The 2012-2013 Winter Outlook Thread

[tarheelwx]

When did JB move back to Accuweather?

TW

[WilkesboroDude]

I would love for that to verify. It does seem mid-atlantic and ne biased though. Do they give any reasoning behind the map that you can share?

The AccuWeather Full-Length Winter Forecast will be released in October.

Right now, all I can see is that their forecast is based entirely on an El Nino pattern. Below is the publicly released map.

Below is the link.

http://www.accuweather.com/en/weather-news/snow-for-i-95-corridor-northeast-winter/69820

[griteater]

For comparison, the SST Anomalies in the NINO 3.4 region have averaged +0.6 over the last 4 weeks (avg is also the same over the last 8 weeks...+0.6)

[mackerel_sky]

Just read some posts on weatheradvance.com.It's a very interesting read,with a lot of info and reasoning on Oct.,and rest of the winter.Actually mentions that Northern Mississippi,thru Carolinas have the best chance of very cold,and very snowy conditions any where in the US! Not savvy enough to post a link!

[Met1985]

Just read some posts on weatheradvance.com.It's a very interesting read,with a lot of info and reasoning on Oct.,and rest of the winter.Actually mentions that Northern Mississippi,thru Carolinas have the best chance of very cold,and very snowy conditions any where in the US! Not savvy enough to post a link!

Ya I have read some stuff on there. There is one kid who seems to like cold and snow a little to much but there is another guy who seems to no what he is talking about. I like this pattern heading into October though. Could be a sign of things to come if all fall into place.

[WilkesboroDude]

[mackerel_sky]

That map looks funny because it has "icy" over the spine of the Ap. mtns,which usually get very little due to elevation.

[valkhorn]

I don't think so Tim. The high country west of the apps isn't going to be rainy if the east coast is snowy. CAD migh happen in the Carolina's but not all the way up the eastern seaboard. Plus, if there is a lot of air moving over the lakes you'll get NW flow events all the way into the mountains. That's why the high elevations always get lots of snow in cold winters unless the lakes freeze.

Also icy weather is confined to small areas like valleys in mountainous terrain.

[WilkesboroDude]

I'm just googling random things.

Lots of interesting things out there...but also lots of trash to dig through unfortunately.

[jburns]

I'm just googling random things.

Lots of interesting things out there...but also lots of trash to dig through unfortunately.

Here's mine. I will go far beyond what you mere mortals forecast.

My 30 year forecast for the entire continental United States.

Both temperatures and precipitation will average out exactly normal based on National Climate Center data.

I can also do century forecasts but that will cost you.

[HWY316wx]

Kirk Melish, one of the better METS in the media down here in ATL has released his early winter thoughts:

Numerical Weather Prediction teleconnection index forecasts and deterministic model guidance are forecasting a turn to below-normal temperatures into the Southeast US before mid October with at least a chance of early frost if not freeze for parts of Georgia and adjacent states outside of central Florida between the 9th and 18th give or take a few days. The NAEFS shows a 60-70% chance of below-normal temperatures and that probability has been trending up. It's possible freeze or frost will come a month or so early and for the northern Plains and upper Midwest there can be some snow with a weather pattern more akin to Thanksgiving week for a good chunk of the country. So it now looks like October and November may average a degree or so cooler than normal for Georgia with rainfall near-normal to above-normal averaged over the two-month period. If the precipitation outlook verifies that would be good news since the drought continues unabated to date.

A +PNA west coast ridge (REX block type with upper low underneath) and a Midwest to east coast jet stream trough is forecast to bring a sharp chill especially to areas West and North of Georgia but we will get our share of that air mass too.

Computer projections continue to show a weak Modoki type El Nino (central Pacific) condition fading late winter to next summer. The name " El Niño Modoki " was first coined by Prof. Yamagata. Researchers of the Climate Variations Research Program of Frontier Research Center for Global Change (FRCGC) lead by Prof. Yamagata documented this phenomenon. Current Pacific Ocean surface temperatures are more neutral but below the surface water is warmer. This is a trend away from the previous state of a double La Nina.

The Atlantic Ocean remains in a warm biased tripole configuration. Meanwhile solar output remains muted despite being near the sunspot cycle max. This will be the second El Nino since the PDO went negative. The Pacific-Atlantic patterns are similar to the 1950s.

