A significant and widespread heatwave is expected to grip Utah and southwest Wyoming through early next week, with temperatures projected to challenge daily, monthly, and even all-time high records. The National Weather Service issued an area forecast discussion late Friday, warning that much of the valley will see highs at or above 100 degrees through Sunday.
Record Temperatures Expected
The National Weather Service in Salt Lake City reported Friday night that a strong ridge centered over southern California is moving eastward. This feature has already caused maximum temperatures to trend upward, averaging 5 to 8 degrees above seasonal normals. As the ridge strengthens and continues its trek over the weekend, it is expected to peak on Sunday.
Meteorologists warn that almost all valley locations will experience high temperatures of at least 100 degrees from Saturday into Sunday. The most significant temperature anomalies are expected in northern Utah and southwest Wyoming, where maximum temperatures could run up to 15 degrees above normal.
In the northern portions of the forecast area, the heat may challenge monthly and all-time records. According to the National Weather Service, there is a 75 percent chance that Logan will surpass its all-time record high of 103 degrees Fahrenheit. Similarly, Evanston, Wyoming, faces a greater than 60 percent chance of breaking its all-time record of 95 degrees Fahrenheit.
While northern areas face the highest risk of record-breaking heat, southern locations may see slightly lower probabilities for all-time records. The National Weather Service indicated there is a 10 percent chance of tying or breaking the 107-degree Fahrenheit all-time record in Salt Lake City.
Extreme Heat Warnings have already been implemented across several zones. An Extreme Heat Warning is in effect from noon Saturday until 6 AM MDT Tuesday for several Utah zones, including areas identified as UTZ101, 108, 114, 116, 118, and 121. Other regions, such as UTZ115, 122, and 128, are under warnings through 6 AM MDT Monday. Additionally, a warning is in place for Wyoming zone WYZ021 until 9 PM MDT Monday.
The intense heat brings an increased risk of heat-related illnesses for the general population in most valley and mountain valley locations through the weekend, and through Monday for northern valleys. The National Weather Service advises those with planned outdoor activities to move them away from the hottest parts of the day whenever possible.
To maintain safety, officials recommend staying hydrated and remaining inside cooled areas when possible to prevent heat-related illnesses.
Conditions at Salt Lake City International Airport reflected the rising temperatures on Saturday morning. Weather observations from the National Weather Service showed that by 10:54 AM MDT on July 11, the temperature had reached 88 degrees Fahrenheit with a heat index of 88 degrees. Earlier that morning, at 7:54 AM, the temperature was recorded at 79 degrees Fahrenheit.
The heat is expected to coincide with dry conditions that could impact fire weather. The National Weather Service noted that high pressure building across the region through the weekend will result in single-digit relative humidity and poor overnight recovery. This daytime heating is expected to create unstable conditions both Saturday and Sunday afternoons.
As the center of the ridge moves east of the area by Sunday, a shift in airflow will likely bring monsoonal moisture into the state. The National Weather Service expects this moisture to begin spreading into the region as early as Sunday night, with convection developing over southern Utah by Monday afternoon and across much of the forecast area by Tuesday.
While the influx of moisture may provide some relief from the heat, it brings an elevated threat of flash flooding, particularly for southern Utah. This threat of convection and flash flooding is expected to persist throughout much of the upcoming week.
