Wednesday, February 25, 2015

Winter '14 / '15 - Interim Standings: 4


Under the ‘two-thirds’ rule … forecasters who have entered at least four forecasts are included in these interim standings.

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Complete interim statistics table and charts at the Contest/s web site here.
All verified forecast statistics from all forecasters for all Winter '14 / '15 contest storms here.

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SUMSQ errors for each contest snow storm are normalized 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. Same idea as dropping the lowest quiz score before computing the final grade.

Thursday, February 19, 2015

Winter '14 / '15 - Storm #6: FINAL Results

Full forecast verifications and summary for Storm #6 at the Contest/s web site.
     
 1st - Donald Rosenfeld 
 SUMSQ:31.60  
 SUMSQ Z:-0.935  
 STP:5.2 (1) 
 TAE:20.2 (1) 
 AAE:0.88 (1) 
     
 2nd - Brad Yehl 
 SUMSQ:40.01  
 SUMSQ Z:-0.814  
 STP:12.8 (3) 
 TAE:24.6 (4) 
 AAE:0.99 (2) 
     
 3rd - WeatherT 
 SUMSQ:44.9  
 SUMSQ Z:-0.743  
 STP:14.3 (5) 
 TAE:22.9 (2) 
 AAE:1.00 (3) 
     
 HM - donsutherland1 
 SUMSQ:45.2  
 SUMSQ Z:-0.739  
 STP:12.9 (4) 
 TAE:24.3 (3) 
 AAE:1.01 (4) 
     

SUMSQ: sum of square errors
STP: storm-total precipitation error
TAE: total absolute error
AAE: average absolute error
(number): category rank

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Click images to enlarge.

Wednesday, February 18, 2015

Winter '14 / '15 - Storm #6: Preliminary Verification

Preliminary storm-total snowfalls for MON and TUE from CDUS41 and CXUS51 bulletins.  Good coverage and reporting.

SBY/s STP estimated by applying RIC/s SN:H2O (10.4:1) to SBY/s storm-total liquid precipitation.

HYA/s STP interpolated from vicinity reports carried in PNSBOX.

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One new daily record
TUE ... 17-FEB-15
ISP - 3.4" (2.5"; 1996)

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Interesting to see the dramatic difference in SN:H2O where the 850-700 mb layer was warmer over southern portions of the forecast area.

Please report any errors in Comments along with a link to the correct data.

Final results THU evening.





Tuesday, February 17, 2015

Winter '14 / '15 - Storm #5: FINAL Results

Full forecast verifications and summary for Storm #5 at the Contest/s web site.
     
 1st - TQ 
 SUMSQ:379.25  
 SUMSQ Z:-1.436  
 STP:27.5 (1) 
 TAE:56.3 (1) 
 AAE:2.09 (1) 
     
 2nd - donsutherland1 
 SUMSQ:477.79  
 SUMSQ Z:-1.194  
 STP:42.2 (2) 
 TAE:69.0 (2) 
 AAE:2.56 (2) 
     
 3rd - Mitchel Volk 
 SUMSQ:590.9  
 SUMSQ Z:-0.916  
 STP:44.5 (4) 
 TAE:79.8 (4) 
 AAE:3.07 (4) 
     
 HM - snowman 
 SUMSQ:688.2  
 SUMSQ Z:-0.677  
 STP:75.0 (9) 
 TAE:90.7 (8) 
 AAE:3.36 (7) 
     

 SUMSQ: sum of square errors
 STP: storm-total precipitation error
 TAE: total absolute error
 AAE: average absolute error
 (number): category rank

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Click images to enlarge.

Winter '14 / '15 - Season-total Snowfall Forecast Contest: JAN Totals

Monthly station snowfall summary for JAN-15.
Rank ordered by percent of monthly normal.
 
Green ==> 75th percentile
White ==> Less than 75th and greater than 25th percentile
Red ==> 25th percentile
 
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Teleconnection Indexes
AO:  +1.092
NAO:  +1.79
PNA:  +0.14
PDO:  +2.45 (monthly record)
QBO:  -26.70 (monthly record)
MEI:  +0.406 (DEC-JAN)

Winter '14 / '15 - Season-total Snowfall Forecast Contest: DEC Totals

Monthly station snowfall summary for DEC-14.
Rank ordered by percent of monthly normal.
 
Green ==> 75th percentile
White ==> Less than 75th and greater than 25th percentile
Red ==> 25th percentile
 
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Teleconnection Indexes
AO:  +0.413
NAO:  +1.86
PNA:  +0.37
PDO:  +2.51 (monthly record)
QBO:  -25.35  (monthly record)
MEI:  +0.578 (NOV-DEC)

Winter '14 / '15 - Storm #6: The Forecasts!

Rookie 0
Intern 0
Journey 1
Senior 9
TOT 10


Forecasts are ranked by their storm-total precipitation (STP).

BLUE ==> 25th percentile.
RED ==> 75th percentile.
STP cells without color are between the 25th and 75th percentile.

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Heaviest snowfall (+6") consensus along and to the right of a line from  BWI - SBY - RIC - IAD - BWI

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Strong PNA signal.
AO playing catch-up.
NAO still wandering the wilderness.  Once NAO goes negative ... winter will turn cold and snowy.

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Everyone/s station-by-station forecast at the Contest/s web site.

Winter '14 / '15 - Storm #5: Preliminary Verification


Preliminary storm-total snowfalls for SAT and SUN from CDUS41 and CXUS51 bulletins.
Generally good coverage and reporting; although ... daily liquid reports not available for ORH and PVD.

SBY/s 0.2" STP estimated from the METAR 6-group at 10:1 SN:H2O and observation of -TSSN.

HYA/s STP interpolated from vicinity reports.

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One new daily record
SUN ... 15-FEB-15
BOS - 13" (8.5"; 1904)

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Please report any errors in Comments along with a link to the correct data.
Final results TUE evening (if the power stays on at NEWxSFC World Headquarters)