Summery Monday followed by wintry Tuesday
Sunday, September 6, 2020
The headline is not hyperbole! After several days of well-above average temperatures in Steamboat Springs, including a 90 F reading at the Bob Adams airport this past Saturday, we will be going to bed after a summery Monday and waking up to a snowy Tuesday!
The temperature in Steamboat Springs is currently 78 F on this Sunday noon, on its way into the mid-eighties, which is around ten degrees above our average high of 75 F. More warm, but increasingly windy, weather is expected for tomorrow before an unseasonably strong and winter-like cold front blasts through Colorado Monday night.
We should see snowflakes in town with accumulations of an inch or two on grassy surfaces and foliage by Tuesday night possible, so be sure to shake your trees to prevent limb damage. Temperatures during the day Tuesday should be around forty degrees below Monday, with a hard freeze almost certain by Wednesday morning. Unsettled weather and below-average temperatures look to stick around through Thursday before we dry out and temperatures return to more reasonable levels heading into next weekend.
Currently, a Pacific storm that has traveled over the top of a ridge of high pressure in the Gulf of Alaska is mixing with some cold air originally sourced from the North Pole, and will bring a strong cold front through the northern Rocky Mountain states on Labor Day. The cold front will leave most of Monday unaffected for our area, except for strong pre-frontal winds from the west. So fire danger will remain elevated through the day before the front is expected to blast through overnight. Luckily, the bulk of the long Labor Day weekend travel should be completed before the wintry weather arrives.
But travel will likely become difficult over the mountain passes on Tuesday as wet heavy snow should overcome the warm road surfaces and create areas of slush and limited visibility at the higher elevations, and maybe even briefly at lower elevations. And as bad as it will be west of the Continental Divide, more significantly snow east of the Divide and unprepared drivers will likely make the roads down to and possibly within the Front Range treacherous, including the I-70 corridor.
So after high temperatures in the forties during the day Tuesday, Tuesday night will be bone-chilling cold, with the current forecast for our zone from the Grand Junction weather office indicating lows in the 5 to 15 F range! That sounds a bit aggressive to me, but be prepared for a hard freeze Wednesday morning with low temperatures in the teens.
The weather forecast models have struggled with the placement and speed of this storm over the last week, with the latest nod going to the European ECMWF as it looks like the storm will cut off from the main jet stream and form an eddy over the Four Corners region, as suggested by some earlier and more recent iterations of that model.
This eddy, or so-called Four Corners low, is forecast to slowly move northeastward through Thursday, keeping cool and unsettled weather over our area for another couple of days. While precipitation is expected to mostly subside by Wednesday, we may see another round of precipitation wrap around the northern side of the storm for Thursday. And while this will likely be rain at the lower elevations, higher elevations may continue to accumulate snow. Combined with the cold temperatures, all persons recreating or hunting in the higher elevations need to be prepared for winter-like weather from Tuesday through Thursday.
The sun is still high in the sky, so it will do a good job of modifying the air mass starting Wednesday, even in the presence of clouds. Obviously, more clouds mean cooler temperatures, so the longer the storm lingers the cooler it will be, but right now I would expect high temperatures in the fifties on Wednesday, sixties by Thursday and seventies by Friday.
The sun should return for the weekend, perhaps as soon as Friday, as temperatures return to normal to above normal. Still warmer and dry weather is currently advertised for the following work week. I’ll have a synopsis of at least the first part of this impressive winter-like storm for my next regularly scheduled weather narrative on Thursday afternoon.
Hot temperatures through the weekend followed by snow on Tuesday
Thursday, September 3, 2020
Temperatures are already near eighty degrees early this sunny Thursday afternoon in Steamboat Springs as we continue to recover from the cool start to the work week. Temperatures are expected to soar toward ninety this dry Labor Day weekend, followed by a dramatic cold front that may bring snow down the the Yampa Valley floor on Tuesday.
A ridge of high pressure currently over the West Coast will move over our area through the Labor Day weekend, with temperatures forecast to soar ten to fifteen degrees above our average of 76 F. But the dry air will keep our cool nights around, and with an average low temperature of 39 F, we could see several more days of fifty degree intra-day, or diurnal, temperature swings.
Enjoy the summery weather because wintry weather is forecast for Tuesday. As in snow, perhaps down to the valley floor! A chunk of cold air currently moving southward from the North Pole will merge with a Pacific system moving over the top of the ridge of high pressure and bring a strong cold front through our area around Monday night. The current timing will be fortuitous for what is expected to be a big travel weekend, as right now it is likely that most travel should be completed by the time the weather excitement begins.
