textproduct: Salt Lake City

KEY MESSAGES

- Patchy fog development is possible for fog-prone areas across the Cache Valley and Wasatch Back overnight into Sunday morning.

- After a couple dry and mild couple days, another weather system impacts the region with widespread rain and mountain snow on Tuesday into early Wednesday.

- A second storm will bring another round of valley rain and mountain snow Thursday into Friday; this storm has potential to bring lower snow levels, but low confidence at this time.

DISCUSSION

Clearing skies behind today's cold front will make for quite the crisp night across Utah and southwest Wyoming, with some of the coldest low temperatures of the season so far. Many lower elevation valleys will see temperatures dip into the low to mid 30s, except the low 40s across lower Washington County. Given recent rainfall and clearing skies tonight, there is a 20% chance for fog-prone areas across the Cache Valley and Wasatch Back to see freezing fog develop overnight. The limiting factor will be how quickly a deck of high clouds moves into the region, as these clouds could limit radiational cooling overnight.

High pressure builds in across the Intermountain West on Sunday into Monday, keeping conditions dry and mild through this period. This pattern will be brief, as another system is slated to impact the region on Tuesday. This next system looks quite similar that of today's: a fast-moving negatively tilted trough swinging through the Great Basin, bringing widespread rain and mountain snow ahead of a cold front. As such, likely looking at similar impacts with this upcoming storm. H7 temperatures around -4 to -5C indicate snow levels as low as 7000 feet, though best chances for accumulating snowfall will generally be above 8000-9000 feet. Current forecast calls for snowfall amounts between 3 to 8 inches for most mountains above 8000 feet, except locally up to 10 inches for the southern mountains.

Behind the cold front passage late Tuesday, precipitation gradually tapers off through early Wednesday, drying out briefly ahead of yet another storm expected to impact our area on Thursday into Friday. There is more considerable uncertainty regarding this late-week storm, as models struggle to converge on the track and magnitude of the associated closed low. While this system is likely to bring another round of widespread precipitation, the uncertainty lies in the precipitation accumulations and just how cold of an airmass this storm brings to the region. Current H7 temperature spread late Thursday is between -3 to -9C, with the latter supportive of snow down to valley levels. This scenario is still on the lower end, with around 20% of models resolving this colder airmass, but still something to keep an eye on as we get closer.

AVIATION

KSLC...A ridge will quickly shift overhead allowing for dry conditions. Enough moisture will be maintained in this though to result in SCT to BKN VFR cloud cover above 14 kft or so. Winds are expected to maintain a southerly component and remain less than 10 kts.

REST OF UTAH AND SOUTHWEST WYOMING...An upper level ridge will translate through overhead quickly through Sunday. This will maintain dry conditions, though anticipate SCT to BKN VFR mid/upper cloud cover through much of the TAF period. Winds at area terminals will largely follow a diurnally normal pattern, if not go light and variable at times. If cloud cover is slow enough to build in, localized patchy fog may develop at some sheltered terminals prior to sunrise.

SLC WATCHES/WARNINGS/ADVISORIES

UT...None. WY...None.