CONTEST STATUS - Updated: WED ... 31-JUL-19 @ Noon EDT

Winter '19 / '20 - Snowfall Forecast Contests
21st Annual 'Regular Season' Snowfall Forecast Contest
Contest starts once the flakes start a'flyin'

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19th Annual 'Season-total' Snowfall Forecast Contest
Deadline for entries: 11:59 PM EST ... SAT ... 30-NOV-19
Verification period: 01-DEC-19 through 31-MAR-20

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Winter '19 / '20 - Snowfall Forecast Contests
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Winter '18 / '19 - Snowfall Forecast Contests
20th Annual 'Regular Season' Snowfall Forecast Contest
FINAL Results here

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18th Annual 'Season-total' Snowfall Forecast Contest
FINAL Results HERE
Forecaster verification table HERE

Tuesday, August 20, 2019

Winter '19 / '20 - Outlooks

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

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CPC ...



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Judah Cohen (AER) via Twitter ...

Wednesday, July 31, 2019

Winter '19 / '20 - NCDC Issues Updated Period-of Record Snowfall Climatology

Here


It's only been four years since the last update.

More NCDC climo data here

Tuesday, April 23, 2019

Winter '18 / '19 - 20th Annual 'Regular Season' Snowfall Forecast Contest: FINAL Results

After five snow storm forecasting contests ... under the ‘two-thirds’ rule … forecasters who entered at least FOUR forecasts are included in this season's FINAL standings.

Full table with all other error statistics at the Contest/s web site here (direct link).
Individual forecaster's storm statistics here (direct link).


Best Forecasts by Storm

Top 10 Forecasts (Error statistic:  SUMSQ Z)

SUMSQ Error Z is the primary measure of forecaster skill (lower the better).
Accounts for the magnitude and distribution of the storm-total snowfall for all stations.

Top 10 Forecasts (Error statistic:  Total Absolute Error Z - TAE)

TAE Error Z is the secondary measure of forecaster skill (lower the better).
Accounts for the magnitude of snowfall at each station.

Top 10 Forecasts (Error statistic:  RSQ Z) 

RSQ is a measure of the how well the 'forecast' snowfall captured the variability of the 'observed' snowfall (higher the better).
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Twenty unique forecasters submitted a total of 1,609 stations forecasts.
Seven forecasters entered all five contests.
Five forecasters entered four contests.
The remainder entered fewer than four.

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Hope to see y'all again next winter.

Monday, April 8, 2019

Winter '18 / '19 - 18th Annual 'Season-total' Snowfall Forecast Contest: FINAL Results

UPDATE (08-APR-19)
Forecaster verification table at the Contest web site (direct link)
Season-total snowfall v period-or-record normal trend chart

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Original post:  (07-APR-19 @ 8:30 PM EDT)

Congratulations to Donald Rosenfeld for his 1st Place finish.
Donald also placed first in '05 / '06 and '12 / '13.

Forecasters ranked by their total absolute error.



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Season-total snowfall from all stations (784") came in 14% below the period-of-record normal (914").
Winter '18 / '19 ranks 11th among other Contest years since winter '04 / '05 ... the season when BGR and BGM were added to the station list.

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Apologies for the abbreviated recap.
Will add to the pile a little at a time this week including each forecaster's station-by-station verification.

Winter '18 / '19 - Season-total Snowfall Forecast Contest: Preliminary STP Verification

UPDATE (08-APR-19 @ 11:55 AM EDT)
Added links to monthly snowfall totals

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Original post (06-APR-19 @ 6:42 PM EDT)

Preliminary sum-total season snowfalls for the verification period 01-DEC-18 though 31-MAR-19 collected from monthly climate bulletins (CLMxxx; CXUS51 ... CXUS52).

Seven forecast stations (28% of all stations) with bonus season-total snowfalls [more than Period-Of-Record-Normal (P-O-R-N)].

Rank ordered descending by percent of P-O-R-N.

Green ==> 75th percentile
White ==> Interquartile range (< 75th & > 25th percentiles)
Red ==> 25th percentile

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Please report any errors in Comments along with a link to the correct data.
FINAL results expected NLT SUN evening.

