textproduct: Salt Lake City

KEY MESSAGES

- Deep moisture will continue to bring an elevated threat of flooding to portions of southern and eastern Utah through at least Friday.

- A Flood Watch for flash flooding has been issued from late tonight until Thursday morning for portions of southern and eastern Utah including Zion National Park, Capitol Reef National Park, Glen Canyon Recreation Area, the greater Grand Staircase- Escalante National Monument area, and the lower Paria including Buckskin Gulch and Paria Canyon north of the Arizona border.

- A marginal risk for excessive rainfall (level 1/4 continues for Thursday and Friday across southern and eastern Utah.

DISCUSSION

Quick discussion due to ongoing severe and flash flood threat. Increasing moisture across southern and eastern Utah will continue to bring the threat of flash flooding through at least Friday, though the highest potential will be through Thursday morning. Given trends in CAMS with shortwave troughs ejecting across the area ahead of the parent low off the Pacific Coast, multiple rounds of strong convection with a heavy rain threat will occur. A majority of CAMS solutions develop an area of thunderstorms with heavy rain across southwestern and south central Utah near to after midnight, becoming widespread across eastern and southern Utah by late Wednesday morning, mainly east of I-15.

This threat will continue through at least late Wednesday night, potentially into Thursday morning as yet another shortwave trough ejects across the region.

As the upper level low ejects across the Great Basin Friday into Saturday, drier conditions will build into the state from west to east.

A Flood Watch for flash flooding has been issued for portions of southern and eastern Utah from late tonight through Thursday morning. Depending on trends, this may need to be extended to include additional zones in the state and/or extended into at least Thursday night by later shifts.

AVIATION

KSLC...Northwesterly winds will likely prevail through the afternoon, transitioning to southeasterly around 03-04z. Overnight showers and thunderstorms may approach the terminal as early as 04z, gradually increasing in coverage through roughly 10-12z before diminishing by as late as 15z. Winds could be a bit squirrelly with these storms, with a greater chance for strong outflow winds expected Wednesday afternoon as thunderstorms build after 22z.

REST OF UTAH AND SOUTHWEST WYOMING...Southwesterly winds will build across much of the area this afternoon, with scattered thunderstorms focused primarily over southeastern Utah, roughly southeast of a line extending from KCDC-KU69. Intermittent showers and thunderstorms will likely continue through the overnight hours across mainly areas south of KOGD, where winds could be gusty and erratic at times.

FIRE WEATHER

An ongoing moisture surge will bring an increased threat of showers and thunderstorms across eastern and southern Utah through at least Friday. For locations west of I-15, humidities will increase above critical levels by Wednesday, however gusts to 30 mph will continue through Thursday.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Flood Watch from Wednesday afternoon through late Wednesday night for UTZ121-129.

Flood Watch from midnight MDT tonight through late Wednesday night for UTZ124-128-130-131.

WY...None.