Thursday, August 29, 2019
After a couple of cool nights with low temperatures in the thirties and scattered areas of frost, some higher level moisture has infiltrated the Steamboat Springs area this Thursday morning. Our best, but still modest chance of wetting rains occurs on Friday before hot and dry weather returns for the long Labor Day weekend.
Currently, our area is underneath a flat ridge of high pressure sandwiched between a large and cold storm that extends from near the North Pole southeastward towards Hudson Bay and a storm in the Gulf of Alaska. Moisture drawn from the west and south has produced some mid and high level clouds over our area today, with only a small chance of a weak storm that would produce more wind than rain thanks to the dry lower levels of the atmosphere.
We should have a better chance of some storms producing rain that actually reaches the ground on Friday afternoon as the atmosphere has had a day to moisten as the mid and upper level moisture mix downward to the surface.
By Saturday, both the Gulf of Alaska and the Hudson Bay storm move eastward, allowing the ridge of high pressure to amplify over the Rocky Mountains. Warming and drying occurs as the winds turn from the north-northwest on Friday to the west on Saturday and eventually the southwest by Labor Day. In fact, Labor Day may end up being one of the warmest days of the summer, which is appropriate irony considering the late start to summer which included snowfall in town on both June 21 and June 23.
Early in the work week, there is considerable disagreement among weather forecast models and their trends regarding the fate of the Gulf of Alaska storm as it is forecast to undergo some degree of splitting as it approaches the Pacific Northwest coast around Sunday night. Currently, there is a good chance of a weak monsoonal surge of moisture reappearing as early as Tuesday over our area and lasting in some form through the work week, though it is not clear if it will be strong enough to produce wetting rains.
Also of note for the the southeastern corner of the U.S. is Hurricane Dorian, which is expected to eventually be a Category 4 hurricane. The speed and track of major hurricanes are notoriously difficult to predict, but current forecasts have the storm making landfall around the east coast of central Florida on Labor Day before re-curving to the north and slowing or stalling over the Georgia / South Carolina area during the work week.
The weather for the following weekend over Steamboat Springs will be highly dependent upon the evolution of the Pacific Northwest storm and how much energy is left behind off the West Coast after the storm splits. Some models have upstream Pacific energy absorbing the leftover storm and carrying it over our area by the weekend, leading to a much better chance of precipitation.
Thursday, August 22, 2019
The warm temperatures experienced the last two days in Steamboat Springs will continue for the upcoming week. Though several surges of cooler air will be in our proximity that will be most noticeable on the Front Range, we will see an increase in breezy to windy conditions around and behind the fronts.
The recent high temperatures of five to ten degrees above our average of 80 F will continue today ahead of a cool front that will graze our area on Friday. We will see clouds this afternoon and only slightly cooler temperatures tomorrow behind the cool front, with a chance of showers both today and tomorrow, possibly producing brief periods of locally moderate to heavy rain. Aside from any gusty winds associated with passing showers, winds will veer from the southwest today to westerly or northwesterly later on Friday behind the cool front.
Daytime wind speeds should remain elevated through the weekend thanks to a seasonally strengthening jet stream situated to our north as temperatures once again rise to five to ten degrees above average.
Another weak cool front may decrease temperatures a bit for Monday, though again the effects will be most noticeable for areas east of the Divide.
Meanwhile, by midweek, some Pacific energy that mixed with some cool air in western Canada travels to our north and eventually forms a strong storm around Hudson Bay. Cool air drawn southward along the western side of the storm will keep at least the central part of the U.S. cool, and while it is a good bet that the Front Range will see the cooling, it is not clear if the cool air will make it far enough west to cross the Divide and affect our area on Wednesday.
After midweek, there are a couple of opportunities for moisture to increase over our area; first from a tropical disturbance currently off Baja that moves northward along the West Coast during midweek before being absorbed by the clockwise flow around the ridge and eventually directed eastward towards our area, and second from a possible brief reappearance of the North American Monsoon over our area as southerly flow underneath the ridge transport moisture northward.
The end result will be our best chance of showers in two weeks as we head into the long Labor Day weekend. However, what happens for the second half of the weekend is uncertain as it is dependent upon the path and speed of a strong storm forecast to travel across the Gulf of Alaska and how it affects the ridge of high pressure over the West.
Sunday, August 18, 2019
After a relatively active weather day yesterday associated with a cool front in our vicinity, this cloud-free Sunday morning in Steamboat Springs is sunny and quickly growing warmer. We should have mostly sunny, warm and dry days for the upcoming week, save for some clouds and a small chance of afternoon and evening showers on Tuesday and Wednesday.