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Winter '18 / '19 monthly snow totals
DEC:  http://newxsfc.blogspot.com/2019/01/winter-18-19-season-total-snowfall.html
JAN:  http://newxsfc.blogspot.com/2019/02/winter-18-19-season-total-snowfall.html
FEB:  http://newxsfc.blogspot.com/2019/03/winter-18-19-season-total-snowfall.html
MAR:  http://newxsfc.blogspot.com/2019/04/winter-18-19-season-total-snowfall.html

Saturday, April 6, 2019

Winter '18 / '19 - Season-total Snowfall Forecast Contest: MAR Totals

MAR-19 snowfall summary by Contest forecast station.
Rank ordered descending by percent of monthly period-of-record-normal (P-O-R-N).


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Green ==> 75th percentile
White ==> Interquartile range (< 75th & > 25th percentiles)
Red ==> 25th percentile

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MAR Forecast Station Highlights
Eleven stations above P-O-R-N
MA: 5
NE:  6

BDR ... NYC ... ABE ... MDT
At least 200% of monthly P-O-R-N

Biggest losers
Observed v P-O-R-N (% P-O-R-N)
RDU:  0" v 1.0"
ORH:  0" v 0.9"
RIC:  0" v 2.2"
SBY:  T v 1.8" (3%)
DCA:  0.3" v 2.1" (14%)

Wednesday, March 20, 2019

Winter '18 / '19 - Regular Season: Status

Philly
Winter '18 / '19 getting long in the tooth for another contest-worthy snow storm; although ... it/s happened four times previously in April ('02 ... '03 ... '07 ... and '11) which works out to a five-year 'return period' so maybe we get lucky.

Friday, March 8, 2019

Winter '18 / '19 - Regular Season Interim Standings: #3

CORRECTED (09-MAR-19)
Don Sutherland had been identified incorrectly as the Chief 'Regular Season' forecaster when that honor belongs to Brad Yehl.  We regret the error and thank Don Sutherland for bringing it to our attention.

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After five snow storm forecasting contests ... under the ‘two-thirds’ rule … forecasters who have entered at least FOUR forecasts are included in interim standings #3.


Complete interim statistics table and chart at the Contest/s web site HERE (direct link)
Forecaster statistics for Winter '18 / '19 contest snow storms HERE (direct link)

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SUMSQ errors for each contest snow storm are normalized (i.e., standardized) with a 'Z-score' ... then averaged to compute the standings. If a forecaster has issued forecasts for more than two-thirds of all snow storm contests ... then Z-scores from their 'best two-thirds' forecasts are used to calculate the Interim and Final standings.

Similar idea as dropping the lowest test score before computing the final grade.

Wednesday, March 6, 2019

Winter '18 / '19 - Snow Storm #5: FINAL Results

Forecasters' station verifications and the storm summary available at NEWxSFC/s home page.
http://www.newx-forecasts.com/


SUMSQ:  sum of square error (")
SUMSQ Z:  Z-score
STP:  storm total precipitation error (")
TAE:  total absolute error (")
AAE:  average absolute error (")
(#):  category rank


Forecast by Observed Snowfall Scatterplots for Top Forecasts
Dotted blue line below (above) solid red line ==> under (over) forecast


Station by Station Comparison of Top Forecasters

Tuesday, March 5, 2019

Winter '18 / '19 - Snow Storm #5: Preliminary STP Verification

Preliminary storm-total snowfalls for SUN and MON from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins.  Good coverage and reporting.

Exceptions
CON
No daily snowfall reported in CF6 or CLI bulletins for 03-MAR-19.
PNSGYX carried 5.8" ASOS
STP may be amended if official data reported prior to posting of FINAL results.

HYA
STP estimated by inverse distance weighting of Barnstable county vicinity reports within 10 miles of the station carried in PNSBOX.

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Stations observing >= Trace - 22 (81%)
Given stations with measurable snowfall ... stations observing at least:
4" - 14 (64%)
6" - 8 (36%)
8" - 3 (14%)
10" - 1 (5%)

Max snow melt-water (minimum SLR 10:1)
BOS:  1.06"
ORH - 0.88"
BDL - 0.65"

Max precipitation (frozen + freezing + liquid):
HYA:  1.53"
PVD - 1.20"
BDR - 1.08"

New daily record(s)
04-MAR-19
BDR - 6" (1.5"; 1971)
ISP - 0.5" (0.05"; 1971, 2010)

Image courtesy NOHRSC

SFC analysis:  06z ... 04-MAR-19
Image courtesy NWS / NCEP /WPC

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Please report any errors in Comments along with a link to the correct data.
FINAL results expected NLT WED evening.