A moderate risk of excessive rainfall and flash flooding was maintained for portions of Utah in a notice issued by the NWS Weather Prediction Center. The forecast indicated that widespread convection is expected as dual shortwaves lift northward from Mexico and California.
The weather pattern involves enhanced ascent in a region already experiencing pronounced synoptic lift. According to the notice, deep layer lift will act upon extreme thermodynamics, with precipitable water values above 1 inch lifting as far north as the Utah Swell. While there is uncertainty regarding how quickly convection will develop due to morning CINH, the development of MLCAPE could support another day of widespread convective activity.
Thunderstorms associated with these conditions have a 20-30% chance of producing hourly rainfall exceeding 1 inch. The report noted that impacts may be most significant over sensitive features such as dry washes, slot canyons, and burn scars. While storms may be progressive, the alignment of propagation vectors indicates a strong threat for repeating cells, which could enhance the rainfall risk.
The rainfall risk for the region is expected to decrease during the following period as a mid-level trough moves onshore the California coast, which will shift the moisture and favorable corridor for ascent further east.
