One thing I don't hear much about is the inversion factor in El Nino winters. You'd think that if there was a ton of high pressure between late November and early February, the resulting inversions might actually cause below-average temperatures in the Northwest's lowlands. But for some reason both this year and early 2005 were relatively dry without getting too much in the way of "cool pools" in the Willamette Valley, Umpqua/Rogue Basin, and Columbia Basin. I'd like to hear an explanation of why this is the case.
After about the 2nd week of February it makes sense that dry would also mean warm due to the strong sun angle. Oddly enough this March hasn't been that warm overall yet. Imagine how far along the deciduous trees might have been by now if the first half of the month had come out 3F or 4F above seasonal norms!
Karl S. Bonner
Amateur meteorology and botanical phenology geek
Comments
El Nino winters
One thing I don't hear much about is the inversion factor in El Nino winters. You'd think that if there was a ton of high pressure between late November and early February, the resulting inversions might actually cause below-average temperatures in the Northwest's lowlands. But for some reason both this year and early 2005 were relatively dry without getting too much in the way of "cool pools" in the Willamette Valley, Umpqua/Rogue Basin, and Columbia Basin. I'd like to hear an explanation of why this is the case.
After about the 2nd week of February it makes sense that dry would also mean warm due to the strong sun angle. Oddly enough this March hasn't been that warm overall yet. Imagine how far along the deciduous trees might have been by now if the first half of the month had come out 3F or 4F above seasonal norms!
Karl S. Bonner
Amateur meteorology and botanical phenology geek