Sunday, July 24, 2016
A weak wave off the Pacific Northwest coast will allow a low-amplitude ridge to rebuild over the western states, which will increase temperatures to above normal again for the beginning of the work week. As this wave moves inland around Tuesday, this shallow ridge elongates eastward, allowing a modicum of moisture from the south to move northward over Colorado on the western periphery of the ridge. This will result in a very weak monsoonal pattern, increasing the chance of afternoon storms for Tuesday.
This brief and unimpressive surge of moisture will be replaced with dry air by Wednesday as the wave moves through the northern Rockies. An additional wave taking a similar path will also pass north of our area by the end of the work week. Models have trended this wave further north as it is deflected by the western ridge and it no longer looks to bring any cooling to our area as was the possibility in the last forecast. Instead, more cool air forecast to move into the Gulf of Alaska will allow the western ridge to grow even stronger, bringing hot temperatures well above normal to the Steamboat Springs area by next weekend.
Longer-range models do have relief from the heat after next weekend as more cool air is forecast to move into the Gulf of Alaska and produce an upper level trough off the West Coast that may again allow monsoonal moisture to be drawn northward over Utah and Colorado from western Mexico. The longest-range model I regularly view hints that this wetter pattern may persist through at least the first week of August.
Friday, July 22, 2016
Another Pacific Northwest storm made landfall near Washington state last night, and looks to drag a weak cool front across the Steamboat Springs region tonight as the storm moves through Montana.
Winds will become breezy and veer from the previous southerly direction to the westerly or northwesterly direction by Saturday, effectively ending the influx of monsoonal moisture from the south as the western ridge flattens. Remaining moisture will continue the threat of afternoon storms for the weekend, especially for Saturday, under much less humid conditions and warming temperatures.
A weak wave redevelops near northern California late in the weekend allowing a low-amplitude western ridge to rebuild which will increase temperatures to above normal again. As this wave moves inland around Tuesday, this shallow ridge also moves eastward, allowing some moisture from the south to move northward over Colorado on the western periphery of the ridge. This will result in a very weak monsoonal pattern, increasing the chance of afternoon storms for Tuesday and Wednesday.
This brief surge of moisture will be replaced for Thursday and Friday with dry air as several Pacific Northwest waves phase with a storm moving across the Canadian Plains and bring some cooling to the area in dry and breezy westerly to northwesterly flow. Currently, the last wave timed for Friday will be the strongest and may be strong enough to increase the threat of showers as the cool front moves through.
Monday, July 18, 2016
A large storm currently off the Pacific Northwest coast has forced a ridge to build over the western US, allowing south-southwesterly flow to carry monsoonal moisture from Mexico northwards over Colorado. This moist flow is a day or two faster than my previous forecast, keeping temperatures closer to normal today as clouds periodically inhibit the sunshine.
Very short range models indicate showers redeveloping overnight as old storm boundaries interact and force storms in the moist and unstable airmass.
Additional ill-defined waves from the south will continue to travel over Colorado for the work week, keeping a mix of sun, clouds and showers around with near normal temperatures.
Though models have pieces of energy ejecting from the Pacific Northwest later in the work week, the western ridge will deflect them to our north with minimal impact on the monsoon. However, the storm finally makes landfall late in the work week, and looks to drag a cool front across the Steamboat Springs region late Friday or early Saturday.
Winds will veer from the southerly direction to the westerly or northwesterly direction, effectively ending the influx of moisture from the south as the western ridge flattens. Remaining moisture will continue the threat of afternoon storms for the weekend under much drier conditions and warming temperatures.
Thursday, July 14, 2016
A Pacific Northwest storm near the Canadian border will move inland overnight and drag a shallow cool front across our region after midnight, continuing the string of cool nights for the Steamboat Springs area. Additionally, cool air moving southward from western Canada will moderate a building western ridge this weekend, replacing the near-normal temperatures of this past week with warming temperatures.
There may be some clouds Friday through Sunday as some mid and upper level moisture from Hurricane Darby in the eastern Pacific moves over the area in west to southwest flow, and this will also warm the overnight temperatures.
Cool air from Siberia currently crossing the North Pole will spin up another Pacific Northwest storm late in the weekend, and that will allow a stronger ridge to build over the western US by early next week as the storm digs further to the south along the West Coast than the previous Pacific Northwest storms.
The end result will be temperature soaring to well above normal early in the week before monsoonal moisture from Mexico brings clouds and showers and the attendant cooler temperatures to the region around midweek.
Longer range models indicate the monsoonal pattern may hang around after next week as a trough of low pressure lingers off the West Coast, keeping the moist south-southwesterly flow going over our area.
Monday, July 11, 2016
The cold front that passed through the Steamboat Springs area last night brought freezing temperatures to the top of Mt. Werner this morning and kept daytime temperatures pleasantly below normal. Though the strongest westerly winds will decrease by midweek, continued westerly flow with embedded waves will keep the cool nights and pleasant daytime temperatures with breezy afternoon winds going through most of the rest of the work week.
A Pacific Northwest storm crossing the coast near the Canadian border on Friday will cause the flow to back to the southwest and bring still dry weather but warmer temperatures to our area by the end of the work week and through the weekend.
More cold air from Siberia will cross the North Pole and spin up another unseasonably strong storm off the Pacific Northwest coast by early next week. Not only will this increase temperatures to well above normal again as a western ridge builds ahead of the storm, but will also allow some monsoonal moisture to our southwest to be drawn over our area.
Current models have this as the beginnings of another monsoonal surge that may introduce considerable moisture for Colorado starting around next midweek.