Tuesday, March 03, 2015

Winter '14 / '15 - Storm #7: Call for Forecasts!

ACY Boardwalk - 1928
Pattern change may be coming but not before  there's another contest-worthy snow storm. 

Real mess of mixed precipitation types and Arctic temperatures in the offing will make for a challenging late-season forecast.

Contest for Storm #7 may be cancelled prior to the deadline if fewer than six stations are likely to observe at least a 4" snowfall.

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Forecast element: storm-total snowfall
Deadline for entries:  10:30 PM EST ... WED ... 04-MAR-15

Verification begins:  12:01 AM EST ... THU ... 05-MAR-15
Verification ends:  when the snow stops falling

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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.

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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).

Wednesday, February 25, 2015

Winter '14 / '15 - Ice Rings Manhattan Island

Brooklyn Bridge
AP Photo/Seth Wenig

Saturday, February 21, 2015

Winter '14 / '15 - VCP32: Nothing Left to Live For


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.

Friday, February 20, 2015

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)