Meager rain chances best on Friday and Sunday
Thursday, August 25, 2022
Cloudy skies with temperatures in the mid-seventies are over the Steamboat Springs area this Thursday mid-afternoon. A couple of storm systems passing to our north on Friday and Sunday will give us our best chance for meager rainfall, with Saturday looking like the sunniest day of the weekend.
The northern half of the ridge of high pressure that was over the West this week has gone missing thanks to a storm system currently moving east across northern Idaho. But the clockwise circulation around the remaining southern half of the high pressure has allowed monsoonal moisture from the southwest to move overhead, creating the cloudy skies. Storm chances are slim today, but slightly better tomorrow as the Idaho storm moves into Montana. We could see some afternoon and evening showers as the southern end of that storm combines with a disturbance in the monsoon flow currently near Las Vegas.
Saturday looks mostly sunny and dry with temperatures around our average of eighty degrees before the upstream storm system responsible for pushing the Idaho storm eastward crosses the Gulf of Alaska and takes a similar track, but slightly further south. We should see a grazing cool front on Sunday afternoon which will drop temperatures by several degrees and increase winds from the west. There may be some showers ahead of the storm overnight Saturday and later Sunday, though those chances currently are slim.
The ridge of high pressure is forecast to rebound over the West following the weekend disturbances with sunny weather and high temperatures exceeding eighty degrees for the work week. This currently looks to extend through the long Labor Day weekend, but stay tuned to my next regularly scheduled weather narrative on Sunday afternoon where I’ll have any updates for the traditional end-of-summer weekend.
Summer returns after a fall-like weekend
Sunday, August 21, 2022
After a morning of light rain, a mix of sun and clouds is over the Steamboat Springs area with temperatures in the upper sixties, lending a fall-like feel to the weather. But summer returns for at least the first half of the week with mostly sunny skies and high temperatures around eighty degrees, perhaps followed by another monsoonal surge of moisture to close out the work week.
An eddy of low pressure in western Colorado is currently trapped under a high pressure system over much of the West. The eddy is forecast to slowly move to the southeast through Monday morning before passing into New Mexico by the afternoon. Any showers this afternoon and evening will be moving generally from east to west, opposite of the normal storm motion, as winds move counter-clockwise around the eddy, especially later in the day.
By Monday, the eddy will be far enough removed from north-central Colorado that winds will turn to be more from the north as air follows a clockwise rotation around the still dominant western high pressure system. Expect drier air bringing mostly sunny skies with high temperatures several degrees above our average high of eighty degrees along with a slight chance of a passing storm in the afternoon or evening through Wednesday.
Meanwhile, a storm currently off the Pacific Northwest coast is forecast to penetrate the western ridge of high pressure and loiter over Washington State through the beginning of the week before being pushed eastward by some energy ejecting out of a large storm in the Gulf of Alaska. While the eddy is forecast to travel across the northern tier of states, it will be close enough so that the southerly flow ahead of the storm will once again carry monsoonal moisture from the south over our area. So right now, good chances for more wetting rains occur on Thursday and Friday before another brief drying tend is advertised for the following weekend.
That the current eddy over Colorado and the one forecast to form over Washington are penetrating the ridge of high pressure rather than being deflected around it is a sure sign that fall is coming. This is certainly not to say that some hot days are not still ahead, but the cold air from the northern latitudes is growing colder each day, and eventually a storm will blast through the ridge of high pressure rather than just meandering through it. So enjoy another summery work week, and check back on Thursday afternoon for my next regularly scheduled weather narrative.
Shower chances and some smoke for the weekend
Thursday, August 18, 2022
Temperatures in the low eighties and mostly sunny skies are over Steamboat Springs this Thursday afternoon. After the past couple of days of cooler weather with some hints of fall, the more usual summertime weather returns for the weekend with chances for showers each day. And unfortunately it appears like we will see some smoke from the wildfires burning in Idaho.
A ridge of high pressure currently sitting over the Intermountain West is under assault by an eddy located over Lake Tahoe slowly moving east and a developing storm over Wisconsin moving south. The center of the high pressure is currently over Idaho and part of it is forecast to move southeastward toward Colorado tonight. A chaotic pattern then emerges that will make the specifics of a weather forecast difficult, especially for north-central Colorado.
After a warm and dry day today, with high temperatures several degrees above our average of 81 F, we should see increasing haze on Friday as smoke from the Idaho wildfires moves overhead thanks to the southward moving high pressure cell. By the afternoon, that cell is forecast to be dissipating over central Colorado, but not before encouraging monsoonal moisture from the south to eventually move over our area by the afternoon, bringing the chance of afternoon and evening thunderstorms. While the storms are far from certain, we should at least see some clouds around which should give us several degrees of cooling.
By Saturday, that Lake Tahoe eddy is forecast to slide into the Great Basin, with the southerly flow ahead of the eddy encouraging more monsoonal moisture to move over Colorado. The winds overhead will be variable, and it is not clear if the smoke hangs around and if we see better moisture, so a chance of afternoon storms remain, including the possibility that they may occur overnight. And if we get the storms, rainfall could be heavy at times along with small hail, frequent lighting and gusty winds.
