Here comes Harold with unsettled weather to follow for the weekend
Thursday, August 24, 2023
Temperatures are approaching eighty degrees under mostly sunny skies in the Steamboat Springs area this Thursday mid afternoon. But clouds are building as the remnants of tropical storm Harold move northward from the Four Corners region, with good rainfall expected from later today through Friday night as the former tropical storm moves overhead. Saturday should be a quieter day, but still with good chances for storms, and though more drying is forecast for Sunday, we may still see good chances for showers as a weak cool front approaches our area.
A broad ridge of high pressure is still entrenched over the the Gulf States, though its northern extent has been recently limited by storm systems traveling along the Canadian border. But the key feature for our area to start the weekend is the remnants of the former tropical storm Harold, which developed from that easterly wave I discussed in the last weather narrative.
The remnants are currently just north of the Four Corners region and are forecast to move first north and then east across our area on Friday. While good showers will be possible from later this afternoon through Friday night, the best chance for the strongest thunderstorms will be in the afternoons and evenings of both days. High temperatures will fall to the low seventies on Friday, a bit more than five degrees below our average of 80 F thanks to the abundance of clouds and showers.
The remnants of Harold will be east of our area by Saturday, but the the rich moisture will be slow to leave so the chance for afternoon and evening storms will remain. A wave of energy currently in the Gulf of Alaska is forecast to quickly move across the Canadian border early in the weekend and intensify over the Great Lakes by Monday, shifting our winds to be from the northwest and bringing a grazing cool front near our area by late Sunday. So while Sunday will be drier than Saturday, there may still be chances for afternoon and evening thunderstorms.
There is some uncertainty about this cool front, and thunderstorms may linger on Monday before drier air makes it back into the area by later Tuesday. It’s been a while since we had a generally gray and showery day over our area, so enjoy the break in the hot weather tomorrow, and check back to my next regularly scheduled weather narrative on Sunday afternoon for more details about the weather for next week.
Hot start to the work week
Sunday, August 20, 2023
Temperatures in the low eighties under mostly sunny skies are over the Steamboat Springs area this Sunday noon. Dry skies and high temperatures approaching ninety degrees are forecast for today and Monday before the rest of the work week sees cooling temperatures and increasing precipitation chances.
Our area is currently sandwiched between a ridge of high pressure centered over Oklahoma that extends from the Rocky Mountains to the East Coast and three low pressure areas to our west. One of these is the remnants of former hurricane Hilary moving over northern Baja which is expected to bring inundating rains to the normally very dry areas of southern California and Nevada. The former hurricane is expected to interact with a low pressure area currently off the coast of central California later today and tonight and eventually a storm moving southward along the coast of British Columbia on Tuesday.
All of this weather will stay first to our west and then northwest while we stay under the influence of the expansive high pressure over the Central Plains. Winds rotating clockwise around the ridge will keep winds generally from the south over our through midweek, and while that normally means shower chances for our area thanks to the North American Monsoon, dry air incorporated into the clockwise flow from the East Coast last week means hot and dry weather today and Monday.
We should see high temperatures approaching ninety degrees today and tomorrow, and though the record of 91 F set in 2020 today will likely hold, the high temperature record of 88 F set in 1960 should be challenged.
But the dry air leaves our area by later Monday, and monsoon moisture begins to return by Monday night. It’s likely we won’t see much more than increasing afternoon and evening clouds on Tuesday with only slight shower chances on Wednesday before good chances appear starting around Thursday.
These chances substantially increase thanks to two mechanisms. The first is the flattening of the ridge of high pressure thanks to the remnants of hurricane Hillary, the low pressure off the California coast and the low pressure from British Columbia merging and moving over the northern Rockies around midweek.
The second is a well defined area of low pressure currently off the west coast of southern Florida, which is known as an easterly wave with origins in the eastern Atlantic off the coast of Africa. This wave is forecast to travel from east to west across the Gulf of Mexico and around the southern periphery of the Central Plains high pressure early in the work week, and be eventually carried near or over our area around Thursday and Friday.
While it currently looks likely there will be wetting rains after midweek, there are a lot of moving pieces that may change by then, so be sure to check back to my next regularly scheduled weather narrative on Thursday afternoon for the latest details.
Some precipitation chances to start the weekend
Thursday, August 17, 2023
Near record high temperatures of 89 F are already over Steamboat Springs under mostly sunny skies this Thursday mid afternoon. Moisture rotating around a ridge of high pressure centered over the Texas Panhandle should make it over our area by tonight with modest chances of precipitation on Friday and Saturday, along with cooler temperatures. But the hot and dry weather returns for Sunday and the beginning of following work week.
Troughs of low pressure are currently located over the Great Lakes, off the northern British Columbia coast and off the central California coast while a ridge of high pressure is centered over the Texas Panhandle. Additionally, hurricane Hilary is moving northward toward Baja and is expected to begin merging with the low pressure area off the California coast by the end of the weekend, bringing excessive rainfall first to southern California and then points north.
Hilary is forecast to rapidly weaken as it encounters the cold upwelling currents off the West Coast, though it may still retain tropical storm status as it makes landfall over southern California. That would be a rare feat as that last happened in 1939, and it would be the first tropical storm to hit Nevada if it maintains its strength and current projected track.
But our weather will be far more benign as all that excitement stays to our west. Monsoonal moisture caught up in the clockwise circulation around the Texas Panhandle ridge should be drawn over our area starting tonight, with afternoon and evening showers possible on Friday and Saturday.
The record high temperature of 90 F will be threatened today, though we will have to wait for the official temperature records of the weather station by the high school to be published. High temperatures will fall to around our average of 82 F on Friday and Saturday as afternoon clouds gather and bring modest chances of precipitation that will last into the night.
The high pressure ridge over the Texas Panhandle is forecast to move toward eastern Oklahoma by the end of the weekend and amplify over the Central Plains, cutting off our moisture supply and returning our high temperatures back to the upper eighties on a dry Sunday and mid eighties to start the work week.
There is hope for more moisture around or just after midweek as the merged former hurricane and California trough travel northward early in the work week and merge with another wave of low pressure forecast to cross the Gulf of Alaska. All of this should eventually nudge the Central Plains ridge of high pressure eastward, opening our door for another surge of monsoonal moisture from the south.
So enjoy another summer weekend and be sure to check back for my next regularly scheduled weather narrative on Sunday afternoon where I’ll be discussing what right now appears to be good chances for precipitation starting around midweek.
Hot and dry days ahead
Sunday, August 13, 2023
Temperatures are currently in the mid seventies in Steamboat Springs under mostly sunny skies early this Sunday afternoon. Mid summer like heat is returning to the Yampa Valley for most of the work week, and though some moisture may trickle overhead starting midweek, any meaningful chances for precipitation will hold off until the start of the weekend.
Ridges of high pressure are currently centered over the Pacific Northwest coast and Texas with a trough of low pressure stubbornly located off the southern coast of California. Some moisture has been present the last few days as southerly winds between the low pressure off Califonia and the high pressure over Texas brought monsoonal moisture northward, but our area was too far north to see any more than clouds, sparse raindrops and gusty winds.
A separate area of low pressure is currently located over the Dakotas, and northerly winds behind the trailing cool front has shunted most of the moisture over our area south, leading to a dry day today with gusty afternoon winds from the north and northwest and pleasant high temperatures around eighty degrees.
This low pressure is forecast to travel into the Ohio River Valley through the early part of the work week, forcing the Texas ridge of high pressure back westward to the Four Corners by midweek. So look for mid summer like heat to envelope Colorado through most of the work week, bringing high temperatures to the low eighties on Monday and mid to upper eighties on Tuesday, Wednesday and Thursday, almost five degrees above our average of 82 F.
Some moisture may lurk underneath the ridge of high pressure near and mostly south of our area on Wednesday and Thursday, though any meaningful chances for precipitation will have to wait for the end of the work week. Longer range weather forecast models agree that a low pressure area currently over the Aleutian Islands will weaken as it approaches the Vancouver coast around Friday, and push the ridge of high pressure over the Four Corners back east toward Texas.
Combined with the low pressure area still loitering off the coast of southern California, winds from the south or southwest should carry another healthy monsoonal surge of moisture toward our area by the start of the weekend.
There is also a tropical weather system forecast to move toward Baja by the end of the work week, and some moisture from that may be routed towards our area, though there is considerable weather forecast model disagreement on the track of that disturbance, especially later in the weekend.
So soak up the mid summer heat, and I’ll be back with my next regularly scheduled weather narrative on Thursday afternoon where I’ll discuss the possible return of moisture to the Yampa Valley for the weekend.
Passing showers possible through the weekend
Thursday, August 10, 2023
Temperatures are in the upper seventies under mostly sunny skies in the town of Steamboat Springs this Thursday mid-afternoon. After a couple of delightfully cool and dare I say fall-like days this past Tuesday and yesterday, look for temperatures to rebound to the low eighties today and lasting through the weekend. Some moisture has returned to the region today and may result in a chance of passing showers in the afternoon and evening, with those chances highest, but still modest, today and Friday.
A ridge of high pressure is currently over Texas while a weak and broad trough of low pressure is off the West Coast. Winds from the south between these features have transported warmer temperatures and some monsoonal moisture overhead, leading to today’s clouds. There may be a possibility of passing showers today that produce more wind than rain as whatever falls out of the cloud evaporates in the dry lower levels of the atmosphere.
More of the same is forecast for Friday, with perhaps a slightly better chance of rain reaching the ground as the lower atmosphere moistens thanks to any windy showers today. While another push of monsoonal moisture is forecast across most of Colorado on Saturday, northwesterly winds associated with the jet stream to our north may be far enough south to discourage that moisture from making it over our area, or not.
A wave in the jet stream currently approaching the southern British Columbia coast is forecast to graze our area on Sunday, though not much weather will be associated with it as moisture is sparse and the still strong mid August sun will quickly modify the air mass.
Previous iterations of the weather forecast models had monsoonal moisture returning to our area by Sunday afternoon, but now the latest runs show the grazing cool front strong enough to keep the monsoon moisture south of our area on Sunday, and likely Monday as well.
So be sure to enjoy another summer weekend from our rapidly dwindling supply, and check back to my next regularly scheduled weather narrative on Sunday afternoon where I’ll discuss whether our area sees a return of monsoonal moisture after the start of the next work week.
