December Forecast Discussion

[Doorman]

Also the Euro bias MJO agrees with the UKMET and NCEP MJO showing more amplitude through 7 8 1  .

The trough should find its way east by then .

PB 

So we extrap that image out..... ten days???

 

DEC 5th time stamp on that image

 

thanks dm

[PB GFI]

PB 

So we extrap that image out..... ten days???

 

DEC 5th time stamp on that

 

thanks dm

I always thought there was a lag for the response downstream . How many days I am not sure .

[Weathergun]

Also the Euro bias MJO agrees with the UKMET and NCEP MJO showing more amplitude through 7 8  .

The trough should find its way east by then .

 

The UKMET is often good indicator, which MJO forecast is between NCEP and ECMWF is more likely to closer to be correct. The NCEP has big bias amplified bias in phases 7/8/1. But I've seen the ECMWF often try to weaken the MJO too much, towards the end of it's forecasts, as well.

[PB GFI]

I mean we'll almost definitely have some sort of +PNA in the 2nd week of December, but the airmass as of now looks pretty stale and the Atlantic pattern is pretty bad. 

 

Fair, but it just has to be "cold enough " . When devoid of  blocking I kick the big storm idea out the door . But  a shortening of the wave lengths COULD  do the trick  just away from the coast .

[KEITH L.I]

12z GFS OP pretty cold in the long range..big PNA

[Weathergun]

I mean we'll almost definitely have some sort of +PNA in the 2nd week of December, but the airmass as of now looks pretty stale and the Atlantic pattern is pretty bad. 

 

The +PNA comes with an active STJ and no sustained -NAO or vortex over SE Canada. We can easily see bigger SE ridge, ahead of energy ejecting out the SW. Then cold shots behind the storm.

[MJO812]

 GFS shows  colder and stormier weather by mid December with a deep trough in the east.

[Dsnowx53]

The +PNA comes with an active STJ and no sustained -NAO or vortex over SE Canada. We can easily see bigger SE ridge, ahead of energy ejecting out the SW. Then cold shots behind the storm.

 

 

Yeah that's kinda how I feel right now. Though if the flow is fast enough, any shortwave could hopefully stay weak and we can pull off some light overrunning events...at least the +PNA and STJ give a shot of that.

 

This is not the pattern we want for a big storm. Any strong storm would amplify and go too far north. 

[Doorman]

 a small refresher

 

https://www.youtube.com/watch?v=f5lvCSk2slI#t=30

 

We climate smart....... BABY!!!!!!   

 

[ag3]

Something to watch for the middle of next week. Nice Cold air damming signature. Inland areas look to do well with this. Too warm for the coast as of now.

http://mag.ncep.noaa.gov/Image.php?fhr=096ℑ=data%2Fgfs%2F06%2Fgfs_namer_096_10m_wnd_precip.gif&model=gfs&area=namer&param=10m_wnd_precip&group=Model+Guidance&preselected_formatted_cycle_date=20141129+06+UTC&imageSize=M&ps=area

You aren't getting CAD on the coast with a high east of Maine.

That's a terrible setup for this area. Good for far interior sections with elevation.

[Juliancolton]

Incidentally, the 12z Euro is a bit interesting for next weekend. An upper low closes off to our west and south and hangs around for a bit, as depicted. It isn't beautiful by any means, but it would keep us preoccupied for several days.

[SnoSki14]

The +PNA comes with an active STJ and no sustained -NAO or vortex over SE Canada. We can easily see bigger SE ridge, ahead of energy ejecting out the SW. Then cold shots behind the storm.

You can get well timed storms in a good +PNA setup but it's not too common without Atlantic help at least not until deeper into winter. Even if the NAO never cooperates the Pacific still looks to be on our side and there will always be hope if that's the case.

Things don't look as good as they did a couple weeks ago though so it's ok to worry. Even folks in the New England are far more skeptical than I've seen them be. The pattern may not be bad for them but here itll obviously be worse and milder.

Things could change in a hurry though so we will see and a recurving typhoon could throw another curve ball into the mix. I wonder if the pattern for this month will repeat itself for December where the first half is a bit above normal and the second half is much colder. Perhaps our winter pattern has already been set if that's the case.

