Friday, 24 October 2014

Winter Outlook Update: Brief Summary of Thoughts

Based on the research i've been doing on the upcoming winter here is my revised forecast. I will keep it to a brief summary of my thoughts. I want to note that I am expecting a weak nino, with a -QBO, SSN ~80-100, +PDO, +AMO and weak walker cell.

- Following chill in the first few days of the month, warmer then normal conditions are expected overall in the first ten days of the month with a -PNA and trough axis along or east of the East Coast. 
- RNA pattern continues in weeks 2-4 with a SE ridge and trough axis over northern rockies and plains. Storm track active through the great lakes. Potential for early season snow's across Ontario and Quebec when anticyclonic waves break into Alaska sending arctic air into the plains/prairies/Lakes. Tropical forcing shifts into phases 7-1. Overall month near to slightly above normal temperature wise with above normal precip across On, Que. Below normal across B.C with above normal precip.

-Classic El nino look with a Very -PNA and neutral EPO(SE GOA low with Poleward Aleutian High). Ridge axis over rockies/plains with NW flow dominating ON/Que. Secondary trough off the east coast/maritimes area.
- Below normal Temperatures expected for Toronto, Montreal, Ottawa and Vancouver. Below normal snowfall across Eastern Canada(YYZ,YUL,YOW) and the Great Lakes(outside of the LES belts). Above normal snow across B.C.
- Neutral NAO with +AO.
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- Very -AO/NAO with a SSW expected. Well Below normal temperatures across the N Plains, Lakes, and New England including S/E On, S Que and B.C. Secondary trough east of the East Coast.
- Negative PNA with Eastern Lakes/Interior storm track in the means. N-S temp gradient across the U.S with above normal temps in the Southern Plains, Miss Valley and Southeast.
- Above normal snowfall across Southern Ontario, B.C and Alberta. Near normal E On/S Que. Below normal snowfall NE of YOW-YUL including Atlanta Canada with blocking HP dominating.
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- Negative PNA continues with +WPO and Strong Bering Sea low. Trough axis off East Coast remains stagnant. 
- Slightly -AO/NAO.
- Above normal snowfall across the Pac NW, SW U.S and SE U.S. Near to slightly below normal snowfall across the great lakes, S and E Ontario and Quebec.
- Dry/warm conditions over the priaries.
- Above normal snowfall across the Maritimes if -NAO backs off. Otherwise, snowfall remains below normal.
- Below normal temps across the GL's although suppression is an issue.
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- Strong NE Pac high forms off the W coast of B.C. PNA spikes positive although core of the ridge axis is west of the PNA and SE of the EPO region. +PNA/-EPO means that cold tongue forms from the NWT through the plains and all the way to the SE U.S. 
- Core of cold over N Plains/Western Great Lakes. Well below normal temps for YYZ,YOW and YUL. Warmer then normal temps across S B.C.
-Negative NAO/AO returns with above normal snowfall across the eastern lakes, northeast and mid atlantic as well as the maritimes. Above normal snowfall across YYZ/YOW/YUL.
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In summary for On/Que... winter will start off relatively slow in the snow department following a November full of potential if the storm track is not positioned too far West. December should end up below normal temperature wise especially across S Ontario and S Que. January and March have the most potential to carry above normal snowfall across ON/Que in addition to well below normal temperatures. February is slightly colder then normal but relatively benign in the snowfall department with suppression and a NW flow.

Analog Years...
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Any questions? Feel free to shoot away. 

Monday, 20 October 2014

Winter Possibilities: Canadian Warming v.s No Canadian Warming

Couple December scenario's I want to outline this evening.

Case 1: -QBO/El Nino Years following a November Canadian Warming. If the increased polar ozone, stronger BDC and nino help keep the wave activity high enough we could see one. 4 of my analog years have this setup but we would need to see major wave breaking pretty quickly.

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Case 2: No November CW. My analogs are hinting at a classic Nino look with a warmer then normal N and NW with cooler anoms limited to the EC/South. The S Plains look too warm however.
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As we head into Jan note how both the CW years and regular analogs have a similar pattern. Jan is probably the highest confidence month for me given the likelyhood of a Major SSW by then. Note the major AO reversal in Jan(makes sense given the OPI,SAI,Nino,-QBO and moderate solar).
CW Years
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Regular Analogs
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Feb CW Years(Note the reversal across the plains and NW to significantly warmer). Interesting how they tend to be colder early on but the opposite as you get latter into winter.
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Regular Analogs
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Have a good night!

Sunday, 19 October 2014

Warm November coming up for the East, Plains and Lakes?

A few very important things i'm noticing this morning that should be pretty important for the November forecast. A Poleward/weak NH Hadley Cell has developed(especially near Indonesia) and is making it very hard for trough's to amplify across the SE Asia/Japan sector all the way through D10. This is having major impacts downstream across the CONUS because it makes it tough for waves to breakdown the C NA ridge. Instead they get displaced well to the NE towards atlantic Canada and New England.

E Asian Jet Forecast:

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500mb Omega:

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This entire pattern coincides with an H5 setup that is very supportive of poleward propagating anticylones into the mid latitudes with +AAM anomalies into the subarctic(50N-70N region). This is supportive of a major spike in the AO which should occur shortly.

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Until the hadley cell returns to normal, E asian cyclogenesis will remain sparse and the NPAC jet will favour waves breaking into Bering Sea with a -PNA. This in conjuncture with classic Basin Wide nino forcing is helping amplify the GOA trough. At the same time we will see little help from the NAO region until very late Nov or December in my opinion. I do think there is a window for some chill in the 10-15 as the GWO is pretty strong right now and headed for nina like phases(we'll see if its enough to shift the C NA ridge South and East). Beyond that point it should get pretty "torchy" from the Plains to the EC(especially the further N you go) until forcing can shift into the W-C Pac to W IO sector. In other words, it looks like Nov could be less nina like and warmer then normal across the lakes/plains/NE(with the exception of extreme Northern New England and the Maritimes). It's all part of the seasonal progression that should bring us towards a cold DJFM period over the central/Eastern CONUS. Have a great day!

Thursday, 9 October 2014

Winter Analog's Revised-- looking good for Ontario!

Just went through and revised some of my analog years yesterday, coming up with 51-52,69-70,02-03,03-04,93-94 and 12-13 in the set. Mostly focused on monthly SSN/QBO/MEI numbers with some focus on PDO,AMO,ONI lead up, ENSO configuration, Walker Cell etc. These years appear to hint at a cool and very nino like start to winter with a more nina like finish as the el nino weakens and -EPO forcing takes over. This would more then likely cause the storm track to shift into a more favourable position for our region with the presence of a weak SE ridge. Based on my analogs/research Jan-Mar should be the month's to watch for average to above average snowfall which actually contradicts the modelling(NMME/Euro) which have a wetter/stormier dec and more suppressed storm track from Jan-March.

Dec has that RNA,+WPO,+EPO and neutral NAO/AO look:


March(+PNA,-WPO,Neutral EPO,-NAO/AO)

Oh and maybe we can pull off a snowy november finally... very exciting times ahead.