Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
685 FXUS65 KSLC 102126 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 326 PM MDT Mon Jun 10 2024 .SYNOPSIS...Very hot temperatures will build into the region Wednesday into Thursday, with the potential for the Wasatch Front to breach the century mark. An upper level low may bring cooler temperatures and precipitation by Friday. && .SHORT TERM (Through 00Z Friday)...A weak cold front brought a bit of relief from the very hot temperatures for a good portion of the Beehive State today...though this relief is short-lived as high pressure once again builds across the region. Afternoon upper air and satellite analysis indicate a shortwave trough embedded in the northern stream quickly moving into the High Plains. A cut-off low is located off the southern California coast with a broad upper level ridge across the eastern Pacific. Relatively weak convection is firing on an instability gradient across northern Utah into Uinta County WY, with the typical convection near the Boulder Mountain area. As per usual with a relatively dry sub-cloud environment, isolated microbursts are possible. As high pressure builds into the area, temperatures will again reach toward well above normal levels by Wednesday. For example, looking at the Salt Lake City temperatures, the deterministic National Blend of Models suggests 100F will be breached Wednesday and Thursday. While this isn`t the earliest (the earliest was June 4, 2021), it would be within the top 10 earliest 100F on record. Either way, anomalously hot temperatures can be expected Wednesday and Thursday. An Excessive Heat Watch remains in effect for Glen Canyon National Recreation Area, though the latest guidance suggests cloud cover may reduce temperatures a few degrees. For this reason, held off on upgrading to a warning. For the Wasatch Front, Heat Advisories may be needed Wednesday and Thursday if future forecast runs continue to show 100F+ across the area. Regardless, it will be very hot state-wide Wednesday and Thursday. .LONG TERM (After 00Z Friday), Issued 416 AM MDT...The heat will not last long as a closed low situated off the coast of SoCal begins to shift inland, reaching southern/eastern UT by Friday. Highs on Friday will thus decrease by around 5-15 degrees across the area with the greatest decrease across eastern areas along the track of the low. Scattered high-based convection is also looking more likely along and east of the central spine of Utah mountains during the afternoon. Heading into the weekend, uncertainty in the longwave pattern increases. Ensemble guidance favors some sort of trough moving into the PacNW early in the weekend, though there is plenty of disagreement in how it evolves across the Intermountain West. Roughly 59% of ensemble members favor a deeper trough resulting in a greater cooldown over Utah, while the other 41% of members suggest the trough remains fairly zonal and far to our north. To quantify this uncertainty further, the 25th-75th percentiles for 700-mb temperatures range from +4C to +13C...dropping from +17C on Thursday. && .AVIATION...KSLC...Light northwest winds will transition to southeast around 06Z with clear conditions. Clear or mostly clear conditions will continue, with a transition to northwest winds around 18Z. .REST OF UTAH AND SOUTHWEST WYOMING...Isolated showers for portions of northern and southern Utah will diminish by 03Z. Showers will be capable of gusty, erratic outflow winds. Clear or mostly clear conditions are likely overnight with light winds. Similar conditions will continue through the day. && .FIRE WEATHER...A brief break in the very hot temperatures continues across the area this afternoon. Temperatures will climb once again as high pressure builds into the area, with well above normal temperatures expected by Wednesday. With a dry airmass in place, winds will increase across southwestern Utah ahead of a weak upper level system slowly crossing into southern California. This will bring locally critical fire weather conditions Wednesday and Thursday to southwestern Utah. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Excessive Heat Watch from Wednesday morning through Thursday evening for UTZ131. WY...None. && $$ Kruse/Cunningham/Wilson For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity