Rain chances high for most of the work week
Sunday, July 30, 2023
Temperatures are already around eighty degrees in Steamboat Springs under sunny skies late this Sunday morning. Today will be the hottest day of the week with high temperatures once again around ninety degrees before significant moisture belatedly arrives in the first monsoonal surge of the season. Good precipitation chances will exist through at least midweek as high temperatures gradually cool into the seventies ahead of a possibly brief drying trend for the end of the work week.
An upper level ridge of high pressure is currently sitting over the West while a lower level ridge of high pressure is located over Oklahoma. Clockwise flow around the Oklahoma high pressure is bringing moisture from Mexico northward over the Desert Southwest on the backside of the high in a belated arrival of the North American Monsoon.
We’ve already seen some of the moisture over our area this weekend, which is earlier than I thought in last Thursday’s weather narrative, and this has led to some thunderstorms producing as much as a few hundredths of an inch of rainfall scattered around town along with gusty winds yesterday. This additional moisture has also lead to warmer overnight lows around five degrees above our average low temperature of 47 F as it insulates the earth like a blanket.
More of the same is on tap for today as high temperatures once again rise to around five degrees above our average high of 84 F, with modest chances for afternoon and overnight storms. But those chances increase on Monday as copious moisture arrives over our area and precipitation is enhanced by disturbances rotating along western periphery of the high pressure centered over Oklahoma through midweek.
Wetting rains associated with monsoonal surges are usually on the meager side near the beginning as the atmosphere moistens, but look for increasing precipitation chances as storms form later in the day and overnight Monday. And high temperatures will cool to around average thanks to the cloud cover, though those overnight clouds will also keep low temperatures mild and in the low fifties.
Unfortunatley, the same winds transporting the moisture overhead will also transport smoke from the recently started York wildfire in California, located near the southern tip of Nevada, over our area starting tonight and lasting through Monday according to the latest NOAA smoke plume model.
Good chances for wetting rains exist on Tuesday and Wednesday both during the day and overnight as the core of the monsoonal moisture surge remains overhead and high temperatures cool to the mid-seventies. By Thursday, the monsoonal moisture plume is interrupted by winds turning to be from the west ahead of several Pacific disturbances moving inland. Significantly, this is the first time this season the Pacific jet stream has enough energy to modify the persistent ridge of high pressure over the West, and the jet stream will only strengthen going forward as cold air begins to build over the North Pole.
There will likely be enough residual moisture for afternoon and evening storms on Thursday with continued high temperatures in the mid-seventies, with some brief drying ahead of what looks like a period of northwest flow and embedded thunderstorms heading into next weekend. So be sure to check back to my next regularly scheduled weather narrative on Thursday afternoon where I’ll be discussing this upcoming pattern change and what it means for next weekend.
