![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
000 FXUS65 KSLC 112214 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 414 PM MDT Tue Jun 11 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/6PM Thursday)... The main impact in the short term will be the hot temperatures. With the focus starting in southern Utah for the Glen Canyon NRA/Lake Powell area where an Excessive Heat Warning is in place for Wednesday and Thursday. The heat then expands northward into northern Utah, starting Wednesday, but really peaking on Thursday. Heat Advisories have been added for the Wasatch Front and West Desert zones in for Wednesday and Thursday. High pressure will continue to build over the Four Corners area into Wednesday, with the ridge axis amplifying northward into Northern Utah. By Thursday, the ridge will start to be pinched downstream as filling closed low moves inland off from the southern California Coast. This will increase the southwesterly flow across the forecast area as the flow accelerates between the low to our west and high to our east, as well as pull the thermal ridge axis farther north, into northern Utah. H7 temperatures will reach +16 to +18C Wednesday and Thursday. Also on Thursday, mid- level moisture will start to increase from south to north, mainly focused across the central spine of mountains eastward. This will start to limit the heat slightly for southern and eastern portions of UT, but northern UT will remain under hot/dry and breeze conditions. All this to say that Wednesday and Thursday will both be hot across the region, but the heat will maximized across southern Utah on Wednesday, followed by northern Utah on Thursday. In addition, the cloud cover will increase into northern Utah Thursday night, along with elevated winds ahead of the low pressure system. This will keep northern Utah valleys well mixed and insulated with the cloud cover overnight, all working together to keep temperatures elevated overnight. Thus the HeatRisk for northern Utah is more elevated into Thursday given the hot daytime temperatures around 100 followed by a very warm night Thursday night. Temperatures at KSLC will likely struggle to cool out of the 80s and into the mid-70s by early Friday morning. These warm overnight lows act to increase the HeatRisk through limiting nighttime relief from warm temperatures for vulnerable populations. Otherwise, the chance for showers moving into south-central and eastern Utah increases Thursday night ahead of the low pressure system as is continues weakening and moving toward the Four Corners. .LONG TERM (After 00Z Friday/6PM Thursday), Issued 339 AM MDT... Friday marks the transition to more unsettled weather across northern UT and southwest WY, at least to start the long-term period. A closed low over SoCal will weaken as it moves inland, tracking across southeastern UT on Friday and bringing a decent mid-level moisture surge with it...PWATs across southeastern UT jump from an ensemble mean of 0.35" up to 0.75". Thus, scattered showers will develop in eastern UT beginning late Thursday night, with thunderstorms and high-based convection developing Friday afternoon. Temperatures will also decrease across the area on Friday, with eastern UT seeing the largest decrease by about 10-15 degrees as compared to Thursday afternoon highs. Moving into the weekend, our sensible weather starts to be peripherally influenced by a low pressure system settling over the PacNW, though the air mass remains quite dry. Currently, the biggest impact looks to be a cooling trend beginning Saturday, mainly across northern areas. Model guidance really starts to diverge in the upper- level pattern on Sunday, which will ultimately determine the extent of this cooling trend across the area. Ensemble members are split roughly 70-30, with 70% of members favoring a stronger cooldown on Sunday into Monday, associated with a more amplified trough. The other 30% favor not much of a cooldown at all. To further illustrate the high uncertainty, highs at KSLC on Monday range from 70F to 85F (25th to 75th percentiles). In St. George, this range isn`t quite as big, but still ranges from 92F to 100F. && .AVIATION...KSLC...Light northwest winds will transition to southeast around 03Z with clear conditions. Clear conditions will continue through around 18Z when winds transition to northwest. A few clouds will build around nearby terrain through the day, but conditions will stay mostly clear. .REST OF UTAH AND SOUTHWEST WYOMING...Clear conditions with light winds will last through the night. Clear conditions will last through the morning, with clouds likely building around nearby terrain in northern Utah during the afternoon. Southwest winds will gust around 25 knots throughout southwest Wyoming and southern Utah from 18-03Z. && .FIRE WEATHER... High pressure will maintain hot and dry conditions across the area Wednesday and Thursday with temperatures running above average, and very low humidity values into the teens and single digits. Locally critical fire weather conditions will develop across portions of western and eastern Utah on Thursday. There is about a 40-60% chance of seeing RH values <10% combined with wind gusts of 35 mph or greater across western Utah, mainly in zones 495 and 492. There is similarly a 20-50% chance of those same weather conditions across eastern UT zones of 498, 494, and 489. Moisture will increase across eastern Utah on Friday brining a low chance for wetting precipitation, as well as increasing humidity. This will also increase the thunder/lightning potential, as well as the potential for gusty/erratic outflow winds. Very dry conditions however will persist across western Utah which will remain west of the main moisture axis. Looking into next week there is an increasing potential for cooler temperatures, especially across northern Utah, either near or slightly below normal. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Heat Advisory from 11 AM Wednesday to 6 AM MDT Friday for UTZ101- 104>106. Excessive Heat Warning from 11 AM Wednesday to 10 PM MDT Thursday for UTZ131. WY...None. && $$ SHORT TERM...Church LONG TERM...Cunningham AVIATION...Wilson FIRE WEATHER...Church For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity