Winter Predictions

[Jesse]

Looking at the modeled pattern going forward, my guess would be only parts of MT/ND will end up below normal by end of month. Probably a much smaller area of below normal anomalies across the northern tier than what you see now.

 

That being said, 1996 did have a similar temp pattern across the U.S. to what we're seeing this month. It was high on my original list of analogs and I still think it's solid, though I'd put some other years ahead of it at this

 

1970, 1995, and 2007 were also cooler across the northern tier, with a similar temp profile.

I think you are still playing the torchy November up a bit. Right now the GFS ensembles hint that we could go back to near or below average around the 25th, after 4-5 days of pretty solid torching.

[Front Ranger]

I think you are still playing the torchy November up a bit. Right now the GFS ensembles hint that we could go back to near or below average around the 25th, after 4-5 days of pretty solid torching.

 

I'm just going by the overall guidance for the next 10-15 days. It's been painting a pretty warm picture for the vast majority of the West. PNW coastal regions probably have the best chance of not torching at times over that period, but as of now, it still looks above normal overall.

 

The main thing is that this is big picture stuff...hard to say if PDX or OLM or any other given station will finish the month cool or warm. But the analog-led idea that the majority of the West would turn warm, and the East turn cool, appears to be working out.

[Front Ranger]

Good stuff, thanks! I don't see a way except for maybe far western MT overcoming a -10 to -15 temp anomalies even with the going forecasts though. I would expect the Nov 1996 map will end up pretty darn close to reality come month end this year.

 

Interesting enough, 1970, 1995 and 2007 were all coming off of weak to moderate Niños the previous winters. The 1996 analog is the only second year Niña on that list...

 

Yeah, areas of west of the divide are probably most likely to end up warm, at least in MT. But it looks to me like WY, CO, UT, ID, and probably OR/WA will all end up warmer than 1996.

 

Of course, the exact lines of anomalies over a calendar month don't really matter. What matters is the large-scale evolution of the North American pattern over the past few weeks. That's mainly what I'm looking at now for leading analogs.

[Front Ranger]

I'd say the Western torch has officially verified. Interesting to see the Cascades below normal in a sea of warmth.

 

[MossMan]

My official forecast...Olympia north will get blasted the week of Christmas that will turn into a 1949-50 massive event.

[Black Hole]

No sign of winter in Utah anytime soon. The warmth will slow down a little bit, but no real winter weather coming anytime soon.

[Front Ranger]

If the long range EPS and GEFS are to be believed, there is very little chance that most of the West ends up cool or even close to normal overall for November. Let's assume that plays out.

 

This would narrow down my primary analogs going forward to: 1954, 1962, 1970, 1981, 1989, 1995, and 2007. Rolling those years forward to December yields:

 

dec.png

 

Thanks. Mid winter is certainly looking more promising for major cold chances across the CONUS. 

 

For our PNW friends, I think it's worth mentioning that only one of the analog years saw any cold weather of note before Christmas (1970, which featured a little cold snap with some lowland snow at the beginning of December, and then a more moderate cold wave with some lowland snow the week leading up to Christmas). 1995 did feature a couple minor cold spells, and 2007 had several bouts with chilly, low snow levels. The rest of the years were mostly warm the first half of the month, and somewhat cooler the second half.

 

Looks at this point that this analog composite moving forward into December is still solid. Overall guidance is favoring a warm west/cold east first half of December.

 

[SilverFallsAndrew]

Looks at this point that this analog composite moving forward into December is still solid. Overall guidance is favoring a warm west/cold east first half of December.

 

post-949-0-15240400-1510796688.png

 

I like your analogs.

[Front Ranger]

I like your analogs.

 

Certainly plenty of snow for your area with several of them, especially Jan-Mar.

[SilverFallsAndrew]

Certainly plenty of snow for your area with several of them, especially Jan-Mar.

 

95-96 was actually a really good year for foothills snow too. A ton in late January, and then a lot again in late February. I remember going sledding at Silver Falls in late Feb' 96' and there was about 18" on the ground. 

[Phil]

Specifics aside, I'm happy with how these analogs have captured the overall system state progression.

 

No matter how I tweak things, I keep getting a warm November/December and a cold January/February.

 

I'm skeptical of the December aggregate, but the state of the subtropical Pacific on that image is highly suggestive of a PV breakdown that month, probably sometime around the holidays verbatim. We'll see.

 

Individual months, October - February:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/C32D0D2D-7A25-41D0-9859-D78090B0D900_zps9pmbaidj.pnghttp://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/62FA459B-5659-4D86-BEC2-E757F9C5F9B3_zps0znlh6q3.pnghttp://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/B2BDC011-3A27-4F2F-9938-127D04897BDC_zpsqpz2taxm.pnghttp://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/CD57BBB2-AA12-4C60-8BAE-6678F9B62144_zps72dcvj24.pnghttp://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/262D23B0-1BF0-4B6F-900B-631F7DC6A107_zpsfspnikas.png

[Jesse]

What's scary about those analog years is that all of the ones that have occurred in the last two decades featured pretty forgettable winters in the lowlands.

[Deweydog]

What's scary about those analog years is that all of the ones that have occurred in the last two decades featured pretty forgettable winters in the lowlands.

Luckily this winter has a Jimpossible to miss money back guarantee. Restrictions apply.

[Front Ranger]

What's scary about those analog years is that all of the ones that have occurred in the last two decades featured pretty forgettable winters in the lowlands.

2011-12 had some memorable moments many places. Just not Portland metro.

[Phil]

What's scary about those analog years is that all of the ones that have occurred in the last two decades featured pretty forgettable winters in the lowlands.

Yeah, but there was a method to my madness in terms of which years I blended. We're far enough lagged in the QBO cycle that we'll probably avoid the +EPO/-PNA slop-fest until February.

[Jesse]

Yeah, but there was a method to my madness in terms of which years I blended. We're far enough lagged in the QBO cycle that we'll probably avoid the +EPO/-PNA slop-fest until February.

That would be nice.

 

What the heck was going on in January 2006?

[TigerWoodsLibido]

That would be nice.

 

What the heck was going on in January 2006?

I remember a cold January spell in Eugene in 2006. Bit of snow then got down to like 15 degrees the next day.

[Deweydog]

I remember a cold January spell in Eugene in 2006. Bit of snow then got down to like 15 degrees the next day.

That seems very unlikely.

[BLI snowman]

I remember a cold January spell in Eugene in 2006. Bit of snow then got down to like 15 degrees the next day.

 

That was 2007.

[TigerWoodsLibido]

That was 2007.

Ah, I was a year off, then.

[snow_wizard]

I think 1956 has to be kept as an analog.  It was one of the few blocky La Nina winter to have a -QBO, and I also realized it had a big persistent ridge right over head in late November.  The inversion from that contributed to that November being a bit on the cold side.  It was also one of the better matches to this year as far as high surface pressure over the NE Pacific in the autumn.  In that year the big late November ridge retrograded to allow a nice blast in early Dec.  The timing that year was just a bit different.

[SilverFallsAndrew]

2011-12 had some memorable moments many places. Just not Portland metro.

 

Don't get me started on how amazing....Never had a minimum below 23 that winter though...Pretty amazing considering how much snow fell. 

[Front Ranger]

2017-18 Winter Outlook

 

December

 

Strong signal for cold across the northern tier of the U.S., with the cold anomalies centered in the northern plains/upper Midwest. Warm across much of the southern tier. Anomalously high heights over the Aleutians, with the polar vortex likely spending some time in northern Canada. -1 to -3 anomalies predicted in the PNW, with northern areas likely to see the greatest cold. Decent chance this is the coldest month of the winter for New England.

 

Precipitation:

 

There is an above average chance that this winter ends up drier than normal for much of the West Coast and northern plains. Near normal precip for the Great Basin/Rockies, and wetter than normal storm track along southern plains and lower Midwest, which should be the battle ground between warmth/cold.

 

Time to check in and see how December went. 

 

The northern tier did end up with the bulk of cold, although it was not centered in the northern plains/upper Midwest until the second half of the month. New England was the coldest part of the country...let's see if this ends up their coldest month.

 

 

 

Most of the PNW also ended up below normal, with every I-5 station colder than normal, ranging from -.6 at SEA and Seattle WFO to -2.9 at EUG. -1 to -3 ended up verifying well overall.

 

Precip-wise, the West Coast is running below normal overall, while the storm train in the southern plains and lower Midwest has started to emerge. Will be interesting to see if these trends continue.

 

[Kayla]

Time to check in and see how December went. 

 

The northern tier did end up with the bulk of cold, although it was not centered in the northern plains/upper Midwest until the second half of the month. New England was the coldest part of the country...let's see if this ends up their coldest month.

 

MonthTDeptUS.png

 

14dTDeptUS.png

 

Most of the PNW also ended up below normal, with every I-5 station colder than normal, ranging from -.6 at SEA and Seattle WFO to -2.9 at EUG. -1 to -3 ended up verifying well overall.

 

Precip-wise, the West Coast is running below normal overall, while the storm train in the southern plains and lower Midwest has started to emerge. Will be interesting to see if these trends continue.

 

MonthPNormUS.png

 

I obviously knew precip was well above average here but that last graphic really shows just how above average the whole state of MT was and how incredibly dry the west coast and SW was.

[Front Ranger]

I obviously knew precip was well above average here but that last graphic really shows just how above average the whole state of MT was and how incredibly dry the west coast and SW was.

 

Yup, crazy difference. Storm track through the Southwest has been completely absent.

[Dan the Weatherman]

It was one of the driest falls on record for southern CA. We could not buy a decent cold front passage during this time period, because the storms weren't tracking through the SW just as Front Ranger mentioned above.

 

It is looking like our first major rain event of the season will be this coming week from Monday afternoon through Tuesday night.

[Front Ranger]

2017-18 Winter Outlook

 

Based on differently weighted factors and trends, including: ENSO, QBO, PDO, AO, NAO, EPO, NPI/Jim's index, solar, and overall pattern progression. 

 

Top tier analogs: 1954, 1970, 1984, 1989, 1996, 2000

Second tier analogs: 1956, 1962, 1974, 1981, 1985, 2007

Third tier analogs: 1949, 1961, 1967, 1971, 1995, 2013

 

More difficult winter outlook than normal, due to a lack of analogs without major holes, and fairly different timing of patterns depending on if November ends up warm or cold in the West.

 

IF November ends up cold in the West, I'd strongly favor 1956, 1961, 1971, 1985, and 2000. 

 

IF November ends up warm, I'd favor 1954, 1962, 1989, 1995, 2007 and 2013.

 

December

 

Strong signal for cold across the northern tier of the U.S., with the cold anomalies centered in the northern plains/upper Midwest. Warm across much of the southern tier. Anomalously high heights over the Aleutians, with the polar vortex likely spending some time in northern Canada. -1 to -3 anomalies predicted in the PNW, with northern areas likely to see the greatest cold. Decent chance this is the coldest month of the winter for New England.

 

January

 

Good signal for cold throughout the West, centered in the interior West/Great Basin. Expect NE Pacific ridging near the sweet spot for Arctic blasts offshore of North America, with the intensity of said blasts depending on amplification of the ridge. -2 to -5 anomalies predicted for the PNW. Under the influence of -EPO and perhaps weak -NAO, the rest of the country looks cool to near normal. Some moderation likely in the northern Plains.

 

February

 

Two main signals emerge this month: strong SE ridging, and a weakening of the -EPO, with strong ridging alternating between offshore and over the West coast. Expect most of the West to be below normal once again, but with the coldest anomalies shifting back to the northern plains. Warmth likely extends all the way up the east coast. Much of Canada is VERY cold. -1 to -3 for the PNW.

 

March

 

Hardest month to read by far, with not much in the way of meaningful signals. Moderation looks likely for the middle of the country, though the Northwest could easily remain cool. There is still some ridging in the NE Pacific, but also increasing likelihood of +EPO. The entire southern tier should be warm, especially the SE. 0 to -2 for the PNW.

 

Winter Temperature:

 

winterforecast.png

 

Precipitation:

 

There is an above average chance that this winter ends up drier than normal for much of the West Coast and northern plains. Near normal precip for the Great Basin/Rockies, and wetter than normal storm track along southern plains and lower Midwest, which should be the battle ground between warmth/cold.

 

Going through month by month...

 

December: I was correct about cold generally across the northern tier, with the coldest anomalies in the Upper Midwest and New England (not so much the northern plains). Definitely the coldest month of the season so far for New England. A-

 

January: Yikes. I was wrong about pretty much everything. Warm month for the West, cold month for the SE. F

 

February: Much better. Strong SE ridging did indeed emerge, and warmth surged all the way up the East Coast. Most of the PNW ended up in the -1 to -3 range I predicted, and the coldest anomalies were centered in the northern plains and Montana. Much of Canada was very cold. A

 

Temp forecast has not been great, with cold anomalies centered further east than I was thinking in the middle of the country. It will take a cold March in the West for me to be close. C-

 

The precip forecast has worked out well. Drier than normal for much of the West Coast, and wetter than normal storm track in the southern plains/lower Midwest. A-

 

 

Overall, two good months, one bad month, a mediocre temp forecast, and a good precip forecast. With March still to go, I'd give myself a B- for this winter forecast to date.