2025 forecast contests -- enter for December 2025 contest (deadline 06z Dec 1st) and also for winter snowfall forecast contest (see latest post in thread for details)

[Roger Smith]

Tracking anomalies and projected end of month ...

_____________________________ DCA _NYC _BOS __ORD _ATL _IAH ___DEN _PHX _SEA

_____ (anom 1-16) __________ -9.2 _ -8.7 _ -7.7 __-10.7 _-4.9 _-3.2 __+8.3 _ +5.1 _ +6.4

_____ (p anom 1-31) ________ -5.0 _ -4.5 _ -4.0 __-6.0 _-2.5 _-1.0 __+6.0 _ +3.5 _ +2.5

 

(17th) _ A more variable regime will cut into large negative anomalies in eastern and central regions. It will stay generally mild in the western regions but SEA will have a larger reversal as arctic air builds in for a while later in the month. 

 

[PositiveEPOEnjoyer]

6 hours ago, Roger Smith said:

Tracking anomalies and projected end of month ...

_____________________________ DCA _NYC _BOS __ORD _ATL _IAH ___DEN _PHX _SEA

_____ (anom 1-16) __________ -9.2 _ -8.7 _ -7.7 __-10.7 _-4.9 _-3.2 __+8.3 _ +5.1 _ +6.4

_____ (p anom 1-31) ________ -5.0 _ -4.5 _ -4.0 __-6.0 _-2.5 _-1.0 __+6.0 _ +3.5 _ +2.5

 

(17th) _ A more variable regime will cut into large negative anomalies in eastern and central regions. It will stay generally mild in the western regions but SEA will have a larger reversal as arctic air builds in for a while later in the month. 

 

No chance ORD finishes at -6. Something like -3 or so is more likely to be the final departure, maybe even -2 if we get a few super warm days.

[so_whats_happening]

Man went for a warmer BOS than anticipated. Also the lack of a break in the warmth out west a bit of a surprise.

[Roger Smith]

Yes, Edmonton Alberta is running 12 F below normal (7 C below) but that colder regime has stayed locked into central Canada most of the last week to ten days. It hasn't even been below average here near the US border.

Just a general note to all participants, I will open up a thread for 2026 contest forecasts and see how that goes, perhaps we will continue on, and perhaps not. Depends on level of interest, it's easy enough for me to keep doing what I normally do but at the same time, I don't want people to enter out of anything other than an enthusiasm for tackling the challenge. 

So if anyone happens to post Jan 2026 forecasts after this post, I will move them over to the new thread which will be open almost as soon as I post this. Happy new year, I am not going to post any preliminary scoring for December, we will let the results be a total surprise on January 1st or 2nd. 

[Roger Smith]

As I was told, ORD did not stay that close to -6 F  above normal but they didn't get into the real core of that crazy warmth that is now about to get the boot east ... it has played havoc with my ATL and IAH estimates and DEN has stayed well above +10 just turning cold yesterday. 

Think the final values now look like being around

-5.0 _ -5.0 _ -5.0 __ -4.0 _ +1.5 _ +4.0 ___ +10.0 _ +6.0 _ +3.5

will present some preliminary scoring on that basis, going to need to figure out max-60 mercy rule scoring for the western locations. 

[Roger Smith]

Preliminary scoring for December 2025

(version 1, raw scores only) _ note for raw scores in anomalies greater than +5 or -5, error deductions are 1 pt per 0.1 error in range 5.0 to actual, and raw scores are no lower than 0.1 per correct-sign predicted 0.1 deg. When an anomaly exceeds 10.0, scores are then based on a proportional basis, for example, a +5.5 forecast against an +11.0 outcome scores 50 (raw). As another example, a forecast of +0.7 scores 07 if that is higher than the raw score would otherwise be. ... then a max-60 rule is invoked if no raw score is above 60. These max 60 scores are generally in equal increments from zero to 60, adjusted by fairness considerations when compared to the spread of raw scores. I have some objective rules that I try to apply to that adjustment but with contest results perhaps depending on exactly what the details will be (you can see DEN, PHX scores and possibly IAH will need adjustments), I will just give you the raw scores now and will be working out how adjustments affect the overall annual outcome. No idea in advance what that's going to look like (although I can't see potential for outcome to be changed by the max-60 adjustments) ...

<<< Raw scores only >>>

FORECASTER _____________ DCA_NYC_BOS _ east _ ORD_ATL_IAH _ cent _ c/e_ DEN_PHX_SEA_west_TOT 

Mercurial ______________________ 00 _ 00 _ 00 _000 _ 30 _ 80 _ 60_ 170 _170_ 00 _ 00 _ 00 _000__ 180

hudsonvalley21 ________________ 00 _ 00 _ 00 _000 _ 52 _ 96 _ 50_ 198 _198_ 04 _ 26 _ 24 _054__ 252

Scotty Lightning _______________ 00 _ 00 _ 00 _000 _ 40 _ 80 _ 40_ 160 _160_ 10 _ 10 _ 40 _060__ 220 

____ Normal ____________________00 _ 00 _ 00 _000 _ 20 _ 70 _ 20 _ 110 _110__ 00 _ 00 _ 30 _030__ 140

wxallannj ______________________ 20 _ 22 _ 26 _068 _ 34 _ 86 _ 54 _174 _242 _ 20 _ 34 _ 80 _134__ 376

