459
FXUS65 KSLC 171810
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1210 PM MDT FRI JUL 17 2026
KEY MESSAGES
- SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS
PORTIONS OF CENTRAL, SOUTHERN, NORTHEAST UT, AND SOUTHWEST WY EACH
AFTERNOON WITHIN THIS FORECAST AS MONSOONAL MOISTURE CONTINUES
MAKING ITS WAY NORTH.
- THE RISK FOR FLASH FLOODING EXISTS ACROSS THE MAJORITY OF THE
FORECAST AREA, HIGHLIGHTED BY WPC WITH A MARGINAL RISK (1/4) OF
EXCEEDING FLASH FLOOD GUIDANCE EACH DAY ENCOMPASSING NEARLY ALL OF
UT. A SLIGHT RISK (2/4) OF EXCEEDING FLASH FLOOD GUIDANCE EXISTS
ACROSS SOUTHWEST UT THIS AFTERNOON AND SATURDAY.
- A FLASH FLOOD WATCH REMAINS IN EFFECT FOR SOUTHERN UT AND PORTIONS
OF CENTRAL UT THIS AFTERNOON, ENDING AROUND MIDNIGHT. ANOTHER FLASH
FLOOD WATCH HAS BEEN ISSUED FOR TOMORROW AFTERNOON, ENCOMPASSING THE
SAME AREAS.
DISCUSSION
A FAVORABLE MONSOON PATTERN PERSISTS ACROSS THE
SOUTHWEST AS LARGE-SCALE RIDGING REMAINS OVERHEAD. BENEATH THIS
RIDGE, MOISTURE CONTINUES TO ADVECT NORTH ACROSS UT RAISING PWATS
AREAWIDE IN EXCESS OF 1" OF WATER ACROSS NEARLY ALL VALLEY LOCATIONS
WITH LOWER WASHINGTON COUNTY POTENTIALLY SEEING PWATS IN EXCESS OF
1.6" THIS AFTERNOON. THIS PATTERN IS FORECAST TO PERSIST OVER THE
NEXT WEEK OR SO, KEEPING CHANCES FOR RAIN AND THUNDERSTORMS EACH
AFTERNOON IN THE FORECAST FOR MOST LOCATIONS ACROSS THE STATE WITH A
PARTICULAR EMPHASIS ON SOUTHERN UT. CHANCES FOR RAIN AND
THUNDERSTORMS BEGIN TO INCREASE ACROSS NORTHERN UT TODAY, INCREASING
MORE NEAR THE END OF THE WEEK AS DEEPER MOISTURE CONTINUES TO ADVECT
NORTH.
WITH PWAT ANOMALIES STATEWIDE RANGING FROM 0.5" TO NEARLY 1" THIS
AFTERNOON, THE THREAT FOR FLASH FLOODING IS EXPECTED TO CONTINUE.
THE THREAT REMAINS ELEVATED DUE TO WEAK STEERING FLOW ALOFT YIELDING
STORM MOTIONS GENERALLY AROUND 10KTS OR LESS. WHILE THIS HAS
INCREASED SOMEWHAT OVER THE PAST COUPLE DAYS, DEEPER MOISTURE
COUPLED WITH A TALLER, SKINNIER CAPE PROFILE (POTENTIALLY IN EXCESS
OF 1000J/KG) WITH A DEEPER WARM CLOUD LAYER SUPPORTS ANOTHER ROUND
OF EFFICIENT RAINMAKERS WITH HEAVY RAIN EXPECTED FROM MATURE STORMS.
THE STRONGER INSTABILITY AXIS WITH CAPE VALUES >= 1000J/KG CURRENTLY
RESIDES ACROSS SOUTHWESTERN UT, SUPPORTED BY BOTH SPC MESOANALYSIS
AND CURRENT CAM GUIDANCE, WITH STORMS EXPECTED TO INITIATE ALONG
HIGHER TERRAIN AND PROPAGATE DOWN TERRAIN TOWARD THE INSTABILITY
GRADIENTS. THE MAIN CONCERN WITH A MORE ELEVATED FLOODING THREAT
FURTHER SOUTHEAST WOULD BE COLD POOL DEVELOPMENT AS STORMS PROPAGATE
WEST POTENTIALLY RAISING CIN ACROSS SOUTHEASTERN UT. IF INITIATION
WERE TO OCCUR EARLIER, HOWEVER, A LOCALLY HIGHER FLOODING THREAT MAY
DEVELOP ACROSS SOUTHEASTERN UT THIS AFTERNOON. A NEARLY IDENTICAL
THREAT EXISTS SATURDAY AS WELL GIVEN SIMILAR SYNOPTICS AND MOISTURE
QUALITY ACROSS THE REGION.
