Heidke Skill Score (HSS) values for each verification season from Oct-Dec 1999 onwards for the Interior Southwest domain Each core region was verified as a "Hit" if the correct tercile was predicted, and as a "Miss" if the wrong tercile was predicted, or if the predicted tilt in the odds was under 3% (be it for above-normal, near-normal, or below-normal moisture in the tercile sense), or if the prediction was ambiguous (3% or higher tilt in BOTH tail terciles). There are two skill scores: if all missed forecasts (in the above sense) are counted as a total loss, the Heidke Skill Score is labeled "non-EC HSS", and is followed in the table below by its areal coverage (=number of cores that had an unambiguous tilt of 3% or more, as percent of total number of cores in that season). If all ambiguous or small-tilt (under 3%) predictions are considered "climatological forecasts", they are scored with a 1/3 hit rate, and added into the "all HSS" score (=number of "Hits", plus 1/3 times the number of small-tilt (and ambiguous) predictions, divided by the total number of cores in that calendar season, times 100%). Skill is computed at 1/2 month lead-time (issued in the month just prior to the target season). Since not all of the station data is in hand at this point, some skill scores may still change at a later point. However, that should not result in a systematic bias. The chosen lead-time reflects the best skill performance for all seasons except for July-September which has been slightly better predicted at 1.5 months lead-time than at 0.5 months (forecasts issued in May have performed better than the ones issued in June). YEAR TARGET FORECAST SKILL SEASON non-EC areal all HSS coverage HSS 1999 OND +25 67% +17 2000 JFM +06 89% +05 2000 AMJ 0# 67% 0# 2000 JAS +14 70% +10 2000 OND -50# 83% -42# 2001 JFM +06 89% +05 2001 AMJ 0# 67% 0# 2001 JAS +33* 90% +30* 2001 OND +100* 67% +67* 2002 JFM 0 100% 0 2002 AMJ +14 78% +11 2002 JAS -17 90% -15 2002 OND -50# 67% -33 2003 JFM -13# 89% -12# 2003 AMJ +36 78% +28 2003 JAS -29# 70% -20# 2003 OND 0 50% 0 2004 JFM -13# 89% -12# 2004 AMJ +06 89% +05 2004 JAS +33* 90% +30* 2004 OND +10 83% +08 2005 JFM 0 100% 0 2005 AMJ +57* 78% +44* 2005 JAS +06 80% +05 2005 OND +63 67% +42 2006 JFM +67* 100% +67* 2006 AMJ +25 67% +17 7yr AVG OND +14 69% +10 7yr AVG JFM +08 94% +08 7yr AVG AMJ +20 75% +15 6yr AVG JAS +06 83% +06 For each calendar season, the best individual forecast is flagged by an asterisk (*) - or two, if there was a tie (as in JAS), while the worst forecast is flagged by a pound symbol (#) - ties occur in OND, JFM, and AMJ. Reminder: HSS = -50 = every single prediction was in the wrong tercile = WORST possible case, HSS = 0 = one third of all predictions were in the correct tercile = "coin-toss", HSS = +50 = two out of three predictions were correct = "very good", HSS =+100 = every single prediction was a "hit" (OND2001!) = BEST possible case. A detailed analysis of these results will be posted after the Jul-Sep 2006 results are in. Meanwhile, the bottomline is that ON AVERAGE there is above-zero skill in all seasons!