[uncle W]

there are not many Decembers that started out cold and snowy from the beginning to end of the month...1989 was cold but not snowy and had a warm ending...usually the great winters like 1947-48 and 1995-96 had snow and cold from the 10th on...Cold snowy periods in December were none existent in the 1970's...

the below table has at least 10" of snowfall and an average temperature of 32.0 or lower for 15 days...

15 day period.............AT..max/min...Precip"..Snow"BS"....SC"

Dec. 10-24.........1945..23.7..45..10..1.27"..12.2"....8.3".....9"
Dec23-Jan.6.1947-48..29.7..37..18..4.55"..32.1"..26.4"...26"
Dec 14-28..........1948..30.8..51..10..2.70"..21.3"..16.0"...16"
Dec 11-25..........1960..25.8..49....8..2.50"..16.6"..15.2"...15"
Dec 11-25..........1963..27.0..39..11..1.19"..10.3"....6.6".....7"
Dec29-Jan12....87-88..24.7..45....8..1.63"..13.8"....5.8".....9"
Dec 9-23............1995..28.9..44..15..1.77"..11.5"....7.7".....7"
Dec22-Jan5......00-01..25.2..34..14..1.12"..14.6"..12.0"...12"
Dec19-Jan2......09-10..31.9..55..16..3.07"..12.6"..10.9"...11"
Dec 14-28..........2010..29.3..40..19..1.62"..20.1"..20.0"...20"

[doncat]

there are not many Decembers that started out cold and snowy from the beginning to end of the month...1989 was cold but not snowy and had a warm ending...usually the great winters like 1947-48 and 1995-96 had snow and cold from the 10th on...Cold snowy periods in December were none existent in the 1970's...

the below table has at least 10" of snowfall and an average temperature of 32.0 or lower for 15 days...

15 day period.............AT..max/min...Precip"..Snow"BS"....SC"

Dec. 10-24.........1945..23.7..45..10..1.27"..12.2"....8.3".....9"

Dec23-Jan.6.1947-48..29.7..37..18..4.55"..32.1"..26.4"...26"

Dec 14-28..........1948..30.8..51..10..2.70"..21.3"..16.0"...16"

Dec 11-25..........1960..25.8..49....8..2.50"..16.6"..15.2"...15"

Dec 11-25..........1963..27.0..39..11..1.19"..10.3"....6.6".....7"

Dec29-Jan12....87-88..24.7..45....8..1.63"..13.8"....5.8".....9"

Dec 9-23............1995..28.9..44..15..1.77"..11.5"....7.7".....7"

Dec22-Jan5......00-01..25.2..34..14..1.12"..14.6"..12.0"...12"

Dec19-Jan2......09-10..31.9..55..16..3.07"..12.6"..10.9"...11"

Dec 14-28..........2010..29.3..40..19..1.62"..20.1"..20.0"...20"

Yeah Dec 1989 was super cold averaging 24.6 degrees here but only had 1.4" of snow.

[WeatherFox]

Also tues night into wednesday morning has to be monitored closely as a big strong high is located to the north of us and with proper timing of  overrunning snow in the metro is possible. Just something to watch for now.....this so called "warm up" might be more like getting back to normal temps before the pattern change to colder and stormier mid month........

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014112918/gfs_mslp_pcpn_frzn_us_13.png

IMO & off the cuff I would have very low confidence for overrunning snow in the metro area early in Dec.  Rain yes, snow no.  Especially no accumulating snow for NYC.

[TwcMan]

Joe cioffi hinted at overrunning snow for Tuesday night on his Facebook page..

[Doorman]

Joe cioffi hinted at overrunning snow for Tuesday night on his Facebook page..

 

 

http://www.wpc.ncep.noaa.gov/pwpf/wwd_accum_probs.php?ftype=probabilities&fpd=72&ptype=snow

[IsentropicLift]

Somewhat of a freezing rain/drizzle signature for Tuesday, especially in the favored inland areas. The high to the northeast isn't in a great position but the WAA is relatively weak. Lighter freezing rain tends to accumulate better.  

