textproduct: Salt Lake City

KEY MESSAGES, Issued 1002 PM MDT Sun Jun 28 2026

- Localized frost to brief freezing conditions will be possible Monday morning in portions of northern Utah valleys and high mountain valleys like the Wasatch Back. - Abnormally cool temperatures will gradually warm through midweek, returning back to near normal by Thursday.

- Little in the way of appreciable precipitation is expected over the next week. Southwesterly winds are favored to increase by midweek, which in combination with widespread dryness and warming temperatures will result in areas of Critical Fire Weather conditions likely returning Thursday and Friday.

DISCUSSION, Issued 1002 PM MDT Sun Jun 28 2026

Evening analysis shows a broad longwave trough placed across the majority of the W CONUS. Mid level water vapor loop shows a cutoff shortwave lobe of this broader trough digging southward deeper through the Great Basin. While available moisture remains limited, a corridor of near normal PWAT values is allowing for continued shower activity near this feature, as well as near the convergence zone of a cold front associated with the broader scale trough. While cold air associated with the trough is more noticeable in the form of temperatures running 10-25 degrees below normal, it is also helping steepen lapse rates a bit to allow for an isolated thunderstorm or two, though suspect with the cessation of daytime heating any lightning will become more sparse with the continued shower activity.

Sunday night into Monday will see the core of the broader longwave trough very slowly start to shift eastward while embedded shortwave impulses continue to dig southward through the Great Basin and W CONUS near the Pacific coast. Locally, anticipate enough moisture and forcing to maintain some isolated shower chances, especially across northern Utah. Interestingly, these chances look to be further aided in areas generally east of the Great Salt Lake as the abnormally cold airmass overriding the warm lake will have potential (~30% per GFS derived LE guidance) of yielding some lake enhanced shower activity early Monday morning. It does appear tonight into Monday morning will likely be the coldest night for most locations. There is uncertainty though on how much the precipitation potential and associated cloud cover can help limit radiational cooling though. While somewhat borderline, would not be surprised to see some areas in northern valleys (such as the Cache) or mountain valleys (like the Wasatch Back) briefly fall to freezing, or see some frost development. Particularly if winds can calm and clouds clear. Given how limited the threat area is, opted to not issue any headlines, but those with sensitive vegetation in these areas may want to consider bringing plants inside or covering them as possible/needed.

Monday on into midweek will see the broader longwave trough more or less maintained across the W CONUS while individual shortwave impulses continue to ripple through its base. With moisture becoming further limited, shower chances will be quite low, with the highest chances arising Tuesday afternoon in the form of isolated shower chances largely over the high terrain, particularly the high Uintas. Otherwise, the airmass will more or less moderate day to day, allowing temperatures to gradually warm in turn. With the exception of some elevated to locally critical fire weather conditions where a combination of winds and low humidity can combine (best chances across southern to eastern Utah), impactful weather chances will remain fairly low.

Model consensus has not changed significantly for Thursday into the weekend. The favored pattern evolution is that of a continued W CONUS trough enhancing southwesterly flow, continuing the warmup and maintaining dry conditions, and bringing about potential for more areas of critical fire weather conditions. That said, there still remains fairly considerable uncertainty on specifics including the depth of the trough driving the mild southwesterly flow, and just if/how quick it begins to shift eastward. Canadian Ensemble members seem most bullish on a slower progressing deeper W CONUS trough, where the ECM Ens/GEFS are somewhere in the middle with a bit more eastern progression. Biggest impact would be in terms of fire weather, with the deeper/slower trough solution allowing potential for a longer period of southwesterly winds into the weekend. In any case, very little ensemble membership offers anything in the way of appreciable precipitation chances, so the dry conditions are likely to persist at a minimum.

AVIATION, Issued 1002 PM MDT Sun Jun 28 2026

KSLC...VFR conditions prevail at the terminal through the forecast period. A period of showers and perhaps an isolated thunderstorm is expected between 6-12z, but impacts will be minimal outside of terrain obscuration. Otherwise, dry conditions are expected with gradually clearing skies late Monday morning. Northwesterly winds transition to southeasterly after ~10z, shifting back northwest around 19z.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions prevail for all regional terminals. Generally light, terrain driven winds prevail overnight across the airspace through Monday, except portions of eastern Utah and southwest Wyoming where afternoon gusts to 25 kts are expected. Some isolated showers are possible along the Wasatch Front between 6-12z; otherwise, dry conditions prevail with gradually decreasing cloud cover through late Monday morning.

FIRE WEATHER

More stable conditions will build into the region behind a disturbance shifting into the central Rockies today. Southwest flow will gradually develop across Utah through Tuesday as yet another disturbance approaches the area, with critical fire weather conditions developing across the San Rafael Swell and Henry Mountains Tuesday afternoon and evening, and locally critical fire weather conditions across the western Uinta Basin and Grand Staircase. Overnight recovery will become increasingly poor after Monday night.

Winds will decrease Wednesday behind this disturbance but will begin to increase once again Thursday into Friday, with more widespread critical fire weather conditions expected.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Fire Weather Watch from Tuesday afternoon through Tuesday evening for UTZ489-494.

WY...None.