Marine Weather and Tide Forecast for Springdale, UT

.SHORT TERM (Through 12Z/6AM Friday)...A Pacific Northwest trough moving just north of Utah and southwest Wyoming has put a cold front near a KTPH-KRKS line this morning. Showers have developed along this boundary, currently strongest with the Nevada portion of the boundary but still producing some decent precipitation over far northern Utah. The front will track south across Utah during the day, gradually losing steam as it becomes further disconnected from the parent trough. As a result, associated band of showers will be strongest this morning over northern Utah, becoming more spotty in nature as it moves into central and southern Utah, where the boundary is on track to stall and weaken this evening.
As the antecedent airmass is on the mild side, snow levels will be on the high side, 8,000 feet or greater, with light accumulations for the higher terrain. The temperature change behind the front will be most noticeable over northern Utah and southwest Wyoming, where maxes are expected to run up to 5F below seasonal normals, with little to no cooling over central and southern Utah.

An ejecting piece of the Pacific Northwest trough is expected to strength and close off over the California coast this evening, slowly meandering over the Desert Southwest for a few days thereafter before weakening. The main impact of this for Thursday will be to keep conditions unsettled over southern Utah, resulting in continued convection, particularly along the higher terrain and along the stalled boundary. Temperatures over southern Utah will remain similar to or slightly below Wednesday's values due to the associated cloud cover as northern portions of the forecast area return to values just above seasonal normals.

.LONG TERM (After 12Z/6AM Friday)...An expansive ridge will be in place for much of the west Friday, although a weakening closed low in the southwest will linger. Both systems will slide east through Friday, with the closed low weakening into the mean flow. Remnant moisture, instability, and lift will bring isolated or scattered showers to southern Utah, primarily for the mountains. Temperatures will be around 5-10F warmer than normal, with most valleys into the 70s.

A longwave trough approaching the west coast Saturday will bring enhanced southwest winds throughout southwest Wyoming and Utah.
Gusts will peak in excess of 30 mph for much of western Utah, with the strongest gusts in southwest Utah. Showers and thunderstorms will become likely Saturday afternoon as moisture increases and forcing enhances as the trough approaches. Showers and thunderstorms will be capable of gusty, erratic outflow winds, as strong warm air advection will push valley temperatures to around 80F in northern Utah and into the 80s further south. Although clouds and precipitation will build in, dry conditions will continue closer to the surface, which will be favorable for dry microbursts.

There is good agreement on the track of the longwave trough and associated closed low as it tracks into the western U.S. It will dig into southern California Sunday. That will bring more gradual cold air advection, with around a 5-15F decrease in temperatures. Winds will decrease for western Utah, but increase further east into Castle Country and Lake Powell. Showers and afternoon thunderstorms will increase in coverage compared to Saturday with more moisture advection and better dynamics.

The low will track near the Utah and Arizona border Monday, with precipitation continuing and conditions cooling for southwest Wyoming and Utah. Winds will diminish for many locations, although a closed low near that border is a good set up for easterly flow that could bring enhanced canyon or downslope winds for east-west oriented canyons in northern Utah Monday and Tuesday.

The track of the trough will bring the coldest conditions aloft to southern Utah, where snow levels will be around 9000-9500 feet Saturday, 7500-8000 feet Sunday, and 6500-7000 feet Monday. Snow levels for southwest Wyoming and northern Utah will be similar Saturday, then around 1000 feet greater Sunday and Monday.

Showers could linger through Tuesday, especially for the mountains as the trough slides east.

Southwest Wyoming and much of Utah are set to get measurable precipitation from Saturday through Monday, with most precipitation Sunday and Monday. Peak precipitation will most likely be in the southern mountains.

AVIATION
KSLC...Scattered rain showers are likely through around 21Z. There is a 20-30% chance for thunderstorms from around 17-21Z.
VFR conditions will prevail, although clouds will be low enough for mountain obscuration. Light northwest winds will prevail through the day.

REST OF UTAH AND SOUTHWEST WYOMING
Scattered showers will last into the afternoon for southwest Wyoming and northern Utah. There is a 20-30% chance for thunderstorms for these locations from around 17- 21Z. VFR conditions will prevail, although there will be mountain obscuration. Dry conditions will last through much of the day for southern Utah, with isolated to scattered showers after 00Z.

SLC WATCHES/WARNINGS/ADVISORIES
UT...None.
WY...None.