textproduct: Salt Lake City

KEY MESSAGES

- Isolated showers and thunderstorms will develop again over portions of northern and central Utah this afternoon into the early evening.

- There is an increasing chance of critical fire weather conditions developing where fuels are dry over southwest Utah on Tuesday, with a low chance of wind gusts in excess of 40 mph. Winds will be stronger with higher gusts more widespread on Wednesday, with the potential of critical fire weather conditions for eastern Utah lingering Thursday into Friday.

DISCUSSION

A fairly similar weather pattern exists over the region today as it did yesterday, however, moisture content is greater across roughly the northern third of Utah and southwest Wyoming. That said, current satellite imagery reveals convective development of low level clouds and rain showers over the high terrain features over a portion of central and southern Utah. These clouds and showers will continue to develop through the remainder of the day, with coverage expected to be the greatest across the northern half of the forecast area. As was the case with yesterday, heavy rainfall, flash flooding, and any threat of severe weather will be low given the lack of lower-level moisture content and shear in the environment.

The loosely defined ridge axis pushing into Utah today will crest the region later this evening, helping to further increase temperatures as we head through the day on Monday... especially across the northern area. As such, high temperatures will reach their peak across the forecast area on Memorial Day. On the backside of this ridge axis, lower and mid-level moisture is expected to increase, ushering in higher chances for showers and thunderstorms. The increased chances for precipitation will be seen across southern Utah, particularly in the high terrain, while the remainder of the area (northern/ central UT, southwest WY) will see an increase in probability by Tuesday as our next weather system interacts with the moisture. With the warmest overhead temperatures departing to the northeast on Tuesday, expect cooler temperatures across the area.

The previously mentioned weather system will dive into the Great Basin region from Monday evening through Tuesday evening, lingering in the West through the end of the week ahead. As a result of this low pressure system, relatively active weather is expected through the next week. While precipitation chances will be fairly low (20-40% chance depending on where in the area you are... high terrain favored), breezy conditions are expected to develop. Breezy conditions pairing with dry surface relative humidity and critically dry fuels may pair to create critical fire weather conditions across a portion of the forecast area. In addition to these potential fire weather conditions, strong south to southwest winds developing each afternoon from Wednesday through Thursday may create difficult driving conditions on routes experiencing crosswinds and could pick up loose debris, yard decorations, and other lightweight objects. Current model guidance shows the highest probability (50-90% chance) of wind gusts in excess of 45 mph over Carbon and Emery County on both of these days, with the second highest probability area (20-50% chance) over western Juab, Millard, and Beaver Counties.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions will persist for the entire airspace through the period. Mostly dry conditions with mid level clouds will continue. There is a 30% chance of afternoon convection across the northern and eastern airspace that could produce some erratic gusty outflow winds impacting nearby terminals. Otherwise, expect typically diurnally driven winds.

FIRE WEATHER

High based showers and isolated thunderstorms are expected across northern Utah this afternoon, bringing little in the way of precipitation alongside potential for localized strong outflow wind gusts. A warming and drying trend is expected across Utah through Monday before a low pressure system drops into the region late Monday through Wednesday. Ahead of this low pressure system, strong southerly winds are expected to increase across the southern two-thirds of Utah from Tuesday through at least Thursday. Current trends support Tuesday as the higher potential for critical fire weather conditions as relative humidity remains below 15 percent across a more widespread area alongside high probability (80-95% chance) of wind gusts exceeding 30 mph. While winds are expected to increase Wednesday and Thursday, relative humidity will be a bit more marginal. That said, elevated to near critical fire weather conditions are still expected to be in place through at least Thursday. In addition to the increases in winds, periods of elevated moisture increase will bring a chance for isolated to widely scattered thunderstorms over a portion of Utah (varying each day) from Monday through Friday.

SLC WATCHES/WARNINGS/ADVISORIES

UT...None. WY...None.