Looking ahead to winter I expect a split-jet stream pattern with solid input from a southern stream making for a more active weather pattern for precipitation and big swings in temperature. ENSO should stay neutral to weakly positive. The PDO should be predominantly negative and the AMO positive for the winter months. I expect the EPO to be somewhat negative on average. I expect the PNA to average positive with the QBO in a west mode for the most part by late winter. It is currently in an easterly phase. The AO/NAO, perhaps the most important predictand for the winter forecast is the most difficult to predict far in advance. Last year's warm winter was in large measure a result of the lack of blocking of the northern jet stream as indicated by a positive to neutral NAO. The Atlantic Ocean temperature pattern and expectations for the QBO favor a more negative AO/NAO this winter which should close the door to another warm winter like the last one. So a repeat is not expected for the winter of 2012-2013. That having been said, we have to be careful not to expect some sort of horrific winter at this point, as the cold PDO can mean a SE ridge can flex its muscle for mild and dry and the warm pool Northwest of Hawaii is not a cold signal for the SE either.

The analog set will come from trying to match the above factors to past years that were similar to make a winter forecast. As always similar does not mean the same, but it at least gives us something to hang our hat on as the saying goes. The QBO and NAO/AO are critical and if they end up being different than my expectations when I make the final winter outlook, then the outlook would likely fail even if the other expectations are largely on the mark. This happened last winter when the ENSO La Nina etc. were as forecast, but the NAO/AO ended up opposite and that was the whole ball game. This is the curse of weather forecasting you can get a lot right about patterns but still be wrong about sensible weather which is all we care about.

[griteater]

Surprised at the number of outlooks showing an active southern stream for this winter given the weak ENSO signal of a low end weak El Nino or positive neutral on the heels of a double Nina.

[tazaroo]

Sounds ok and much better than last year but anything is LOL.

Kirk Melish, one of the better METS in the media down here in ATL has released his early winter thoughts:

[Isopycnic]

lol. What 5yo weenie created that?

Bad Mountain Snow's must suck.

No snow for western NY?

[GaWx]

Folks,

It will be interesting to see if KATL can attain a record low during this month. 23 Oct.'s had at least one record low. Fwiw, which isn't too much lol, the 6Z GFS per Meteostar has a low of 36 on 10/13, which would be a record low. The subsequent winters' temperatures after Oct.'s with record lows have averaged below normal and have included eight all-star cold winters: 1917-8 (also had major IP and ZR), 1935-6 (also had TWO major ZR's and a major S), 1939-40 (also had major S and ZR), 1962-3, 1976-7, 1978-9 (also had major IP and ZR), 1981-2 (also had snowjam!), and 1987-8 (major IP). Included in here are the 1st, 4th, 5th, and 7th coldest winters in recorded ATL history! Considering that only ~1/6 of all recorded winters have a record low in Oct., having 4 of the 7 coldest winters following the Oct. record low(s) is pretty impressive.

In addition to these eight all-stars, there were seven good (not great since no major S/IP) winters following Oct.'s with record lows: 1913-4 (4.4" S/IP), 1948-9 (warm but had a major ZR), 1957-8 (cold and 2.7" S/IP), 1965-6 (cold), 1968-9 (cold and 2.2" S/IP), 1979-80 (4.4" S/IP), and 2000-1 (3.1" S/IP). So, there were only eight duds of the 23 winters being analyzed. Dud = near or above normal temp.'s with below avg. S/IP and no major ZR: 1895-6, 1906-7, 1924-5, 1937-8, 1952-3, 1974-5, 1985-6, and 1989-90. So duds = 35% of the 23. Longterm dud rate: 43% (57 of 133 winters). So, lower than avg. dud rate.

Of the 23 analyzed winters (DJF), ten were cold, eight were near normal, and only five were warm.

Conclusion: A record low in Oct., based on history, would tilt things somewhat in the good direction for DJF at KATL based on climo. So, root for a record low at KATL if you want to have a better than average chance for an interesting winter at KATL (which implies the same for much of the SE US).

**Edit mainly for Tony: three of the biggest KATL IP storms in history, including the three biggest since 1900, were preceded by an Oct. with at least one record low temp: 1917 had three record Oct. lows (none on adjacent days), 1978 had two (not on adjacent days), and 1987 had one!

