743 FXUS65 KSLC 031015 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 415 AM MDT Tue Jun 3 2025 .SYNOPSIS...Unsettled pattern continues through the week, especially for southern Utah. Drier and milder conditions with temperatures above normal return for the weekend into early next week. && .SHORT TERM (Through 12Z/6AM Thursday)...A remnant frontal boundary is situated near the I-70 corridor this morning. With better forcing associated with an ejecting trough lessening, shower activity near this boundary has more or less ceased. Morning water vapor loop otherwise shows a broader scale trough across much of the northern states along with a cutoff low churning just off the lower California coast. The interaction between the aforementioned forecast features will serve as the primary forecast influence over the next couple of days. For Tuesday, cooler afternoon highs are expected behind the front across the northern half of the area, while southern Utah will see warming conditions. The remnant boundary will move minimally through the day, and in combination with diurnal heating and some very minor PVA in the broader trough`s cyclonic flow, will see redevelopment of isolated afternoon convection. With the extra convergence near the boundary, anticipate coverage to be maximized near to south of the boundary accordingly in portions of southern Utah. Overall available moisture will be less than prior days, and as such the drier low levels in what isolated convection does develop will contribute to a higher based nature and attendant gusty outflow wind threat. While HREF LPMM QPF and other model QPF output do suggest a lower flood threat Tuesday, any sufficiently strong cell that forms or drifts over a more sensitive location (slot canyon, typically dry wash, slickrock area, etc.) will have potential to be locally problematic, so those planning recreation to any such areas should still keep an eye on the weather. Forecast pattern remains unsettled into Wednesday as the upper low currently off of the California coast ejects inland, phasing to a degree with the broader northern stream trough as it does so. Deeper moisture which was confined south of the remnant boundary will advect further northward, and with the extra forcing from the larger scale synoptic elements, will see diurnal heating lead to more widespread convection. While chances will spread a bit further north, current forecast carries best chances of precipitation at areas generally south of the I-70 corridor. Subcloud layers don`t appear quite as dry as Tuesday, though DCAPE ~500 J/kg will still support potential for a gusty outflows from any cells that can organize/mature sufficiently. Locally heavy rainfall appears to be the bigger threat Wednesday, though some uncertainty remains in how high the threat is. If clouds increase early enough, or precipitation develops rapidly and over a wide enough area late morning before stronger destabilization occurs, corresponding increase in cloud cover will have potential to provide a stabilizing effect, with lighter rain more stratiform in nature generally more easy to be handled by appropriate runoff/drainage basins. Less cloud cover and more time to destabilize conversely would lead to stronger updrafts more capable of localized heavy rain, and potential flood threat to rain sensitive areas. The spread in CAM guidance for QPF is unsurprisingly fairly large, though the increase in HREF LPMM values does suggest a higher risk than that of Tuesday. All that said, main impacts will be to those planning recreation that could take them to any of those rain sensitive areas. .LONG TERM (After 12Z/6AM Thursday)...A broad, weak and disorganized trough will remain draped over the interior Western U.S. late in the week, acting moreso to provide general instability across the region rather than acting as a cooling mechanism. The prevalence of south to southwest flow in the lower levels will help to push moisture farther north through Thursday, allowing chances for showers and thunderstorms to expand into portions of northern Utah (pushing as far north as the Provo area mountains). This lower level moisture will coincide with moisture in the mid-to-upper levels, increasing the overall likelihood of moderate to heavy rainfall. For southern areas, this means another day of potential for flash flooding in slot canyons, slick rock, and normally dry washes. Into central and northern Utah, we not only continue to see the potential for flash flooding in these similar areas, but will also see the threat expand to areas surrounding recent burn scars. Something to pay attention to heading through the week. Friday through Monday the trend in the sensible weather across the region will be warming and drying as moisture wanes and an upstream ridge begins to encroach the West. Enough moisture should remain in place on Friday and Saturday to generate afternoon showers and thunderstorms over the high terrain, but with decreasing deep layer moisture the overall threat of flash flooding will wane. That said, if a storm lines up in the right place, flash flooding will still be possible... but coverage of storms and moisture content will make the overall chances much lower than earlier in the week. As far as temperatures go, each day is anticipated to warm by upwards of 3-5 degrees through Sunday, bringing high temperatures back to about 7-10 degrees above normal. Though daytime high temperatures by Sunday and Monday will be pushing afternoon heat risk into the "moderate", or 2 out of 5, category, overnight low temperatures are expected to fall low enough to allow for at least some relief for those who do not have access to artificial cooling. At this point in time, we are not expecting to have to issue any heat related headlines... just run on the mill hot early season temperatures. There is potential for a shortwave trough to translate through the ridge early next week, which would mainly act to bring an increase of moisture across the region. As such, will see increasing chances for showers and thunderstorms across mainly the northern half of the area by Tuesday. && .AVIATION...KSLC...Minimal operational concerns are forecast for the KSLC terminal through the period. Northwesterly winds will decrease in speed through 11-12Z, becoming light out of the southeast thereafter. South winds, with periods of light and variable flow, will be expected for only a couple of hours before reverting back to a north flow by 15-16Z. .Rest of Utah and Southwest Wyoming...VFR conditions are expected across the region today with northwesterly to westerly flow expected across most airfields. Largely clear skies are expected across a majority of the area, however, far southern Utah will see mid to high level cloud cover. Isolated showers will also be possible in the southern mountains, bringing a low end chance for gusty and erratic outflows, mainly for areas near KBCE. && .FIRE WEATHER...Lingering moisture along a largely stalled frontal boundary will result in the redevelopment of isolated convection across southern Utah Tuesday afternoon. Combination of an upper level low lifting through to the south and a deepening trough from the north will then result in more widespread activity both Wednesday and Thursday afternoon, with activity spreading a bit further north. This pattern will then support at least one more day of scattered afternoon convection Friday before ridging takes back over as a more dominant influence, subduing higher precipitation chances. Wednesday and Thursday appear to show the more favorable odds for wetting rains, largely at areas south of the I-70 corridor. Any convection each day will carry the threat of lightning and gusty erratic outflow winds as well. As high pressure increases influence through the weekend, afternoon minimum relative humidity values drop and temperatures return to above normal levels for early June. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ SHORT TERM...Warthen LONG TERM...Webber AVIATION...Webber FIRE WEATHER...Warthen For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity