Mid May Dip

High cirrus and stratocumulus have filled in across Utah through the early Saturday morning hours. A few high based showers and virga have also inched in across far western portions of the state. The clouds and showers are forming out ahead of the next weather disturbance to impact the state, which is expected to bring cooler temperatures, valley rain/thunderstorms and high mountain snow.

GOES-18 West True Color Imagery 5/16/2026

Currently, a long wave trough is moving off the Pacific into the PNW. At the base of this trough, a short wave and associated energy will eject eastward from CA/NV into Utah Saturday. During the day Saturday, a cold frontal boundary will slide south across northern into central Utah. Impacts from the short wave trough and cold frontal disturbance will largely be focused across the southern and eastern tier of the state where moisture and energy will be available. 

700mb Analysis 15z 5/16/2026: heights, wind, temperature, and RH

Enough instability, from the slight cooling in the mid to upper levels and spring time surface heating, will bring the potential for few thunderstorms over portions of the state going into this afternoon. Most thunderstorm activity is likely to be focused near the cold frontal boundary as it sags south and along or off the higher terrain. Gusty outflow winds are the main concern with any thunderstorms or other high based showers that do develop. Precipitation amounts will generally be on the lower end, but a heavier burst is not out of the question.

NAM 3km Init 12z 5/16/2026: Simulated composite radar reflectivity 16z 5/16 - 03z 5/17/2026

And The larger and more vigorous long wave trough will carve south into Utah, filling in behind the weak disturbance on Saturday. A reinforcing shot of cold air and moisture will spread across the state Sunday into Monday, bringing much more widespread precipitation. As of now, however, the heaviest precipitation amounts are expected over central, southern and eastern portions of the state, with the highest amounts focused over the higher elevations in each of those respective regions. The Uintas in particular could be the winner - in terms of liquid - with the Sunday into Monday storm. Storm liquid totals across the mountains and high valleys look to be in the 0.5-1.5" range. There is some uncertainty in the location and amounts of precipitation due to potential changes in how the storm will orient itself across Utah. 

In terms of snowfall, snow levels will bottom out near 5500-6000' Sunday afternoon into Monday as the coldest air and heaviest precipitation arrives. Accumulating snowfall is possible for higher elevation valley areas across the entire state. Some mountain locations will pick up relatively significant amounts of snow, with 8-12" possible in the upper Cottonwoods. The Uintas in particular could see significant totals of 12+" from this spring snow storm. 

The storm clears out of the state by late Monday, with conditions drying. Temperatures will rebound from the 50s Sunday and Monday through the remainder of the workweek, gradually climbing back up into the 70s and 80s for valley areas. After this mid month storm and cool down, May will be out in full force, with mild and largely dry weather is expected through the bulk of the second half the month...