CONTEST STATUS - Last update: THU ... 20-APR-17 @ 9:40 PM EDT

Winter '17 / '18 - Snowfall Forecast Contests

19th Annual 'Regular Season'

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17th Annual 'Season-total'

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Winter '16 / '17 - Snowfall Forecast Contests
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18th Annual 'Regular Season'
FINAL results here
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16th Annual 'Season-total'
FINAL results here

Thursday, April 20, 2017

Winter '16 / '17 - 18th Annual 'Regular Season' Snowfall Forecast Contest: FINAL Results


Four contest-worthy storms this season.  Tied with Winter '05 / '06 for 15th place.
Under the ‘two-thirds’ rule … forecasters who entered at least THREE forecasts are included in this season's FINAL standings..

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Top 5 Forecasts (Error statistic:  SUMSQ)
SUMSQ is the primary measure of forecaster skill (lower the better).
Accounts for the magnitude and distribution of the storm-total snowfall for all stations.

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Top 5 Forecasts (Error statistic:  Total Absolute Error - TAE)
TAE is the secondary measure of forecaster skill (lower the better).
Accounts for the magnitude of snowfall at each station.

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Top 5 Forecasts (Error statistic:  RSQ)
RSQ is a supplementary measure of forecaster skill (higher the better).
Accounts for how well the variability of the observed snowfall was accounted for by the forecast.


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Average Z-scores for Forecasters who submitted entries for all four snow storms.

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Winter '16 / '17 was only the third season without a JAN snow storm.
 
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Hope to see y'all again next winter.

Saturday, April 8, 2017

Winter '16 / '17 - 18th Annual 'Regular Season' Snowfall Forecast Contest: The End is Nigh

Central Park ... NYC
19-FEB-41
Despite our longing for one more contest-worthy snow storm ... the long wave pattern shows little inclination to alter its ridiculously stubborn regime of processing 'all' SFC LOWs through the Great Lakes region.

Sure hasn/t been a great season for nor'easters in general or nor'easters climbing the coast from low latitudes specifically.

Most seasons ... it/s all said and done by early MAR.
Average date of the last 4" or greater snowfall:
CAR 23-MAR
BGR 15-MAR
PWM 08-MAR
ORH 07-MAR
BTV 06-MAR
CON 06-MAR
ALB 06-MAR
BGM 06-MAR
BOS 25-FEB
BDL 24-FEB

However ... there are exceptions.
Latest date of the last 4" or greater snowfall:
CAR 16-MAY
PWM 11-MAY
CON 10-MAY
ALB 10-MAY
ORH 09-MAY
BGR 24-APR
BTV 23-APR
BGM 22-APR
BDL 21-APR
BOS 10-APR

Source:
NOWData http://www.nws.noaa.gov/climate/index.php



The end of the Winter '16 / '17 snowfall forecasting season appears nigh.
All else equal ... the season will close on SAT ... 15-APR.

Sunday, April 2, 2017

Winter '16 / '17 - 16th Annual 'Season-total' Snowfall Forecast Contest: FINAL Results



Complete station-by-station forecaster verifications at the Contest/s web site here.

Two perfect forecasts
Donald Rosenfeld 100" @ CAR
Mitchel Volk 15" @ PHL

Near misses
Jessica_wxgirl 0.05" error @ RIC (7.2")
Shillelagh and Jessica_wxgirl 0.1" error @ MDT (23.9")
donsutherland1 0.1" error @ ORH (75.4")
MillVillWx 0.2" error @ ALB (58.3")
kevinmyatt 0.2" error @ NYC (30.2")
weathermbug ... TQ ... and DAROOSTA 0.2" error @ SBY (9.8")
Herb @MAWS and weathermbug 0.2" error @ ORF (5.4")
snowman 0.3" error @ BTV (91.7") and 0.2" error @ EWR (31.4")
Donald Rosenfeld 0.5" error @ BGM (104.5")


Season-total snowfall from all stations (1041") came in 14% above the period-of-record normal (914").  Winter '16 / '17 ranks 6th highest among other Contest years since winter '04 / '05 ... the season when BGR and BGM were added to the station list. 

Saturday, April 1, 2017

Winter '16 / '17 - Season-total Snowfall Forecast Contest: Observed Snowfall Station Summary

New England FTW!
 