So while we will be ten to fifteen degrees above average ahead of the cold front over the weekend, leading to record to near-record temperatures, we may be twenty to thirty degrees, or more, colder behind it. While it is not that unusual to see fifty degree temperature swings between the high and low of the day, especially in late summer, it is more unusual to see forty to fifty degree temperature swings between days, which we may approach if the storm evolves as current predicted. And I suspect that we may set some sort of two-day record for the largest temperature swings within a day and between consecutive days, though will have to leave that up to the climatologists to document, if such a record even exists.
It does appear, however, that while Labor Day will be dry and mostly sunny with increasing winds from the northwest, we may see the high temperatures dip a bit from the weekend ahead of the front. So we may not see a fifty-fifty degree intra-inter-day swing by Tuesday, but it may be of more of the forty-forty degree variety.
So according to the current forecast timing, we should wake up to quite the change Tuesday morning. At this point, I would guess we’ll see snowflakes in town, and accumulating snow on the mountain by Tuesday night. There is disagreement among the weather forecast models, as expected, with the European ECMWF more consistent in forecasting a wetter system further west than the Amercian GFS. In fact, the ECMWF cuts the storm off from the jet stream and forms an eddy over the Four Corners region (a so-called Four Corners low), and this may keep cool and unsettled weather around through the rest of the work week. The American GFS, on the other hand, ends the storm by midweek with warmer, but still below average, dry weather forecast for the rest of the work week.
My next regularly scheduled weather narrative on Sunday afternoon will be quite interesting, and I’ll certainly have more details on this upcoming mercurial weather event.
Weak cold front tonight followed by strong cold front Monday night
Sunday, August 30, 2020
Sunny skies are over the Steamboat Springs area this Sunday noon behind the showery day on Saturday, where areas within the city limits picked up between a third and a half inch of precipitation. Most of this occurred just before 5 pm as a line of storms moved through, accompanied by wind gusts of fifty miles per hour at the Bob Adams airport.
A weak cool front is forecast to move through tonight followed by a second strong cold front on Monday night, finally bringing some below average temperatures on Tuesday. But temperature rebound on Wednesday and stay warm through most of the weekend before another cold approaches around the end of weekend.
This afternoon, we should see breezy westerly winds ahead of the fairly dry and weak cool front tonight, with high temperatures once again above our average of 78 F.
High temperatures on Monday should cool a bit and be in the seventies behind the first front, but we’ll see another round of breezy westerly winds ahead of the second front for Monday night. This front is the real deal, and will be accompanied by some moisture, so expect a showery night with some snowflakes at the highest elevations.
Tuesday should have hints of fall, entirely appropriate for the first day of meteorological fall, with high temperatures five or so degrees below average. The cool-down will be brief though, as the still-strong sun will quickly modify the air mass and bring high temperatures on Wednesday back above average.
Parts of a storm currently riding over the top of a ridge of high pressure in the Gulf of Alaska will mix with some cold air currently over the Canadian Plains and may graze our area on Thursday morning. While the brunt of the cold air will be east of the Divide, we could see a chilly Thursday morning that would make it the coldest of the week, especially if we see clear skies.
But again, temperatures will quickly warm under mostly sunny skies, so expect the warm, above average highs to persist into the following weekend. There is some agreement among the longer-range weather forecast models that another Pacific storm will round the ridge of high pressure over the Gulf of Alaska and bring another cold front through our area around Sunday. Early indications are this front would be colder than the one coming this Monday night, but dry and windy, so stay tuned to my regularly scheduled weather narrative on Thursday afternoon where I’ll have more details.
Hot and showery weather ahead of our first cold front around Sunday night
Thursday, August 27, 2020
Temperatures in the mid-eighties and partly cloudy skies are over the Steamboat Springs area this Thursday mid-afternoon. We’ll see continued hot temperatures through the weekend, with afternoon and evening showers possible until the first cold front of the season passes through northern Colorado around Sunday night. And as if to highlight the coming of meteorological fall on Tuesday, the first of September, there may be some snowflakes at the highest elevations of Colorado around Sunday and Monday nights as we finally see temperatures drop to below average for a couple of days.