Edit #2: the 12Z GFS and Euro runs have nothing near a record Oct. daily low at KATL fwiw.

[dsaur]

Folks,

It will be interesting to see if KATL can attain a record low during this month. 23 Oct.'s had at least one record low. Fwiw, which isn't too much lol, the 6Z GFS per Meteostar has a low of 36 on 10/13, which would be a record low. The subsequent winters' temperatures after Oct.'s with record lows have averaged below normal and have included eight all-star cold winters: 1917-8 (also had major IP and ZR), 1935-6 (also had TWO major ZR's and a major S), 1939-40 (also had major S and ZR), 1962-3, 1976-7, 1978-9 (also had major IP and ZR), 1981-2 (also had snowjam!), and 1987-8 (major IP). Included in here are the 1st, 4th, 5th, and 7th coldest winters in recorded ATL history! Considering that only ~1/6 of all recorded winters have a record low in Oct., having 4 of the 7 coldest winters following the Oct. record low(s) is pretty impressive.

In addition to these eight all-stars, there were seven good (not great since no major S/IP) winters following Oct.'s with record lows: 1913-4 (4.4" S/IP), 1948-9 (warm but had a major ZR), 1957-8 (cold and 2.7" S/IP), 1965-6 (cold), 1968-9 (cold and 2.2" S/IP), 1979-80 (4.4" S/IP), and 2000-1 (3.1" S/IP). So, there were only eight duds of the 23 winters being analyzed. Dud = near or above normal temp.'s with below avg. S/IP and no major ZR: 1895-6, 1906-7, 1924-5, 1937-8, 1952-3, 1974-5, 1985-6, and 1989-90. So duds = 35% of the 23. Longterm dud rate: 43% (57 of 133 winters). So, lower than avg. dud rate.

Of the 23 analyzed winters (DJF), ten were cold, eight were near normal, and only five were warm.

Conclusion: A record low in Oct., based on history, would tilt things somewhat in the good direction for DJF at KATL based on climo. So, root for a record low at KATL if you want to have a better than average chance for an interesting winter at KATL (which implies the same for much of the SE US).

**Edit mainly for Tony: three of the biggest KATL IP storms in history, including the three biggest since 1900, were preceded by an Oct. with at least one record low temp: 1917 had three record Oct. lows (none on adjacent days), 1978 had two (not on adjacent days), and 1987 had one!

Edit #2: the 12Z GFS and Euro runs have nothing near a record Oct. daily low at KATL fwiw.

Larry, I'm somewhat surprised that a record low in Oct. could be a predictor of cold, and sleety weather later. Mostly because I'm surprised we don't get more record cold air in Oct. I would have thought the 60's would have been rife with records!

Thanks for your always outstanding climo stats!! Now, I've got one for you. What happens after Tony gets over 6 inches of rain from one slow low at the beginning of Oct. Granted I unleashed the Moles with a pop test, but even with mole mojo, 6 + during a big time drought is beyond ridiculous, and has got to be a precursor of the ip storm to end ip storms, lol. I mean, with a split flow, and storms like this, during an historic minimum, we could get covered up And I'm ready, but skittish. It has been a very long time since I've seen rain like this. Up until today, I though the 5 in 3 days in early July was magic. Larry, the moles are scaring me, lol. What if I pull out the moles in Jan. and get 5 inches into 31.1 at the surface, but 33 up over the trees? Power like this is scary stuff I may need help in knowing when to call it up, or better, when to leave it lie!! T

[GaWx]

Larry, I'm somewhat surprised that a record low in Oct. could be a predictor of cold, and sleety weather later. Mostly because I'm surprised we don't get more record cold air in Oct. I would have thought the 60's would have been rife with records!

