Marine Weather and Tide Forecast for Hanksville, UT

DISCUSSION
Utah and southwest Wyoming are under a dry zonal flow aloft this morning with a low pressure system currently centered over northern Montana. While the vast majority of the moisture and instability with this system will remain north of the area as the system tracks east today and tonight, it will bring a dry cold front into northern and central Utah late this afternoon into the evening.

Ahead of the system, will continue to see west to southwest winds pick up, particularly over southeastern Utah. With conditions remaining very dry, a Red Flag Warning continues through the evening over those southeastern zones. With the passage of the front during the late afternoon/early evening, will see wind gusts pick up substantially over northwest Utah, with a high chance of isolated gusts in excess of 40 mph during this time. Though relative humidity values will be increasing, the airmass ahead of the front is extremely dry, so even with this increase RH values will be critically low. Thus, have added northwest Utah to today's Red Flag Warning.

Behind the exiting storm system, winds will relax substantially for Thursday through Saturday, finally decreasing the fire danger somewhat over the area. Over northern Utah, looking at maxes up to 5F below seasonal normals for Thursday afternoon behind the front, with rather mild conditions persisting over southern Utah. The airmass will then steadily warm Friday into Saturday with the ridge strengthening off the Pacific coast. As a result, highs will warm up to 15F above seasonal normals to start the weekend.

Guidance has become increasingly bullish about a Canadian trough dropping over the top of the ridge into Idaho and Montana on Saturday. The trajectory of the flow over Utah and southwest Wyoming would become more southwesterly with this placement of the low, advecting some moisture northward. For example, latest GFS is indicating PW values in the 0.7 to 0.9 inch range across southern Utah for Saturday afternoon. This would be more than enough for convective initiation over the higher terrain of southern Utah during that time. Given anticipated dry lower levels, storms that develop would produce little if any rainfall, raising concerns about dry lightning.

The current most likely scenario in guidance is for the Canadian trough to cross southwest Wyoming and move into Colorado on Sunday, bringing another front across northern and central Utah.
Current thinking is areas along and behind the front would be mostly dry, but moisture from Saturday would remain in place for areas ahead of the front on Sunday, bringing more afternoon convection for the higher terrain. Additionally, increase in winds over southern Utah ahead of the front may be enough to produce area of critical fire weather conditions. Still some spread in the guidance with regard to the track of the trough, which would influence potential impacts.

With the exit of that trough, there is increasing confidence that the Pacific ridge will build more substantially over the Great Basin through at least day seven, bringing dry conditions and the potentially for quite unseasonably warm temperatures by the middle of next week.

AVIATION
KSLC...Northwesterly to northerly winds will persist through much of the valid TAF period, increasing to gusts around 30kts for a few hours starting 01-02z with a cold front passage.
There is a 10% chance that wind gusts during this time could even exceed 35kts out of the north. Winds will gradually decrease overnight, potentially shifting to light and southeasterly between 10-16z. VFR conditions will prevail with clear skies.

REST OF UTAH AND SOUTHWEST WYOMING
Breezy westerly winds will persist this afternoon, eventually turning to gusty northerly winds as a cold front moves through the state. The cold front will enter northern UT around 22-23z, make it through the Wasatch Front by 03z, and KCDC-KSGU by 07-09z. The highest winds, reaching up to 35-40kts, are possible along much of the I-15 corridor, including KSVR-KPVU- KU14-KSGU. VFR conditions will likely persist, though blowing dust in prone areas could result in MVFR VIS with the cold front.

FIRE WEATHER
Very dry conditions continue over the state of Utah today. West to southwest winds will remain elevated ahead of an approaching front that will move through the area late this afternoon into the evening. Thus, the Red Flag Warning continues for southeastern Utah due to the combination of gusty winds and low relative humidity values. Have added northwest Utah to the Red Flag Warning for today as winds become quite gusty during the late afternoon and early evening with the passage of the front. Though relative humidities will be rising, it looks like they will still be low enough to produce areas of critical fire weather conditions. Winds will relax Thursday into Saturday under the influence of a Pacific ridge, though relative humidities will remain rather low with poor overnight recoveries. There is a high chance of moisture increasing over southern Utah Saturday with lower levels remaining dry. Thus, there is the potential for afternoon storms over the higher terrain that will produce little in the way of rainfall, bringing the potential for dry lightning, and this could continue for Sunday afternoon. Winds are expected to increase Sunday into Monday ahead of another cold front, and this may be another factor that increases fire danger over southern Utah.

SLC WATCHES/WARNINGS/ADVISORIES
UT...Red Flag Warning until 10 PM MDT this evening for UTZ478-484-489- 493-494-496-498.

WY...None.