The First AR of Season

NWS Grand Junction is doing a much better job of covering the upcoming storm event than any other NWS office in the Region.  Here are some snippets from GJT's coverage:

A low pressure system moving out of Siberia into the Bering Sea is the system that will eventually become the winter storm that will impact the region this weekend. The NPJ will pick up this low to strengthen it and carry it southeast over the Pacific Northwest and to eastern Utah and Western Colorado. 

Where might such moisture be coming from? And, why such an abrupt change in weather pattern, you ask? Well first, guidance from the latest Atmospheric River (AR) outlook by CW3E, identified two plumes of integrated water vapor transport (IVT) making landfall along the PacNW by Thursday, and the second pulse Friday into Saturday. This event is declared the first AR of water year 2023. 

Even though it`s on the weaker end of the AR scale (AR 1), it`ll bring appreciable rainfall along the PNW, and eventually, stream across the Central Rockies within the next 5 days. Taking a look at IVT analyses and forecasts, the computer-generated deterministic guidance all carry the secondary pulse southward Saturday, with a magnitude of at least 300 kg/(m*s) progged to reach our area by Sunday. In terms of moisture content, this magnitude of IVT translates to 0.5 to 0.8 inches of precipitable water, of which equates to roughly 200 percent of normal for this time of year. 

On top of that, this moisture surge is timely matched with maximized forcing, jet dynamics, and a sharp frontal boundary dragging across the region. The aforementioned ingredients combined for, roughly, an 18 hour period across the West Slope will result in a widespread precipitation event beginning Saturday night and continuing into Sunday. Winter weather returns as snow levels drop overnight, plunging further down the hill under convective showers, and even lower in the wake of the cold front. In terms of elevation, snow could fall as low as 6000 feet with significant accumulations above 8500 feet as colder air filters in. Heaviest snowfall rates will be combined with maximized forcing, which for now, are expected late Saturday for the Uintas, then Saturday night and into Sunday morning for western Colorado ranges. During this period, desert valleys remain too warm to see any white gold, though a good soaker still remains probable with this event.

You can follow GJT's discussions here:
https://forecast.weather.gov/product.php?site=GJT&issuedby=GJT&product=AFD&format=ci&version=1&glossary=1

Comments

Post a Comment

Popular posts from this blog

Our typical route south

Image
We're definitely not staying up here as long as we did last year! (Christmas Day 2017) It isn't creative or "out there" but it has always served us well.  We've driven it too many times to remember.  This year we added a new wrinkle: The Brigham City Walmart parking lot. OK, here how it goes. We leave Idaho Falls mid-afternoon on a Saturday and drive to the Brigham City Walmart.  It MUST be a Saturday.  No other days will do. We don't unhitch the trailer.  We wake up as soon as possible Sunday morning and get on I-15 early, early, early!  This way we get to drive through the white knuckle gauntlet of Salt Lake City with no white knuckles.  Sometimes there are so few vehicles it seems like it's our own private interstate highway!  We beat feet through the 100-mile Belly Of The Beast, as we are wont to call it and arrive at a convenient pit stop in Payson, Utah, well before lunch time.  It's as blissful as can be, at least for hauling our ...
Read more

Save The Hoback

Image
 The deeper we dig the more and MORE interesting stuff we uncover.  We had no idea that the Upper Hoback River was such a hotly contested area or that the natural gas drilling was staved off.  It's quite a story.  We think it's possible drive out and camp in some of that purple area--maybe on Cliff Creek Road.  Hopefully, we will get to see some of the "rescued lands". For a decent short video of the area and the campaign see: https://youtu.be/jq0RwHyFsUw?feature=shared As the southern anchor of the Greater Yellowstone Ecosystem—the largest intact temperate natural system in the Northern Hemisphere—the Hoback Basin is home to magnificent mountains, vibrant forests, and the headwaters of the Wild and Scenic Hoback River. Generations of Americans have come here to fish, hunt, paddle, hike, or to simply enjoy Wyoming’s backcountry. But the future of this unspoiled landscape was at risk, for beneath the Hoback lies a highly valued resource—natural gas. Specifically,...
Read more

La Barge

Image
  La Barge touts itself as a small community nestled in the peaceful Green River Valley and claims to be "Home of The Frontier Trapper".  There's not much going on in La Barge and that's what makes The Moon Dance Diner Story stand out.  The Moon Dance Story begins as a classic "hope springs eternal" small town saga.  The once vibrant Moon Dance dreams fell on hard times and the story faded to a sad ending. It all began sometime in 2007 when lifelong La Barge residents Vince and Cheryl Pierce somehow became smitten with the idea to buy an iconic New York City diner--The Moon Dance.  The couple paid $7,500 to buy the building but then spent thousands more to move it to La Barge.   Then the real spending began and the Pierces ultimately invested around $300,000 in the little diner.  It opened with great local fanfare in late January 2009.  Unfortunately, the age-old business mantra "location, location, location" was not kind to the Moon Dance an...
Read more