568
FXUS65 KSLC 181034
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
434 AM MDT FRI SEP 18 2026
KEY MESSAGES, ISSUED 1018 PM MDT THU SEP 17 2026
- PERIODS OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TONIGHT INTO
FRIDAY, WITH THE BEST COVERAGE OVER NORTHERN UTAH AND SOUTHWEST
WYOMING. HEAVY RAIN, GUSTY WINDS, AND HAIL WILL BE THE PRIMARILY
THREATS.
- A COLD FRONT WILL BRING DRIER CONDITIONS WITH MORE SEASONABLE
TEMPERATURES SATURDAY THROUGH THE REMAINDER OF THE WEEKEND WITH
MOISTURE EXPECTED TO INCREASE AGAIN TO START THE WORK WEEK.
DISCUSSION, ISSUED 1018 PM MDT THU SEP 17 2026
UTAH AND SOUTHWEST WYOMING REMAIN UNDER A MOIST,
UNSTABLE, AND BREEZY SOUTHERLY FLOW THIS EVENING IN BETWEEN HIGH
PRESSURE OVER THE CENTRAL UNITED STATES AND A BROAD LOW OVER THE
CALIFORNIA COAST. SATELLITE DERIVED PWS ARE IN THE 0.7 TO 1.0 INCH
RANGE ACROSS THE AREA, WITH THE HIGHEST VALUES OVER SOUTHEAST
UTAH. THE POSITION OF THE UPPER JET ON THE FRONT EDGE OF THE LOW
HAS BROUGHT THE BEST DIVERGENCE ROUGHLY TO NORTHEASTERN PORTIONS
OF THE AREA WITH A WEAK WAVE PROVIDING ADDITIONAL INSTABILITY,
PARTICULARLY TO AREAS NORTH OF I-70 AND EAST OF I-15, WITH ONE
STORM PRODUCING PING PONG BALL TO GOLF BALL SIZED HAIL IN THE CITY
OF MIDWAY.
OVERALL, THE CURRENT ROUND OF SHOWERS AND THUNDERSTORMS IS ON THE
DECREASE WITH A LACK OF DAYTIME HEATING, WITH JUST A FEW STRONGER
CELLS REMAINING. AS A RESULT, HAVE CANCELED THE GOING FLOOD WATCH
FOR FLASH FLOODING AS THE THREAT HAS ENDED. HOWEVER, AS THE LOW
SLIDES INTO NEVADA AND BRINGS AN INITIAL BOUNDARY THROUGH, SHOWERS
ARE EXPECTED TO LIGHT UP DURING THE EARLY MORNING, FOCUSED OVER
NORTHERN UTAH AND SOUTHWEST WYOMING. THE LOW IS THEN ON TRACK TO
GRAZE NORTHERN PORTIONS OF THE AREA AS IT MOVES BY THROUGH
SATURDAY. AS A RESULT, LOOKING AT THE MOST WIDESPREAD CONVECTION
TO BE ON FRIDAY AFTERNOON IN ASSOCIATION WITH THE MAIN TROUGH AND
ASSOCIATED COLD FRONT. CAMS CONTINUE TO INDICATE THE BEST COVERAGE
TO BE OVER NORTHERN PORTIONS OF THE AREA, BUT A FEW STORMS OVER
SOUTHERN UTAH COULD BRING AN ISOLATED THREAT OF FLASH FLOODING.
THE PASSAGE OF THE SYSTEM WILL ALSO HAVE A NOTICEABLE EFFECT ON
TEMPERATURES, WITH HIGHS FRIDAY INTO THE WEEKEND RUNNING 5-10F
BELOW SEASONAL NORMALS FOR NORTHERN UTAH AND SOUTHWEST WYOMING,
AND NEAR SEASONAL NORMALS FOR SOUTHERN UTAH. AS THE TROUGH EXITS,
THE FLOW ALOFT WILL MOVE TO A MORE WEST TO NORTHWESTERLY
DIRECTION, ALLOWING SOME DRIER AIR TO MOVE IN. WITH THE TROUGH NOT
ENTIRELY OUT OF THE PICTURE ON SATURDAY, STILL ANTICIPATING SOME
SCATTERED CONVECTION FOCUSED OVER NORTHEASTERN PORTIONS OF THE
FORECAST AREA, WITH SUNDAY EXPECTED TO BE DRY WITH WEAK RIDGING
MOVING IN.
