275
FXUS65 KSLC 201019
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
419 AM MDT MON OCT 20 2025
SYNOPSIS
COOLER TEMPERATURES AND DRY CONDITIONS WILL BE IN
PLACE ACROSS THE REGION TODAY AS HIGH PRESSURE BUILDS IN THE WAKE
OF A COLD FRONT. A WEAK LOW PRESSURE SYSTEM MOVES THROUGH SOUTHERN
UTAH MID-WEEK, WITH TRANSIENT TRAILING HIGH PRESSURE GIVING WAY TO
CONTINUED ACTIVE WEATHER BY THE WEEKEND.
SHORT TERM (THROUGH 12Z/6AM FRIDAY)
A COLD FRONT CONTINUES TO
TRACK ACROSS THE WESTERN HALF OF UTAH EARLY THIS MORNING, AND IS
SLATED TO ARRIVE IN SOUTHWEST UTAH BEFORE SUNRISE. IN THE WAKE OF
THIS FRONTAL BOUNDARY, WE'LL SEE TEMPERATURES ACROSS MUCH OF THE
AREA 5 TO 15 DEGREES LOWER THAN WHAT WAS SEEN ON SUNDAY. FOR THE
NORTHERN HALF OF THE AREA, HIGH TEMPERATURES WILL GENERALLY BE 5
TO 10 DEGREES BELOW CLIMATOLOGICAL NORMALS WHILE THE SOUTHERN HALF
WILL FALL BACK TO/ REMAIN RIGHT AROUND AVERAGE. PUTTING A NUMBER
ON THINGS: LOW-TO-MID 50S FOR THE WASATCH FRONT, MID-40S FOR
SOUTHWEST WYOMING, MID-60S FOR THE CEDAR CITY AREA, AND UPPER-70S
FOR LOWER WASHINGTON COUNTY. REMNANT COLD AIR AND CLEAR SKIES
MONDAY NIGHT INTO TUESDAY MORNING WILL BRING POTENTIAL FOR
FREEZING TEMPERATURES FOR AREAS WHICH HAVE NOT YET EXPERIENCED A
WIDESPREAD FREEZE, SUCH AS EASTERN BOX ELDER COUNTY AND NORTHERN
WEBER COUNTY.
THROUGH TUESDAY, HIGH PRESSURE WILL REESTABLISH ACROSS THE REGION
WITH WEAK WARM ADVECTION SPREADING ACROSS THE EASTERN GREAT BASIN.
AS SUCH, WE'LL SEE LARGELY CLEAR SKIES ACROSS MUCH OF THE AREA
WITH TEMPERATURES JUMPING BACK UP TO NEAR, OR SLIGHTLY ABOVE,
AVERAGE FOR THIS TIME OF YEAR.
AS THIS HIGH PRESSURE BUILDS FOR A SHORT DURATION, A LONG-LIVED
AND WEAKENED OFFSHORE LOW OFF THE COAST OF CALIFORNIA WILL BEGIN
TO TRACK EASTWARD. BY WEDNESDAY, THE CENTER OF THIS FEATURE WILL
CROSS ONSHORE AND TRACK THROUGH SOUTHERN UTAH INTO THURSDAY. THOUGH
NOT AS SIGNIFICANT IN COMPARISON TO PREVIOUS MOISTURE EVENTS,
ABOVE NORMAL PRECIPITABLE WATER WILL STREAM INTO THE REGION AS
THIS LOW SLIDES ACROSS UTAH. BROAD ATMOSPHERIC LIFT PROVIDED BY
THE WAVE WILL PAIR WITH THE MOISTURE AND INFLUENCE OF TERRAIN TO
KICK OFF A ROUND OF PRECIPITATION THAT LOOKS TO SPREAD INTO THE
SOUTHERN HALF OF UTAH AS EARLY AS LATE WEDNESDAY MORNING. A
MAJORITY OF THE FORCING ASSOCIATED WITH THIS SYSTEM WILL ARRIVE
DURING THE EVENING AND OVERNIGHT HOURS ON WEDNESDAY, WHICH WILL
FAVOR A MAJORITY OF THE PRECIPITATION DURING THE OVERNIGHT HOURS.
A FEW EMBEDDED THUNDERSTORMS MAY ARISE DURING THIS PERIOD AS
INSTABILITY WILL PEAK AS THE MID-LEVEL LOW TRACKS OVERHEAD,
HOWEVER, LITTLE IMPACTS ARE EXPECTED IN REGARDS TO HEAVY RAINFALL.
ADDITIONALLY, TEMPERATURES WILL BE WARM ENOUGH WITHIN THE LOW THAT
SNOWFALL WILL ONLY BE A CONCERN FOR THE HIGHEST ELEVATIONS OF
SOUTHERN UTAH (I.E. TUSHAR MOUNTAINS). LIGHT RAIN SHOWERS WILL BE
SEEN AS FAR NORTH AS THE SOUTHERN TO CENTRAL WASATCH FRONT AND THE
UINTA MOUNTAINS, BUT AGAIN, VERY LITTLE IMPACTS ARE EXPECTED AT
THIS TIME.
