Cooler temperatures to start Friday accompanied by shower chances through Saturday
Thursday, July 25, 2024
The temperature has reached 88 F this Thursday mid-afternoon in Steamboat Springs under mostly sunny but hazy skies. The wildfire smoke from California and the Pacific Northwest should diminish as an approaching cool front drops temperatures into the low eighties on Friday, clearing the smoke from the area and bringing thunderstorm chances that continue through Saturday.
A vortex of low pressure currently centered over central Alberta has disrupted the high pressure ridge over the West, and waves of energy traveling around the vortex will shift our winds to be from the west and southwest starting tonight. Compared to the high temperatures above our average of 84 F the last few days, high temperatures will drop into the comfortable low eighties starting Friday and continuing through the weekend. Fortunately, the NOAA smoke model, which I have started posting again, shows the smoke clearing from our area behind the first wave tonight.
The southern end of these waves will also introduce moisture to our area, bringing moderate shower chances lasting from this evening through Saturday. This includes nocturnal, or overnight showers for tonight and Friday nights that may last into the morning. A short-range weather forecast model predicts clearing later each morning, and any sun that appears will cook the atmosphere and contribute to stronger afternoon and evening thunderstorms on Friday and Saturday. The localized stronger varieties will be able to produce brief moderate to heavy rain, gusty winds and small hail.
Even as the Alberta vortex moves across the central Canadian Plains through the weekend, trailing energy from the Gulf of Alaska keeps a general trough of low pressure over the northern two-thirds of the West Coast through the weekend. Much drier air from the southwest is introduced to our area by Sunday for a very pleasant day with low storm chances.
As the Alberta storm continues to move eastward, the temporarily vanquished ridge of high pressure rebuilds over the West, bringing warmer temperatures in the mid-eighties with very little chance of precipitation to start the work week.
Precipitation amounts are generally underwhelming through Saturday and forecast to be around a tenth of an inch or two, save for the localized storms which are impossible to predict, especially this far in advance. So enjoy the cooldown, hope for some productive storms and check back to my next regularly scheduled weather narrative on Sunday afternoon.
Work week to see slim shower chances and increasing temperatures
Sunday, July 21, 2024
After reaching the low-seventies around noon this Sunday in Steamboat Springs, temperatures have fallen into the sixties behind some early afternoon thunderstorms. Shower chances will persist today on the coolest day of the week before steadily rising high temperatures approach ninety degrees by Thursday. Only slim shower chances exist through Thursday before monsoonal moisture returns by Friday.
As was the case this past week, a stout ridge of high pressure extending from the Mexican Plateau through the Intermountain West toward the Arctic Circle is sandwiched between areas of low pressure over the Gulf of Alaska and Hudson Bay. Fortunately for us, cool air traveling southward along the east side of the ridge has kept the hottest temperatures to our west, and has carried some moisture overhead today that will keep chances for additional showers through the early evening. If we see some afternoon sun, high temperatures may approach eighty degrees, otherwise, we may be left with the noontime high which would be ten degrees below our average of 84 F.
The Gulf of Alaska storm is forecast to slowly wobble ashore along the southern British Columbia coast through midweek and nudge the ridge of high pressure toward our area. Weakening winds from the north will carry increasingly dry and warm air overhead through midweek, with high temperatures reaching average by Tuesday and upper-eighties by Wednesday.
By Thursday, the Gulf of Alaska storm is forecast to be moving along the Canadian border, pushing the top of the ridge eastward and over our area even as the bottom of the ridge remains stubbornly entrenched over the Desert Southwest. Light winds from the west will carry the warmest air of the week overhead on Thursday with high temperatures approaching ninety degrees.
By Friday, the ridge of high pressure will be tilted from the Desert Southwest toward the Great Lakes, allowing winds from the southwest to carry monsoonal moisture overhead. We could see high temperatures drop back toward average on Friday with good shower chances that would persist heading into the weekend.
So enjoy the cool start to the work week, and check back for more details on the weekend weather in my next regularly scheduled weather narrative on Thursday afternoon.
Temperatures to cool toward eighty degrees by Sunday
Thursday, July 18, 2024
Temperatures reached the mid and upper eighties early this Thursday afternoon in Steamboat Springs, but have cooled a bit thanks to a passing shower near the Steamboat Ski Resort that left no measurable rain. Today will likely be the warmest day through the weekend while Sunday will likely be the coolest with high temperatures only reaching around eighty degrees. Shower chances are highest on Friday and decrease considerably for the weekend.
A stout ridge of high pressure extending from the Mexican Plateau through the Intermountain West toward the Arctic Circle is sandwiched between areas of low pressure over the Gulf of Alaska and Hudson Bay. None of these features will move much through the weekend, leaving our area under the influence of subtle features moving southward through the jet stream.
One such feature is a wave of energy currently moving through Montana that is forecast to graze our area on Friday. High temperatures will drop a few degrees toward the mid-eighties along with the best chance for showers through the weekend. However, moisture is limited, so generally only meager precipitation amounts are expected, but a localized thunderstorm could produce brief moderate to heavy rain along with gusty winds.