[SnowGoose69]

The Tuesday event is not much, I'd be more inclined to watch the one a couple of days later.

[SnoSki14]

What a torch the first half is expected to be. Very ugly pattern with highs mainly 50s. Recent runs are weakening the brief cool shots and warming things up in the LR.

[atownwxwatcher]

  http://www.aer.com/science-research/climate-weather/arctic-oscillation   Very good read on where things are now and what to expect..

[CIK62]

Heavy reading in that Cohen article.   Well at least the JMS is still cold for us.

 

http://www.jamstec.go.jp/frcgc/research/d1/iod/sintex_f1_forecast.html.en

Choose surface temps.

 

This apparently gets updated tomorrow because this is as of Nov. 01.

By the way while taking all this tech talk in,  I have been flipping coins, dealing out Bridge hands and using the NYS Lottery Android random number generator on the side, and I am now ready to make my winter forecast.............................................................LOL.

[NEXtreme]

What a torch the first half is expected to be. Very ugly pattern with highs mainly 50s. Recent runs are weakening the brief cool shots and warming things up in the LR.

Torch??? It's not going to be in the 50's everyday. A few days in between cool downs or quick cold shots. Average highs drop into the upper 40's during the 1st week of December. If there is going to be some relaxation of the pattern then let it be now.

[PB GFI]

Days 5- 15 are above . But that was expected and has been opined to death . 

 

Once into week 3 the pattern should reload .  No one likes giving up 15 plus days in any winter but when the splits are 48- 38 at the park if I have to give up a sliver of winter  I am just glad its not mid Jan .

[SnoSki14]

At least the it's only November excuse can't be used anymore. We have about a 2 month window to get something going every winter and wasting even a week or two is costly.

The best period is Dec 15-Feb 15 give or take a few days especially in Feb for snow chances so there's still time.

[Doorman]

DEC 15th

NCEP anomaly  guidance 

GEFS 200mb spag 

 

How long will it take, for the retooling ?

 

 

http://mag.ncep.noaa.gov/Image.php?fhr=384ℑ=data%2Fgefs-spag%2F06%2Fgefs-spag_npac_384_200_1176_ht.gif&model=gefs-spag&area=npac&param=200_1176_ht&group=Model+Guidance&preselected_formatted_cycle_date=20141130+06+UTC&imageSize=&ps=area

 

http://www.esrl.noaa.gov/psd/map/images/ens/t850std_f360_nh.html

 

loop

http://www.esrl.noaa.gov/psd/map/images/ens/t850std1_nhsm_animation.html

 

 

Did someone say punt????

[Allsnow]

light snow on the euro at 12z for tuesday afternoon….

[MJO812]

light snow on the euro at 12z for tuesday afternoon….

A litte colder and juicer than previous rus

[PB GFI]

Interesting day 10 euro OP trough in the east . That was no where to be found on any of this week's ensembles for that time period.

[Doorman]

 

 

PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK 

NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 

300PM EST SUNDAY NOV 30 2014 

 

30-DAY OUTLOOK DISCUSSION FOR DECEMBER 2014 

 

THE DECEMBER 2014 OUTLOOK REMAINS CHALLENGING, THOUGH FOR SOMEWHAT DIFFERENT 

REASONS THAT THOSE DISCUSSED BELOW FOR THE 0.5 MONTH LEAD OUTLOOK. A DRAMATIC 

PATTERN CHANGE IS ANTICIPATED ACROSS THE NORTH-CENTRAL CONUS, WHERE MUCH 

BELOW-NORMAL TEMPERATURES FOR THE FIRST COUPLE DAYS OF THE MONTH ARE FORECAST 

TO BE REPLACED BY ABOVE-NORMAL TEMPERATURES THROUGH AT LEAST THE SECOND WEEK OF 

THE MONTH. A SIMILAR SITUATION IS FORECAST FOR THE NORTHEAST, WHERE A SERIES OF 

CANADIAN HIGHS ARE FORECAST TO DOMINATE SURFACE CLIMATE EARLY. THE ARCTIC AIR 

IN CANADA EARLY IN THE PERIOD IS THUS EXPECTED TO PROGRESS MORE EAST THAN 

SOUTH, AS A +NAO CIRCULATION IS EXPECTED EARLY IN MONTH. THIS LEAVES AREAS TO 

THE SOUTH MILDER THAN CLIMATOLOGY FOR MOST OF THE FIRST 10 DAYS OF THE MONTH OR 

SO. 

 

IN THE MEDIUM RANGE PERIOD, THE MODELS ARE IN GOOD AGREEMENT THAT AN ANOMALOUS 

TROUGH WILL FORM IN THE NORTH PACIFIC, THOUGH THERE IS SOME DISAGREEMENT AS TO 

ITS LONGITUDINAL CENTER. THE GLOBAL ENSEMBLE MEANS INDICATE A FAIRLY LONG 

WAVELENGTH PATTERN, APPEARING AS A HYBRID OF THE CANONICAL +PNA AND 

LOW-FREQUENCY ENSO FOOTPRINT. THE LATTER REMAINS SUSPECT AS THE EXPECTED 

CONVECTIVE RESPONSE TO EL NINO IN THE CENTRAL PACIFIC REMAINS TENUOUS. 

 

THE MJO HAS REMAINED ACTIVE OVER THE PAST TWO WEEKS, AND IS FORECAST TO 

PROPAGATE INTO THE PACIFIC OVER THE NEXT WEEK TO 10 DAYS. THIS FAVORS A COLDER 

SOLUTION RELATIVE TO NORMAL ACROSS MUCH OF THE CENTRAL AND EASTERN CONUS FOR 

THE LAST 10 TO 15 DAYS OF THE MONTH. 

 

COMBINING THE ABOVE FACTORS WITH UNANIMOUS MODEL AGREEMENT AMONG THE EXTENDED 

RANGE ECMWF, CFS, AND JMA, A WARMER-THAN-NORMAL DECEMBER FOR MUCH OF THE CONUS 

AND ALASKA IS FAVORED. SOME BELOW-NORMAL TEMPERATURES ARE FAVORED ALONG THE 

GULF COAST WHERE A +PNA HAS A STRONG TEMPERATURE FOOTPRINT, AND WHERE ANY 

PATTERN CHANGE LATE IN THE MONTH WOULD CONTRIBUTE TO BELOW-NORMAL TEMPERATURES. 

PROBABILITIES ARE GENERALLY LOW, HOWEVER, REFLECTING THE MIDDLE AND LATE MONTH 

UNCERTAINTY, GIVEN THE MJO SIGNAL FOR A PATTERN CHANGE. 

 

THE PRECIPITATION OUTLOOK IS CHANGED TO REFLECT THE CHANGES IN MODEL GUIDANCE 

FROM THE ECMWF, CFS, AND JMA, AS WELL AS TO HARVEST THE HIGH CONFIDENCE 

SHORT-RANGE FORECASTS FOR THE NEXT SEVERAL DAYS. COMBINING THESE FACTORS WITH 

THE WEEK-2 OUTLOOK INFORMS THE PRECIPITATION OUTLOOK FOR THE MONTH. EQUAL 

CHANCES ARE INDICATED OVER MUCH OF THE EASTERN CONUS, WHERE PRECIPITATION 

SIGNALS ARE WEAK EARLY IN THE MONTH. IN THE SOUTHEAST, THOUGH BELOW-MEDIAN 

PRECIPITATION IS FAVORED FOR THE FIRST 10 DAYS OF THE MONTH, THE MJO AND ANY 

LOW-FREQUENCY ENSO SIGNAL FAVOR NEAR- TO ABOVE-MEDIAN PRECIPITATION LATER IN 

THE MONTH. 

 

http://www.cpc.ncep.noaa.gov/products/predictions/long_range/fxus07.html

 

 

http://www.cpc.ncep.noaa.gov/products/predictions/30day/off15_temp.gif

 

http://www.cpc.ncep.noaa.gov/products/predictions/30day/off15_prcp.gif