Winter '23 / '24 - 23rd Annual 'Season-total' Snowfall Forecast Contest: FINAL Results

BWI - Park Avenue (1948)

Congratulations to Senior Forecaster WXCHEMIST for issuing the best 'season-total' snowfall forecast for Winter '23 / '24.  WXCHEMIST also issued the best 'season-total' snowfall forecast for Winter '13 / '14.

Complete forecaster verification table at the Contest/s web site.

Forecasters ranked ascending by their Total Absolute Error (TAE).

BLUE ==> 1st Quartile
WHITE / GREY ==>  Interquartile range
RED ==> 4th Quartile
ORANGE:  Winter '22 / '23 Chief 'Season-total' Forecaster (winner of  '21 / '22 contest)

The '%MPRV over PORN' metric indicates how much the forecast was better or worse than the Period-Of-Record-Normal (P-O-R-N).  Skillful forecasts beat P-O-R-N.

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Winter '23 / '24 - 'Season-total' Snowfall Forecast Contest: MAR Snowfall Totals

BOS - Adams Square
(14-FEB-40)

MAR-24 snowfall summary by forecast station.

Rank ordered descending by percent of monthly period-of-record-normal.

Green ==> 4th quartile
White ==> less than 4th and greater than 1st quartile (inter-quartile range)
Red ==> 1st quartile

'Obs' reporting '0.05' denote 'Trace' amounts (observed but not measurable)

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Winter '23 / '24 - Snow Storm #3: FINAL Results and Storm Summary

BOS - Fenway Park
(01-APR-97)

Complete forecaster verification table and the FINAL Results / Storm Summary
available at NEWxSFC/s home page.

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

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Forecast by Observed Snowfall Scatterplots for Top 4 Forecasts

Forecast/s dotted blue line below (above) the Observed snowfall/s solid red line ==> under (over) forecast bias.

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Comparison of Top 4 Forecasts and Observed Snowfall by Station

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Forecaster Skill Score (measured against NWS ER WFOs)

Skill: positive values indicate the forecast/s percentage improvement over NWS forecasts.

Bias:  the arithmetic difference between the average Forecast snowfall and the average Observed snowfall (avgForecast - avgObserved).

Winter '23 / '24 - Snow Storm #3: STP Verification - Preliminary

VT - Marshfield cemetery (1953)

Preliminary verification of storm-total snowfalls for WED though FRI based on reporting from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Excellent coverage and reporting.

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Snow-to-liquid ratios (SLR) less than 8:1 are not reported for stations with measurable snowfall b/c significant liquid and / or freezing precipitation also occurred during the verification period.

The 'TOT SLR' field is the quantity-weighted average of those forecast stations with at least an 8:1 SLR.

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Winter '23 / '24 - Snow Storm #3: The Forecasts!

Rookie      -
Intern      -
Journey      -
Senior      9
GOVT      1
PWSP      -
TOT      10 

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

BLUE ==> 1st quartile
RED ==> 4th quartile
WHITE and GREY STP cells range between the 1st and 4th quartile

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

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Teleconnections

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

Winter '23 / '24 - Snow Storm #3: RAW Forecasts

Click through on Read more >> to see forecasts.

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Winter '23 / '24 - Snow Storm #3: Call for Forecasts!

RDU - 300-block East Martin St.
03-APR-1915

A rare contest-worthy snow storm in APR expected over northern portions of the forecast area.

The last time this happened was 13 years ago in 2011 and only three times prior in the Contest/s 25-year history.

- Enter your forecast at the NEWxSFC/s home page at http://www.newx-forecasts.com/

- Follow the top-of-page link from 'Enter Snow Storm Forecast'

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Forecast element: each station/s storm-total snowfall

Deadline for entries:  10 PM EDT TUE ... 02-APR-24
Verification period BEGINS:  12:01 AM EDT WED ... 03-APR-24
Verification period ENDS:  11:59 PM EDT the day snow stops accumulating

By entering ... you also get the chance to see how well your forecast stacks up against NWS Eastern Region's Weather Forecast Offices. Turns out they/ve been easy to beat!

Who Can Enter
Amateur and professional forecasters; broadcasters with or without trained Seals; any and all other weather-biz types and / or wanna-bees; wish-casters ... astrologers ... along with any other universally recognized class of dreamers; Pollyannas or Cassandras ... registered Nostradamuses ... non-violent megalomaniacs ... woolly-bear caterpillars or their Agents ... pest detectives ... ne.wx news group survivors; riders on the StormVista ... refugees from AmericanWx and/or USWeather free agents ... including self-imposed exiles from Eastern Wx ... and of course ... meteorologists.

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Winter '23 / '24 - 'Season-total' Snowfall Forecast Contest: FEB Snowfall Totals

DC
APR-1924

FEB-24 snowfall summary by forecast station.

Rank ordered descending by percent of monthly period-of-record-normal (P-O-R-N).

Green ==> 4th quartile
White ==> less than 4th and greater than 1st quartile (inter-quartile range)
Red ==> 1st quartile

'Obs' reporting '0.05' denote 'Trace' amounts (observed but not measurable)

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FEB Forecast Station Highlights
3 of 25 stations (12%) observed at least 100% of their monthly P-O-R-N snowfall
1 station (ABE) >= 150% of P-O-R-N

Biggest Losers
9 of 25 stations (ALB ... BGR ... BOS ... PWM ... DCA ... SBY ... ORF ... RDU ... RIC) observed <= 10% monthly P-O-R-N.

Not a single flake ... ice pellet ... or hailstone observed at RDU or RIC.

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Season-total-to-Date
FEB P-O-R-N contributes 266" (28%) toward the season-total (D-J-F-M) snowfall of 936"

FEB-24 observed snowfall:  109" (41% of monthly P-O-R-N; 12% of P-O-R-N season-total snowfall)

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Teleconnections

AO / NAO / PNA data

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DEC snowfall totals here
JAN snowfall totals here

Winter '23 / '24 - Snow Storm #2: FINAL Results and Storm Summary

MA - Rte 128
FEB-1978

Complete forecaster verification table and the FINAL Results / Storm Summary available at NEWxSFC/s home page.

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

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Forecast by Observed Snowfall Scatterplots for Top 4 Forecasts

Forecast/s dotted blue line below (above) the Observed snowfall/s solid red line ==> under (over) forecast bias.

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Comparison of Top 4 Forecasts and Observed Snowfall by Station

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Forecaster Skill Score (measured against NWS ER WFOs)

Positive skill values indicate the degree of a forecast/s improvement over NWS forecasts.

Bias:  the arithmetic difference between the average Forecast snowfall and the average Observed snowfall (avgForecast - avgObserved).

Winter '23 / '24 - Snow Storm #2: STP Verification - Preliminary

NYC - Central Park
West Historic District (20-MAR-56)

Preliminary verification of storm-total snowfalls for TUE based on reporting from CDUS41 (CLI) ... CXUS51 (CF6) ... METARs ... and PNS bulletins issued by NWS.

Excellent coverage and reporting.

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HYA
STP derived by applying an inverse distance weighting scheme to BOSPNS vicinity reports from Barnstable county.

Snow-to-liquid ratios (SLR) less than 8:1 are not reported for some stations with measurable snowfall b/c significant liquid and / or freezing precipitation also occurred during the verification period.

The 'TOT SLR' field is a quantity-weighted average.

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