textproduct: Salt Lake City

UPDATE

Updated key messages to reflect upgrade from SPC to slight risk for this afternoon and evening and upgrade of the High Wind Watch to a High Wind Warning. Updated fire weather discussion and aviation discussion based on current trends and upgraded SPC outlook. Previous discussion follows.

KEY MESSAGES

- The Storm Prediction Center has upgraded portions of northern Utah and Uinta County, WY to a slight risk for severe thunderstorms this afternoon and early this evening. There is a ~20% chance of wind gusts in excess of 58 mph in this area within 25 miles of a point and a ~10% chance of wind gust in excess of 65 mph within 25 miles of a point between noon and 7 PM today.

- Red Flag Warnings remain in effect for portions of southwestern Utah this afternoon and evening due to gusty winds and very low relative humidity.

- Strong wind gusts up to 60 mph will occur in the wake of a cold front across northwestern Utah near the Raft River Mountains and along I-80 from Wendover to Knolls from 6 PM until about 3 AM. A High Wind Warning is now in effect.

- Critical fire weather conditions may return to southwest Utah Saturday as gusty southerly winds will combine with low humidities in this area once again.

DISCUSSION

Issued at 1031 PM Tuesday May 12, 2026

Another day dominated by a strong ridge of high pressure Tuesday. While this ridge is continuing to slowly progress eastward, it has resulted in afternoon highs around 15-25 degrees above normal, tying or breaking records in some locations. While more cloud cover formed off of the terrain, and even a few light echoes were noted over the high Uintas, largely the area has remained very dry.

Wednesday looks to have potential to be an active day in terms of weather, and multifaceted in potential weather related hazards. This will be due to the ridge continuing to shift east while a trough and associated cold front push deeper into the Great Basin.

Deep southwesterly flow between the two features will increase, but 700 mb temperatures around 10C to 12C will result in another day with anomalously warm temperatures. While forecast highs are a few degrees or so cooler than that of Tuesday, in general still expect temperatures to run 10F to 20F above normal. With reasonable cooling overnight, HeatRisk will drop somewhat, but remain in the "Minor" category (risk level 1 of 4). This would pose the greatest threat to those sensitive to heat, especially without proper cooling or hydration. Those planning any strenuous outdoor activities should have a means to stay well hydrated and cool down as needed.

The aforementioned deep southwesterly flow will also result in a corresponding increase to winds and gusts across the area through the day Wednesday. Widespread gusts of 25-40 mph are expected, with around a 20-40% chance to see gusts exceed 45 mph in portions of southwest and west Utah. These strong winds will have potential to result in patchy areas of blowing dust, which could result in locally reduced visibility. Additionally, the south to southwesterly directional component could yield some moderately hazardous travel conditions to higher profile vehicles on routes where this would be a crosswind, such as I-80, US-50, and SR-21. The combination of strong winds and dry conditions will also result in areas of critical fire weather conditions in portions of southwestern Utah Wednesday afternoon and evening (see Fire Weather discussion).

The synoptic flow pattern will also become more favorable for modest moisture advection into the area Wednesday. In combination with widespread destabilization on the order of around 200-400 J/kg MUCAPE, anticipate convective development through the afternoon and evening hours. Coverage is anticipated to be highest in northern Utah and southwest Wyoming, and down through central Utah along/east of the high terrain north of the I-70 corridor or so. This moisture will be more concentrated in the mid levels, and given a well mixed deep boundary layer due to the strong heating, convection will be high-based in nature. The resulting vertical profile is that of an "interted-V", which would support potential for strong wind gusts in what storms do form, especially those that become better organized. To that end, effective shear on the order of 20-40 kts should support some of these storms becoming more organized, and even offering potential for some isolated small hail in addition to strong wind gusts (the primary threat). With that, the SPC has highlighted portions of northern Utah and southwest Wyoming in a categorical Marginal Risk (level 1 of 4) for severe weather Wednesday, particularly for severe wind gust potential (58 mph or greater). While the probability is lower, a couple storms may even be capable of significant wind gusts at or above 75 mph. Showers and thunderstorms will diminish in coverage and shift out of the region through the evening hours.

