043
FXUS65 KSLC 171906
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
106 PM MDT THU SEP 17 2026
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON
AND EVENING ACROSS NORTHERN AND CENTRAL UTAH. AFTER A BRIEF LULL
OVERNIGHT, ACTIVITY RAMPS BACK UP LATE FRIDAY MORNING.
- FLASH FLOODING REMAINS THE MAIN CONCERN ACROSS CENTRAL UTAH
THROUGH FRIDAY, WHILE SEVERE WINDS AND LARGE HAIL REMAINS THE
MAIN THREAT ACROSS NORTHERN UTAH.
- A COLD FRONT BRINGS DRIER CONDITIONS WITH MORE SEASONABLE
TEMPERATURES SATURDAY THROUGH THE REMAINDER OF THE WEEKEND.
DISCUSSION
WITH DEEP MOISTURE AND MODEST INSTABILITY IN PLACE
ACROSS NORTHERN AND CENTRAL UTAH THIS AFTERNOON, CONVECTION IS
EXPECTED TO REDEVELOP THROUGH THIS EVENING. ACROSS NORTHERN UTAH,
COVERAGE IS EXPECTED TO BE MORE ISOLATED GIVEN THE CONVECTIVE
ACTIVITY THAT ALREADY MOVED THROUGH THIS MORNING. HOWEVER, RECENT
MESOANALYSIS INDICATES THAT GREATEST INSTABILITY AND SHEAR WILL
BE FOCUSED ACROSS THE NORTHERN WASATCH FRONT THIS AFTERNOON AND
EVENING WITH 500-1000 J/KG OF MLCAPE AND ABOUT 30-40 KTS OF
EFFECTIVE SHEAR. AS SUCH, ANY STORMS THAT CAN DEVELOP THROUGH
THIS EVENING WILL BE CAPABLE OF SUSTAINING UPDRAFTS THAT WOULD BE
CAPABLE OF PRODUCING AN ISOLATED WIND GUST IN EXCESS OF 58 MPH AND
HAIL GREATER THAN 1 INCH. ACROSS EAST-CENTRAL UTAH, MORE MODEST
INSTABILITY WILL EXIST WITH MUCH DEEPER MOISTURE (PWATS 1.0-1.2")
IN PLACE. AS SUCH, STORMS IN THIS AREA WILL BE CAPABLE OF
PRODUCING HEAVY RAINFALL, WITH RAINFALL RATES OF 0.5-1+" PER HOUR
POSSIBLE. GIVEN RECENT RAINFALL ACROSS PORTIONS OF CENTRAL UTAH,
ESPECIALLY THE SAN RAFAEL SWELL AND WASATCH PLATEAU, CONDITIONS
ARE FAVORABLE FOR FLASH FLOODING ACROSS THESE AREAS.
CONVECTIVE ACTIVITY WILL WANE LATE THIS EVENING AND OVERNIGHT,
BUT LINGERING INSTABILITY ASSOCIATED WITH A CLOSED LOW PRESSURE
SYSTEM MOVING EASTWARD ACROSS THE GREAT BASIN MAY ALLOW SHOWERS
AND THUNDERSTORMS REINVIGORATE ACROSS NORTHERN UTAH EARLY FRIDAY
MORNING. A VORTICITY LOBE EJECTS THROUGH THE NORTHERN HALF OF THE
STATE LATE FRIDAY MORNING, MAXIMIZING INSTABILITY ACROSS THE
REGION AND RESULTING IN INCREASING COVERAGE OF CONVECTION ACROSS
NORTHERN AND CENTRAL UTAH AND SOUTHWEST WYOMING THROUGH THE
AFTERNOON. CONDITIONS WILL ONCE AGAIN BE FAVORABLE FOR SEVERE
WIND AND HAIL ACROSS NORTHERN UTAH.
CONVECTION CLEARS OUT LATE FRIDAY NIGHT, WITH DRIER CONDITIONS
PREVAILING THROUGH SATURDAY BEHIND THE CLOSED LOW. MUCH COOLER
CONDITIONS ARE EXPECTED TO GIVE US ANOTHER TASTE OF FALL ON SATURDAY,
WITH HIGHS AROUND 10 DEGREES BELOW AVERAGE. THIS COOLER AND DRIER
TREND WON'T STICK AROUND LONG AS ANOTHER LOW PRESSURE SYSTEM DIGS
DOWN THE COAST OF SOUTHERN CALIFORNIA ON MONDAY, YIELDING MOIST,
SOUTHERLY FLOW ACROSS THE REGION WHICH WILL BRING INCREASED
CHANCES FOR SHOWERS AND THUNDERSTORMS MAINLY ACROSS SOUTHWEST UTAH
EARLY NEXT WEEK.
AVIATION
KSLC...EXPECT SOUTHERLY WINDS TO CONTINUE AT THE KSLC TERMINAL
THROUGH THE AFTERNOON. THERE IS A LOW CHANCE (AROUND 15-20%) A
THUNDERSTORM WILL DIRECTLY IMPACT THE TERMINAL BETWEEN 19-23Z.
GUSTY, OUTFLOW WINDS AND BRIEFLY REDUCED CEILINGS TO AROUND 5000
FEET AGL WOULD BE THE MOST LIKELY IMPACTS.
REST OF UTAH AND SOUTHWEST WYOMING...THUNDERSTORMS WILL IMPACT
NORTHERN AND EASTERN TERMINALS, GENERALLY NORTH OF KSLC AND EAST OF
THE WASATCH CREST THROUGH THIS EVENING. OTHERWISE, EXPECT GENERALLY
TYPICAL TERRAIN-BASED WINDS.
FIRE WEATHER
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP ACROSS PORTIONS OF CENTRAL AND NORTHERN UTAH
THIS AFTERNOON AND EVENING. DEEP MOISTURE IN PLACE ACROSS EASTERN
PORTIONS OF THE STATE WILL FAVOR A THREAT FOR HEAVY RAINFALL AND
FLASH FLOODING, ACROSS EAST-CENTRAL UTAH, MAINLY ACROSS THE SAN
RAFAEL SWELL AND WASATCH PLATEAU. OTHERWISE, STORMS WILL BE
CAPABLE OF PRODUCING LIGHTNING, LARGE HAIL, AND GUSTY OUTFLOW
WINDS. SIMILAR CONDITIONS ARE EXPECTED ON FRIDAY AFTERNOON AND
EVENING, THOUGH DRIER AIR MOVING INTO THE REGION WILL MODERATE THE
HEAVY RAINFALL RISK SLIGHTLY. A COLD FRONT WORKS ITS WAY THROUGH
NORTHERN UTAH ON SATURDAY, RESULTING IN MUCH COOLER AND DRIER
CONDITIONS THROUGH THE REMAINDER OF THE WEEKEND. SOUTHERLY FLOW
DEVELOPING ON MONDAY AHEAD OF A LOW PRESSURE SYSTEM DEEPENING
ALONG THE SOUTHERN CALIFORNIA COAST WILL INTRODUCE INCREASING
MID-LEVEL MOISTURE ACROSS SOUTHWEST UTAH THROUGH MID-NEXT WEEK,
WITH IMPROVEMENTS IN BOTH DAYTIME RH AND OVERNIGHT RECOVERIES
THROUGH THIS PERIOD.
SLC WATCHES/WARNINGS/ADVISORIES
UT...FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR UTZ113-117-120-121.
WY...NONE.
PUBLIC...WHITLAM
AVIATION...KRUSE
FIRE WEATHER...WHITLAM
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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