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CFS Brings In The Cold Late In January


bluewave

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The interesting thing about the CFS is how good its monthly forecasts have been from later in the previous
month. You can see how well the model did with the forecasts for November and December.






Many posters have been commenting on the cold look the CFS has been showing for January.




The model did a great job getting the warmth correct for last January.




The models have been backing off the amount of cold that they were showing for the first
week of January. They are also showing milder temperatures building over the Upper
Midwest, Upper Plains, and Southern Canada. This warmth would shift into the East
next week.

So the big question is the CFS actually seeing something for the second half of the
month, or is it headed for a big miss this January?


Many posters at this point are probably saying that they will believe 
it when they see it due to the warmer pattern this first week
than originally expected. But so far the CFS is not backing down.

 

 

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Normally I don't pay too much attention to the CFS, although it's definitely interesting to see how well it does considering it has done well for November and December, and still insists on a colder than average January while the model guidance backed away from the intensity of the cold this week followed by an apparent January thaw for the 2nd and 3rd weeks of the month.

 

Taking the Central Park observed temps today and the NWS forecast for the next 6 days into consideration, keeping in mind the NWS forecast could be incorrect especially towards its longer range, the first 7 days of January would be at least 1 degree colder than average - this takes into consideration the colder first 5 days of the month and the warming trend starting on the 6th. The CFS outlook from 12/25 for the first 5 days of January has -6 K (about -11 F) anomalies not far to the north of NYC, and the 12/23 outlook for the first 7 days had similar anomalies as well. As recently as 12/29, it even had similar anomalies for the majority of the region for the Jan 5-9 time period, which given the recent model guidance looks to bust way too cold, before slightly backing down with the 12/30 run.

 

Its week 2 and 3 outlooks have been more variable; although some do show a much colder pattern developing by then, its handing of the first 10 days of January, should the current model guidance verify and the CFS end up too cold, would have an impact on its overall outlook for January. A stronger, sustained cold pattern in the second half of the month and a weaker mid-month mild spell would be required to overcome the mid-month warmer period and the slightly cooler than average anomalies of the first week for the month to be solidly colder than average. This is not impossible to achieve and remains a possibility, but the second half of the month would have to make up for the significant cold anomalies that the first 10 days will fail to produce, especially if temperatures in the middle of the month are above-well above average, which by itself is not a guarantee either.

 

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The Jan 1 CFS still develops an extremley west-based -NAO by weeks 3 and 4. But it doesn't bring cold air to East, until towards the end of the Jan. I'm skeptical though on how extremely west-based -NAO becomes, during this time frame. After the current SSW event ends, the GFS and ECMWF have the PV only dropping over Northern Hudson Bay or Central Canada. Which would still keep us on the warm side of gradient on average. We need a huge Lakes/Apps cutter in mid-Jan, to shift the PV or gradient further south and east:

 

drfgox.jpg

 

nvp1z4.jpg

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The main difference goin forward between the CFS and the Euro weeklies  is the US generated models paint the trough east of Hawaii ( NEG EPO ) and the Euro weeklies bring the trof into cali ridge east of Hawaii and trof west of Hawaii ( POS EPO ) . The winner of that battle , wins the Jan forecast .

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Despite the warmth here this December, parts of Western and Central Canada were

able to build cold. This was a much different from December 2011. So the idea that

Canada begins to cool down after the coming warm up has merit. The big question

for the second half of the month is whether the teleconnections will align to get

it colder here in the Northeast?

 

December 2011

 

 

 

December 2012

 

 

 

Colder Forecast for Canada after early January thaw

 

 

 

 

 

 

 

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Agree Chris. Plenty of cold air is and will continue to be on our side of the globe, which is a major step in the right direction from last winter. The stats for -AO/NAO winters overall are fairly strong in years with blocking during the November-December time frame, and that points to another, renewed 30-40 day episode of -AO blocking. The question is when will that occur. Stratospheric warming events are very difficult to forecast in terms of their tropospheric effects, so I'm not willing to utilize it as a prognosticating tool just yet. Tropical forcing will generally be unfavorable over the next week to 10 days, but the MJO has been very weak this season so far (not much help forecasting wise).

 

 

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The Jan 1 CFS still develops an extremley west-based -NAO by weeks 3 and 4. But it doesn't bring cold air to East, until towards the end of the Jan. I'm skeptical though on how extremely west-based -NAO becomes, during this time frame. After the current SSW event ends, the GFS and ECMWF have the PV only dropping over Northern Hudson Bay or Central Canada. Which would still keep us on the warm side of gradient on average. We need a huge Lakes/Apps cutter in mid-Jan, to shift the PV or gradient further south and east:

 

 

The big lakes cutter on 12-13th, might be enough to keep the gradient further south. We will be mild before it though:

 

 

2vt4lzk.jpg

34dr8eq.jpg

2livbll.jpg

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Take it with a grain of salt this far out. But the CFS shows a possible Nor'easter Jan 24-25th.

 

fwhw08.jpg

 

6joqqo.jpg

 

It does still have a west-based -NAO for this period. Also the MJO possibly in phase 7, at this point..

 

2yubuhe.jpg

 

Now the CFS and ECMWF OP are in agreement for a Nor'easter Conducive Pattern between January 20th-25th. 

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