Contest # 7 - Teleconnections

Five new daily snowfall records. PNA did its part. No help at all from the all important NAO during the run-up or day of event. AO apparently off vacationing in the Caymans @ +5 STD.

Contest # 7 - Verification

Preliminary storm-total snowfalls from CDUS41...PNS...and CF6 bulletins for FRI.

CAR had a period of -SN overnight and BGR was observing -SN @ post time...but its intensity was light. TAFs forecast TEMPO -SNSH along the SNE coast this morning. Significant new accumulations are not expected...altho final verification will reflect any new amounts.

CAR/s CDUS41 report is suspect with 0.1" SN from 0.02" liquid for an odd 5:1. BTV and BGR SN:H2O were 20+.

New daily records (2/22)
BDL: 7.8"
BDR: 7" (1.6"; 1950)
EWR: 6.8" (5.5"; 2001)
JFK: 6.9" (4.7"; 2001)
ISP: 5.5"

Please report errors in Remarks.
Final results and storm summary SUN evening.

Contest # 7 - The Forecasts

Forecasts for Contest # 7 have been posted to the web site.

12 forecasts
3 rookies
9 veterans

Consensus heavy snowfall axis from ORH - BOS - BDL - ORH where 7 - 8" expected.

Storm-total Precipitation (STP)
MIN: 70.45" (WintersGrasp)
MAX: 122.09" (wxduff)
AVG: 87.89"
Median: 87.83"

Contest # 7 - Call for Forecasts

Latest forecast challenge features dueling streams and dynamic model solutions. Vertical temperature profiles expected to be complex...promising plenty of phase change complications.

Deadline: 10:30 PM EST THU…21 FEB 2008
Forecast verification begins: 12:01 AM EST FRI…22 FEB 2008

Enter your forecast via the Contest/s web site.
Follow the link to 'Enter Storm Forecast.'

Please enter 0.05 for trace amounts instead of a 'T.'

The Contest Administrator will post all forecasts to the NEWx Google Group within 30 minutes after the deadline and to the Contest web site the following day.

Contest subject to cancellation before the deadline…if forecast conditions warrant.

Updates and announcements are posted on the Contest/s web log.

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Forecasters need to register once before entering…even if they were registered last year.

Registration is simple…requiring only a username and password. If you provide a valid e-mail address…a copy of your forecast will be sent to you. Please ensure your browser is enabled to accept first-party cookies.

Each contest must have a minimum of seven (7) forecasters for the results to be included in the end-of-season standings.

The NE.Wx Snowfall Forecast Contest (NEWxSFC) is a multi-month event that continues into late March or early April. In general…contests are held whenever a decent…synoptic-scale storm rears its head and threatens at least a half-dozen forecast stations with more than nuisance snowfall amounts. Forecasters are called to post their 'storm total' snowfall predictions…on deadline…for 27 NWS / FAA observing stations scattered about New England and the Mid-Atlantic regions. The Contest Administrator determines the deadlines for entries…verifies all forecasts…and publishes the final results to the Contest/s web site.

Please be sure to read the rules before entering the contest b/c your entry constitutes agreement to abide by them.

You can find the Contest Rules and additional information about error scoring…current monthly snowfall climatology from NCDC…daily CPC teleconnection indices…daily NESDIS N-Hemi snow cover…and NWS Daily Climate Bulletins (CDUS41) by pointing your browser here.
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Steel Cage Grudge Match - GFS v. NAM / SREF

The screen capture is too dark in its reduced Blogger size. Click it for better resolution.



It/s a comparision of the 84-hour 5H and PMSL fields from today/s 09z SREF and the 12z runs of the NAM / GFS.

Notable 5H amplification differences in the GFS lead to significant differences in the HIGH/s placement prior to precipitation/s onset. The flatter GFS soln pushes the HIGH into the Atlantic Ocean.

The GFS HIGH is offshore directing SE wind into the mid-Atlantic; whereas...the NAM / SREF HIGH is farther west producing northerly wind flow.

The GFS 85H 0°C isotherm (not shown) is along the NC / VA border but it/s ~150 miles farther south along the NC / SC border in the NAM / SREF.

Contest # 7?

Global LR models are in close agreement in establishing favorable values of the North Atlantic Oscillation (NAO) and Pacific North-American (PNA) toward week/s end.




Development of GFS-progged northern stream short-wave on the EC FRI and SAT appears inhibited from carving out a full-latitude trof by stubborn SE heat ridge. Could well be a case where teleconnection indices are loaded and pointed in the right direction but are insufficient to overcome other features.

Interim Standings

There have been six Contests to date. Under the ‘two-thirds’ rule…forecasters who have entered at least four forecasts are included in this interim summary.



Donsutherland1 remains in 1st place with a best '4-out-of-6' average SUMSQ Error Z-score of -1.214.

2nd Place: Shanabe (-0.928)
3rd Place: TQ (-0.731)



Complete data table @ the Contest web site.

SUMSQ errors for each contest snow storm are normalized with a 'Z-score'...then averaged to compute the standings. Forecasters who have entered at least 2/3 of all snow storm contests are included in the standings.

If a forecaster has participated in more than two-thirds of all snow storm contests...then Z-scores from their 'best two-thirds' forecasts are used to calculate interim and final standings. Same idea as dropping the lowest quiz score before the final grade is computed.

Click images to enlarge.

Contest # 6 - Results

Donsutherland1 (aka WxMachine?) spanked us all AGAIN with a rousing SUMSQ error of 40.4"...a 60% improvement over the Consensus error of 102".

He hit the trifecta AGAIN placing 1st in Total Absolute Error (23.1")...Average Absolute Error (0.86").

His Storm Total Precipitation (STP) error of 2.1" was within 5% of the observed STP and 87 eye-popping percent better than Consensus.

Congratulations...Donsutherland1. Nicely done!

2nd Place: Mitch Volk
3rd Place: dmcguriman
HM: TQ

Full forecast verification and summary at the web site.

One entry was disqualified from ranking because the normalized SUMSQ Error was an extreme outlier (more than 3 standard deviations above the mean).

Contest # 6 - Verification

(UPDATED 2/15 - record snowfall @ CAR)

Preliminary storm-total snowfalls from CDUS41...PNS...and CF6 bulletins for TUE and WED.

No suspect reports.

New daily records:
None
2/13
CAR: 8.1" (7"; 1994)

Final results and storm summary FRI.

RDU - Winter '08

SPECI KRDU 140356Z 32009G15KT 290V350 6SM -SN BR FEW007 BKN014 OVC028 02/00 A2980 RMK AO2 RAE55SNB55 P0000

SPECI KRDU 140446Z VRB06KT 3SM -PLSN BR OVC007 01/M01 A2982 RMK AO2 RAE0355SNB0355PLB18 P0002

METAR KRDU 140451Z VRB05KT 3SM -PLSN BR OVC007 01/00 A2983 RMK AO2 SLP100 RAE0355SNB0355PLB18 P0002