After a record setting Wednesday temperature-wise, and a near record day expected Thursday, some much cooler temperatures will be on their way for the weekend. The warm ridge of high pressure over the Great Basin will start to break down a bit on Friday as a back-door low pressure center drops down from Alberta, bringing a cold front that is unlikely to give us any rain or snow this far to the west (although a shower or two isn’t impossible Sunday), but will certainly cool us down from these record levels. Look for the high on Friday to drop to the low 60s, the low 50s on Saturday, and the mid-40s by Sunday. None of these numbers are unusual for this time of year, but will come as a shock to the system after our latest hot spell.
“If a butterfly in Tokyo flaps its wings, it can cause rain a week later in New York” is an old adage that at least holds some truth in theory, if not being absolutely provable. So landmasses can certainly produce some effect on jet streams, even though the effect isn’t always obvious. Tomorrow, I’ll talk about ways land can affect winds six or more miles above it.