 18-20 which is progged on the 180hr GFS and Euro moving across the upper Midwest or Great Lakes. The same wave also ushers in relatively "colder" air and plays nicely into the idea I spoke of the other day in my post about the pocket of relatively "colder" air arriving during the Dec. 21-23 time frame based off of GWO analogs for the eastern US.Using that same concept for the GWO I expect another batch of colder air Dec. 27-30. And Following the spike in the 10 and 30 mb temps that peaked back on Dec. 6 seems we should see a good shot of colder air Dec 30-Jan 3.

With the newest GWO numbers today the latest analogs indicate a 15-20F warm up in sfc temps Jan 3-Jan 6 compared to prior days highs across Midwest or NE (the Dec. 31-Jan 3 cold episode) and analogs suggest a stair stepped 15-20F temperature fall behind the warm up 1-2 days after that, meaning another spell of colder air Jan 5-8.

I extended my outlook through Jan 8 on Dec. 14. I still feel comfortable with those dates and with the newest GWO analogs and latest 10 and 30 mb temp forecast it appears the time frame between Jan 8-10 will see a warm up over the east with a short wave moving through the east Jan 10-11 with cooler air dropping in behind it for Jan 10-13 across the MW/GLKS and then pockets of cooler air arriving Jan 15-19 time frame for the east followed by a second reinforcement of cooler air Jan 20-24. My GWO analogs only take me out to Jan 9 so there may be another short wave or two to add to the 2 already expected for the Jan 9-24 time frame. I will update as the newest GWO numbers come out over the next week and half.

I was going to wait until we were upon the first wave of cold air in my date windows but things are slow again in here and the models look like there are in pretty good agreement so I think it's safe to post a analysis and extend the forecast.

First Dec. 27-30 window mentioned back on Dec. 13...we have the Euro 39h 850's for Dec. 30 with the cold pool of -10 to -12C air covering most of the MW/NE.

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After a brief stint of southerly flow on the back side of a hp over Florida 850's warm to 0 to -2C over IN, OH and parts of MI for Dec. 31

Second window Dec. 30-Jan 3 mentioned back on Dec 13...signs still pointing to much colder air arriving over the Eastern US...the Euro at 156h 850's for Jan 4 0z---Jan 3 7pm EST with -20 to -22C over WI and N. MI which migrates eastward in the following days.

post-3697-0-37058700-1356745788_thumb.jp

It appears the Jan 20-24 cold shot should be comparable in magnitude of the upcoming Jan 2-3 airmass. Also latest GWO numbers are currently trending towards an agreement of the Jan 20-24 date. I will have concrete confirmation or rejection of that assumption by Tues.

Extending the outlook Jan 24-26 show up as next pocket of cooler air...although I will say signals are mixed on this window date so I'm not too confident on this time frame producing a cooler airmass for the MW/NE.

Although Jan 26-30 looks very impressive and should out do the Jan 2-3 850mb cold air wrt temps. The newest ECMWF strat. temp forecast shows a ~+48C warming at 10mb from Dec. 29 through Jan. 2 and a ~+42C warming from Jan1 to Jan 2. There is also a wind reversal forecasted to take place Jan 2 at 1mb and 10mb at 60N. This should qualify as a MAJOR SSW since only a +25C temp change is required over a week period for a minor SSW and I believe the wind reversal is extensive enough to qualify also. If not it is still a minor SSW. The EP vector is also forecasted poleward at least at 90N which is a good signal that the SSW will in fact allow arctic air to spill southward. This event should produce the Jan 26-30 window cold pocket...Although I don't have much experiencing timing out SSW events so this may not be the exact window, it may have to be adjusted forward or backwards by a few days.

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I will also say that it appears a lot of these dates are back to back and should mention that these forecasted chunks of cooler/colder air are cooler/colder relative to the air in place that they displace. So I don't claim to know the temperature range of the 850mb temps arriving...The concept can only forecast that it will be "colder" than the one that will be in place at the time of it's arrival and are associated with shortwaves so there will be brief time frames of southerly winds ahead of the short waves that will produce WAA ahead of waves and as a result might produce brief minor spikes in 850 temps and sfc temps in transition from time frame to time frame. So for example over a period of days (windows) it could just go from -2C...cool to -5C (window/event 1) then warm to 0C and cool to -4 (window/event 2) where event 2 ends up "cooling" but ends up actually with warmer temps than just a few days prior but cooler compared to just 1 or 2 days prior. This also doesn't elude to AA temps or BA temps just "relative" so even with all the time frames for shortwaves thus...colder airmasses; it doesn't rule out that the resulting cooler temps still produce above average temperatures for daytime highs. When the signals are stronger an estimation of the temp of the air is possible such as the Jan. 2-3 and Jan 20-24 and Jan 26-30 episode. The other time frames are just hiccups in the stat. signal and coincide to minor dips in sfc temperatures relative to previous days' highs but I figure they are worth mentioning.

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HM

HM

Posted
Posted

I don't have time to get into things today but the 1/4-1/9 window still holds promise, despite the increasing "negative" influences from various forces into mid-January. Also, I agree that a polar vortex breakdown is on the way this month and it could save the second half of winter from being a torch.

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QVectorman

QVectorman

Posted
Posted

I don't have time to get into things today but the 1/4-1/9 window still holds promise, despite the increasing "negative" influences from various forces into mid-January. Also, I agree that a polar vortex breakdown is on the way this month and it could save the second half of winter from being a torch.