By Sunday, it appears the Great Basin eddy will have moved far enough east to directly affect our weather, so expect good chances for showers during the day and overnight, with high temperatures around average. This looks to extend into Monday followed by a drying trend, but check back for my next regularly scheduled weather narrative on Sunday afternoon to see if that forecast persists.
Showers likely through Monday
Sunday, August 14, 2022
A nice shower has passed through the Steamboat Springs area early this Sunday afternoon and dropped temperatures from the low eighties to the mid-sixties. Shower chances look to stay high for the rest of today, overnight, and through Monday before decreasing for the rest of the work week ahead of another possible monsoon surge for next weekend.
A ridge of high pressure over much of the West has been and is still sandwiched between two persistent areas of low pressure, one over the Aleutian Islands and Gulf of Alaska and another centered over Hudson Bay and extending southward along the East Coast. Storminess traveling through the Gulf of Alaska and crossing the British Columbia coast has been modifying the ridge of high pressure this summer by either deforming it or nudging it eastward, or both, as it travels along the Canadian border well north of our area.
The monsoonal moisture plume drawn northward on the backside of the ridge of high pressure has been incredibly persistent this summer, and looks to hang on past its usual mid-August demise. Currently, some energy crossing the Pacific Northwest coast has nudged the ridge of high pressure to the east and reinforced a wave moving northward on the backside of the high pressure, which will keep good shower chances present for today, tonight and tomorrow. The clouds and showers tomorrow should drop our high temperatures on Monday into the mid-seventies, around five degrees below our average of 82 F.
By Tuesday, as that wave of energy moves to our east, the ridge of high pressure squirts back to the west and brings warmer and drier air overhead. There is weather forecast model disagreement on whether there will be enough moisture around for Tuesday showers, but more sun than Monday will allow high temperatures to approach average.
Wednesday and Thursday are looking on the dry side with just above average temperatures, though a quick afternoon or evening shower cannot be ruled out. By Friday, the weather forecast models agree that a wave of energy traveling through the area of low pressure over the Gulf of Alaska will affect the area of high pressure over the West in some way, and the winds from the south ahead of that low pressure may carry another surge of monsoon moisture overhead for the weekend. So stay tuned to my next regularly scheduled weather narrative on Thursday afternoon where I’ll know more about the shower chances for the coming weekend.
Moderating temperatures and increasing shower chances for the weekend
Thursday, August 11, 2022
Temperatures are already in the mid-eighties this Thursday afternoon along with some developing storm clouds along the higher terrain. The current stretch of unseasonably hot temperatures this week will cool a couple of degrees each day through early next week, along with good chances for afternoon and evening showers thanks to another surge of monsoonal moisture.
A ridge of high pressure extending through the Rocky Mountains is currently sandwiched between broad areas of low pressure located off the Pacific Northwest coast and Hudson Bay. Clockwise rotation around the center of the high pressure located just to our north near the Wyoming border is bringing winds from the southeast and east overhead, which is unusual and opposite of what normally occurs.
Bob Adams airport recorded a high temperature of 92 F at 5:15 pm DST yesterday thanks to the ridge of high pressure, but we also saw elevated temperatures and winds in some areas of town on Tuesday and Wednesday as shown in the accompanying time series for the last three days of temperature at my weather station near the base of the Steamboat Ski Resort and winds near the top. Note the temperature spike from 64 F to 74 F just before midnight on the 10th and the near 80 F temperatures that extended through midnight on the 11th in the first chart. Also note the strong winds from the southeast observed near the top of the mountain each night, which carried the mountain-top air down the slope of the Park Range where it warmed as it descended.
The low pressure area off the Pacific Northwest coast is forecast to rotate and weaken as it is forced into the Canadian Rockies through the weekend by yet another mass of cold air currently moving over the Aleutian Islands. This will weaken the ridge of high pressure overhead and nudge it eastward, which will allow monsoonal moisture from the south to move overhead.
The storms today will probably be confined first to the higher elevations before they move off the terrain and bring a threat of showes to the lower elevations through this evening. As the high pressure continues to move to our east tomorrow, winds switch to be from the south with a better chance of showers for the afternoon and evening as monsoonal moisture is brought overhead, and high temperatures drop a few degrees.
More of the same is expected for the weekend and into early next week as the ridge of high pressure is nudged further to the east, eventually forcing winds to be from the southwest and west in the more usual pattern. While high temperatures continue to drop a few degrees each day, reaching our average high of 82 F by Sunday, there are also likely to be areas of energy rotating around the high pressure for Sunday and early next week which will provide a better environment for wetting rains.
So be on the lookout for storms moving in the opposite direction of what you’re used to today, and check back for my next regularly scheduled weather narrative on Sunday afternoon where I’ll discuss the prospects for another week of monsoonal shower chances.