Thanks for your always outstanding climo stats!! Now, I've got one for you. What happens after Tony gets over 6 inches of rain from one slow low at the beginning of Oct. Granted I unleashed the Moles with a pop test, but even with mole mojo, 6 + during a big time drought is beyond ridiculous, and has got to be a precursor of the ip storm to end ip storms, lol. I mean, with a split flow, and storms like this, during an historic minimum, we could get covered up And I'm ready, but skittish. It has been a very long time since I've seen rain like this. Up until today, I though the 5 in 3 days in early July was magic. Larry, the moles are scaring me, lol. What if I pull out the moles in Jan. and get 5 inches into 31.1 at the surface, but 33 up over the trees? Power like this is scary stuff I may need help in knowing when to call it up, or better, when to leave it lie!! T

Congrats!!! For a nontropical system in autumn (although a good bit of the high level moisture came from a Pacific TC, Norman), that is incredible! I looked at KATL rainfall events of 2"+ that were within 5 days of 10/1 and weren't directly associated with an Atlantic basin TC. I found seven that were during the following years: 1936, 1938, 1962, 1963, 1985, 1988, 1989. An impressive three of these seven went on to have a record daily low in Oct.: 1962, 1985, and 1989! Two of the subsequent winters were very cold: 1962-3 and 1963-4.

[dsaur]

Congrats!!! For a nontropical system in autumn (although a good bit of the high level moisture came from a Pacific TC, Norman), that is incredible! I looked at KATL rainfall events of 2"+ that were within 5 days of 10/1 and weren't directly associated with an Atlantic basin TC. I found seven that were during the following years: 1936, 1938, 1962, 1963, 1985, 1988, 1989. An impressive three of these seven went on to have a record daily low in Oct.: 1962, 1985, and 1989! Two of the subsequent winters were very cold: 1962-3 and 1963-4.

Ok, Doc. L, I've got the rains down, so next up is several record lows. Goofy seems to want to drop some highs down, so we should have chances! I'm optimistic. I'm working real hard this year for a major sleeting But to get one we are always dancing around the z monster, so if I mess up, look out, lol.

Will you be wintering in Atl., or Sav? If we get a low parade you might be ok in either place, but I believe you are better focused on winter, when away from the beach Ice cream by the sea just makes you too danged content, which is unseemly in winter, lol. T

[GaWx]

Ok, Doc. L, I've got the rains down, so next up is several record lows. Goofy seems to want to drop some highs down, so we should have chances! I'm optimistic. I'm working real hard this year for a major sleeting But to get one we are always dancing around the z monster, so if I mess up, look out, lol.

Will you be wintering in Atl., or Sav? If we get a low parade you might be ok in either place, but I believe you are better focused on winter, when away from the beach Ice cream by the sea just makes you too danged content, which is unseemly in winter, lol. T

Tony,

I'll be in both although I'll be in Atl more than I was last winter, which was almost none of it. By the way, regarding ice cream by the sea, they may use sea salt to make it. If so, I'd think that that would be the magic ingredient.

Tony/all,

I have found two more 2"+ nontropical rain events that occurred in late Sep.: 1979 and 1980. 1979 went on to have a daily record low in Oct. So, four of the nine (44%) 2"+ late Sep./early Oct. nontropical rainfall event years had a record low in the respective Oct. That's impressive when considering that only ~1/6 of all years had a record low in Oct.

[WilkesboroDude]

Henry Margusity Fan Club

Reminder...The AccuWeather.com Winter Forecast will be released Wed AM. Get ready for a wild Winter Coming...

Like · · Share · 47132 · 50 minutes ago via HootSuite ·

[dsaur]

Tony,

I'll be in both although I'll be in Atl more than I was last winter, which was almost none of it. By the way, regarding ice cream by the sea, they may use sea salt to make it. If so, I'd think that that would be the magic ingredient.

Tony/all,

I have found two more 2"+ nontropical rain events that occurred in late Sep.: 1979 and 1980. 1979 went on to have a daily record low in Oct. So, four of the nine (44%) 2"+ late Sep./early Oct. nontropical rainfall event years had a record low in the respective Oct. That's impressive when considering that only ~1/6 of all years had a record low in Oct.

I love how unusual weather events cluster, and the clusters point to later clusters. I was sure the cloudy, 70 degree day a year ago July, was a sure fire special event, but it led to cluster mate of record 90+ days, and that foretold the hottest winter I can remember.