While the storms wane, a dry cold frontal boundary associated with the trough will begin to advance from northwest to southeast into Utah Wednesday evening. While the airmass associated with it is not really anomalously cold, the push into the departing record warm airmass results in a strong thermal gradient, and a correspondingly strong pressure gradient along the front. In turn, as the front passes it will cause an abrupt shift to gusty northwest winds. While at most lower elevations the period of gusts associated with frontal passage aren't anticipated to be too impactful (~20-35 mph), prone areas of northwest Utah especially downwind of terrain will see wind gust potential amplify. These places, such as Curlew Junction, Park Valley, and Wendover will see around a 40-70% chance of a period of gusts in excess of 58 mph for a few hours following frontal passage. In regards to timing, the current consensus has the front advancing into northwest Utah around 6 PM, reaching the I-80 corridor and portions of the Wasatch Front by around 9 PM, and continuing southeastward thereafter.

Thursday will see more quiescent conditions across much of the area. Cooler air associated with the trough will sink at least as far as the I-70 corridor or so. Forecast afternoon highs in turn decrease around 5-10 degrees in central Utah, and 10-20 degrees or so in northern Utah and southwest Wyoming. Modestly gusty post frontal winds around 25-40 mph or so will continue Thursday afternoon across some areas such as the western Uinta Basin and Castle Country.

Near to slightly above normal conditions continue into Saturday, with dry conditions maintained across most of the area. Breezy conditions appear set to return Saturday as another trough and associated frontal boundary progress through the Great Basin. Ensemble consensus continues to support this trough in some fashion, with a frontal passage late Saturday into Sunday. There is still a bit of uncertainty in details though. Approximately 60% of ensemble members carry a shallower and drier trough, with the other 40% deeper, colder, and more moisture rich. In either case, as of now it appears favored that we'll see a pretty substantial shot of cold air with this one. Forecast temperatures Sunday fall substantially, with afternoon highs forecast around 5-10 degrees below normal across central to northern Utah and southwest Wyoming, and near normal across southern Utah. Temperatures would then start to gradually moderate back upwards into the early portion of next week.

REST OF UTAH AND SOUTHWEST WYOMING

Southerly winds will increase across most terminal this morning, with gusts up to 40 mph from gradient winds after 15-18Z. High-based showers and thunderstorms will develop across the northern half of Utah after 18Z. There is a 20% chance of wind gusts in excess of 58 mph will occur within 25 miles terminals from roughly Utah County north and a 10% chance wind gusts will exceed 65 mph with 25 miles of terminals from Utah County north between 19-00Z today. A strong but dry cold front will bring a marked wind shift to the northwest for KENV near 03Z, with winds shifting across the remainder of northern Utah terminals after 03Z.

FIRE WEATHER

As a disturbance approaches Utah this afternoon and evening, gusty southwesterly winds up to 40 mph will combine with minimum humidities at or below 10 percent to bring critical fire weather conditions to fire weather zones 495, 496, and 497. Red Flag Warnings remain in effect for these zones.

Across northern and eastern Utah, high-based showers and thunderstorms will develop after noon today. Given strong heating, dry low-levels and robust mid-level winds, any high-based showers and thunderstorms will be capable of strong, gusty microburst winds. For areas roughly from Utah County and north, there is a 15-20% chance of wind gusts in excess of 58 mph near any thunderstorms, with less of a threat south of this area.

A dry cold front will cross into northwestern Utah this evening and gradually shift across the state. Strong northwest winds up to 60 mph will occur behind this cold front across northwestern Utah. While wind gusts will be less across the Wasatch Front and south, expect a few gusts in the 50s through the first half of the overnight period tonight.

Cooler temperatures can be expected Thursday especially across northern Utah. A gradual warming trend will continue Friday. Another system will approach the region Saturday, with gusty winds and low humidities bringing another round of potential critical fire weather conditions to portions of southwestern Utah Saturday afternoon and evening. Much cooler, unsettled conditions can be expected as a cold front crosses the area Sunday.

SLC WATCHES/WARNINGS/ADVISORIES

UT...High Wind Warning from 6 PM this evening to 3 AM MDT Thursday for UTZ101.

Red Flag Warning from noon today to 9 PM MDT this evening for UTZ495>497.

WY...None.