THIS FEATURE EJECTS EASTWARD THROUGH THE DAY ON THURSDAY WITH AN
UPSTREAM SHORTWAVE RIDGE BUILDING INTO THE REGION THEREAFTER. AS
SUCH, WILL SEE LIGHT SHOWERS DETERIORATING FROM EAST TO WEST
THROUGH THE DAY ON THURSDAY WITH EVERYTHING WRAPPING UP LATE IN
THE EVENING.
LONG TERM (AFTER 12Z/6AM FRIDAY)
LOW AMPLITUDE (AND TRANSIENT)
RIDGING WILL BRING THE WARMEST DAY OF THE WEEK LOCALLY ON FRIDAY,
BUT WILL BE SHORT LIVED AS THE MEAN PATTERN UPSTREAM WILL BE
TRENDING MORE DYNAMIC AND ON-SHORE ACROSS THE PACNW. MODEL
CONSENSUS CONTINUES TO KEY IN ON THE FIRST NOTABLE AR EVENT OF THE
SEASON ACROSS THE PACNW COASTAL REGION BEGINNING FRIDAY, WITH
INLAND PENETRATION INTO THE NORTHERN ROCKIES REGION AND PORTIONS
OF THE NORTHERN GREAT BASIN THEREAFTER THROUGH THE WEEKEND. BIG
PICTURE DETAILS ON THIS REMAIN ON THE HIGHER SCALE OF CONFIDENCE,
BUT THE DEVIL REMAINS IN THE DETAILS LOCALLY AS THE NORTHERN HALF
THE FORECAST AREA LARGELY SITS ON THE SOUTHERN MOST FRINGE OF THE
MORE IMPACTFUL OUTCOMES.
CURRENT SUITE OF ENSEMBLE GUIDANCE TRANSLATES THE INITIAL SHORT WAVE
PUSH ACROSS NORTHERN UTAH SATURDAY AFTERNOON, WITH A TRAILING SHORT
WAVE PASSAGE ROUGHLY 24HRS LATER. EXTENT OF REMNANT AR MOISTURE TBD,
BUT AT LEAST SOME INFLUENCE SHOULD BE NOTED GIVEN THE BIG PICTURE
CONSISTENCY IN THE LONG WAVE AND ON-SHORE STREAMLINES DEPICTED. HOW
FAR SOUTH THE ATTENDANT PRECIP IS REALIZED LOCALLY REMAINS ONE OF
THOSE EXPECTED CHALLENGES IN DETAIL GIVEN HOW FAR OUT, AND WILL BE
DRIVEN BY SUBTLETIES IN UPSTREAM AMPLITUDE OF THE TROUGH AS IT
EVOLVES. CURRENT FORECAST CONTINUES TO TREND POPS INTO THE LIKELY
RANGE ACROSS THE NORTHERN THIRD LEADING INTO SUNDAY, WITH THE
NORTH/SOUTH DELINEATION OF PRECIP CHANCES ROUGHLY BISECTING THE
FORECAST AREA. BOTTOM LINE...INCREASINGLY ACTIVE ACROSS THE NORTH
BEGINNING SATURDAY, BUT THE SOUTH LEANS INTO THE HIGHER CONFIDENCE
REALM OF MISSING OUT ON TANGIBLE PRECIP THIS GO.
AVIATION...KSLC
LOCALIZED AND PERIODIC MOUNTAIN OBSCURATION
OF LOCAL TERRAIN REMAINS A POTENTIAL THROUGH 17-18Z, BUT IN LARGE
VFR CONDITIONS WILL DOMINATE THIS CURRENT TAF PERIOD. LIGHT AND
VARIABLE WINDS ARE EXPECTED TO CONTINUE THROUGH THE MAJORITY OF THE
MORNING PRIOR TO BECOMING A PREVAILING NORTHWEST AFTER 18Z.
REST OF UTAH AND SOUTHWEST WYOMING
A WEAKENING COLD FRONT WILL
CONTINUE TO GRADUALLY SHIFT SOUTH ACROSS THE AIRSPACE THIS
MORNING PRIOR TO DISSOLVING THIS AFTERNOON. LOCALIZED MOUNTAIN
OBSCURATION IS EXPECTED WITH AND BEHIND THIS FRONTAL PASSAGE EARLY
THIS MORNING, BUT WILL RAPIDLY WANE BY 15/16Z ALLOWING VFR
CONDITIONS TO DOMINATE THE REMAINING HOURS OF THE CURRENT TAF
PERIOD. NORTHERLY SURFACE WINDS WILL TREND TO PREVAIL WITH DAYTIME
MIXING THIS AFTERNOON...GENERALLY LIGHT ACROSS THE WESTERN HALF OF
THE AREA, BUT GUSTS OF ~20KTS WILL REMAIN POSSIBLE ACROSS MUCH OF
THE EASTERN HALF.
SLC WATCHES/WARNINGS/ADVISORIES
UT...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
UTZ103.
WY...NONE.
SHORT TERM...WEBBER
LONG TERM...MERRILL
AVIATION...MERRILL
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page