I like your current event cluster predictors better, lol. Let's hope for some freezing in early Oct. The first cold nights have often been around the 20th. so freezing before then ought to do it. T

[griteater]

CPC/IRI ENSO Update - http://iri.columbia....nfo/update.html

04 October 2012

During September 2012, the trend towards El Niño slowed in several key oceanic and atmospheric indicators. However, the Pacific basin reflects borderline ENSO-neutral/ weak El Niño conditions. Equatorial sea surface temperatures (SST) remained elevated across the Pacific Ocean (Fig. 1), although anomalies decreased during the month as indicated by weekly index values in the Niño regions (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) anomalies also weakened (Fig. 3), but continued to show large regions of above-average temperatures at depth across the equatorial Pacific (Fig. 4). Interestingly, low-level westerly wind anomalies were evident over the equatorial western Pacific Ocean (Fig. 5), which may portend possible strengthening of the subsurface anomalies in the coming months. Despite these winds, the atmosphere was still largely ENSO-neutral, as reflected by the Southern Oscillation index and near-average upper-level and lower-level winds across much of the Pacific. Tropical convection increased near the Date Line, which is consistent with weak El Niño conditions, but also remained elevated over eastern Indonesia, which is further westward than expected (Fig. 6). Thus, the atmosphere and ocean indicate borderline ENSO-neutral/ weak El Niño conditions.

Compared to the past few months, the chance is reduced for El Niño to develop during Northern Hemisphere fall/winter 2012-13 (see CPC/IRI consensus forecast). Due to the recent slowdown in the development of El Nino, it is not clear whether a fully coupled El Niño will emerge. The majority of models indicate that borderline ENSO-neutral/ weak El Niño conditions will continue, and about half suggest that El Niño could develop, but remain weak (Fig. 7). The official forecast therefore favors the continuation of borderline ENSO-neutral/ weak El Niño conditions into Northern Hemisphere winter 2012-13, with the possibility of strengthening during the next few months.

[nrgjeff]

Weaker Nino forces a look at other parameters. PDO also weakening. So, the conflicting cold/warm signals are fading? Water remains very warm near Japan, but the key PDO warm spot is fading out near the Dateline. The eastern Pac, esp near Calif. is still cool which casts doubt on persistent +PNA (or a cool SE). That cool water could promote the West trough/mild East, but the warmer couplet near the Dateline is missing which reduces the chance of super-mild pineapple express and Southeast ridge. The above is all neutral news by my analysis.

Sunspots are increasing - a mild signal. The cold minimum is over. We are either in a solar minimum or not; and, in-between counts as mild. Kind of like "with us or against us." Sunspots are against snow lovers. While we had a slow U-shaped min like Dalton, sunspots are increasing at a good rate of acceleration now. QBO might favor cold iff it stays where it is; however, it is fluctuating like it seems every other index. I have to bank on a continued/building +AO, after a brief dip, for several weeks to a few months. That +AO trend plus the sunspots favors +NAO at least the first 1/3 to 1/2 of winter, which is mild. Jury out past that.

[griteater]

QBO might favor cold iff it stays where it is; however, it is fluctuating like it seems every other index

QBO is on some strange ride in negative land. At 30 hPa, the negative anomalies in green have flatlined since mid-June. Normally, the westerly winds (yellow / orange) would be descending toward 30 hPa. Looks like a solid bet that we stay with a -QBO through December, likely rising + in early 2013.

[griteater]

Probably not the best place for this, but thought it was most applicable to winter model watching...

Upgrade of Canadian Regional Model (RGEM)…

http://dd.weatheroff..._021644___00044

MAJOR UPGRADE TO THE REGIONAL DETERMINISTIC PREDICTION SYSTEM (RDPS-VERSION 3.0.0) AT THE CANADIAN METEOROLOGICAL CENTRE

ON WEDNESDAY OCTOBER 3 2012, STARTING WITH THE 1200 UTC RUN, THE CANADIAN METEOROLOGICAL CENTRE (CMC) OF THE METEOROLOGICAL SERVICE OF CANADA (MSC) WILL IMPLEMENT VERSION 3 OF ITS REGIONAL DETERMINISTIC PREDICTION SYSTEM (RDPS), HEREAFTER REFERRED TO AS RDPS-300. THIS UPDATED SYSTEM INCLUDES AN INCREASE IN RESOLUTION TO 10 KM FROM THE PREVIOUS 15 KM, A 4D-VAR DATA ASSIMILATION SYSTEM REPLACING THE PREVIOUS 3D-VAR, AS WELL AS IMPORTANT CHANGES IN THE GEM MODEL PHYSICS. THIS RESULTS IN SIGNIFICANT FORECAST IMPROVEMENTS ESPECIALLY FOR THE WINTER SEASON.

