Winter '13 / '14 - Wolf at the Door

Winter '13 / '14 - Typhoon Wipha Brings Early Season Snows to Obihiro Airport...Japan

From Western Pacific Weather...

Thus far today Obihiro Airport has seen 20cm of snowfall and JMA is calling for an additional 10-15cm on top of that.  This is 36 days earlier than usual and the earliest since records first started in 1892.

The snow has been causing traffic problems and also ushers in a severe risk of power outages as leaves have just started changing colors in Northern Japan and or are still green. This adds extra weight to tree branches and brings the risk of branches snapping and power outages.

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Winter '13 / '14 - Eurasia Snowcover: September

Rutgers' Global Snow Lab reports a dramatic increase in September/s areal snow cover over Eurasia.

2,362,682 km^2
7th highest overall
49% above the period-of-record (1967 - 2013) normal of 1,587,905 km^2.
120% above 2012.
Largest areal coverage since 2001.

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Top chart:
BLUE - areal snow cover in millions of km^2
ORANGE - mean areal snow cover
YELLOW - +/- 1 standard deviations
RED - 9-point binomial filter

Bottom chart:
BLUE - period-of-record (1967 - 2013) median areal snow cover in millions of km^2
RED - observed areal snow cover (2013)

Rutgers data here.

Winter '12 / '13 - Arctic Oscillation: New Record for March



Rockefeller Center - NYC
09-FEB-69
(FEB-69 AO:  -1.325; MAR-69 AO:  -2.084)

 The MAR-13 AO of -3.176 crushes the old record of -2.848 set 51 years ago in 1962.

The last time the March AO went below -1 was in 2006.

The last time the March AO tanked below -2 was in 1984.

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The AO for the preceding meteorological winter (D-J-F) averaged -1.122.

The AO/s 5-year moving average during meteorological winter is -0.909

The AO during meteorological winter has been negative...
....four of the last five seasons (average = -0.413)
...nine of the last 10 seasons (average = -0.368)
...12 of the last 15 seasons (average = -0.255)

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Not that any of these trends are abnormal.
The 5-year moving average was negative during the vast majority of the time between mid-50s to late '80s.  The abnormal 'positive ' period occurred between 1989 and 1996.

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Monthly AO data here.

Winter '12 / '13 - 12th Annual Season-total Forecast Contest: FINAL Results

Donald Rosenfeld FTW!
He was the only forecaster to beat climatology this season.

The 'season-total' snowfall forecast contest/s error statistic is total absolute error.

For each forecast station...the absolute value of (Forecast - Observed) is calculated....then summed.

Forecasts with the lower 'total absolute forecast' errors have more skill than those with higher 'total absolute forecast' errors.

PORN is the 'Period Of Record Normal' or climatology.

Skillful season-total forecasts are those that beat climatology.

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Another big season for SNE...especially BDR at 216% of normal...along with BOS and PVD whose 'normal' snowfall falls inside the interquartile range but this season's 'observed' snowfall pushed them in the upper quartile (>= 75 percentile).

Other over-achievers...albeit less notable...were ACY and RIC b/c their 'normal' season-total snowfalls are in the lower 25th percentile of all forecast stations yet they climbed into the interquartile range this winter.

Biggest 'losers' were stations where the 'normal' snowfall is in the upper quartile of all forecast stations yet did not finish the season in the upper quartile.  This year finds CAR...BTV...and BGM on the 'walk of shame.'

Other 'loser' seasons occurred at PHL and IAD.  Their 'normals' fall in the interquartile range but their season-total snowfall put them in the lower quartile.

GREEN - 75th percentile and above.

RED - 25th percentile and below

WHITE - The interquartile range located between the 25th and 75th percentiles.

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Everyone's forecast has been verified and posted to the Contest/s web site here.

Hope to see y'all back again next winter.

Winter '12 / '13 - 12th Annual 'Season-total' Forecast Contest: MAR Totals

MAR totals were 24% above period-of-record normal.

ACY more than three times normal.

Twelve stations measured at least 100% of nornmal....five of which were at least 200% of normal.

The season-total snowfall to date (D-J-F-M) over the entire forecast area was 7% above normal.

Monthly totals for DEC and JAN here...FEB here.

Winter '12 / '13 - VCP32: Life After Death

Winter '12 / '13 - Storm #7: Call for Forecasts

UPDATE
Call for Forecasts - CANCELLED

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(Originally posted 3/22/13 @ 3:08 PM EDT)

SW Harbor...ME
28-JAN-40

Today/s 12z NAM and GEM-GLB argue for a contest-worthy storm Sunday evening.
GFS not so much.

Would hate to miss a late season opportunity...especially for the snow starved M-A...so a call goes out for forecasts.

The contest for Storm #7 may be canceled prior to deadline if NWP indicates a fizzling event.

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Forecast element: storm-total snowfall
Deadline for entries: 10:30 PM EDT SAT...23-MAR-13

Verification period begins: 12:01 AM EDT SUN...24-MAR-13
Verification period ends: when the snow stops.

Enter your forecast at the Contest's home page here.
Follow the link from 'Enter Storm Forecast.'

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As always...there/s no cost...or fee...or advertising...or annoying requests for personal information to enter a forecast. It's just a fun exercise for winter wx enthusiasts to see who can make the best synoptic-scale snowfall forecast.

If you are issuing your first forecast this winter...or you entered the 'season-total' forecast contest...you/ll need to create an account (user name / password / valid e-mail...if you want a copy of your forecast sent to your Inbox).

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Want to be notified via e-mail when the 'Call for Forecast' is issued?
Send requests to 'newx at newx-forecasts dot com'.

Winter '12 / '13 - Interim Standings 4

Under the ‘two-thirds’ rule…forecasters who have entered at least four forecasts are included in this season/s third Interim Standings.

SUMSQ errors for each contest storm are normalized with a 'Z-score'...then averaged...to compute the standings.  Lower (higher) average Z-scores indicate more (less) skillful forecasts.

If a forecaster has participated in more than two-thirds of all contests...then Z-scores from their 'best two-thirds' forecasts are used to calculate Interim and Final standings. More or less the same idea as dropping the lowest quiz score(s) before the final grade is computed.

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Complete table of Interim stats by Forecaster at the Contest/s web site here.
Forecaster summary storm data set here.

Winter '12 / '13 - Storm #6: Final Results

Composite Reflectivity
Mid-afternoon 19-MAR-13

1st - Donald Rosenfeld
SUMSQ:	47.02
SUMSQ Z:	-0.609
STP:	10.90	(6)
TAE:	23.70	(1)
AAE:	0.99	(1)
2nd - iralibov
SUMSQ:	55.26
SUMSQ Z:	-0.537
STP:	8.80	(4)
TAE:	28.50	(3)
AAE:	1.14	(3)
3rd - donsutherland1
SUMSQ:	56.68
SUMSQ Z:	-0.524
STP:	7.30	(1)
TAE:	29.70	(4)
AAE:	1.24	(5)
HM - snowman
SUMSQ:	58.96
SUMSQ Z:	-0.504
STP:	14.40	(8)
TAE:	26.60	(2)
AAE:	1.06	(2)

SUMSQ: sum of square errors

STP: storm-total precipitation error

TAE: total absolute error
AAE: average absolute error
(number):  category rank

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Full forecast verification and summary for Storm #6 here.