Slightly drier air behind the eave will bring a degree or two of cooling for Saturday even as slim afternoon and evening shower chances persist.
The Gulf of Alaska low pressure area is forecast to move across the Gulf of Alaska through the weekend, squeezing and amplifying the ridge of high pressure over the Intermountain West. Fortunately, our area will be on the eastern side of this ridge, allowing cool air from the north spinning around the Hudson Bay vortex to drop our high temperature on Sunday toward eighty degrees, almost five degrees below our average of 84 F and our first below-average day in almost two weeks.
There is dry air lurking underneath the ridge of high pressure centered to our west, and it is not clear yet if that will be close enough on Sunday for another day with only slim shower chances.
Not much change in the jet stream is forecast until later in the work week as the Gulf of Alaska storm makes landfall around Vancouver and pushes the ridge of high pressure eastward, perhaps opening the door to some monsoonal moisture from the southwest on the backside of the ridge. So enjoy the pleasant weekend, and check back to my next regularly scheduled weather narrative on Sunday afternoon for more details about that possible pattern change.
Temperatures to moderate this week along with a chance of showers
Sunday, July 14, 2024
A third straight ninety-degree day is only hours away as temperatures are already in the mid-eighties under mostly sunny skies early this Sunday afternoon in Steamboat Springs. Unlike the previous two days, building clouds to our south herald the arrival of some modest moisture that will bring a chance of showers today through Tuesday along with cooling temperatures. Those chances are reduced on Wednesday and Thursday before reappearing on Friday.
A storm on the Canadian Plains has squashed the ridge of high pressure over the West, but not enough to temper another ninety-degree day today. The flattened ridge has allowed light winds from the west to carry monsoonal moisture from Utah over our area, increasing the chance of afternoon and evening showers starting this afternoon and lasting through Tuesday.
While the rain from any showers today will likely evaporate in the dry lower atmosphere before reaching the ground, causing gusty winds, there is a better chance of raindrops hitting the ground on Monday and especially Tuesday as the lower atmosphere moistens. However, amounts will likely be fairly meager as the monsoonal moisture is recycled under the ridge of high pressure over the West.
Additionally, cool air rotating around the storm in Canada will graze our area through Tuesday, first dropping our high temperatures into the upper-eighties on Monday and then near our average of 84 F on Tuesday as the grazing cool front encourages stronger storms. Incidentally, that 84 F average represents our highest average summer temperature, and will be with us for the last two weeks of July and the first week of August.
By midweek, the Canadian storm is forecast to move over the Great Lakes and nudge the rebounding western ridge back to the west. This places our area in a drier northwest flow for Wednesday and Thursday, though afternoon and evening storms will still be possible. Better storm chances reappear for Friday as some energy ejecting out of a Gulf of Alaska storm passes through the ridge, with weather forecast models disagreeing on whether that moisture sticks around through the weekend.
So let’s hope for some rains this week, and I’ll have more details on the weekend forecast in my next regularly scheduled weather narrative on Thursday afternoon.
Hot, hot, hot this weekend
Thursday, July 11, 2024
Though some afternoon clouds are trying to temper the heat, temperatures are already in the upper-eighties under mostly sunny skies this Thursday mid-afternoon. And we can expect even warmer temperatures with a nine handle through the weekend for the hottest days of the summer so far.
A ridge of high pressure currently over the West is sandwiched between areas of low pressure in the Gulf of Alaska and the Great Lakes. A storm moving through the northern Canadian Plains will keep the ridge from amplifying further while nudging it eastward and toward our area this weekend.
The associated heat dome under the ridge means the hottest temperatures of the season so far will be with us this weekend, with high temperatures of ninety degrees or a bit more, almost ten degrees above our average of 83 F. But our daily records in the mid-nineties do not look to be challenged by this heat wave.
Mostly sunny mornings will accompany the heat, and after a mostly sunny Friday, there may be afternoon clouds around on Saturday with the slightest chance of an isolated shower as the intense heating of the ground lifts some meager moisture trapped under the ridge.
Thankfully, mostly clear skies will allow the overnight temperatures to drop to around fifty degrees, around five degrees above our average of 46 F.
More Pacific energy forecast to cross the British Columbia coast late in the weekend should nudge the West Coast ridge eastward on Sunday. Light winds from the south on the backside of the ridge are forecast to carry moisture pooling over the Mexican Plateau over our area by Sunday afternoon in a classic North American Monsoonal pattern, which usually gets going this time of year.
So we should see some more clouds and a slightly better chance for an isolated shower on Sunday, with those chances and coverage increasing to start the work week. Right now, the weather forecast models show only modest moisture through midweek before the West Coast ridge rebounds ahead of another Gulf of Alaska storm and cuts off the limited monsoonal moisture supply.
But subtle changes in the position of the ridge of high pressure over the West can change this forecast, and I’ll have the latest details in my next regularly scheduled weather narrative on Sunday afternoon.