Winter '16 / '17 - Season-total Snowfall Forecast Contest: MAR totals

Station snowfall summary for MAR-17.
Rank ordered by percent of monthly normal.


Station snowfall summary for Winter '16 / '17 - Season-to-date snowfall through MAR

Green ==> 75th percentile
White ==> 50th percentile
Red ==> 25th percentile
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Teleconnection indexes and month-over trend (updated as they become available)
AO:  1.365⇧
NAO:  0.74⇩
PDO:  0.74⇧
QBO:  14.35⇩
SOI:  5.1⇧

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Winter '16 / '17 - Last Gasp?

Philly
THU and FRI/s snowfall over our northern forecast stations may have been this winter/s last gasp for a contest-worthy snow storm.

Station / NWS mid-range forecast (") / STP (")
ALB / 3.5 / 1.8
BDL / 0 / 1
BTV / 2.5 / 2.5
ORH / 5 / 1.5
BOS / 5 / 0.6
CON / 10 / 5.7
PWM / 5 / 3

Four measly stations (five if you include the upper limit at ALB) were expected to see more than nuisance snowfalls.   In the end ... but one came through.

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Will keep the window open a little longer for the possibility for one last snow storm.

Over the forecasting contest/s 18 seasons ... there have been five contest snow storms in April ... the last one coming in 2011.  The return period is 4.5 years ... so we're 'overdue' for another.  If not ... the 'Regular' season will end with four snow storms (ranked 15th; top-ranked seasons:  '02 / '03 and '03 / '04 with 10 storms each).

Winter '16 / '17 - Temperature Departure from Normal: Progress Report

UPDATED for MAR anomalies:


  
 
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Cohen has some ground to make up in the east.
 
Will FEB offer a lifeline?
CFSv2 image courtesy WxAmerica
 

Sunday, March 26, 2017

Winter '16 / '17 - Snow Storm #4: NESIS

Rank:  23
NESIS:  5.03
Category:  3
Description:  Major

Large format image here.

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NOAA has yet to report how many square miles the storm covered and how many millions of people it affected.

Friday, March 24, 2017

Winter '16 / '17 - Interim Standings: 2

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


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Complete interim statistics table and charts at the Contest/s web site here.
Forecaster verification statistics for Winter '16 / '17 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.

Saturday, March 18, 2017

Winter '16 / '17 - Snow Storm #4: FINAL Results

UPDATE:
THX to Forecaster Roger Smith for alerting us to important errors in the STP verification data (forgot in include 13-MAR snowfall - 1D10T error).  Stats and standings have been corrected.

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Original post 17-MAR-17 @ 10:15 PM EDT
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Forecaster's station verifications and the storm summary at NEWxSFC/s home page.
http://www.newx-forecasts.com/

     
 1st - Shillelagh 
 SUMSQ:864  
 SUMSQ Z:-1.627  
 STP:28.9 (5) 
 TAE:86.8 (1) 
 AAE:3.47 (1) 
     
 2nd - WeatherT 
 SUMSQ:1264  
 SUMSQ Z:-1.024  
 STP:45.8 (9) 
 TAE:129.0 (3) 
 AAE:5.16 (3) 
     
 3rd - Brad Yehl 
 SUMSQ:1401  
 SUMSQ Z:-0.816  
 STP:46.3 (10) 
 TAE:133.1 (4) 
 AAE:5.32 (4) 
     
 HM - JessicaCain 
 SUMSQ:1417  
 SUMSQ Z:-0.792  
 STP:49.1 (11) 
 TAE:138.1 (5) 
 AAE:5.53 (6) 
     

 

Thursday, March 16, 2017

Winter '16 / '17 - Snow Storm #4: Preliminary Verification

Table of preliminary storm-total snowfalls for TUE and WED from CDUS41 and CXUS51 bulletins.

Exceptions:
HYA
Storm-total snowfall report from PNSBOX.

ORH and BDL
15-MAR/s daily CLI and CF6 bulletins carry 'MM' as daily snowfall at post-time.  Daily snowfall total assessed as 'T' after evaluation of METARs.  Value subject to change pending CDUS41 and CXUS51 bulletin updates.