Currently, a ridge of high pressure over the central and southern Rockies is surrounded by rapidly weakening hurricane Laura to the southeast, storms to our north and a dry area of low pressure over northern California. Monsoonal moisture traveling northward along the western side of the Rockies ridge will remain over our area through the weekend, and portions of the storm to our north and then northern California will combine with the moisture for the chance of afternoon and evening storms. While most of the rain should be light and showery, there is the possibility of brief moderate to heavy downpours around the strongest cells.
A big pattern change comes to our area around Sunday night with the arrival of our first cold front of the season. A storm currently in the Gulf of Alaska is forecast to mix with some cold air from the North Pole and shift our winds to be from the current southwest to the west on Sunday and the northwest by Monday. There may be enough moisture around for some snowflakes at the highest elevations of Colorado, though it is not clear if that happens Sunday night and/or Monday night when a trailing wave passes through.
The most noticeable effect on our weather will be the much cooler temperatures on Monday and Tuesday, with lows in the thirties, below our average of 41 F, and highs falling from five to ten degrees above our average of 78 F before the first front to five to ten degrees below average after the front. Much drier air and breezy northwesterly winds will then invade our area as a stable ridge of high pressure builds over the Gulf of Alaska, keeping this pattern going through the work week.
And while daytime temperatures will warm back towards average starting around midweek, several waves of energy traveling along the eastern side of the ridge look to periodically mix cold air from northern Canada and keep cool morning temperatures in the thirties. After such a hot summer, next week should certainly have hints of fall.
The ridge of high pressure over the Gulf of Alaska is forecast to amplify by next weekend, which might enable Pacific energy traveling over the top of the ridge to again mix with cold Canadian air and bring another cold front through our area around the end of the following weekend or early the next work week.
I should have a better idea of whether we see any snow-dusted peaks early in the coming work week by my next regularly scheduled weather narrative on Sunday afternoon.
Moisture increases this week
Sunday, August 23, 2020
Another hot and hazy day is in store for Steamboat Springs this Sunday with the temperature already up to 84 F on this mostly sunny Sunday noon. Moisture from the southwest is forecast to increase over our area starting tomorrow and lasting for about a week. We need to make the best of what moisture will be available though, as it appears our first cool front, currently forecast for just before the first day of meteorological fall, September 1, will sweep any moisture over our area to the east.
A ridge of high pressure currently centered over the Four Corners will be suppressed to the south and nudged eastward over the upcoming week by a series of storms moving through the Gulf of Alaska and eventually the northern U.S. While the remnants of former-hurricane Genevieve look to skirt north of our area, the southwesterly flow on the western side of the ridge of high pressure will bring monsoonal moisture from the Mexican Plateau over our area. Unfortunately, it may also transport smoke from the Pine Gulch fire near Grand Junction and the Grizzly Creek fire near Glenwood Springs back to the region.
Though hurricane Marco, currently in the Gulf of Mexico and soon-to-be-hurricane Laura, currently over the Dominican Rebublic are forecast to threaten the Gulf Coast through the work week, our area will not be seeing any moisture from these tropical storms. We will have to rely on much more modest monsoonal moisture for the next week, and can expect at least some clouds that will help reduce our forecast high temperatures to around five degrees above our average high of 79 F.
The moisture will also insulate the surface during the night, so expect much warmer low temperatures around ten degrees or more above our average low of 42 F.
Chances for rain increase starting on Monday afternoon, though showers associated with the early part of a monsoon surge usually yield more wind than rain as it takes a day or two for the lower levels of the atmosphere to moisten. In any event, none of the work week days look to produce significant accumulations, though storms that develop could produce brief but locally moderate to heavy rain. Additionally, the moister atmosphere makes it more likely that we may see some rainfall overnight as well.
Our best chance for significant rain will likely wait until later next weekend as one of the Gulf of Alaska storm mixes with some cold air from the North Pole, bringing our first cool front since spring through our area around the beginning of the following work week. There is a lot of variability in the forecast strength and southern extent of this storm, with the American GFS bringing the storm across in several pieces while the European ECMWF has a more coherent storm that passes through earlier.
But both increase rain chances on Sunday before the passage of the cool front, and both eventually have much drier air behind the front as the westerly flow severs the monsoonal moisture tap, with longer-range models keeping the dry air around through at least the next work week.
So for the upcoming week, hope for rain and minimal smoke, and I’ll have more details about our first impending cool front of the season on my next regularly scheduled weather narrative on Thursday afternoon.
