Wet Monday and Tuesday followed by warming and drying
Sunday, August 1, 2021
Comfortable temperatures in the mid-seventies and mostly sunny skies are over the Steamboat Springs area early this Sunday afternoon. We’ll see a downturn in rain chances today before they increase substantially for Monday and Tuesday ahead of warmer and drier weather that is forecast to last into next weekend.
As has been the case for much of the summer, a ridge of high pressure over the West is sandwiched between areas of low pressure located over the Gulf of Alaska and the Hudson Bay region. However, the orientation of the ridge since this past Wednesday has allowed moisture associated with the North American Monsoon to infiltrate our area as it travels northward along the backside of the ridge, leading to some rain over our region each day. Additionally, an eddy from a storm off the Northeast coast last weekend has slowly traveled across the Gulf Coast states last week and near our area these last few days, providing increased lift and a focus for storms.
In fact, some of the daily rainfall observations have been impressive, but inconsistent, as some areas received good rainfall one day only to see the best rainfall shift to another area the following day, which is usual during monsoon season. Luckily, the regional totals since last Wednesday are more evenly distributed, with generally around a half inch near town and around twice that in some areas in north and south Routt county.
Rainfall chances will decrease for today, though still be present later this afternoon and through the evening as the ridge of high pressure is nudged westward by a storm currently traveling through the Great Lakes that is associated with that Hudson Bay area of low pressure. This shift temporarily moves the monsoonal moisture plume to our west for the day and results in a decreased chance of showers.
However, rainfall chances increase on Monday, and even more so on Tuesday as that eddy originally from the east mixes with some energy ejecting out of the Gulf of Alaska low pressure area and nudges the ridge of high pressure back to the east. This allows the monsoonal moisture stream to move back overhead, and combined with the forcing from the eddy, could produce periods of moderate to heavy rainfall from Monday afternoon through Tuesday night.
Around Wednesday, energy that had earlier ejected out of a strong storm in the Bering Sea will begin moving pieces of that Gulf of Alaska storm eastward, with the southern part of the storm crossing the northern California coast midweek and the remaining part crossing the Pacific Northwest coast early in the weekend.
The first piece of the storm will nudge the ridge of high pressure to the east and bring dry air overhead, warming temperatures and substantially decreasing rain chances, with storm activity relegated back to its usual afternoon and evening time slot.
Even warmer temperatures closer to and a bit above our average of 82 F are forecast for the rest of the work week and the beginning of the weekend, with only small chances for late-day storms. Incidentally, our average daily temperature, shown in the Local Temperatures, Winds & Precipitation section on the SnowAlarm home page, took its first dip of the season today, indicating that, on average, the hottest part of the summer has passed.
Our weather could get more interesting again as soon as the end of next weekend as the northern piece of the Gulf of Alaska storm moves close enough to encourage moisture-rich flow from the south to move back over our area. The timing and evolution of this pattern will almost certainly change over the coming week, but right now it looks like good chances for precipitation later Sunday and overnight followed by cooler weather with continued shower chances to start the next work week.
I expect to again be reviewing good rainfall totals for the coming couple of days in my next regularly scheduled weather narrative on Thursday afternoon, as well discussing that evolving Gulf of Alaska storm and it’s effect on our late-weekend weather, so be sure to check back for the details.