 SBY and RIC
 METAR reports of PL

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Stations observed at least:
Trace - 25
4" - 17
6" - 14
8" - 11
10" - 11
12" - 11
15" - 6
18" - 2

Max melt-water at BGM (1.92")
Other stations with > 1" melt-water:
MDT (1.75")
ALB (1.58")
ORH (1.54")
BDL (1.54")
ABE (1.28")
BTV (1.13")
PWM (0.99")

Snow-Liquid Ratios (SLR) for areas with mixed precipitation ... such as ISP and JFK ... are not reported.

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15 new daily records.
14-MAR-7
BGM - 31.2" (5.9"; 1991)
BTV - 17.8" (10"; 1980)
ALB - 17" (12.9"; 1958)
PWM - 16.3" (10.6"; 1961)
CON - 15.6" (6.6"; 1984)
MDT - 14.7" (8.3"; 1999)
ORH - 14.4" (11.5"; 1958)
ABE - 12.4" (8.4"; 1958)
BDR - 7.1" (3"; 1958)
EWR - 7" (4.6"; 1958)
BOS - 6.6" (3.8"; 1942)
JFK - 5.1" (2.1"; 1999)
IAD - 4.1" (4"; 1999)
ISP - 3.4" (2"; 1999)

15-MAR-17
BTV - 12.6" (4.1"; 1940)


Please report any errors in Comments along with a link to the correct data.
Final results expected NLT FRI evening.




Monday, March 13, 2017

Winter '16 / '17 - Snow Storm #4: The Forecasts

Rookie 1
Intern 0
Journey 0
Senior 13 (includes NWS)
TOT 14

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

BLUE ==> 25th percentile
RED ==> 75th percentile
White STP cells range between the 25th and 75th percentile.

Heaviest snowfall (>= 15") consensus along and the right of CAR - BGR - PWM - BOS - ISP - ORH - CON - CAR with a closed action center around ABE.  Lollypop expected at ORH.

What's that conventional wisdom about the NAO and NE snowstorms again?

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Everyone/s station-by-station forecasts posted to NEWxSFC/s web site @ http://www.newx-forecasts.com/

Preliminary snowfall verifications will probably be posted FRI evening as long as significant snowfall doesn't extend into FRI.
FINAL results possibly by SAT evening.

Saturday, March 11, 2017

Winter '16 / '17 - Snow Storm #4: Call for Forecasts!

NYC
19-MAR-56
So much for spring giving winter the bum's rush!

Forecast element: storm-total snowfall
Deadline for entries:
10:30 PM EDT ... SUN ... 12-MAR-17
Verification period begins:
12:01 AM EDT ... MON ... 13-MAR-17
Verification period ends:
When the flakes stop flyin'

Enter your forecast at the NEWxSFC/s home page @ http://www.newx-forecasts.com/
Follow the top-of-page link from 'Enter Storm Forecast.'

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As always ... there/s no cost ... no fees ... no advertising ... nor 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 ) and a valid e-mail ... if you want a copy of your forecast sent to your Inbox.

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Contest may be cancelled before deadline if storm appears to fizzle.

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Post has been updated to correct the month of the verification period beginning

Friday, March 10, 2017

Winter '16 / '17 - Today's Unworthy Snow Storm

NYC
Alfred Stieglitz (1870s)

UPDATE (11-MAR-17 @ 11:30 EST)
Yesterday's system turned out to be more of a nuisance than anything else and certainly not contest-worthy.

Plowable snowfall (inches):
HYA - ~7
ABE - 4.5
PVD - 4.4
BDR, ISP - 4

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Yesterday afternoon, NWP models and operational weather forecasters finally caught on to today/s marginally contest-worthy snow storm over the northern M-A and coastal SNE.  This coming after several days and multiple runs suggesting skimpy snowfall totals i.e., less than plowable ... and unwelcome liquid precipitation over the forecast stations.

Not the first time this has happened this season nor seasons in the past; however ... it does point to a significant lack of consistent ability to forecast snow storms where the storm-total may or not be plowable and whether the event is contest-worthy.

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Some have suggested issuing a 'Call for Forecasts' whenever it appears there's a chance for a contest-worthy snow storm.  If were only that simple!

A fair amount of work comes with issuing a 'Call for Forecasts'.

Hundreds of email invitations have to been sent (50 at a time ... 30' apart so as not to be flagged as spam by your ISP or blocked by my ISP).
The contest/s web site has to be updated.
The contest/s web log has to be updated.
The contest/s Facebook page has to be updated.

Then it becomes a judgment call deciding whether the storm was contest-worthy (six to eight stations with more than nuisance storm-total snowfall i.e., >= 4").