DonSutherland1 ________________20 _ 40 _ 40 _100 _ 86 _ 80 _ 52 _218 _318 _ 14 _ 12 _ 32 _058 __ 376

BKViking _______________________24 _ 26 _ 34 _084 _ 54 _ 88 _ 44 _186 _270 _ 13 _ 34 _ 60 _107 __ 377

___ Consensus ________________26 _ 34 _ 36 _ 096 _76 _ 86 _ 42 _204 _300_ 10 _ 20 _ 40 _070__370 

so_whats_happening __________ 28 _ 26 _ 32 _084 _  72 _ 86 _ 44 _202 _286 _ 11 _ 32 _ 42 _085__ 371

Tom ____________________________38 _ 54 _ 56 _148 _ 98 _ 52 _ 30 _180 _ 328 _ 06 _ 20 _ 52 _078__ 406

RJay ___________________________ 40 _ 40 _ 40 _120 _ 80 _ 94 _ 30 _204_ 324_ 10 _ 20 _ 40 _070__ 394

RodneyS _______________________ 72 _ 60 _ 46 _178 _ 86 _ 20 _ 38 _126 _ 304 _ 13 _ 05 _ 40 _058__ 362

Roger Smith ____________________ 80 _ 76 _ 90_ 246_ 62 _ 04 _ 00 _066 _312_ 00 _ 00 _ 00 _000__ 312 

wxdude64 ______________________88 _ 62 _ 66 _ 216 _ 86 _ 20 _ 06 _112 _328_ 00 _ 08 _ 76 _084__ 412

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(highest and lowest forecasts above are color coded; all forecasts are below normal for ORD)

__ Persistence ___(Nov 2025)___ 00 _ 16 _ 10 _026 _ 00 _ 60 _ 72_ 132 _158_ 57 _ 59 _ 72 _188 __346

 

EXTREME FORECASTS as of preliminary scoring ...

DCA _ wxdude would win with lowest forecast

NYC, BOS _ Roger Smith would win with lowest forecasts

ORD _ currently just outside a win-loss outcome (4th lowest forecast high score) ... outcomes below -4.1 would make it a win-loss (RodneyS, wxdude64 win; Roger Smith loss)

IAH, DEN, PHX, SEA _ definitely four wins for wxallannj with high forecasts, Mercurial also (as non-regular entrant for IAH). BKViking ties for PHX. 

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<<< RAW SCORES for DEN and PHX will need converting to max-60, IAH possibly also but adjustments there would be very small anyway >>>

Will adjust around end of month and merge with annual scoring ... given the lead Tom had before this month I cannot see how the raw-score to max-60 adjustments can remove enough of his differential to make much difference to what currently looks like Tom maintaining a 150-200 point advantage over nearest rivals. 

(actual forecasts)

 

FORECASTER __________________ DCA _NYC _BOS __ORD _ATL _IAH ___ DEN _PHX _SEA 

Mercurial ______________________ +4.0 _+2.0 _+1.0 __-0.5 _+0.5 _+2.0___ -1.0 _ -3.0 _ -1.5

hudsonvalley21 ________________ +1.3 _+1.4 _+1.0 __ -1.6 _+1.7 _ +1.5 ___ +0.4 _+1.8 _-0.3

Scotty Lightning _______________ +1.0 _+1.0 _+0.5 __ -1.0 _+0.5 _+1.0 ___+1.0 _+1.0 _+0.5

____ Normal ____________________ 0.0 __0.0 __0.0 ____ 0.0 __0.0 __0.0 ____ 0.0 __0.0 __0.0

wxallannj ______________________ -1.0 _ -1.1 __-1.3 ___ -0.7 _+0.8 _+1.7 ___+2.0 _+2.2 _+2.5

DonSutherland1 ________________-1.0 _ -2.0 _-2.0 ___ -3.3 _+2.5 _+1.6 ___+1.4 _+1.1 _ +0.1

BKViking _______________________-1.2 _ -1.3 _ -1.7 ___ -1.7 _+0.9 _+1.2 ___ +1.3 _+2.2 _+1.5

___ Consensus ________________ -1.3 _ -1.7 _-1.8 ___ -2.8 _+0.7 _ +1.1 ___ +1.0 _+1.5 _+0.5

so_whats_happening __________ -1.4 _ -1.3 _ -1.6 ___ -2.6 _+0.8 _+1.2 ___+1.1 _ +2.1 _ +0.6

Tom ____________________________-1.9 _ -2.7 _-2.8 ___ -3.9 _-0.9 _+0.5 ___+0.6 _+1.5 _+1.1

RJay ___________________________ -2.0 _-2.0 _-2.0 ___ -3.0 _+1.2 _+0.5 ___+1.0 _+1.5 _+0.5

RodneyS _______________________ -3.6 _-3.0 _-2.3 ___ -4.7 _-2.5 _+0.9 ___+1.3 _+0.5 _+0.5

Roger Smith ____________________-4.0 _-3.8 _-4.5 __ -5.9 _ -3.3 _ -1.5 ___-3.6 _ -2.9 _ -2.4

wxdude64 ______________________-4.4 _-3.1 _-3.3 __ -4.7 _ -2.5 _ -0.7 ___-0.9 _+0.8 _+2.3

-----------------

(highest and lowest forecasts above are color coded; all forecasts are below normal for ORD)

__ Persistence ___(Nov 2025)___ +0.4 _-0.8 _-0.5 __+1.1 _+3.5 _+5.4 ___+5.7 _+3.9 _+2.1

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