Thursday, July 25, 2019
The Steamboat Springs area is currently experiencing a relatively rare humid Thursday morning, as temperatures in the lower seventies combine with a locally high relative humidity (RH) of 50%. After a chance of afternoon and evening storms tonight and Friday, we’ll see a good chance for wetting rains on Saturday before several days of drier weather are forecast to last through the early part of next week. Moisture then returns around midweek for more precipitation chances.
A 50% RH may not sound high, compared to the seventies and eighties experienced along the Eastern Seaboard this past weekend, but it sure feels humid compared to yesterday when RH was in the low-thirties this time of day. Low-level dry air filtering in from Wyoming this afternoon will help dry the air mass, but there will still be a chance of afternoon and evening storms today and Friday.
A high chance of showers exist for most of Saturday as a monsoonal disturbance currently traveling north across southern California makes its way along the western periphery of ridge of high pressure located over the Desert Southwest. The disturbance will be forced eastward across the Great Basin on Friday, thanks to a storm near Vancouver that crosses the coast early in the weekend, and moves over our area during the day Saturday.
Showers on Saturday could start early in the day, perhaps before noon, before becoming heavier in the afternoon and evening. While afternoon temperatures remain below average due to the clouds, humidity will once again climb leading to periods of localized moderate to heavy rain for those areas fortunate enough to be under a slow-moving storm cell.
Much drier air is forecast to wash over our area starting Sunday behind both the monsoon disturbance and the Vancouver storm racing eastward across the southern Canadian Plains. We should see plenty of sun with temperatures near or slightly above our average of 82 F that last through the early work week.
The ridge of high pressure is forecast to drift eastward from the Desert Southwest to the southern and central Rockies through Monday, and the southerly flow along the western periphery of the ridge will once again draw moisture northward. So afternoon and evening shower chances reappear starting Tuesday and last through the work week, with chances increasing for the following weekend as a more robust surge of monsoonal moisture is advertised by some weather forecast models.
Sunday, July 21, 2019
Steamboat Springs is currently seeing warm temperatures and sunny skies this Sunday morning. High temperatures these past several days have been running up to five degrees above our 82 F average, which is expected to continue for the upcoming week, save for a couple of pulses of monsoonal moisture that will increase shower chances around midweek and again mid-next weekend.
A ridge of high pressure is currently amplifying over the West behind a disturbance traveling across the upper Midwest and ahead of a strong storm in the Gulf of Alaska. While we will see more warm and mostly dry weather on Monday and Tuesday, the cool front associated with this disturbance will bring relief from the excessive heat for the eastern two thirds of the country through midweek.
Meanwhile, a piece of the Gulf of Alaska storm is ejected later Tuesday and once again suppresses the ridge of high pressure over the West southward as it travels across the northern U.S. border. The resultant westerly flow over the Great Basin bends a plume of monsoonal moisture forecast to be over Utah on Tuesday eastward over our area for Wednesday, increasing the chance of wetting rains, with those areas lucky enough to see precipitation possibly experiencing brief and localized moderate to heavy rain.
The forecast for the last several days had this monsoonal moisture plume hanging around for the rest of the work week, but weather forecast now models have a wedge of dry air intruding over Wyoming and northern Colorado. So shower chances now look to decrease markedly or even disappear for the end of the work week and headed into the following weekend, along with some increased westerly winds on Thursday.
But we will be on the edge of better moisture, and indeed, another pulse of monsoonal moisture is forecast for around mid-next weekend. At this point, this does not look to stick around for more than a day or two as dry air is forecast to return to our area for the last week of July.
Thursday, July 18, 2019
The Steamboat Springs area is enjoying a quintessential mid-summer day with sunny skies and warm temperatures. This will continue into the first part of the weekend before a weak cool front grazes north central Colorado and briefly increases atmospheric moisture later Saturday and Sunday. Drying is then forecast for the early part of the work week before a monsoonal surge of moisture moves overhead starting around midweek.
A ridge of high pressure over the west has been flattened by a seasonably strong jet stream traveling across the northern Rockies. Winds will become breezy from the west again today and tomorrow as a disturbance passes north of our area with temperatures several degrees above our average high of 82 F.
By later Saturday, the disturbance drags a weak cool front through northern and eastern Colorado. While the strongest storms will be relegated to the Front Range and eastern Colorado, we will see increasing clouds with a small chance of an afternoon or evening shower on both Saturday and Sunday. These will likely produce more wind than rain as the lower levels of the atmosphere remain quite dry.
