Sunday, July 11, 2021
Temperatures around eighty degrees are over the Steamboat Springs area this Sunday noon under smokey skies from the recently ignited Morgan Creek wildfire 15 miles north of town. The excessive heat observed recently will be absent this week as a series of Pacific storms bring a chance of showers to our area starting Tuesday afternoon, with Wednesday likely bringing the highest probability of precipitation for the upcoming week.
The Morgan Creek wildfire has ballooned in size from the initially estimated 5 acres Friday afternoon to almost 2000 acres. The cool front on Saturday morning likely contributed to the increase in fire size as breezy winds from the north accompanied the front. And while the temperatures cooled to around five degrees above our average of 81 F Saturday thanks to the cooler air mass, the winds from the north also transported smoke from the wildfire directly into town. The NOAA smoke plume model shows the current smoke abating by this evening before increasing again tomorrow before again decreasing by Monday evening.
The dominant ridge of high pressure responsible for the excessive heat that was over the West the last several weeks is under assault by a series of waves ejecting out of a strong storm currently in the Gulf of Alaska. The first such wave brought the cool front early Saturday while the next one will pass to our north Wednesday morning, but not before first leaving a piece of energy and moisture behind that will move over our area that afternoon.
The end result will be that today and Monday will be the warmest days of the upcoming work week with highs around five degrees or so above our average of 81 F and near nil chances for precipitation. The winds will shift to be from the north to be from the west starting Tuesday ahead of the Wednesday wave, which should help keep the wildfire smoke north of town.
The wind shift will bring some increased moisture overhead on Tuesday for a small chance of late day showers, though winds will be increasing on Tuesday and more so on Wednesday as the wave moves north of the state. While the increasing winds are bad news for the wildfire, that leftover piece of energy is forecast to move overhead later in the day Wednesday giving us the best chance of wetting rains for the upcoming week.
Precipitation chances look to decrease substantially on Thursday as some dry air behind the wave tickles our area though they are forecast to increase modestly by Friday as the dry air recedes for a day.
However, cold air from the North Pole is forecast to mix with that Gulf of Alaska storm during the second half of the work week and force it to elongate to the south off the West Coast. The increased flow from the southwest ahead of the storm will reinvigorate the ridge of high pressure over the West by the end of the work week leading to rebounding temperatures well above average and a general decrease in precipitation chances.
There is weather forecast model uncertainty for the following week as the American GFS wants to move the Gulf of Alaska storm inland and displace or deform the ridge of high pressure over the West while the European ECMWF keeps more of the storm off the West Coast. This is important for the development of the North American Monsoon as our area will depend upon that western ridge of high pressure being forced far enough east so that the southerly flow on the backside of the ridge can bring moisture to our south northward. I should have a better idea on whether this may occur in my next regularly scheduled weather narrative on Thursday afternoon.