FROM SUNDAY ON, SOME UNCERTAINTY DEVELOPS REGARDING STORM MOTIONS
WHICH WOULD POTENTIALLY INHIBIT THE FLASH FLOOD THREAT. WHILE
QUALITY MOISTURE REMAINS IN PLACE, STORM MOTIONS MAY POTENTIALLY SEE
A SLIGHT UPTICK BEGINNING SUNDAY AS THE AFOREMENTIONED RIDGE SLOWLY
SHIFTS EAST. SLIGHTLY STRONGER SOUTHWEST FLOW CONTINUES TO PUSH IN
EACH AFTERNOON FROM MONDAY ON, POTENTIALLY INHIBITING THIS FURTHER
AS STORMS MAY TEND TO MOVE OFF TERRAIN QUICKER INSTEAD OF TRAINING
OVER ONE LOCATION. THESE DETAILS MAY BE DIFFICULT TO IRON OUT FULLY
UNTIL THE DAY BEFORE, THOUGH ISOLATED FLASH FLOODING IS EXPECTED AT
A MINIMUM EACH DAY GOING FORWARD FROM SUNDAY ON.
AVIATION...KSLC
LIGHT SOUTHERLY WINDS WILL BE MAINTAINED OVER THE
KSLC TERMINAL THROUGH THE MORNING HOURS, TRANSITIONING TO A
NORTHWEST FLOW AFTER 19-20Z. VICINITY SHOWERS ARE EXPECTED TO BUILD
OVER THE HIGH TERRAIN AROUND 21Z FORWARD, INTRODUCING POTENTIAL FOR
SOUTHERLY OUTFLOW WINDS. THERE IS AROUND A 30-40% CHANCE THAT
SHOWERS/ THUNDERSTORMS MOVE OFF THE TERRAIN AND OVER THE AIRFIELD
AFTER 22Z. VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE
PERIOD, HOWEVER, ANY SHOWERS MOVING OVER THE AREA MAY DROP VIS TO
THE MVFR CATEGORY.
REST OF UTAH AND SOUTHWEST WYOMING...ANOTHER DAY OF AFTERNOON
SHOWERS AND THUNDERSTORMS IS EXPECTED ACROSS UTAH AND SOUTHWEST
WYOMING, WITH CELLS FIRST BUILDING OVER THE HIGH TERRAIN, THEN
DRIFTING IN ADJACENT VALLEY AREAS THROUGH THE AFTERNOON. GUSTY AND
ERRATIC OUTFLOW WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH ANY
STORMS, AS WELL AS HEAVY RAINFALL WHICH MAY REDUCE VIS TO 5SM OR
LESS. OUTSIDE OF ANY OUTFLOWS, WINDS ARE EXPECTED TO BE GENERALLY
LIGHT AND TERRAIN DRIVEN.
FIRE WEATHER
CURRENTLY, MONSOONAL MOISTURE CONTINUES TO SURGE NORTH
INTO UT INCREASING HUMIDITIES AND RAISING CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS THE STATE, BOTH SERVING TO MODERATE FIRE
WEATHER CONDITIONS. CHANCES FOR SHOWERS AND THUNDERSTORMS REMAIN
HIGHEST ACROSS SOUTHWEST UT, HIGH TERRAIN FROM SOUTHERN TO
NORTHERN UT, AND THE UINTAS GENERALLY RANGING FROM 60-90%.
ADDITIONALLY, THESE LOCATIONS ARE WHERE A WETTING RAIN IS FAVORED
THIS AFTERNOON. MOISTURE CONTINUES TO SURGE INTO NORTHERN UT INTO
THIS WEEKEND, KEEPING CHANCES FOR SHOWERS AND THUNDERSTORMS
ELEVATED INTO NEXT WEEK EACH AFTERNOON.
SLC WATCHES/WARNINGS/ADVISORIES
UT...FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR UTZ122>128.
FLOOD WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR
UTZ122>128.
WY...NONE.
PUBLIC...WORSTER
AVIATION...WHITLAM
FIRE WEATHER...WORSTER
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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