Forecasts from 2013 and earlier

Summer 2013

Forecast Period: Jun – Aug 13

Forecast Temperatures: Warmer by about 0.5 sigma, and drier by less than 0.5 sigma. CPC was the same.

Forecast Verification (0-2 points): Cool -1.1 F – 2 · Dry -5.5” -0 · CPC 2/0 · Climo 2/0

Winter 2012-2013

Forecast Period: Dec 12 – Feb 13

Forecast Verification (0-2 points): Warm 0 · Wetter 1 · Climo 0/1 · CPC 0/1

Summer 2012

Forecast Period: Jun – Aug 12

Forecast Temperatures: Warmer than normal (0.5- 1.0σ). CPC cooler (0 – 0.5σ)

Forecast Precipitation: Drier by 0.5- 1.0σ). CPC normal.

Primary Reasoning(s): Forecasts for SSTs early on hinted at a three- peat for La Nina.

Forecast Verification (0-2 points): Warm 1 (+4.2 F)· Dry 1 (-9.5”) · Climo 0 / 0 · CPC 0/ 0

Winter 2011-2012

Forecast Period: Dec 11 – Feb 12

Forecast Temperatures: Cooler than normal 0.5- 1.0σ. CPC Warmer by 0.5- 1.0σ.

Forecast Precipitation: Drier by 0-0.5σ. CPC wetter by 0-0.5σ.

Primary Reasoning(s): SSTs remain La Nina like.

Forecast Verification (0-2 points): Warm 0 (+5.7° F)· Wet 1 (+1.07”) · Climo. 0 / 1 · CPC 1 / 1.

Summer 2011

Forecast Period: Jun – Aug 11

Forecast Temperatures: Warmer than normal by 0.5- 1.0σ, CPC cooler by 0.5σ.

Forecast Precipitation: Drier than normal by 0.5σ, and CPC normal.

Primary Reasoning(s): SSTs are in La Nina and remain there.

Forecast Verification (0-2 points): Warm 1 (+2.5° F)· Normal 2 (- 0.70”) · Climo 0 / 2 · CPC 0 / 2

Winter 2010-2011

Forecast Period: Dec 10 – Feb 11

Forecast Temperatures: Cooler than normal (0.5 – 1.0σ). CPC warmer by same.

Forecast Precipitation: Drier than normal by 0.5σ. CPC forecasts normal.

Primary Reasoning(s): SSTs evolving toward La Nina, with a warm anomaly in the gulf of AK. Could be a winter of blocking.

Forecast Verification (0-2 points): Cold 1(-3.9° F)· Normal 2 (+.38”) · Climo 0 / 2 · CPC 0 /2

Summer 2010

Forecast Period: Jun – Aug 10

Forecast Temperatures: Normal. CPC normal.

Forecast Precipitation: Normal. CPC wet.

Primary Reasoning(s): Forecast near normal precip and temps, don’t have a strong feeling either way.

Forecast Verification (0-2 points): Warm – 0 - +2.3° · Wetter – 1 - +4.11” ·Climo 0 / 1 · CPC 0/1

Winter 2009-2010

Forecast Period: Dec 09 – Feb 10

Forecast Temperatures: Normal. CPC warm.

Forecast Precipitation: Normal. CPC dry.

Primary Reasoning(s): Forecast warmer by less than 0.5σ and near normal precip.

Forecast Verification (0-2 points): Cold – 0 (-4.1°)· Wetter – 1 (+1.44”) · Climo 0 / 1 · CPC 0 / 0

Summer 2009

Forecast Period: Jun – Aug 09

Forecast Temperatures: Warmer. CPC normal.

Forecast Precipitation: Drier. CPC normal.

Primary Reasoning(s): Forecast warmer by 0.5 – 1.0σ and drier by the same / La Nina.

Forecast Verification (0-2 points): Cooler – 0 (-3.0°)· Wetter – 0 (+3.08”) · Climo 0 / 1 · CPC 0 / 1

Winter 2008-2009

Forecast Period: Dec 08 – Feb 09

Forecast Temperatures: Normal. CPC much warmer.

Forecast Precipitation: Normal. CPC normal.

Primary Reasoning(s): Forecast warmer by less than 0.5σ and wetter by 0.5σ.

Forecast Verification (0-2 points): Cooler – 2 (-0.8°)· Drier – 2 (-0.74”) · Climo 2/2 · CPC 0/2

Summer 2008

Forecast Period: Jun – Aug 08

Forecast Temperatures: Warmer. CPC normal.

Forecast Precipitation: Drier. CPC normal.

Primary Reasoning(s): Things look very similar to last year, predict warmer and drier by 0.5 – 1.0σ.

Forecast Verification (0-2 points): Cooler – 0 (-1.2°)· Drier - 0 (+6.79”) · Climo 1/0 · CPC 1/0

Winter 2007-2008

Forecast Period: Dec 07 – Feb 08

Forecast Temperatures: Normal. CPC Much warmer.

Forecast Precipitation: Normal. CPC normal.

Primary Reasoning(s): Predict both warmer and wetter, but by less than 0.5σ, based on A and G type anomalies.

Forecast Verification (0-2 points): Normal – 2 (+/- 0.0°) · Wetter – 0 (+3.85”) · Climo 2 / 0 · CPC 0/0

Summer 2007

Forecast Period: Jun – Aug 07

Forecast Temperatures: Warmer. CPC normal.

Forecast Precipitation: Drier. CPC normal.

Primary Reasoning(s): Predict both warmer and drier (by 0.5 – 1.0σ). Collapse of El Nino and move toward La Nina. A, B, or G type.

Forecast Verification (0-2 points): Warmer – 1 (+2.0°)· Drier – 2 (-4.71”) · CPC 0/1 · Climo. 0 / 1

Winter 2006-2007

Forecast Period: Dec 06 – Feb 07

Forecast Temperatures: Normal. CPC Much warmer.

Forecast Precipitation: Drier. CPC normal.

Primary Reasoning(s): The onset of El Nino is forecast. Probably a weak D-type. Forecast for cooler by 0.5σ.

Forecast Verification (0-2 points): Normal – 2 (+/- 0.0°) · Normal – 1 (+ 0.37”) · CPC 0 /2 · Climo 2 / 2

Summer 2006

Forecast Period: Jun – Aug 06

Forecast Temperatures: Warmer. CPC normal.

Forecast Precipitation: Drier. CPC normal.

Primary Reasoning(s): The onset of B- type anomalies and prolonged, but weak La Nina conditions.

Forecast Verification (0-2 points): Warmer – 1 (+2.3°) · Normal – 1 (-0.26”) · Climo 0 / 2 · CPC 0/2

Winter 2005-2006

Forecast Period: Dec 05 – Feb 06

Forecast Temperatures: Normal. CPC warmer.

Forecast Precipitation: Drier. CPC wetter.

Primary Reasoning(s): No strong SST signal, but fall blocking pushes us toward cooler forecast ( 0.5σ).

Forecast Verification (0-2 points): Warmer -0 (+3.5°) · Drier – 1 (-2.87”) · Climo 0 / 0 · CPC 2/0

Summer 2005

Forecast Period: Jun – Aug 05

Forecast Temperatures: Warmer. CPC normal.

Forecast Precipitation: Drier. CPC normal.

Primary Reasoning(s): El Nino wanes similar to 03, but the emergence of B-types push for warm, La Nina develops.

Forecast Verification (0-2 points): Warmer – 1 (+2.2°) · Wetter – 2 (+3.94”) · Climo 0 / 1 · CPC 0/ 1

Winter 2004-2005

Forecast Period: Dec 04 – Feb 05

Forecast Temperatures: Normal. CPC normal.

Forecast Precipitation: Normal. CPC normal.

Primary Reasoning(s): The onset of D- types were similar to 02-03, but not as strong.

Forecast Verification (0-2 points): Warmer – 0 (+3.6°) · Wetter – 0 (+3.02”) · Climo 0 / 0 · CPC 0/0

Summer 2004

Forecast Period: Jun – Aug 04

Forecast Temperatures: Cooler. CPC normal.

Forecast Precipitation: Wetter. CPC normal.

Primary Reasoning(s): Same as above, A’s slightly biased to cool summers.

Forecast Verification (0-2 points): Cooler – 1 (-4.0°) · Wetter – 2 (+2.46”) · Climo 0 / 1 · CPC 0 /1

Winter 2003-2004

Forecast Period: Dec 03 – Feb 04

Forecast Temperatures: Normal. CPC warm.

Forecast Precipitation: Normal. CPC wet.

Primary Reasoning(s): No strong tropical SST type; A’s prominent when forecast made.

Forecast Verification (0-2 points): Normal – 2 (+0.2°) · Normal – 2 (+0.70”) · Climo 2 / 2 · CPC 1/1

Summer 2003

Forecast Period: Jun – Aug 03

Forecast Temperatures: Normal. CPC normal.

Forecast Precipitation: Drier. CPC normal.

Primary Reasoning(s): El Nino wanes (see Ratley et al. 2002)

Forecast Verification (0-2 points): Below – 0 (-1.9o) · Normal - 1 (-1.85”) · Climo 0 / 2 · CPC 0 / 2

Winter 2002-2003

Forecast Period: Dec 02 – Feb 03

Forecast Temperatures: Cooler. CPC warm.

Forecast Precipitation: Wetter. CPC wet.

Primary Reasoning(s): The onset of a weak F/D El Nino similar to the 68-69 season.

Forecast Verification (0-2 points): Cooler – 2 (-1.8°) · Drier – 0 (-1.48”) · Climo 1/1 · CPC 0/0