GUIDANCE INDICATES THE BREAK IN THE ACTION WILL BE SHORT LIVED,
HOWEVER, WITH YET ANOTHER LOW APPROACHING THE PACIFIC COAST SUNDAY
AFTERNOON. MOST GUIDANCE SHOWS THIS SYSTEM TRACKING EASTWARD INTO
THE DESERT SOUTHWEST TO START THE WORK WEEK, BUT THE ENSEMBLES
DIVERGE NOTICEABLY WITH THE REGARD TO THE POTENTIAL TRACK OF THE
SYSTEM AND HOW MUCH IT WILL WEAKEN ONCE ONSHORE. STILL, CONFIDENCE
IS INCREASING WITH REGARD TO A RELATIVELY QUICK RETURN TO
UNSETTLED WEATHER, AT LEAST FOR SOUTHERN UTAH.
AVIATION, ISSUED 1018 PM MDT THU SEP 17 2026
KSLC...THE SLC TERMINAL WILL SEE VFR CONDITIONS THROUGH THE
OVERNIGHT HOURS WITH SOUTHERLY WINDS. PERIODIC SHOWERS ARE
EXPECTED TO DEVELOP TOMORROW MORNING, MOST LIKELY BETWEEN 10Z AND
12Z, BRINGING THE POTENTIAL FOR PERIODS OF GUSTY AND ERRATIC WINDS
THROUGH THE MORNING. BY THE LATE AFTERNOON, ADDITIONAL SCATTERED
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP, WITH A 30
PERCENT CHANCE OF PRODUCING GUSTY WINDS THROUGH THE EARLY EVENING
TOMORROW.
REST OF UTAH AND SOUTHWEST WYOMING...VFR CONDITIONS ARE EXPECTED
ACROSS THE AIRSPACE THROUGH THE OVERNIGHT HOURS. THE CURRENT ROUND
OF SHOWERS AND THUNDERSTORMS OVER NORTHEASTERN PORTIONS OF THE
AREA IS DIMINISHING, BUT ANOTHER ROUND IS EXPECTED DURING THE
EARLY MORNING, MOST LIKELY BEGINNING BETWEEN 10Z AND 12Z, FOCUSED
OVER NORTHERN PORTIONS OF THE AIRSPACE, LASTING THROUGH MUCH OF
THE MORNING. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE THEN
EXPECTED TO DEVELOP BY LATE AFTERNOON, AGAIN PRIMARILY FOR
NORTHERN PORTIONS OF THE AIRSPACE. ANY STORMS THAT DEVELOP WILL
HAVE THE POTENTIAL TO PRODUCE GUSTY AND ERRATIC WINDS, LIGHTNING,
AND BRIEF MOUNTAIN OBSCURATIONS.
FIRE WEATHER
SCATTERED THUNDERSTORM DEVELOPMENT IS FORECAST TO
CONTINUE THROUGH THE MORNING, PEAKING JUST AFTER 1200 ACROSS
NORTHERN AND CENTRAL UT, WITH SOUTHERN UT FOLLOWING SHORTLY AFTER.
THUNDERSTORM COVERAGE IS EXPECTED TO BE HIGHER ACROSS NORTHERN AND
CENTRAL UT TODAY, WITH THE POTENTIAL FOR SEVERE THUNDERSTORMS
INCREASING WITH THE POTENTIAL OF WIND GUSTS IN EXCESS OF 58MPH AND
HAIL POTENTIALLY IN EXCESS OF 1" WITH FREQUENT LIGHTNING. ACROSS
SOUTHERN AND EASTERN UT, THUNDERSTORMS WILL REMAIN ISOLATED TO
WIDELY SCATTERED, THOUGH ARE EXPECTED TO BE MUCH WETTER AND
POTENTIALLY YIELD A FLASH FLOODING THREAT. ADDITIONALLY, THE
SEVERE THREAT MENTIONED ABOVE MAY ALSO MATERIALIZE WITH THESE
STORMS, THOUGH CONFIDENCE IS LOWER IN THIS.
ON SATURDAY, A COLD FRONT WILL CONTINUE TO SAG SOUTH ACROSS MUCH
OF THE STATE USHERING IN A DRIER AND COOLER AIRMASS WHICH WILL
REMAIN IN PLACE THROUGH SUNDAY. THIS IS EXPECTED TO BE SHORT
LIVED, HOWEVER, AS MOISTURE LOOKS TO RETURN AS EARLY AS MONDAY
AFTERNOON AS SOUTHERLY FLOW RE-DEVELOPS, PULLING MOISTURE BACK
INTO THE REGION.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
PUBLIC...TRAPHAGAN
AVIATION...TRAPHAGAN
FIRE WEATHER...WORSTER
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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