Monarch butterfly populations have fallen over the past few decades, probably because of the increasing number of severe weather events that are killing more and more of these beautiful fliers.
The butterfly effect refers to the unpredictable consequences of small changes — the idea of a butterfly flapping its wings in one part of the world, causing a large storm to occur some time later in another area of the globe. In much the same way, the ever-increasing amounts of heat-trapping carbon dioxide gas that is put into the atmosphere could have consequences we cannot predict. Possibly one tragic example is the Western monarch butterfly that winters along the beaches of the Central Coast. In 1990, nearly a quarter of a million of these orange-and-black-winged creatures could be found at Pismo State Beach in December. This year only about 25,000 monarchs are expected, according to Tim Storton, a local monarch butterfly expert.
Monarch populations have fallen over the past few decades, probably because of the increasing number of severe weather events that are killing more and more of these beautiful fliers.
As the atmosphere warms, it’s able to hold a greater amount of water vapor. When this water vapor condenses into rain or snow, it releases tremendous amounts of latent heat. This is the energy source that storms need to flourish. Unfortunately, these storms are taking a toll on the butterflies.
Monarch butterflies are known for their incredible migration that takes them from coastal California to far-flung locations throughout the West and as far north as Canada.
These insects are cold-blooded, and most begin their journey for the temperate Central Coast beaches before the first cold winter storms, which can freeze them. Unfortunately, these storms are becoming more intense with time.
Monarchs born in August or September make the long migration. Because they live only about eight months, they are only able to make one trip. Every day through mid-December, the butterfly population will continue to increase at Pismo State Beach.
In February, after they mate, they begin to leave for the interior regions of California. They fly east looking for milkweed, which their caterpillars eat nearly exclusively. Another factor contributing to the butterflies’ decline is the drop in milkweed.
The first new generations of butterflies only live for two to six weeks. In fact, it may take several generations of butterflies to reach Canada. The butterflies that return to the Pismo State Beach the following winter are the descendants of the butterflies that took refuge there the year before.
One of the great scientific mysteries is how these new generations of monarchs know the same routes their ancestors flew. Perhaps the navigation and generational life expectancy information is stored in the butterfly’s DNA.
Let’s hope that climate change doesn’t make these beautiful butterflies and their amazing migration just a bittersweet memory.
Today’s weather report
An 80-knot jet stream in the upper atmosphere and strong to gale force (25- to 38-mph) northwesterly winds at the surface will push along a weak but fast moving cold front over the Central Coast this morning as it heads toward Southern California.
This system will produce some light rain showers this morning. Rainfall amounts will be light, around one-tenth of an inch. Many inland locations in San Luis Obispo County may not receive any rain.
Snow levels will drop to 4,000 feet with the majority of the precipitation falling along the Sierra this morning, resulting in possibly 2 to 6 inches of snow accumulation between 4,000 and 6,000 feet.
Clearing will develop this afternoon. Clear and cool conditions will develop tonight into Monday morning with areas of frost in the North County.
Increasing high pressure will produce night and morning gusty northeasterly (offshore) winds. These winds will give clear dry weather with cool nights and mild afternoons Monday through Wednesday.
A wet and windy storm system could move onto the West Coast anywhere from Thursday into Saturday depending on which long-range forecast model you want to believe. At this time, it appears that strong to gale force (25- to 38-mph) southeasterly (prefrontal) winds will develop Thursday, followed by moderate to heavy rain Friday. Today’s surf report
This morning’s 5- to 7-foot northwesterly (310-degree deep-water) sea and swell (with a 5- to 11-second period) will continue at this height and period through tonight.
A 6- to 8-foot northwesterly (300-degree deep-water) swell (with an 11- to 17-second period) will arrive along the Pecho Coast on Monday, decreasing to 5 to 7 feet Tuesday.
This northwesterly swell will further lower to 3 to 4 feet (with an 8- to 11-second period) Wednesday.
Strong to gale force (25- to 38-mph) southeasterly winds will generate a 6- to 8-foot southerly (180-degree shallow-water) seas Thursday, followed by a 10- to 12-foot westerly (270-degree deep-water) swell (with a 15- to 17-second period) Friday.
Seawater temperatures Seawater temperatures will range between 55 and 57 degrees through today, decreasing to 54 and 56 degrees Monday and remaining at this range through Wednesday.