textproduct: Salt Lake City

KEY MESSAGES, Issued 1002 PM MDT Sun Jul 5 2026

- Scattered high based convection will develop Monday afternoon and evening across portions of central and northern Utah, and southwest Wyoming. Gusty outflow winds to around 50 mph will be possible. Limited moisture will then linger across the north Tuesday.

- Areas of elevated to locally critical fire weather conditions will redevelop across portions of southern and central Utah Tuesday and Wednesday given modest southwesterly gusts and dry conditions.

- Anomalous heat builds in late week on through the weekend as a ridge of high pressure strengthens overhead. areas of Major to locally Extreme HeatRisk are likely during the weekend, with potential for record temperatures noted.

DISCUSSION, Issued 1002 PM MDT Sun Jul 5 2026

A shortwave ridge centered over the Four Corners region has resulted in another hot summer day across the region. Most valley locations across Utah achieved mid 90s to low 100s, with KSLC reporting its first 100+ degree day of 2026. Even the mid to upper 80s across SW WY is around 5-10 degrees above normal. Aside from the ridge and heat, a subtle shortwave trough is lifting northeastward through the Great Basin, bringing with it some mid to upper level moisture. This is responsible for the increased cloud cover over the region today, as well as some isolated high terrain showers over the Uintas. With the increased cloud cover, overnight lows Sunday night into Monday morning look to be a few degrees warmer than that of the previous night.

On Monday the shortwave trough will continue to brush by and eject northeastward, with the mid to upper level moisture also remaining overhead. With the corresponding shift of the ridge, southern Utah will generally see temperatures increase a couple degrees while the northern portion of the area sees temps dip a couple degrees. With the moisture and extra lift from the passing shortwave, CAM guidance maintains support for the development of high based convection Monday afternoon into the evening. Generally anticipate the highest coverage of activity across the high terrain and areas downstream to the northeast, though initially convection may struggle to shift off terrain. CAMs are also starting to suggest maybe a bit more activity across northern Utah to southwest Wyoming, closer to where the better forcing from the shortwave and upper jet is expected. With strong surface heating and moisture largely at or above the mid levels, dry subcloud layers will support widespread DCAPE of around 1000-1500 J/kg, and locally higher. In turn, this will support gusty outflow winds from what does form, with most models showing potential gusts ~40-50 mph. That said, HREF/REFS max does carry some isolated 60+ mph gusts, which is also marginally supported by some sources of ML guidance.

Tuesday and to a lesser extent Wednesday will see a similar pattern as the moisture is slow to lift northeastward out of the region, a modest STJ remains extended through the Great Basin, and the ridge slowly shifts a bit southwestward. Coverage of high based convection is not too dissimilar for Tuesday, with the best chances starting to shift a bit north. On Wednesday, any activity looks likely to further shift north as the moisture departure continues. Like Monday, little in the way of water is expected from most activity, but the high based nature will be supportive of gusty and erratic outflow winds. By Thursday moisture will largely scour out, and the ridge will become more centered from the Desert Southwest through the lower California coast.

The ridge will become the dominant forecast influence Friday on through the weekend as it strengthens and shifts to become centered more or less overhead. Individual models and the broader suite of ensemble members continue to have high confidence in this occurring, with mean H7 temperatures likely pushing into the 20-24C range or so. This would be well above the 90th percentile climatologically, if not at or near the climatological max. Temperatures will push upwards as the ridge builds in, likely peaking over the weekend. Current forecast carries low to mid 90s for southwest Wyoming, around 100-105 for much of the Wasatch Front and urban corridor, mid 90s to low 100s for most other Utah valleys, and around 105-110 in low elevation southern Utah areas like Lake Powell, lower Zion, and lower Washington County. Overnight lows will also be fairly mild, only offering modest relief. The prolonged anomalous heat will increase the risk of heat related illness, with the HeatRisk product already favoring widespread areas of "Major" (level 3/4) HeatRisk, and locally "Extreme" (level 4/4). Those with outdoor work or recreation plans should remain aware of this, and be prepared to take appropriate heat precautions (lightweight light colored clothing, ample hydration, take breaks and have a way to stay cool, etc).

While still a ways out and details are still quite murky, models still maintain some semblance of the synoptic pattern beginning to open up the tap for some return of monsoonal type moisture by the middle of July. Currently, July 14th-15th still looks like the earliest we'd see this.

AVIATION, Issued 1002 PM MDT Sun Jul 5 2026

KSLC...VFR conditions are expected to persist through the TAF period. Winds should turn southeasterly by 04z this evening, then southwesterly by 18Z tomorrow and increasing in magnitude. There is a chance (20-40%) that a lake breeze develops with northwesterly winds tomorrow afternoon. There is also a small chance (10-20%) of rouge outflow winds reaching the terminal - outflow winds would be due to increased mid-level moisture bringing potential for high- based virga from around 18Z to 03Z tomorrow afternoon/evening.

REST OF UTAH AND SOUTHWEST WYOMING...Mostly VFR conditions will continue. Increased mid-level moisture tomorrow will bring a greater chance of high-based showers and thunderstorms for all but far southwest Utah. Additionally, winds tomorrow will be a bit stronger than recent days, generally from the southwest for most terminals by around noon.

FIRE WEATHER

Midlevel moisture will continue to spread into the area today, resulting in mainly high-based showers with isolated dry thunderstorms. The bulk of these showers are expected to develop over the northern and central Utah mountains and drift into the eastern valleys, while another area of showers can be expected across northwest Utah. With this increase in moisture, afternoon relative humidities are expected to rise above 15-20% over the higher terrain, but remain around 15% or less in the valleys, though overnight recoveries will improve over recent nights.

As a drier westerly flow starts to develop over the area, the areal coverage of high-based showers and thunderstorms is expected to be slightly decreased for tomorrow, then trend more isolated for Wednesday. The showers tomorrow will largely occur in the same areas as today, while Wednesday they are expected to be limited more to northern Utah. The westerly winds may also be strong enough to bring marginal or isolated critical fire weather conditions to the area.

Strong high pressure will build into the area towards the end of the week and through the weekend. This will bring hot and dry conditions to the area, with many valleys expected to see max temperatures in the triple digits. These hot temperatures will be paired with minimum relative humidities in the single digits.

SLC WATCHES/WARNINGS/ADVISORIES

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