Bonneville Power Administration operators are prepared for the energy anomaly that they see every Thanksgiving Day.  They have planned for an unusual bulge, or peak, in the morning as millions of people across the Pacific Northwest gather to cook meals, which rely heavily on the use of ovens and other appliances.  After the big meal, system operators will be on hand to ramp power down during the tryptophan drop off.   On a typical November weekday, BPA’s regional load sees two peaks — one in the morning and one in the evening.  But on Thanksgiving a different pattern emerges, ramping up at 9 a.m. as people cook their turkeys and pies.  Power consumption on Thanksgiving then tends to stay up higher throughout the morning compared to a normal day when loads drop off in the middle of the day.  When Thanksgiving loads start to wane, they stay low for the rest of the day, as cooking is done and the tryptophan sets in, rather than increasing again to an evening peak as they would on normal weekdays.