CONTEST STATUS - Updated: TUE ... 23-APR-19 @ 12:10 PM EDT

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

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Winter '17 / '18 - Snowfall Forecast Contests
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19th Annual 'Regular Season'
FINAL results HERE

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17th Annual 'Season-total'
FINAL results 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.

Monday, March 4, 2019

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

FEB-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 ==> less than 75th and greater than 25th percentile (inter-quartile range)
Red ==> 25th percentile

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FEB Forecast Station Highlights
CAR
56% > monthly P-O-R-N

Biggest losers
Observed v P-O-R-N (% P-O-R-N)
RDU:  T v 2.4"
ORH:  T v 2.9"
RIC:  0.1" v 4" (3%)
NYC:  2.6" v 8.9" (29%)
SBY:  1" v 3.4" (29%)

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Season-to-Date
On average ... FEB contributes 257" (28%) toward the average season-total snowfall (D-J-F-M) of 914".

FEB-19 observed snowfall:  220" (24% of season-total snowfall)

Bonus snows in the M-A may seem like a distant memory; however ... five of the seven forecast stations with at least 95% of the annual average snowfall are in the M-A at this point in the season.

Sunday, March 3, 2019

Winter '18 / '19 - Snow Storm #5: The Forecasts

Rookie      -
Intern      -
Journey  1
Senior      11
GOVT      1
PWSP      -
TOT      13

Forecaster table ranked ascending by storm-total precipitation (STP)


BLUE ==> 25th percentile.
RED ==> 75th percentile.
WHITE and GREY STP cells range between the 25th and 75th percentile.


Heaviest snowfall (+6") consensus along and to the right of BGR - PWM - BOS - BDL - ORH - CON - BGR.  Lollypop expected at ORH.


Teleconnections still on vacay.

Everyone/s station-by-station forecast at the Contest/s web site.
Direct link to the forecast table HERE

Friday, March 1, 2019

Winter '18 / '19 - Snow Storm #5: Call for Forecasts! Take 2

Boston Commons
MAR-33

Snow Storm #5 ... a late season nor'easter ... takes aim at most of the forecast area to open the season/s final quarter.

Rapid deepening of the mid-latitude cyclone during its approach and transit near 'Teh Benchmark' (40N/70W) typically produces bonus snows over SNE/s I-95 corridor.  Lack of Arctic air anchored north of the LOW could play a important role defining the RN / SN transition zone.

NOTE:  Any snowfall observed over extreme northern forecast stations (e.g., CAR ... BGR ... etc.) from the exiting storm during the first few hours of SUN should not be included in your forecast.

The forecasting contest for Snow Storm #5 may be cancelled prior to the deadline if at least six-to-eight stations are unlikely to observe at least a 4" storm-total snowfall.

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Forecast element: each station/s storm-total snowfall

Deadline for entries: 10:00 PM EST ... SAT ... 02-MAR-19
Verification begins: 12:01 AM EST ... SUN ... 03-MAR-19
Verification ends: 11:59 PM EST ... MON ... 04-MAR-19

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Enter your forecast at the NEWxSFC/s home page HERE. (http://www.newx-forecasts.com/)
Follow the top-of-page link from 'Enter Storm Forecast.'

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As always ... there/s no cost ... no fee ... no 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.

You also get the chance to see how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices (turns out they/ve been fairly easy to beat!)

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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).

Friday, February 22, 2019

Wednesday, February 20, 2019

Winter '18 / '19 - Regular Season Interim Standings: 2

Under the ‘two-thirds’ rule … forecasters who have entered at least THREE forecasts are included in Interim standings #2.

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.

Tuesday, February 19, 2019

Winter '18 / '19 - Snow Storm #5: Call for Forecasts!

Norfolk ... CT
17-FEB-69
UPDATE:
Call for Forecasts - CANCELLED

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Two separate snow-producing storm systems expected to affect two separate portions of the forecast area over the course of two days.

Each system taken by itself would not qualify as a 'contest-worthy' snow storm but when we cobble them together ... we get just enough stations likely to observe more than a nuisance snowfall to issue a Call for Forecasts.

The forecasting contest for Snow Storm #5 may be cancelled prior to the deadline if fewer than six stations are likely to observe at least a 4" storm-total snowfall.

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Forecast element: each station/s storm-total snowfall
Deadline for entries: 10:00 PM EST ... TUE ... 19-FEB-19
Verification begins: 12:01 AM EST ... WED ... 20-FEB-19
Verification ends: 11:59 PM EST ... THU ... 21-FEB-19

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Enter your forecast at the NEWxSFC/s home page here.
Follow the top-of-page link from 'Enter Storm Forecast.'

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As always ... there/s no cost ... no fee ... no 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.

You also get the chance to see how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices (turns out they/ve pretty easy to beat!)

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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).

Friday, February 15, 2019

Winter '18 / '19 - Snow Storm #4: 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 Best Forecasts
Dotted blue line below (above) solid red line ==> under (over) forecast


Station by Station Comparison of Best Forecasts

Thursday, February 14, 2019

Winter '18 / '19 - Snow Storm #4: Preliminary STP Verification


Preliminary storm-total snowfalls for MON through WED from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins.

Good coverage and reporting.
No exceptions.

HYA
STP estimated by inverse distance weighting of Barnstable county vicinity reports carried in PNSBOX.

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Stations observing >= Trace - 21 (78%)
Given stations with measurable snowfall; stations observing at least:
4" - 8 (38%)
6" - 4 (19%)
8" - 3 (14%)
10" - 1 (5%)

Max snow melt-water (minimum SLR 10:1)
CAR - 0.87"
BTV - 0.86"
BGR - 0.68"

Max precipitation (frozen + freezing + liquid):
PWM:  1.79"
ACY - 1.71"
BWI - 1.48"

New daily record(s)
13-FEB-19
CAR - 12.9" (8.1"; 2008)

Image courtesy NOHRSC
 
SFC analysis:  12z ... 12-FEB-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 NLT FRI evening.

Monday, February 11, 2019

Winter '18 / '19 - Snow Storm #4: The Forecasts!


Rookie     1
Intern     1 
Journey     1
Senior     13
GOVT     1
PWSP     -
TOT     17

Forecaster table ranked ascending by storm-total precipitation (STP)
[DOH! My apologies for mis-classifying Forecaster JessicaCain - again - as an 'Intern' when in fact she was promoted to 'Journeyman' this year.]

BLUE ==> 25th percentile.
RED ==> 75th percentile.
WHITE and GREY STP cells range between the 25th and 75th percentile.


Heaviest snowfall (+8") consensus along and to the right of BGR - BTV - CAR - BGR.  Lollypop expected at BTV.


Opposite Day on Planet Teleconnections.

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Everyone/s station-by-station forecast at the Contest/s web site.
Direct link to the forecast table.

Saturday, February 9, 2019

Winter '18 / '19 - Snow Storm #4: Call for Forecasts!

Miller-B type cyclogenesis along the nearshore waters of the upper M-A coast associated with a mid-latitude cyclone tracking NE across the Great Lakes throughout the forecast period expected to produce the season/s 4th 'contest-worthy' snow storm.

Vertical temperature profiles from numerical weather prediction models suggest the possibility for mixed forms of frozen precipitation i.e., snow and sleet.  Verifying storm-total snowfall totals will include sleet accumulations.

The contest for Snow Storm #4 may be cancelled prior to the deadline if fewer than six stations are likely to observe at least a 4" storm-total snowfall.

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Forecast element: each station's storm-total snowfall
Deadline for entries: 10:00 PM EST ... SUN ... 10-FEB-19
Verification begins: 12:01 AM EST ... MON ... 11-FEB-19
Verification ends: 11:59 PM EST ... WED ... 13-FEB-19

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Enter your forecast at the NEWxSFC/s home page here. http://www.newx-forecasts.com/
Follow the top-of-page link from 'Enter Storm Forecast.

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As always ... there/s no cost ... no fee ... no 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.

You also get the chance to see how well your forecast stacks up against NWS Eastern Region Weather Forecast Offices (turns out they/ve been pretty easy to beat!)

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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).

Friday, February 8, 2019

Winter '18 / '19 - Regular Season Interim Standings: #1

Under the ‘two-thirds’ rule … forecasters who have entered at least TWO forecasts are included in Interim standings #1.


Complete interim statistics table and chart at the Contest/s web site here (direct link)
Forecaster statistics for Winter '18 / '19 Regular season snow storm contest 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.

Sunday, February 3, 2019

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

JAN-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 ==> less than 75th and greater than 25th percentile (inter-quartile range)
Red ==> 25th percentile

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JAN Forecast Station Highlights
CAR
Record monthly snowfall (59.8")
Old record:  44.5" (1994)

IAD ... DCA ... BTV
More than double monthly P-O-R-N

Biggest losers
Observed v P-O-R-N
RDU:  0" v 2.5"
ORH:  T v 2.9" (2%)
EWR:  0.9" v 8.3" (11%)
BDR:  1.2" v 8.9" (13%)
NYC:  1.1" v 7.5" (15%)
PVD:  1.6" v 10.2" (16%)

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Season-to-Date
On average ... JAN contributes 275.6" (30%) toward the season-total snowfall (D-J-F-M) of 914".
JAN-19 observed snowfall:  296.3" (32% of season-total snowfall)


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Teleconnection indexes and month-over tendency (updated as they become available)
AO:
NAO:
PDO:
QBO
SOI:
⇩⇧

Saturday, February 2, 2019

Winter '18 / '19 - Snow Storm #3: 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

Thursday, January 31, 2019

Winter '18 / '19 - Snow Storm #3: Preliminary STP Verification

Preliminary storm-total snowfalls for TUE and WED from CDUS41 (CLI) ... CXUS51 (CF6) ... and PNS bulletins.

Good coverage and reporting with exceptions at BDR and MDT.

BDR
No snowfall report carried in 30-JAN CLI or F6 bulletins.
METARs reported brief burst of heavy snow with late-day Arctic FROPA.
JFK and ISP observed 0.2" around the same time.
Final STP may be revised from reported value if update issued by WFO OKX.

MDT
No snowfall report carried in 30-JAN CLI or F6 bulletins.
METARs reported brief period of moderate snow with mid-day Arctic FROPA.
Final STP may be revised from reported value if update issued by WFO CTP.

HYA
Trace STP based on METAR analysis and the lack of spotter reports in PNSBOX.

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Stations observing at least Trace - 24 (89%)
Given stations having a measurable snowfall ... stations observing at least:
4" - 8 (33%)
6" - 2 (8%)
8" - 0 (0%)

No new daily records


Image courtesy NOHRSC

SFC analysis:  06z ... 30-JAN-19

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