NE.Wx Snowfall Forecast Contest

Complete Results @ http://www.newx-forecasts.com/

Follow the left-panel link from '24^th Annual Snow Storm Contest > Verified Forecasts > ‘Storm #3’ to see the complete forecasters’ verification table by station

In the table ...

Yellow cells indicate the best score in category.

Forecast STP cells: yellow if within +/- 5% of observed STP.

Blue (Red) cells indicate the 25% (75%) percentile.

SUMSQ: sum of square errors (measure of forecast accuracy accounting for magnitude and distribution of snowfall)

STP: storm total precipitation

TAE: total absolute error
AAE: average absolute error

Final Standings - all Forecasters

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Station by Station Comparison of Top 4 Forecasts and Observed Storm-total Snowfall (STP)

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Perfect Forecasts (Batting Average - Forecast Stations with No Error)

Best Station Forecasts (Batting Average - Forecast Stations with Lowest Absolute Error)

Best Station Forecast Busts (Batting Average - Forecast Stations with Highest Absolute Error)

Skill v. ER NWS WFOs

Positive skill value indicates a forecast/s improvement over the NWS forecasts.

Bias - the arithmetic difference between the average Forecast snowfall and the average Observed snowfall.

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Consensus Forecasts … Extremes … and Observed Snowfall

Consensus forecast best @ BDL … ALB

MAX forecast best @ none

MAX forecast less than observed @ none

MIN forecasts best @ CAR … BOS … ORH … PVD

MIN forecasts more than observed @ BOS

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Total Absolute Error and SUMSQ Error

Strong correlation (R = 0.972) between SUMSQ and TAE Z-scores

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Forecast by Observed Snowfall Scatterplots (Top 4 Forecasts)

A dashed Forecast trend line above (below) solid red Observed snowfall line ==> over (under) forecast

R² value indicates how well the forecast captured the observed snowfall’s variability … i.e., R² = 0.874 ==> the forecast captured ~87% of the observed snowfall’s variability.

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Verification of storm-total snowfalls for FRI and SAT based on reporting found in CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Excellent coverage and reporting.

HYA

Trace retrieved from 041856z METAR

KHYA 041856Z 01021G33KT 3SM RA BR OVC008 03/02 A2938 RMK AO2 PK WND 01036/1838 RAE08B52SNB08E37 PRESRR SLP951 P0001 T00280022

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Snow-to-Liquid Ratios (SLR) of less than 8:1 are unreported for stations where liquid and / or freezing precipitation also occurred during the verification period.