Collecting surface ... upper air ... and remote sensing data used in the final analysis and storm summary reporting takes time while the event is unfolding. All for naught if the storm fizzles.

Believe you me ... no one is more disappointed when a snow storm slips through the cracks.

Bottom line: a contest-worthy storm has to be reasonably well predicted by the numerical models and WPC 24-to-36 hours before the first flakes fall for a 'Call for Forecasts' to be issued.

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Final thought:
The number of forecast stations affected with more than nuisance snow totals is one of several criterion for deciding whether a snow storm is contest-worthy.  The number ranges between six and eight.

In this case ... the number of stations would have been eight instead of six.
The reason:  EWR ... BDR ... JFK .. and ISP are relatively close together as are PVD and HYA and there'd likely be relatively small variations in the storm-total snowfalls between stations.

Saturday, March 4, 2017

Winter '16 / '17 - Season-total Snowfall Forecast Contest: FEB totals

Station snowfall summary for FEB-17.
Rank ordered by percent of monthly normal.

 
Station snowfall summary for Winter '16 / '17 - Season-to-date through FEB

Green ==> 75th percentile
White ==> Less than 75th and greater than 25th percentile
Red ==> 25th percentile

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Teleconnection indexes and month-over trend (updated as they become available)
AO:  0.340⇩
NAO:  1.00⇧
PDO:  0.70⇩
QBO:  14.78⇩
SOI:  -2.2⇩

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Monday, February 20, 2017

Winter '16 / '17 - Sudden Stratospheric Warming: Watch #2 - UPDATE 1

Displacement event/s peak progged for early next week.

 
PV displaced SW by warm pulse.
Center of anticyclone does not advance as far south as 31-JAN/s event.
 
 
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Strong anticyclonic couplet above 10 mb

Sunday, February 19, 2017

Winter '16 / '17 - Interim Standings: 1

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


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Complete interim statistics table and charts at the Contest/s web site here.
Forecaster verification statistics for Winter '16 / '17 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 17, 2017

Winter '16 / '17 - Season-total Snowfall Forecast Contest: JAN totals

Station snowfall summary for JAN-17.
Rank ordered by percent of monthly normal.

 
Station snowfall summary for Winter '16 / '17 - YTD JAN

Green ==> 75th percentile
White ==> Less than 75th and greater than 25th percentile
Red ==> 25th percentile

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Teleconnection indexes and month-over trend (updated as they become available)
AO:  0.942 ⇩
NAO:  0.48 ⇔
PDO:  0.77 ⇩
QBO:  14.92 ⇩
SOI:  1.3 ⇩

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Thursday, February 16, 2017

Winter '16 / '17 - Forecaster Storm Data

Here

Winter '16 / '17 - Sudden Stratospheric Warming: Watch #2

Could be the season/s final stratospheric warming event.
Images from 15-FEB-17 ECMWF run.


Weak high-altitude zonal flow returns after the recent SSW event.

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Flow above 30 mb reverses and strengthens as the PV is once again displaced.
Flow throughout the depth of the troposphere (evidence of the downward propagation from the previous SSW?) also reverses.

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Cold pool from previous SSW event progged to settle above the NOAM/s Arctic Circle near month/s end.

Stratosphere Diagnostics courtesy Freie Universität Berlin

Wednesday, February 15, 2017

Winter '16 / '17 - Snow Storm #3: FINAL Results

Forecaster verifications and storm summary at NEWxSFC/s home page.
http://www.newx-forecasts.com/

     
 1st - donsutherland1 
 SUMSQ:172  
 SUMSQ Z:-0.885  
 STP:6.2 (2) 
 TAE:40.4 (2) 
 AAE:2.25 (3) 
     
 2nd - WeatherT 
 SUMSQ:184  
 SUMSQ Z:-0.814  
 STP:24.3 (6) 
 TAE:43.1 (4) 
 AAE:2.27 (4) 
     
 3rd - Brad Yehl 
 SUMSQ:186  
 SUMSQ Z:-0.805  
 STP:17.3 (5) 
 TAE:42.0 (3) 
 AAE:2.21 (2) 
     
 HM - TQ 
 SUMSQ:224  
 SUMSQ Z:-0.591  
 STP:3.3 (1) 
 TAE:38.9 (1) 
 AAE:2.16 (1) 
     

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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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