Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
894 FXUS65 KSLC 142151 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 351 PM MDT Fri Jun 14 2024 .SYNOPSIS...An increasing hot and dry airmass will bring critical fire weather conditions to portions of southern Utah. A very strong cold front will cross the area Monday afternoon into Monday night bringing a much cooler airmass to the region Tuesday. The relief will be short however as another warming trend will begin midweek. && .SHORT TERM (Through 06Z Tuesday)...A bit cooler today across the Beehive State, with the Wasatch Front in the upper 80s and 90s rather than near or above the century mark. Afternoon upper air and satellite analysis indicates a large upper level low remains off the British Columbia coast. The remnants of a weak upper level low continue to shift away from the CWA through the central and southern Rockies. Southwesterly flow is gradually shifting into the Great Basin. The main story over the next few days will be the return of a hot (though not quite as hot as earlier this week), dry and breezy airmass to the region. In areas with critical fuels, this has prompted Red Flag Warnings to be issued. Be careful with sources of ignition including fireworks, parking over tall grasses, cigarette butts, etc as human caused fires are the number one cause of wildfires in Utah. By Monday, the previously mentioned trough will be crossing into Pacific Northwest and Intermountain Region. This trough will be especially cold for this time of year, with a very strong cold front poised to cross into northern Utah Monday afternoon. 700mb temperatures ahead of this front near 16C or so will very quickly fall to near 0C. Expect strong, gusty northwest winds behind the front...and strong, gusty southwest winds ahead of it. Current guidance is struggling to show sufficient instability with this front for strong convection, but given the punch this front has, would not be surprised to see at the very least a line of high- based convection near the front. The cold front is expected to reach southern Utah by Monday night. Snow levels may fall as low as 6500 feet or so...so any lingering showers may bring a brief period of snow showers to the northern Utah mountains. This cold front may also complicate any ongoing fires, with a very strong and abrupt wind shift. Several relatively large fires are ongoing in central Utah. HRRR smoke modeling suggests plumes should be sufficient to disperse smoke across portions of central and southern Utah and thus have added smoke to the forecast for impacted areas. Smoke near the surface will likely be worse from late evening until about 1000 am to noon. .LONG TERM (After 06Z Tuesday), Issued 430 AM MDT... Tuesday high temperatures are likely to be 10 to 20 degrees below normal, translating to the upper-60s along the Wasatch Front and low-90s in St. George....more akin to highs in early May. There is, however, still some remaining uncertainties in the forecast, mainly pertaining to timing of the frontal passage and the degree of cooling across the area. There are still 20% of members that favor a less aggressive cooldown, with 700-mb temperatures near +4C...in contrast to the other 80% that suggest around -2C. In summary, the biggest impacts with this system will be gusty pre- frontal southwesterly winds, below-normal temperatures, and areas of critical fire weather conditions (see Fire Weather section below). Beyond Tuesday, temperatures will steadily increase once again. && .AVIATION...KSLC...The SLC terminal will see VFR conditions through the evening with scattered clouds. Southerly winds are expected to shift to the northwest by 23Z before returning to the south between 03Z and 05Z. There is a 30 percent chance winds will remain southerly through the afternoon. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected across the airspace through the evening. Scattered showers and thunderstorms will continue over northwest and eastern Utah through the early evening before diminishing. Any storms that develop will be capable of producing gusty and erratic outflow winds. && .FIRE WEATHER...Relatively dry thunderstorms continue across eastern Utah this afternoon with another area of weak high-based showers and thunderstorms near and south of Wendover. Hot, dry, and windy conditions will build across southern Utah Saturday into Sunday. Red Flag Warnings are now in effect for portions of southern and western Utah. By Monday, a strong cold front will cross into northern Utah, bringing strong winds to southern Utah Monday afternoon and evening. Some indication of a subtle increase in humidities across fire weather zones 495 and 496...so these areas are in a Fire Weather Watch for Monday afternoon and evening while Red Flag Warnings continue for fire weather zones 497 and 498. A marked shift to the northwest with this cold front is expected across southern Utah Monday night. Winds may be strong with this cold front. A cooler airmass will be in place across the region Tuesday. Critical fire weather conditions may return as early as Thursday. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Red Flag Warning from noon to 9 PM MDT Sunday for UTZ495-496. Fire Weather Watch from Monday afternoon through Monday evening for UTZ495-496. Red Flag Warning from noon Saturday to 9 PM MDT Monday for UTZ498. Red Flag Warning from noon Sunday to 9 PM MDT Monday for UTZ497. WY...None. && $$ Kruse/Cunningham/Traphagan For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity