textproduct: Salt Lake City

KEY MESSAGES, Issued 1027 PM MDT Fri Oct 9 2026

- Widespread heavy rainfall is expected to occur across the entirety of the forecast area starting Saturday afternoon/evening as Tropical Storm Rachel transitions to an extratropical system to our southwest and interacts with a strong midlevel trough. Widespread rainfall amounts from 1-3" are expected across much of the forecast area, with localized amounts potentially reaching 4+" across locations such as higher terrain locations across southwest Utah, the Book Cliffs, and locations within and adjacent to the Bear River Range.

- A wind threat is expected to accompany this system as it begins to take on extratropical characteristics. Initially, advisory level winds will begin to develop across most Utah valley locations starting just after midnight tonight, becoming more widespread Saturday afternoon. Advisory level winds are forecast to remain in place through at least Monday afternoon.

- A more notable high wind threat looks to develop across the valleys and high terrain of southwest Utah as the potential development of a sting jet looks to occur Sunday. This would bring widespread lower elevation winds in excess of 40 mph with high terrain and ridgelines seeing gusts potentially exceed 70 mph.

- The potential for severe weather exists across southern and eastern Utah Sunday into Monday morning. The primary threat will be severe thunderstorm gusts and possibly isolated tornadoes.

DISCUSSION, Issued 1027 PM MDT Fri Oct 9 2026

Evening synoptic analysis shows westerly flow starting to shift more southwesterly as a large scale trough continues to deepen through the PacNW. Combination of modest energy advection and available moisture resulted in the development of widely scattered showers and thunderstorms through the afternoon and evening, and models support some activity persisting overnight into Saturday. Moisture so far is largely in the mid levels, resulting in modestly high cloud bases. Given that in addition to increasing southwesterly flow, may see activity result in some gusty and erratic winds at times.

Through Saturday the trough will continue to deepen, and Tropical Storm Rachel will begin to approach the coast likely somewhere from southern California to the northern Baja Peninsula. Deeper tropical moisture associated with Rachel will start to be pulled into the trough and into the Intermountain West. With the deepening southwesterly flow, widespread wind gusts of 30-45 mph or so will develop, with some gusts in excess of 45 mph in portions of western Utah and central to northern low elevation valleys. These areas have a Wind Advisory in effect accordingly. Otherwise, will just see scattered shower and thunderstorm activity increase through the day. An isolated strong to severe storm with gusty winds may also be possible given increasing shear leading to potential for better storm organization.

As the trough deepens Saturday into Saturday night, a weak frontal boundary will also advance slowly into northern Utah. The combination of general synoptic support for ascent, the frontal boundary, and increasing moisture will yield a further increase in precipitation. While precipitation will increase areawide as Rachel continues to lift towards the region, where this frontal boundary is situated may see localized enhancement and periods of heavier rainfall. As mentioned in previous discussions, this potential would serve as a Predecessor Rainfall Event (PRE) which would help saturate soils ahead of the more anticipated rain incoming. In any case, soils areawide will begin to saturate as rain increases.

Sunday will see a weakening and decaying Rachel lift through the Great Basin and into the large trough, bringing a potential for a multifaceted weather hazard day. These threats include further heavy rainfall and flooding, areas of very gusty winds, and severe weather including possible tornadoes. Some of these threats will on into at least early Monday for portions of the area.

Starting with rainfall, the forecast has not changed significantly. Overall, a fairly widespread 1-3" is expected. Locally higher amounts, possibly on the order of 4+" will be possible in high terrain of southwest Utah, as well as other favored southerly aspects of terrain around Utah where an upslope component can enhance rainfall. Additionally, some high resolution CAMs show some signal for feeder type bands wrapping towards Rachel's circulation, training or moving very slowly. Such mesoscale features will be difficult to pin down in advance, but would serve as another area that would see potential for higher rainfall amounts. The highest flash flooding threat is noted across typically rain sensitive basins such as slot canyons, typically dry washes, slickrock areas, and recent burn scars. That said, the widespread and at times prolonged nature of the rain will also result in a general flood threat, such as potential for urban flooding or flooding of poor drainage areas and ponding of water on roadways. Additionally, area rivers and creeks will see rises, amount dependent on where exactly the heaviest rainfall occurs.

