


Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
265 FXUS65 KSLC 142149 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 349 PM MDT Mon Jul 14 2025 .SYNOPSIS...Hot conditions will prevail alongside high-based showers and thunderstorms through at least Wednesday, with fairly widespread critical fire weather conditions on Tuesday. Moisture increases in the lower levels by Thursday across far southern Utah, bringing increasing risk of heavy rainfall through at least Saturday. Conditions dry out once again late in the weekend/ early next week. && .SHORT TERM (Through 12Z/6AM Wednesday)...Big picture key messages for Tuesday`s forecast are as follows: - Widespread critical fire weather conditions expected across mainly the western half of Utah. For southern Utah, the concerns relate to strong southwest winds and low relative humidity. For northern Utah, the concern will be for scattered dry thunderstorms following an extended dry period. - High-based showers and thunderstorms will bring an increased risk (Marginal Risk) of strong outflow winds across northern Utah, with potential wind gusts in excess of 45-50 mph through the afternoon hours. - Hot temperatures will remain in place across Utah and southwest Wyoming on Tuesday, reaching their peak values for the week in the northern area. Today, we`ve already seen modest increases in mid-level moisture across much of Utah which has lead to isolated high-based showers and thunderstorms across western Utah/ eastern NV and southern Utah. Today, these high-based showers are not expected to bring many issues, however, isolated strong wind gusts due to outflows may arise in the aforementioned areas. This shower activity is expected to decrease right around sunset this evening, with skies clearing overnight. Hot temperatures across southern Utah will wane as we head into tomorrow, with today marking the peak in temperatures in this area. Existing Extreme Heat Warnings remain in effect through 9PM this evening. Heading through tomorrow, a shortwave trough moving across southern Idaho will bring an increase in southwesterly winds across the southern half of Utah. These winds, combined with relative humidity around 15 percent or less (particularly below 8000ft) will create critical fire weather conditions on Tuesday afternoon across the southern half of Utah (excluding the lower elevation eastern valleys). In addition to the dry low level environment, mid-level moisture increases are expected as this trough pushes in greater moisture from the west, bringing an overall increase in high-based shower and thunderstorm coverage. Scattered dry thunderstorms (producing less than 0.1 inches of rain) are expected across northern Utah during the mid-to-late afternoon hours across northern Utah, warranting a Red Flag Warning for scattered dry thunderstorms following an extended dry period. These scattered high-based showers and thunderstorms will bring increased potential to generate strong outflow wind gusts in excess of 45-50 mph across this same area, raising the overall critical fire weather risk, as well as a general severe weather risk. A "Marginal" risk for severe weather has been issued by the NWS Storm Prediction Center (level 1 of 5 risk). Aside from the widespread critical fire weather conditions, the hottest temperatures of the week are expected across northern/ central Utah and southwest Wyoming as temperatures increase overhead. Along the Wasatch Front, Cache Valley, and central Utah are expected to be in the upper-90s to low-100s. For the Uinta Basin and Uinta County, WY, temperatures will rise into the upper-80s to mid-90s. A weak frontal boundary will move across the northern area overnight into Wednesday morning, bringing at least some "cooler" temperatures to the urbanized areas... or at least cool enough to reduce the overall Heat Risk. .LONG TERM (After 12Z/6AM Wednesday), Issued 404 AM MDT... Ridging aloft remains over the area, although we should see some "relief" from the hot temperatures of Tuesday, if you can really call it that. Following the passage of an upper trough to our north, "cooler" air will filter into the region bringing temperatures to just below or normal for this time of year. Temperatures for the majority of our valleys will generally range from the lower 90s to mid 90s while lower Washington county will see temperatures in the low 100s. Modest moisture return is expected to persist through the long term period as an upper low develops and meanders over the Baja Peninsula and southern CA. This will result in PWATs generally ranging from around 0.5-0.7" across the majority of UT and southwest WY for the majority of the long term forecast. Additionally, both the GFS and EURO are hinting at a chance for PWATs ranging from 1-1.2" across southern UT Thursday-Saturday. While this remains far out in time, it does raise some concern for locally heavy rainfall which could result in flash flooding. Specifics are somewhat difficult to iron out at this time, though it bears watching. && .AVIATION...KSLC...VFR conditions will persist at the KSLC terminal through the TAF period. Gusty northerly winds may persist until 04- 05z before shifting to the southeast if current showers in NW Utah persist after sunset...thus added a Prob30 for periods of gusty and erratic winds should these showers impact the terminal. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected to persist through the TAF period. Generally diurnal winds continue while the overall flow remains light across UT aside from typical gusty westerlies at KEVW. The slight chance for isolated showers and thunderstorms near KCDC and KBCE continues into early evening, with a potential for gusty and erratic winds. && .FIRE WEATHER...A shortwave trough moving through southern Idaho on Tuesday afternoon will bring increasing winds out of the west to southwest across southern Utah and increasing mid-level moisture across much of the area. With poor humidity recoveries still in place across much of the area leading into Tuesday morning, an extended period of dry conditions alongside the expected breezy afternoon winds, potential for high-based dry thunderstorms, and the current fuels and fire behavior advisory, critical fire weather conditions are expected across a majority of the western half of Utah on Tuesday. Elevated fire weather conditions are still expected across the eastern half of Utah on Tuesday as breezy winds combine with dry afternoon conditions, in addition to isolated dry thunderstorm potential following an extended dry period. Various Red Flag Warnings have been issued for gusty winds and low relative humidity across the southern half of Utah (excluding the eastern zones) and for scattered dry thunderstorms across northern Utah (mainly from the Wasatch Mountains westward to the Nevada border). Moisture will continue to increase in the mid-levels of the atmosphere from Wednesday forward, bringing an overall increase in humidity (during both the afternoon and overnight hours). Daily chances for isolated to scattered thunderstorms is expected over the higher terrain, especially across the southern half of Utah. These storms, at least through Wednesday, will produce little, if any, rainfall at the surface and will bring greater potential for dry lightning strikes and gusty outflow winds. By Thursday, lower level moisture begins to creep into southern Utah, bringing higher chances for wetting rains as well as solid improvements to relative humidity values across the region. This moisture is expected to linger across mainly the southern half of Utah through at least Saturday before decreasing late in the weekend/ early next week as drier air moves into Utah from the west. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Red Flag Warning from noon to 9 PM MDT Tuesday for UTZ478-479. Red Flag Warning from noon to 11 PM MDT Tuesday for UTZ492-493- 495>498. Extreme Heat Warning until 10 PM MDT this evening for UTZ123-124. WY...None. && $$ SHORT TERM...Webber LONG TERM...Worster AVIATION...Verzella FIRE WEATHER...Webber For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity