textproduct: Salt Lake City

KEY MESSAGES

- Scattered showers and thunderstorms will continue through Friday evening across central and southern Utah. There is a 10 percent chance of microburst wind gusts up to 45 mph near any of these showers or thunderstorms.

- There is a 50% chance of southerly wind gusts in excess of 45 mph across western Utah on Tuesday.

- Locally critical fire weather conditions due to strong wind and low humidity will occur across much of southern Utah beginning Tuesday in areas where fuels are critical.

DISCUSSION

Scattered showers and isolated thunderstorms are ongoing across southern Utah early this afternoon along a weak boundary, remaining primarily south of I-70. Wind gusts have largely stayed below 35 mph, though with increasing instability this afternoon, a few rogue gusts exceeding 40-45 mph cannot be ruled out. Isolated showers are likely to redevelop Saturday afternoon given lingering mid-level moisture, despite high pressure starting to build across the state. Chances for gusty outflow winds will be similar to today, with a 10 percent chance of exceeding 45 mph.

Temperatures will continue to increase through the holiday weekend, with largely quiescent conditions aside from isolated high-based showers. By Sunday and Monday, expect highs around 5-10 degrees above normal, translating to the mid-80s along the Wasatch Front and many other valleys, and low- to mid-90s in St. George.

Heading into next week, the pattern becomes more active as a weak shortwave moves northward on Monday/Monday night ahead of a more potent closed low. This shortwave will draw mid-level moisture into Utah, resulting in chances for high-based showers once again on Monday and especially Tuesday. Currently, this wave looks to cross Utah on Monday night, not overlapping with the diurnal peak in instability. Thus, coverage of showers and thunderstorms might be a bit more limited than if the timing were to shift earlier or later (which is still in the cards). Dynamics associated with this wave and the approaching closed low could also result in increased shear and potentially a bit more organization with storms that develop.

Alongside an elevated threat of showers and thunderstorms, synoptic southerly winds will begin to increase on Monday, likely peaking on Tuesday and Wednesday across western valleys (Wednesday and Thursday across eastern valleys). Currently, there is around a 50-60% chance of reaching Wind Advisory criteria (45 mph) across western valleys on Tuesday. This will also result in greater chances for critical fire weather conditions given low relative humidity. Large-scale uncertainties still remain, particularly with timing as the track of the closed low could still shift.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions are expected to persist across all terminals this afternoon, except for KCDC where low confidence in isolated dry thunderstorms are expected to develop. Following 02z, conditions will improve making way for VFR conditions this evening.

FIRE WEATHER

Isolated to scattered high-based showers will continue through the afternoon, primarily south of I-70. Gusty outflow winds and isolated dry lightning will be the main threats, with a 10 percent chance winds briefly exceed 45 mph and wetting rain chances around 10-20 percent.

Temperatures will continue to increase through the holiday weekend, with mostly dry conditions expected. Isolated showers and thunderstorms will develop once again across central Utah on Saturday afternoon, with weak showers possible across northern Utah on Sunday afternoon. Gusty and erratic outflow winds will again be the main threat. Minimum RH will be around 10-15 percent across most areas through the weekend and up to 20-30 percent across higher terrain.

More active weather will return Monday as southerly winds begin to increase ahead of the next storm system. The threat of gusty and erratic outflow winds will increase as showers and thunderstorms develop, particularly between late Monday and Tuesday afternoon. Timing uncertainty still remains, though critical fire weather conditions are likely on Tuesday and Wednesday afternoons in particular given strong winds and low RH...potentially lasting through Thursday.

SLC WATCHES/WARNINGS/ADVISORIES

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