Marine Weather and Tide Forecast for Hideout, UT

DISCUSSION
Utah will remain under a dry and mild northwesterly flow aloft this evening while the upstream ridge continues to shift inland. This ridge will flatten tomorrow as a weak shortwave disturbance ejects out of an upper low that is currently noted over the eastern Pacific. The shortwave disturbance will be accompanied by some modest moisture which will result in isolated to scattered, and generally light, showers across northern Utah and southwest Wyoming from mid-afternoon Saturday through Sunday.
Additionally, the airmass will remain on the warm side (coldest H7 temperatures only reach as low as around -2C along the Idaho border), which will ensure high snow levels and minimal impacts.

The approaching upper low is expected bring more widespread and substantial precipitation to the area when it crosses Utah Monday into Tuesday, aided by period of frontogenesis and favorable dynamics from an associated jet streak. The ECMWF Extreme Forecast Index continues to show a signal for anomalous precipitation across portions of northwest and northern Utah, although this signal is weaker compared to 24 hours ago. While cooler air will spread into the area behind the cold front, it will still remain relatively mild. The 25th-75th percentile range of H7 temperatures across Utah on Tuesday is -2 to -5C, with a mean of between -3C and -4C across Utah. This would keep snow levels above 6500-7000 feet. While accumulating snow is expected in the higher terrain (with maxes across the northern Utah mountains), the latest NBM now only has a 50-60% chance of 6 inches or more in the high Uintas, although the upper Cottonwoods has a 70-80% chance of 9 inches or more. Regardless, the bulk of the accumulations greater than 6 inches will be confined to generally elevations above 8500-9000 feet.

Models are still in good agreement on another, colder, storm system dropping in from the northwest late Wednesday through Thursday and potentially into Friday. There remains quite a bit of spread in the evolution of this storm. Latest global deterministics are favoring the development of a split flow pattern, and cluster analysis of global ensembles show 54% of members with a cutoff low over the desert southwest and northwest Mexico by Saturday. How this low gets there and how much favorable dynamics will exist over Utah as the storm splits will obviously factor into the precipitation potential. Models have trended ever so slightly cooler, however, and as such, the chance of measurable snow has increased a bit, but without significant moisture, amounts are still forecast to be light. The latest NBM has a 15% chance or less of 1 inch or greater on most valley floors, and a 20 to 30% chance on the benches, Sanpete Valley, and I-15 corridor through central Utah. For the northern mountains and the Tushars, there is currently a 40-50% chance of 6 inches or more, except in the upper Cottonwoods where this increases to 60-70%.

This splitting system will have to potential to bring easterly winds to northern Utah. Given the continued model spread and the fact that several factors will need to come together to create a favorable downslope wind scenario, see no reason to get too excited about that potential at this point, but it is something worth monitoring over the next several days.

AVIATION
KSLC...VFR conditions will prevail at the KSLC terminal through the TAF period. Light northwest winds are expected Saturday afternoon as clouds increase from the west. Low chances for showers will increase during the evening across northern Utah, though exact timing and coverage are uncertain. For now, introduced PROB30 for showers after 03z at KSLC.

REST OF UTAH AND SOUTHWEST WYOMING
VFR conditions will prevail across all of our TAF sites through the period. Winds will be variable at most sites overnight and into the day on Saturday, with the exception of KEVW which will maintain a west-southwest or southwest wind through much of the period. Showers will increase across northern Utah, but uncertainty on timing and coverage precluded mention at this time.

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