NE.Wx Snowfall Forecast Contest

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

Follow the left-panel link from '22^nd Annual Snow Storm Contest > Verified Forecasts > ‘18-FEB-21’ 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

Station by Station Comparison of Best Forecasts

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)

Consensus forecast best @ PWM … BGM …ISP

MAX forecast best @ CON … HYA

MAX forecast less than observed @ HYA

MIN forecasts best @ BTV … BDL … ALB … BWI … IAD … DCA

MIN forecasts more than observed @ ALB … BWI … IAD … DCA

Strong correlation (R = 0.949) between SUMSQ and TAE Z-scores

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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Storm-total snowfalls for THU (18-FEB-21) through SAT (20-FEB-21) from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins.

Excellent coverage and reporting.

HYA STP estimated from a vicinity report within 2.5 SM of the station carried by the BOXPNS bulletin.

H2O value derived from METAR precipitation groups 7nnnn (24-hour) ... 6nnnn (6-hour) ... and Pnnnn (1-hour).

SBY STP estimated based on METAR 6-hour precipitation report of '60006' and 10:1 SLR.

CON/s Daily Climate Bulletin on THU reported 0.01" liquid but no snowfall total.

Estimated snowfall of 0.1" by applying 10:1 SLR.

SLR not reported for some stations with measurable snowfall b/c significant liquid and / or freezing precipitation also occurred during the verification period.

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Stations observing at least 0.1": 23 (85%)

Given a station had measurable snowfall; stations observing at least ...

4" - 12 (44%)

6" - 2 (7%)

MAX: 7.6"

MAX snow melt-water (minimum SLR 8:1)

ABE: 0.55"

BDR: 0.51"

HYA: 0.36"

MAX precipitation (frozen + freezing + liquid):

ORF: 1.50"