THE TEMPORAL OBSERVATION SELECTION IS EXTENDED SO THAT THE 4D-VAR WILL MAKE USE OF MANY MORE OBSERVATIONS THAN THE 3D-VAR, EVEN THOUGH WE ARE NOT ADDING ANY NEW TYPES OF OBSERVATIONS. THE TEMPORAL RESOLUTION, WITHIN THE 6-HOUR ASSIMILATION WINDOW, IS REDUCED TO 15 MINUTES, DIVIDING THE WINDOW INTO 24 BINS. THEREFORE, MUCH MORE OBSERVATIONAL DATA (SATELLITE AND ASYNOPTIC OBSERVATIONS) WILL BE INCLUDED. OVERALL, AT LEAST TWICE TIMES THE OBSERVATIONS ARE ASSIMILATED IN THE NEW SYSTEM. THE LARGEST INCREASE (FOUR TIMES) IS FOR AIRCRAFT AND AMSUA SATELLITE OBSERVATIONS.

THE HORIZONTAL RESOLUTION OF THE REG-LAM MODEL IS INCREASED FROM 15 KM TO 10 KM AND THE TIME STEP IS DECREASED FROM 450 SEC TO 300 SEC. THESE CHANGES ALLOW A MORE REALISTIC SIMULATION OF SMALL SCALE PHENOMENA AS WELL AS TOPOGRAPHICAL EFFECTS SUCH AS VALLEY WINDS AND SEA BREEZES.

A FEW PARAMETERS OF THE PHYSICS SCHEME WERE MODIFIED TO REDUCE THE VAPOUR FLUXES OVER WATER BODIES TO HELP CONTROL THE POSITIVE BIAS OF PRECIPITATION ACCUMULATION. AMONG THESE CHANGES, A MORE REALISTIC FORMULATION OF THE SURFACE ROUGHNESS LENGTH OVER WATER WAS INTRODUCED AND THE PRANDTL NUMBER WAS INCREASED FROM 0.85 TO 1.0 AS IN THE OPERATIONAL GDPS. THESE CHANGES ALSO HELPED TO REDUCE A BIAS OF THE PREVIOUS SYSTEM FOR OVERDEVELOPMENT OF LOW PRESSURE SYSTEMS, ESPECIALLY OVER THE ATLANTIC OCEAN.

ANOTHER ASPECT EXAMINED CAREFULLY WAS THE TRIGGERING OF DEEP CONVECTION, AND A MODIFICATION WAS MADE TO A PARAMETER WHICH CONTROLS IT. THIS SOLUTION ATTEMPTS TO PROVIDE THE BEST COMPROMISE BETWEEN HAVING TOO INTENSE MAXIMA IN THE PRECIPITATION FIELD AND THE OPPOSITE EXTREME OF HAVING A TRACE OF PRECIPITATION WHICH IS TOO WIDESPREAD. OVERALL, PRECIPITATION IS REDUCED IN WINTER AND IT IS INCREASED SLIGHTLY IN SUMMER DURING THE DAY OVER LAND.

ANOTHER MAJOR IMPROVEMENT TO THE PHYSICS SCHEMES IS A MODIFICATION OF THE VERTICAL DIFFUSION SCHEME WHICH ALLOWS A MUCH BETTER SIMULATION OF VERTICAL TEMPERATURE PROFILES IN THE LOWER ATMOSPHERE. THIS MODIFICATION IS REFERRED TO AS THE INTRODUCTION OF A HYSTERESIS EFFECT IN THE TRANSITION FROM A TURBULENT REGIME TO A NON TURBULENT ONE, AND VICE VERSA. THIS WILL IMPROVE THE FORECAST OF PRECIPITATION TYPES IN AREAS OF INTENSE WARM TEMPERATURE ADVECTION WHERE IT IS MOST NEEDED.

