CONTEST STATUS - Last update: FRI ... 14-JUL-17 @ 8:30 PM EDT

Winter '17 / '18 - Snowfall Forecast Contests
19th Annual 'Regular Season'
Season starts when the first flakes start a'flyin'

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17th Annual 'Season-total'
Entries accepted between 01-NOV-17 and 30-NOV-17
Verification period: 01-DEC-17 through 31-MAR-18

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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

Monday, January 23, 2017

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

Displacement event looms near month's end.
 
 
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QBO > 10 kt
Strong STJ (50 kt)
Weak PV (30 kt)
Flow reversals above 5 mb and below 300 mb
 
 
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Cold air mother lode sits over Hudson Bay with full-latitude trough attending.
 
 
 

Saturday, January 14, 2017

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

A sudden stratospheric warming (SSW) event may be in the works for the last week of the month.

After weeks and weeks of a high-speed rotation ... polar vortex (PV) forecasts suggest a significant slowing / weakening.  Slowing of PV suggests a deep layer of easterlies (light blue; lower right corner) over the Pole.

A maturing of this scenario would portend Arctic air drainage into the mid-latitudes.


Stratosphere Diagnostics courtesy Freie Universität Berlin / Department of Earth Sciences / Institute of Meteorology

Thursday, January 12, 2017

Winter '16 / '17 - Snow Storm #2 - Another NWP and Public Forecast Failure

NYC
The season/s third contest-worthy snow storm out-performed not only the suite of numerical models but the professional meteorologists responsible for issuing the official forecasts.

As of Wednesday afternoon (04-JAN) ... the progs and public forecasts for the Friday/Saturday award-winning event (06-JAN thru 07-JAN) all indicated a low probability (40%) for a meager 4" snowfall across a narrow slice of SE VA and NE NC.

When all was said and done ... heavy snowfall was observed from SE VA (up to 12") ... the Delmarva (up to 13") ... LI (up to 7") ... and Cape Cod (where near-blizzard conditions were reported and up to 16").  Eleven contest stations measured at least 4".

Four new daily records:
PVD  10.7"
ISP  9.7"
RIC  7"
SBY   9"

SLRs where at least 4" of snow was observed ranged between ~12:1 and ~25:1

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Some have suggested a 'Call for Forecasts' be issued whenever a potential snow storm looms.
That way ... a contest-worthy storm would seldom be missed.

Sounds like a good idea and it would be if there wasn't four hours of work involved when issuing the call.

Hundreds of email 'invitations' have to been sent (50 at a time ... 30' apart so as not to be flagged as spam 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.

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Then it becomes a judgment call during the evening of the deadline ... deciding whether the storm will be 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 than me when a good snow storm slips through the cracks.
Bottom line: a contest-worthy storm has to be reasonably well-predicted by the numerical weather prediction models and WPC 36-to-48 hours before the first flakes fall for a 'Call for Forecasts' to be issued.

Monday, January 2, 2017

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

Station snowfall summary for DEC-16.
Rank ordered by percent of monthly normal.

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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:  1.786⇧
NAO:  0.48⇧
PDO:  1.17⇩
QBO:  15.09⇧
SOI:  2.6⇧

Sunday, January 1, 2017

Winter '16 / '17 - Snow Storm #1: FINAL Results

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

     
 1st - shillelagh 
 SUMSQ:51  
 SUMSQ Z:-1.032  
 STP:0.6 (1) 
 TAE:19.4 (2) 
 AAE:0.92 (1) 
     
 2nd - Herb @MAWS 
 SUMSQ:64  
 SUMSQ Z:-0.887  
 STP:9.7 (6) 
 TAE:17.7 (1) 
 AAE:0.99 (2) 
     
 3rd - TQ 
 SUMSQ:79  
 SUMSQ Z:-0.721  
 STP:5.9 (4) 
 TAE:22.4 (3) 
 AAE:1.18 (3) 
     
 HM - WeatherT 
 SUMSQ:96  
 SUMSQ Z:-0.537  
 STP:6.5 (5) 
 TAE:24.5 (5) 
 AAE:1.29 (5) 
     

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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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