CONTEST STATUS - Updated: MON ... 19-OCT-20 @ 6:20 PM EDT

Winter '20 / '21 - Snowfall Forecast Contests
22nd Annual 'Snow Storm' Snowfall Forecast Contest
Season starts when flakes start a'flyin'.
Watch this space ...

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20th Annual 'Season-total' Snowfall Forecast Contest
Deadline for entries: 11:59 PM EST ... MON ... 30-NOV-20
Details here

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Winter '19 / '20 - Snowfall Forecast Contests
21st Annual 'Snow Storm' Snowfall Forecast Contest
Season ended as quickly as it started.
No winner this go'round ... too few storms (minimum of three required)

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19th Annual 'Season-total' Snowfall Forecast Contest
FINAL Results here

Saturday, November 21, 2020

Winter '20 / '21 - Season-total Snowfall Anomalies During La Nina Winters

 Taken at face value M-A snow crows suffer the most ...

The NOAA analysis of Rutgers' Global Snow Lab data does not account for the different categories of La Nina episodes (weak ... moderate ... strong) and it has an end date of 12 years ago.  Since then ... there have been three La Nina winters - '10 / '11 ... '11 / '12 ... and '17 / '18.

Relative to season-total snowfall at 28 NEWxSFC stations ...
'10 / '11 - well above average (moderate La Nina)
'11 / '12 - well  below average (weak La Nina)
'17 / '18 - above average (weak La Nina)

 Image courtesy NOAA Climate

Winter '20 / '21 - Outlooks

Thread updated periodically as new outlooks and forecasts become available from a variety of credible sources.

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CDC - NOV ...



CDC - OCT...


Wednesday, November 18, 2020

Winter '20 / '21 - Multivariate ENSO Index (MEI): Analog Composites of 500 mb Height and 2-meter Temperature Anomalies ... as of SEP / OCT-20

 Analogs and weights for composites:
'70 / '71 (24)
'07 / '08 (5)
'88 / '89 (1)
'95 / '96 (1)
'64 / '65 (1)


 We assess the MEI analog winters with the upcoming winter/s expected states of ENSO (moderate-to-strong La Nina) ... QBO-W ... and (cool) PDO.

Seeing how statistical and dynamic models predict a moderate La Nina this winter ... '64 / '65 and '95 / '96 don/t match the expectation which leaves '70 / '71 ... '07 / '08 ... and '88 / '89 as problem children.

Two concerns about the utility of winters '70 / '71 ... '07 / '08 ... and '88 / '89 ...
Two analogs depict a late winter La Nina intensification (vice expected fade) ... all three had QBO - E contrary to this winter's QBO-W ... and sadly no composites nor forecast guidance. 

MEI analog data table (unranked)
Analog statistic (not shown):  sum of squared errors

The MEI is based on five variables:
Sea level pressure (SLP)
Sea surface temperature (SST)
Surface zonal winds (U)
Surface meridional winds (V)
Outgoing Longwave Radiation (OLR)

Tuesday, November 10, 2020

Winter '20 / '21 - North Atlantic Oscillation (NAO): Analog Composites of 500 mb Height and 2-meter Temperature Anomalies ... as of OCT-20

Analogs and weights for composites:
'61 / '62 (2)
'91 / '92 (0)
'95 / '96 (0)
'99 / '00 (1)
'03 / '04 (0).

Two analogs averaged < 0 over D-J-F
Three analogs averaged > 0 over D-J-F
Little in the way of consensus which isn/t especially unusual for analogs.

We assess NAO/s analog winters with the upcoming winter/s expected states of ENSO (moderate-to-strong La Nina) ... QBO-W ... and (cool) PDO.

Recall ... '95 / '96 of 'Storm of the Century' fame was one of the better winter/s evah; however ... despite its weak La Nina profile ... its QBO-E and warm PDO eliminates the strongest calculated match for Winter '20 / '21 from the running.  Analog weight:  0

'91 / '92 drops out as well b/c its winter had a strong a El Niño ... QBO-E ... and a warm PDO.  The '03/'04 La Nada winter doesn't make the cut either.  Analog weights:  0

The two remaining winters '61 / '62 and '99 / '00 are strong analogs for Winter '20 / '21.  Both were moderate La Nina (per MEI) ... QBO-W < 10 ... and a cool PDO.  '61 / '62 set snowfall records in more than a few stations. Analog weight: 2

Season-total snowfall for '99 / '00 was above average for southern mid-Atlantic stations and generally below average elsewhere.  Analog weight:  1

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The 500 mb and 2m T weighted analyses below are based on the winters of '61 / '62 and '99 / '00.

North Atlantic Oscillation (NAO) analog composites of 500 mb (5H) geopotential height anomalies (GPHa) and 2-meter air temperature anomalies (2m Ta) for Winter '20 / '21.

5H GPHa weighted-composite

Main features:
La Nina ridge over SE CONUS
-PNA
Positive geopotential height anomaly south of Greenland ==> -NAO (??? lo-lat action center)
Storm track across northern CONUS

2m Ta weighted-composite

Main features:
Above normal temperature across the Deep South and SE CONUS
Cold AK ==> warm East


NAO analog data table (unranked)
Analog statistic (not shown):  sum of squared errors


Monday, November 9, 2020

Winter '20 / '21 - Arctic Oscillation (AO): Analog Composites of 500 mb Height and 2-meter Temperature Anomalies ... as of OCT-20

 Analog years and weights for composites:
'89 / '90 (3) ... '90 / '91 (2) ... '97 / '98 (2) ... '02 / '03 (1) ... and '15 / '16 (1).

Sadly ... all analog years were +ENSO winters; not something expected this season so they're of limited utility.

Arctic Oscillation (AO) analog composites of 500 mb (5H) geopotential height anomalies (GPHa) and 2-meter air temperature anomalies (2m Ta) for Winter '20 / '21.

5H GPHa weighted-composite

2m Ta weighted-composite

AO analog data table (unranked)
Analog statistic (not shown):  sum of squared errors


Tuesday, November 3, 2020

Winter '20 / '21 - Eurasia Snow Cover: OCT

~ 11,000,000 SQ-KM

 

Under-performing all year ... 

6% above P-O-RN (~10,320,000 SQ-KM)
9% above median (~10,080,000 SQ-KM)
Period-of-Record:  53 years
Rank: 19th

2nd lowest past 10 years
16 of past 20 years above P-O-R-N

OCT-19:  ~12,700,000 SQ-KM
OCT-20:  14% less than last year

Eurasia snow analog years offer little if any guidance given this winter should have cool ENSO / PDO and QBO-W.

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P-O-RN ==> period-of-record normal

Data courtesy Rutgers University Global Snow Lab
http://climate.rutgers.edu/snowcover/index.php

Monday, October 19, 2020

Winter '20 / '21 - 20th Annual 'Season-total' Snowfall Forecast Contest: Call for Forecasts!

NEWxSFC/s Director of Season-total Snowfall Forecasting
Here comes winter with its oscillating Arctic and North Atlantic indexes ... sudden stratosphere warmings ... so-so ENSO ... and if we/re lucky .... an endless parade of 'Miller A' LOWs raking the eastern seaboard.

NE.Wx/s 20th Annual ‘Season-total' Snowfall Forecast Contest is the absolute best ... biggest ... and possibly ONLY chance to be recognized for your astute long-range forecasting acumen ;/

And it's s-o-o easy.
Cool prizes ... too!

All you have to do is issue the best forecast for the 'season-total' snowfall at 25 east coast stations between RDU and CAR!

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Forecast element:
season-total snowfall @ each station

Forecast period:
01-DEC-20 through 31-MAR-21

Error statistic: total absolute error
[Σ abs(forecast - observed)]

Verification:
NWS climate reports (CLM or CF6)

Low. Score. Wins.

Deadline for entries: MON ... 30-NOV-20 @ 11:59 PM EST (01-DEC-20 @ 4:59 UTC)

Visit the Contest's website to enter your forecast.
Follow the link at the top right corner of the page to 'Enter Season-total Forecast.'

Update your forecast as often as you want prior to the deadline.
Only your last entry gets verified.

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1st place prize (delivered post-paid right to your front door):
... choice of a book from NEWxSFC library
... the august title 'Chief Season-total Snowfall Forecaster' for Winter '21 / '22 and
... a well-deserved place of high esteem and honor with past winners.

2nd place prize (delivered post-paid right to your front door):
... choice of a book from NEWxSFC library

3rd place prize (delivered post-paid right to your front door):
... choice of a book from NEWxSFC library

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The reigning NE.Wx ‘Season-Total’ Snowfall Forecasting Champ-een is Herb @MAWS
Last year's 'Season-total' forecast summary ... verification ... and final results at our website here.

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As always; NO cost ... NO fees ... NO advertising ... NO annoying requests for personal information to enter the contest.  NEWxSFC is a just-for-fun exercise for winter wx enthusiasts to see who can make the best 'season-total' snowfall forecast.

The Contest is open to all including amateur and professional forecasters; broadcasters with or without trained Seals; any and all weather-biz types and / or wanna-bees; wish-casters ... astrologers ... along with any other universally recognized classes of dreamers; Pollyannas or Cassandras ... registered Nostradamuses ... non-violent megalomaniacs ... woolly-bear caterpillars or their agents ... pest detectives ... ne.weather USENET veterans and lurkers ... riders on the StormVista ... refugees from AmericanWx ... US Weather survivors ... including self-imposed exiles from Eastern Wx ... and of course ... meteorologists.

In honor of USENET/s ne.weather patron saint Mr. Joseph Bartlo's final request (RIP); trolls ... goats ... hat3-lsiters ... and psests need not apply.

Sunday, October 4, 2020

Winter '20 / '21 - Severe Weather Europe: Winter Forecast

 Severe Weather Europe ...

"The La Nina phase will reach quite a formidable strength at its peak but is expected to start to weaken towards spring 2021."

"Historically, the most typical effect of a La Nina is a strong blocking high-pressure system in the North Pacific."

"North America winter forecast looks fairly solid to be a classical La Nina type winter. Most of western Canada is to expect colder and snowier conditions, along with Alaska.

"The United States expects to see a “dipole” pattern or a “two-faced” winter. The Northern [sic] United States are expected to be normal to colder and wetter. This increases the chance of more snowfall, but more likely towards the western half, and less likely in the eastern parts.

"The Southern [sic] United States can slowly prepare for warmer and mostly drier than normal winter weather. This however does not imply that [sic] no cold front can reach the southern states. It just implies that [sic] in a La Nina pattern, it is much less likely to get frequent cold fronts down to the very south."

Sunday, September 20, 2020

Winter '20 / '21 - How Arctic Amplification Affects the Polar Vortex

 "AER explains how accelerated Arctic warming, known as Arctic amplification, is increasingly disrupting the polar vortex, leading to widespread severe winter weather across the Northern Hemisphere’s mid-latitudes."

 https://youtu.be/EMeI4N5dui4

Saturday, April 11, 2020

Winter '19 / '20 - 19th Annual 'Season-total' Snowfall Forecast Contest: FINAL Results

Congratulations to Herb @MAWS for his 1st Place finish.
Herb also placed first in '03 / '04 and '09 / '10.

Forecasters ranked by their Total Absolute Error (TAE)
The '%MPRV over PORN' metric indicates how well the forecaster did compared to climatology [(Period-of-Record Normal (PORN)].  The most skillful forecasts beat climatology 

RED ==> 75th percentile
WHITE ==>  interquartile range (>25th & < 75th percentiles)
BLUE ==> 25th percentile

Forecasters' stations with the lowest absolute error