THE RDPS-300 WAS TESTED EXTENSIVELY. MANY CYCLES, EACH COVERING AT LEAST TWO SUMMER MONTHS AND TWO WINTER MONTHS WERE PERFORMED AND EVALUATED DURING THE DEVELOPMENT PHASE. FOR THE FINAL TESTS, OBJECTIVE VERIFICATION OF UPPER AIR AND SURFACE FIELDS AGAINST RADIOSONDE DATA SHOWED A VERY SIGNIFICANT IMPROVEMENT AT ALL FORECAST LEAD-TIMES. THIS WAS GENERALLY TRUE FOR ALL SEASONS TESTED AND FOR ALL REGIONS AND VARIABLES. THE ONLY - SLIGHT - DETERIORATION SEEN WAS WITH THE WINTERTIME COLD BIAS NEAR THE SURFACE, WHICH WE WERE NOT ABLE TO ELIMINATE. THIS IS NOT CONSIDERED A MAJOR PROBLEM WHEN COMPARED TO THE IMPROVEMENTS OF THE

RDPS-300.

[GaStorm]

Weaker Nino forces a look at other parameters. PDO also weakening. So, the conflicting cold/warm signals are fading? Water remains very warm near Japan, but the key PDO warm spot is fading out near the Dateline. The eastern Pac, esp near Calif. is still cool which casts doubt on persistent +PNA (or a cool SE). That cool water could promote the West trough/mild East, but the warmer couplet near the Dateline is missing which reduces the chance of super-mild pineapple express and Southeast ridge. The above is all neutral news by my analysis.

Sunspots are increasing - a mild signal. The cold minimum is over. We are either in a solar minimum or not; and, in-between counts as mild. Kind of like "with us or against us." Sunspots are against snow lovers. While we had a slow U-shaped min like Dalton, sunspots are increasing at a good rate of acceleration now. QBO might favor cold iff it stays where it is; however, it is fluctuating like it seems every other index. I have to bank on a continued/building +AO, after a brief dip, for several weeks to a few months. That +AO trend plus the sunspots favors +NAO at least the first 1/3 to 1/2 of winter, which is mild. Jury out past that.

How often does the PDO get updated? Last time I heard anything it was trending towards weak negative/neutral.

[blizzardof96]

I just released my official winter 2012-13 outlook on my blog here: http://torontowxcenter.blogspot.ca/?m=0

Here are some of my main points but my month to month breakdown and DJF forecast is posted in my full outlook along with much more analysis.

Key points:

1.A split jet stream pattern will occur with the northern branch extending over a ridge stationed along the west coast (positive PNA signal). The southern branch will track through southern california, arizona,texas and east towards alabama, and georgia.

2.Larger snowstorms will track along the east coast this year with a more active southern jet and the northern branch supplying colder air into the pattern.

3.I expect phasing of the branches to occur especially in mid to late december and most of February with storms tracking further north along the east coast. Major strengthening of low pressure systems can occur with very warm water off the east coast.

4.With the jet stream branches well to the north and south of the area the pacific northwest will remain dry and average warmer then normal this winter.

5.The gulf coast and southeastern states will be wetter then normal with a strong

southern jet providing precipitation.

6.The southwestern u.s will stay wetter then normal with higher elevation snows above normal.

7.The midwest and northern plains can be drier then normal with large temperature swings especially in western parts of the midwest.

[dsaur]

Well, Larry, freezing is showing up on the 20th, which I'm inclined to believe could well verify, as that is a favored time for the first good cold weather in this part of Ga. But, I'm doubting it would be cold enough for a record. I expect it would need to be colder, or come sooner, to get us the records we want. If it is still there in a week, it could get interesting At least we are starting to see cold pushes around the favored time, la la outlandish as it may seem that far out. T

[valkhorn]

Well, Larry, freezing is showing up on the 20th, which I'm inclined to believe could well verify, as that is a favored time for the first good cold weather in this part of Ga. But, I'm doubting it would be cold enough for a record. I expect it would need to be colder, or come sooner, to get us the records we want. If it is still there in a week, it could get interesting At least we are starting to see cold pushes around the favored time, la la outlandish as it may seem that far out. T

The fantasy range of the GFS was putting NW flow snow showers into the Appalachians on 10/20.

Typically the first snows up there are in late October to early November.

[Met1985]

The fantasy range of the GFS was putting NW flow snow showers into the Appalachians on 10/20.

Typically the first snows up there are in late October to early November.

Yep that would be nice if that were to verify. The NAO does not seem to stay positive once in positive territory. We will see. Some cold signals out there but when dealing with weeks out it is any body's guess.