Ahead of another disturbance that moves east across the northern Rockies from the Gulf of Alaska later in the work week, the ridge of high pressure over the west amplifies. As discussed in the weather narrative last week, subtle changes in the location and strength of the ridge can alter the trajectory of monsoonal moisture that ends up over our area, but right now Monday and at least most of Tuesday are looking hot and dry as the monsoonal moisture is transported northward into Utah.
By around midweek, the Gulf of Alaska disturbance makes landfall in the Pacific Northwest and again flattens the ridge of high pressure over the west as it moves east across the northern Rockies. This bends the monsoonal moisture plume towards our area around Wednesday when we should see increasing moisture and at least some cloud cover that will lower afternoon temperatures closer to average.
Shower chances look to increase after midweek and into the following weekend as the monsoonal moisture plume is forecast to remain near or over our area.
Sunday, July 14, 2019
A small disturbance in southwest flow brought some clouds to Steamboat Springs earlier this Sunday morning, but sunny conditions have returned as the disturbance moves east of our area. This dry weather will persist through the upcoming week, save for Monday when we will see the best chance for showers in north central Colorado.
Moisture moving northward within the North American Monsoon has been high-based so far, and with the lower levels of the atmosphere remaining dry, storms have been hard to come by. Another surge of moisture is forecast to move over our area from the south on Monday, resulting in the best, but still modest, chance of showers for the upcoming week.
Meanwhile, storminess in the Gulf of Alaska is forecast to move eastward across the northern U.S. this week, and the westerly flow will squash the current ridge of high pressure over the Rocky Mountains. The southern suppression of the ridge will sever the flow of monsoonal moisture from the south and bring dry air over the southwestern corner of the country.
Chances for precipitation will decrease markedly for Tuesday and even further for the rest of the work week, with the main weather highlight being the likelihood of breezy west and southwesterly winds on Wednesday and Thursday as the storm track stays well north of our area.
By the weekend, the parade of Gulf of Alaska storms looks to subside, allowing the ridge of high pressure over the Rocky Mountains that had been squashed by the storms to the north to rebound and expand west. This will reopen the door for additional monsoonal moisture to be carried northward toward our area and increase precipitation chances starting around mid next weekend.
Thursday, July 11, 2019
The warm, dry and sunny weather we are currently experiencing in Steamboat Springs this Thursday afternoon will give way to increasing moisture starting Friday. Clouds will increase along with increasing precipitation chances that will persist through the weekend and into the next work week.
An expansive ridge of high pressure is currently covering the western two thirds of the country, with Tropical Storm Barry threatening the Louisiana coast on the southeastern side of the ridge and continued storminess in the Gulf of Alaska on the northeastern side of the ridge.
Contributing to the strength of the ridge is the strong summer heating of the elevated Mexican Plateau, and the on-time appearance of the North American Monsoon is due to moisture originally from the Caribbean being pulled first westward and then northward around the ridge of high pressure. While we do not see the intensity and persistence of precipitation associated with the Indian Monsoon (which is much stronger due to the higher and broader Tibetan Plateau), our area will see increased clouds with a greater likelihood of locally moderate to heavy precipitation, due to not only the increased moisture but also the relatively slow storm movement thanks to the light winds under the ridge. Another hallmark of the North American Monsoon is warmer overnight temperatures as the increased moisture acts like an earth-blanket, and possibly slightly cooler afternoon temperatures if the clouds are persistent and thick enough to block some of the sun.
And its not certain we will see any precipitation as these monsoonal surges of moisture produce relatively spotty coverage, but there will be some chance on Friday, with more of a chance on Saturday and better chances on Sunday and Monday.
By Tuesday, the Gulf of Alaska storminess is forecast to move inland well north of our area, but the increased westerly flow will not only flatten the ridge of high pressure over the west, but sever our fetch of moisture from the south. The end result is decreasing precipitation chances for Tuesday and Wednesday, along with some breezy westerly afternoon winds.
Subtle changes in the strength and position of the ridge of high pressure can drastically affect the northward extent of monsoonal moisture and the resultant forecast, but right now moisture may begin to increase again for the end of the work week before a more robust surge of monsoonal moisture may occur around the following weekend or soon thereafter.