I once heard Navajo culture characterizes summer’s thunderous, pounding, here-and-gone summer rains as the “male” rains, while winter’s softer, longer, more consistent rains are the “female” rains. I don’t know whether Navajos actually do talk or think about rain this way, but such characterizations make a lot of sense to me. While summer rains get all the press, with their ominous cumulus clouds and their brash flash-flood inducing comings and goings, winter rain is what nurtures and propogates our plants, animals (including homo sapiens). Just like a real momma.
Winter in the desert carries a big question mark, and that question mark belongs to precipitation. How much will fall? When will it fall? Will it fall as water, or as snow? How much water we receive, and the quality of that receipt, is perhaps the most significant factor in the desert year. While the hot, hard, baked earth of summer can’t hope to absorb the torrential blasts of the monsoon season, winter’s supple, porous soils soak up the water it receives to feed the plants, animals, and water table for the remainder of the year.
One of many special interest groups focused on winter precipitation is the “wildflower lobby”. These folks watch the patterns of winter rainfall over years, studying how the quantity and timing of winter rains affects the geography, timing, and abundance of wildflower blooms in each spring. When we get lots of rain, calendars are marked and reservations are made to be sure to catch the spring bloom in all of its glory.
Abby Snow posted this in PDF form over on the Canyons Group, and I thought I’d reproduce it here on the blog. The image represents early precipitation for the 2010 – 2011 winter, as received in Stovepipe Wells, Death Valley (NOT ZION), and the article is oriented to Death Valley wildflowers, but I think the gist of the message is relevant to Zion. If we get some good rain in Jan/Feb/March, look for a great year of wildflowers in Zion and throughout the Desert Southwest!
With the recent winter rainfall, the question on every wildflower fan’s mind is “will it bloom”? The answer is not easy. Even with large amounts of rainfall, if the timing and temperature are not perfect, the bloom can fail. This winter, we are off to a very good start and seedlings are starting to sprout. However, the precipitation has been patchy and unless we get more in the next couple of months, the bloom could be very short lived.The above graph shows monthly precipitation amounts for Cow Creek, going back six years to the great bloom of 2005 (in blue). 2010 was also an excellent year, although the bloom was very late and shorter lived than 2005. 2007 (in gray) was the worst bloom of the decade due to a completely dry winter and very little rain in the spring. Compared to the previous years, December 2010 had an extremely high amount of rain (63 mm). Undoubtedly we will have some bloom this spring. If we get any additional rain in January and February, the bloom will be prolonged.
A huge caveat here is that this is data from just one weather station. The Stovepipe Wells station reported twice the amount of December precipitation. Storms were visible to the North, South and West of Cow Creek September through November. I predict a good bloom in the Stovepipe Wells, Mesquite Flat area in March. I have also heard that at the South end of the Badwater road, there is a lot of green vegetation sprouting. Chances are very good it will bloom somewhere.