textproduct: Salt Lake City

KEY MESSAGES

- A largely mild, calm and dry pattern will persist through much of the upcoming work week. The stable conditions and redevelopment of local valley inversions will in turn lead to potential for haze.

- While uncertainty remains noted, the next system remains most likely in the Friday/Saturday time frame. Precipitation potential continues to trend southward, and appears fairly modest.

DISCUSSION

Not much change to the broader synoptic pattern over the last 24 hours as a deep and dry northwesterly flow persists over the local forecast region, and a broad ridge remains parked over much of the Pacific Northwest. Looking at observations, temperatures are generally running a bit cooler than the prior night, though do not stray significantly from seasonal normal. The most interesting weather at the moment is arguably in the space weather realm with the ongoing geomagnetic storm, with further info on that available from the Space Weather Prediction Center (SWPC).

The forecast for the upcoming work week has also not changed substantially. Dry and stable conditions will more or less persist, and warming/moderating low level temperatures will support the development for valley inversion conditions. While afternoon highs on a broader scale will remain favored to fall above normal, areas where strong inversions and haze build may see temperatures struggle to push upward. These areas (and those around sources of moisture) will also be more favored to see potential for localized fog development.

Guidance continues to generally support some sort of system pushing into the area in the Friday/Saturday time frame, though run to run specifics continue to fluctuate. Compared to yesterday, the biggest change is seemingly models trending further towards this system cutting off and slipping south of the forecast region, with limited at best phasing with the deepening northern stream. With the cutoff system carrying more of the available moisture, precipitation chances have generally trended southward as well. That said though, how much moisture is squeezed out remains a question, as is highlighted by NBM 25th percentile QPF amounts remaining at zero, and 75th percentile amounts a more broad brushed 0.05" to 0.20" water for higher terrain. Even with cold air from the deepening continental trough, corresponding snow amounts in this forecast remain meager, only pushing to around a few inches at best at some of the favored southern terrain. With the nature of cutoff lows though there remains a fair amount of uncertainty in track, timing and amounts, so it'll remain worth monitoring trends. For example, NBM 90th percentile (1 in 10 chance of exceeding) amounts carry water amounts up to around 0.60" even for the northern mountains. Even if it ultimately ends up underwhelming, it is at least something that should likely help provide better ventilation to any valleys suffering from prolonged inversion conditions.

Individual deterministic models show a number of potential pattern evolutions thereafter into the longer term, and some at least maintain some level of activity with brushing systems. That said, looking at the broader range of ensembles does not look promising for those hoping for precip/snow. In general, it seems to appear a W CONUS ridge and E CONUS trough is the favored setup, which locally would continue to support milder/drier than normal conditions. The CPC 8-14 day outlook shows this, with above normal temperatures and below normal precipitation favored across a large portion of the west.

REST OF UTAH AND SOUTHWEST WYOMING

Generally light, terrain driven winds prevail for most regional terminals today except those across southwest Wyoming, where gusty westerly winds are expected between 17-00z. Valley haze across the Wasatch Front will result in periodic slantwise visibility reductions. Otherwise, clear skies yield widespread VFR conditions through the period.

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SLC WATCHES/WARNINGS/ADVISORIES

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