Strong wind gusts will also be a continued threat Sunday into Sunday night. As is typical with tropical cyclones transitioning to extratropical, the low level wind field will expand, with 700 mb winds along and east of the remnant circulation forecast 40-70 kts roughly. Any momentum transfer to the surface will bring potential for gusts around 40-60 mph in turn, with locally higher numbers possible with any spots that can see some downsloping enhancement. Additionally, with the strong 700 mb flow, higher elevation ridgetops will see more persistent gusts in excess of 50 mph, and likely some in excess of 70 mph (especially near higher peaks). With many locations likely having saturated soils, and most area trees still remaining near fully leafed at this point in autumn, these winds gusts may prove particularly damaging in some locations. For now, will hold at least another model cycle before opting whether or not to shift the High Wind Watch to a High Wind Warning to see if there are any notable trends in guidance.

A severe weather threat is also noted, particularly for portions of southern to eastern Utah. REFS shows widespread mean surface instability in excess of 100 J/kg, with around 400-800 J/kg across potions of southern to eastern Utah. Ensemble max (also supported by some other individual CAMs) continues to show potential for pockets of 1000-1500 J/kg, most likely realized if some modest breaks in cloud cover can form. With the strong low to mid level flow, models also support around 40-60 kts of deep layer shear and 100-200 m2/s2 of storm relative helicity. In turn, elongated curved hodographs continue to be noted in model forecast vertical profiles, which would support at least some conditional tornado threat, especially in any activity that can remain discrete to semi-discrete in nature. Otherwise, any storm organization will be likely to further help bring the strong momentum to the surface resulting in some severe level wind gusts. The wind gust threat would be further enhanced if any drier air can start to wrap into the region and enhance DCAPE values.

Rachel's remnants will continue to eject away from the area through Monday, but the broader trough will cut off in the Great Basin and slowly work east through midweek. Sufficient moisture will linger within this cutoff to yield continued elevated precipitation chances, and there will be some potential for periods of moderate to heavy rainfall as synoptic forcing overhead remains relatively strong with the trough. Given the preceding rain from Rachel's passage and saturated soils, any further rainfall will carry some threat of being excessive in some locations. Snow levels will generally run around 8500-9500 ft, allowing some mountain snow at higher elevations as well. While some modest accumulations are possible, warm antecedent conditions and likely poor liquid to snow ratios far below the "standard" 10:1 will largely limit more impactful amounts. A modest cold front will also accompany the trough as it shifts through, resulting in a marked cooldown Tuesday with forecast highs 10-15 degrees below normal. Temperatures are then expected to gradually moderate back upwards through the week, with drier weather favored to return by Thursday.

AVIATION

KSLC...VFR conditions are likely to prevail the KSLC terminal through the TAF period with enhanced southerly winds. Periodic showers and thunderstorms can be expected through much of the day. Erratic outflow winds briefly gusting up to 45 mph may accompany some of the showers and thunderstorms. More widespread rain showers will spread into the area this evening, continuing through Sunday morning. Periods of heavier rain may bring occasional MVFR conditions (10-20% chance) during this time, along with mountain top obscurations.

REST OF UTAH AND SOUTHWEST WYOMING...Enhanced southerly winds are expected across the airspace through the TAF period. Scattered showers and isolated thunderstorms this morning will increase to scattered showers and thunderstorms this afternoon. Some of the stronger storms will produce erratic outflow winds briefly gusting to 40-55 mph. More widespread rain showers associated with deep tropical moisture will spread into the area this evening, continuing through Sunday morning. Periods of heavier rain may bring occasional MVFR conditions to area terminals during this time, while mountain top obscurations become increasingly widespread.

FIRE WEATHER, Issued 218 AM MDT Sat Oct 10 2026

As a storm system approaches the area, southerly winds will continue to increase across the area today, with widespread gusts 30-50 mph. Scattered showers and thunderstorms will also develop across the area today, with increasing chances for wetting rain. The storm will pull in tropical storm remnants late tonight through Sunday, with widespread moderate to heavy rainfall expected. Winds will also likely remain strong in association with the remnants. The storm system will then slowly cross the area Monday through early Wednesday, maintaining an active and cooler pattern with widespread wetting rains through this timeframe. A drying and warming trend is likely for the latter part of the week.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Wind Advisory until 6 AM MDT Sunday for UTZ101>109-115-116-118- 119-122-126-127.

Flood Watch from late tonight through Monday afternoon for UTZ101>112-114-115.

Flood Watch from noon MDT today through Monday afternoon for UTZ113-116>131.

High Wind Watch from Sunday morning through late Sunday night for UTZ115>117-119-122-125>127.

WY...None.