textproduct: Salt Lake City

KEY MESSAGES

- A Wind Advisory is in effect from west central to southwest Utah through early Wednesday evening, with gusts up to 55 mph expected.

- Critical fire weather conditions will persist in portions of south central to southeast Utah through the day Wednesday and Thursday due to gusty winds and low humidity values.

- Cooler and more unsettled conditions return Friday on through the weekend as a broad area of low pressure moves through the area.

- High pressure is favored to return next week, bringing drier weather and warming temperatures.

DISCUSSION

Synoptic analysis shows an expansive area of low pressure continuing to churn through much of the western US while a ridge of high pressure extends through the northern Plains to Upper Midwest. With the local forecast area more or less between these two features, strong deep southerly flow is maintained within the correspondingly sharp pressure gradient. As such, another day of gusty conditions is underway with widespread gusts 25-35 mph noted areawide, and stronger gusts up to around 55 mph in portions of west central to southwest Utah. A Wind Advisory remains in effect for the aforementioned areas into the early evening, after which time the lack of deeper mixing is anticipated to result in a downward trend to wind gusts. Something of a dry slot is also evident on mid level water vapor loop today, which will help largely preclude precipitation chances. With gusty and dry conditions, areas of critical fire weather conditions are once again anticipated in portions of south central to southeast Utah where fuels are sufficiently dry (see fire weather discussion).

Thursday will see limited movement of the driving synoptic features, with the broad low only shifting eastward slightly. Conditions across the forecast region in turn will be quite similar to that of Wednesday. While it will once again be fairly breezy, it does appear that the magnitude of the low to mid level winds decreases slightly, limiting the potential for gusts that would reach necessity for another Wind Advisory. That said, may still see some localized gusts in the 45-55 mph range at areas downwind of terrain near Cedar City, for example. Gusts will be strong enough to result in another day with areas of critical fire weather conditions across portions of south central to southeast Utah.

The broad low pressure area will finally see a more notable shift eastward by Friday. A fairly diffuse baroclinic zone will push in from the west and pull temperatures down around 5-10 degrees, and moisture and synoptic forcing will increase. Instability looks to be fairly meager, but with a little bit of effective shear, wouldn't entirely rule out a storm or two becoming slightly stronger and more organized. For most locations though, just anticipate isolated to scattered showers and thunderstorms through the day, with highest coverage initially on/near Utah's high terrain. Lingering moisture within the broader cyclonic flow will maintain precipitation chances overnight into Saturday, with activity Saturday becoming increasingly focused across northern Utah and southwest Wyoming. Saturday also looks to be the coolest of the period, with afternoon temperatures around 5-10 degrees below seasonal normal for late May. Precipitation becomes much more isolated by Sunday, with the highest coverage shifting to the high Uintas. temperatures will also begin to warm.

The model consensus continues to support high pressure returning as the dominant forecast influence from early next week into at least midweek or so. Precipitation chances will remain very limited as a result, and temperatures will continue to warm to back above normal levels.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions continue for all regional terminals with dry conditions prevailing across the airspace. Gusty southerly winds are expected at all terminals today, continuing through the afternoon. Winds taper off this evening, though are expected to redevelop mid to late Thursday morning. Downsloping winds may impact KCDC as early as 12z, with gusts in excess of 35 kts possible.

FIRE WEATHER

An expansive area of low pressure remains across much of the west. Locally, this is resulting in deep southerly flow which is driving dry and gusty conditions across Utah. With widespread gusts in the 25-40 mph range or so and daytime minimum humidity values in the teens to single digits, elevated to critical fire weather conditions will develop where fuels are sufficiently dry. The most widespread critical fire weather conditions are expected across zones 494 and 498 where fuels are reported to be reasonably cured. Zones 489 and to an extent 484 may see some more localized critical fire weather conditions, but reportedly the rainfall from yesterday has likely moistened fuels enough to limit the areal extent. With that, opted to cancel the Fire Weather Watch for those zones.

Unsettled conditions will return Friday into the weekend as the broad low pressure system finally gradually crosses the area. It will bring cooler temperatures in addition to showers and thunderstorms. Initially precipitation coverage will be favored across the high terrain Friday, shifting to northern Utah overnight on through Saturday as the low lifts out. As such, areas of northern Utah have better chances to see wetting rains. High pressure is then favored to return early next week, resulting in drier conditions along with a warming trend.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Wind Advisory until 7 PM MDT this evening for UTZ115-122.

Red Flag Warning until 9 PM MDT Thursday for UTZ494-498.

WY...None.