That compliments my Jan 5-8 cool/cold window that should arrive across the MW after the brief "warm" up I mentioned for Jan 4-6 after the Jan 2-3 cold snap. I had made mention on my FB page back on the 14th that I thought the short wave that would usher in the cooler air for Jan 5-8 time frame would be a decent weather maker since I thought there would be a good amount of baroclinic instability due to a decent temp gradient being produced over the EC after the Jan 4-6 warm up. But now I'm not so optimistic on that call...as you say it still holds promise and I agree, but it's looking like a weak shortwave/disturbance is more likely than a powerhouse storm due to a weaker temp gradient than previously thought being produced over the EC. But as I have said there is still plenty of time for the models to change. There is more than 10 days to the back end of both our windows!

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ORH_wxman

ORH_wxman

Posted
Posted

I don't have time to get into things today but the 1/4-1/9 window still holds promise, despite the increasing "negative" influences from various forces into mid-January. Also, I agree that a polar vortex breakdown is on the way this month and it could save the second half of winter from being a torch.

Please give me some good news on Feb....I'm not liking stuff past mid-Jan right now. But you know better than me beyond that.

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Ottawa Blizzard

Ottawa Blizzard

Posted
Posted

Looks like the cold holds right thru January esp if the CFS is correct. it just has unabated cold and winter. Euro weeklies have that one week where it cools up ..so maybe we get a day or 2 that tickles 40...Other than that with the PV up near Hudson Bay the pattern north of 40 is wintry overall.

It actually doesn't look as good as it did just a couple of days ago. The cold shot this week has been blunted, particularly for western New York and southern Ontario. I honestly can't see what the CFS forecast for January verifying.

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QVectorman

QVectorman

Posted
Posted

HM and co. how long would it take for the major stratospheric warming being progged by the EC to lead to strong arctic blocking?

It takes one to three weeks for it to propagate to the surface and produce colder air depending on what paper you read and obviously one's latitudinal position plays a roll in arrival time. But if you are looking for specifics to blocking I think this is a good place to start....Young-Joon Kim and Maria Flatau Hindcasting the January 2009 Arctic Sudden Stratospheric Warming and Its Influence on the Arctic Oscillation with Unified Parameterization of Orographic Drag in NOGAPS. Part I: Extended-Range Stand-Alone Forecast.

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Ginx snewx

Ginx snewx

Posted
Posted

I apologize in advance that this post isn't very technical, but I just checked accuweather and they show a pretty good torch starting next weekend for CT with the coldest temps being seasonal and quite a few days at 40-45. Do you guys see this pattern eroding away? Thanks.

It is normal and possible thaw but no torch in sight, some excellent signals for the rest of winter showing up. Enjoy the snow it will be here a while.
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NJwinter23

NJwinter23

Posted
Posted

It is normal and possible thaw but no torch in sight, some excellent signals for the rest of winter showing up. Enjoy the snow it will be here a while.

The 11-15 day euro ensembles have temps 6-12 degrees above normal across the entire eastern U.S....save a little more uncertainty in northern New England. Cant ever really count you guys out up there I guess even when temps are above normal,on the mdoels.. and it cant hurt to have the PV in Canada...But its a huge -PNA /+ NAO pattern on the ensembles

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weathafella

weathafella

Posted
Posted

So ponder this. GFS has tempered everything and the next 10 days average around normal with increasing above normals out in time. Today in Boston it was below normal by a few degrees. 12/31 and 1/1 will be AOA normal. 1/2-5 probably AOB normal. Thereafter the tendency is above. Just a few days ago we were looking at bitter temperatures incoming but now the negative anomalies are tempered. We so badly need a decent EPO. That's what delivered 1993-94 and it is required more than the other teleconnectors imo.

Here's tonight's MEX guidance and it is meh worthy...

KBOS GFSX MOS GUIDANCE 12/31/2012 0000 UTC
FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192
MON 31| TUE 01| WED 02| THU 03| FRI 04| SAT 05| SUN 06| MON 07 CLIMO
X/N 38| 29 39| 19 31| 18 32| 22 32| 15 30| 25 40| 28 42 21 37
TMP 35| 31 31| 20 27| 20 29| 23 26| 16 27| 27 35| 31 37
DPT 21| 19 8| 4 6| 6 14| 9 4| 1 12| 16 22| 21 24
CLD PC| PC PC| CL CL| CL PC| PC CL| CL OV| OV OV| OV OV
WND 14| 14 15| 13 16| 11 9| 15 23| 19 10| 12 14| 15 17
P12 1| 8 4| 0 0| 1 13| 16 11| 7 12| 17 23| 12 22 25 26
P24 |	 8|	 0|	 13|	 21|	 12|	 24|	 25 37
Q12 0| 0 0| 0 0| 0 0| 0 0| 0 0| 0 |
Q24 |	 0|	 0|	 0|	 0|	 0|	 |
T12 0| 0 0| 0 0| 0 0| 1 0| 1 0| 0 2| 1 0
T24 | 0 | 0 | 0 | 1 | 2 | 0 | 2
PZP 0| 1 1| 1 1| 2 1| 2 3| 2 4| 3 1| 2 2
PSN 91| 75 87| 87 88| 82 77| 58 63| 66 56| 45 30| 23 28
PRS 4| 6 1| 0 0| 0 1| 7 4| 0 1| 4 13| 9 8
TYP S| S S| S S| S S| S S| S S| S R| R R
SNW |	 0|	 0|	 0|	 0|	 0|	 |

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