The cool front this past Saturday produced a more active pattern than weather forecast models predicted; in fact even the shortest range model that usually does reasonably well predicting up to 18 hours in advance frustratingly failed to capture the early and late afternoon storms that put down around 0.07” of precipitation over short period of time.
In any event, the upcoming week is looking quite nice as the jet stream stays to our north, with plenty of sun and warm to hot high temperatures exceeding our slowly falling average of 80 F.
While there will be little chance of precipitation early and late in the upcoming week, the ridge of high pressure currently over our area is deformed midweek by some cool air traveling southward from a storm near the Great Lakes. Interestingly, this storm originally brought the cool front through our area yesterday, and it is not done with us as southerly monsoonal flow under the ridge is enhanced by the cool air east of the ridge traveling south in the Midwest.
So we should see more clouds later Tuesday and Wednesday with a slight chance of afternoon and early evening storms that would likely produce more wind than rain.
Meanwhile, incoming Pacific energy crosses the upper West Coast around midweek, and pushes the weak monsoonal moisture plume eastward, restoring the drier atmosphere over our area by Thursday. Dry, warm and mostly sunny weather should continue through most of the following weekend before another round of incoming Pacific energy crosses the upper West Coast early in the weekend. If the current forecast holds, a weak but dry cool front may be around our area late in the weekend or early the following week, along with breezy to windy conditions.
Thursday, August 15, 2019
The beautiful average summer weather the Steamboat Springs area has been experiencing this past week will continue for the upcoming week. Thanks to a storm traveling across the Canadian Plains, the jet stream is forecast to sag over the northern states this weekend,, bringing a weak cool front through northern Colorado on Saturday. Afternoons and evenings will be breezy to windy for several days around the front as the stouter winds aloft are mixed down to the surface, though they should diminish after the weekend as the jet stream retreats back north and allows a ridge of high pressure to rebound over the West.
High temperatures are expected to be near our average 81 F or slightly above, except a bit cooler for Saturday, while low temperatures are expected near our average of 44 F, except for Sunday morning when they may be cooler, perhaps touching the upper thirties.
It appears the front will bring in enough moisture for some clouds on Saturday, with a small chance of an afternoon or evening shower. Otherwise breezy to windy conditions are expected from this Thursday afternoon through the weekend before a ridge of high pressure rebuilds over the West behind the eastward-moving Canadian storm.
And when a ridge is present over the West in July and August, monsoonal moisture from the south can be transported northward along the western periphery of the ridge. This looks to happen as a weak surge of monsoonal moisture is forecast to start as soon as Tuesday afternoon and continue through at least most of the work week. At this time, it is not clear if the surge contains enough moisture for more than some clouds and a slight chance of showers.
More inconsistency appears in how weather forecast models deal with incoming Pacific energy for the end of the work week. The European ECMWF favors a more progressive and less amplified jet stream than the American GFS, which would keep a drier westerly flow over the central and southern Rockies as we head into the following weekend.
Sunday, August 11, 2019
After a good chance of showers this mostly cloudy Sunday afternoon and evening, much drier air overspreads the Steamboat Springs area starting Monday. Warm and dry weather will dominate the upcoming work week before a Pacific Northwest storm eventually passing to our north introduces breezy conditions heading into the weekend.
A storm currently over Idaho will move across Montana tonight and North Dakota tomorrow, swinging our winds from the south to the west. While the current southerly flow ahead of the storm is supporting the good chance of showers this afternoon and evening, with some storms producing locally moderate to heavy rains at times, the westerly flow behind the storm effectively severs the monsoonal moisture tap that has been with us this weekend and brings much drier air overhead.
So high temperatures around or slightly above our 81 F average with mostly sunny skies are expected for the work week. Around Friday, another seasonably strong strong storm crosses the Pacific Northwest coast, bringing breezy to windy southwesterly winds starting as soon as Friday and lasting through some or all of the weekend.
Weather forecast models disagree on the how strong the storm becomes along the West Coast and how quickly it moves across the northern U.S. as it is dependent upon the strength and location of a ridge of high pressure forecast in the proximity of the Gulf of Alaska. The European ECMWF has a stronger and deeper storm that moves mostly north of our area through the weekend in pieces, while the weaker and faster American GFS moves the storm bodily north of us early in the weekend. More details will emerge by my next weather narrative on Thursday, with the forecast varying between cool, dry and breezy according to the ECMWF to warmer with a chance of showers according to the GFS.