596
FXUS65 KSLC 102033
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
133 PM MST SAT JAN 10 2026
KEY MESSAGES
- A PROLONGED INVERSION PERIOD WILL SET UP THIS WEEKEND ACROSS THE
NORTHERN VALLEYS AND PERSIST THROUGH AT LEAST THURSDAY. THIS
WILL RESULT IN AN INCREASE IN HAZE, NOCTURNAL FOG, AND A
DEGRADATION IN AIR QUALITY.
DISCUSSION
AS EXPECTED, HIGH PRESSURE CONTINUES TO BUILD INTO
THE REGION THIS AFTERNOON. LOOKING AT THE CHANGE IN 700MB
TEMPERATURES BETWEEN THE 00Z AND 12Z KSLC SOUNDING, SIGNIFICANT
MID-LEVEL WARM AIR ADVECTION HAS STRENGTHENED THE VALLEY INVERSION
MARKEDLY. AIRCRAFT SOUNDINGS THROUGH EARLY AFTERNOON INDICATE THE
INVERSION HAS REMAINED QUITE SIMILAR TO THE 12Z SOUNDING.
WHILE STRATUS KEPT TEMPERATURES ELEVATED OVERNIGHT ACROSS THE
NORTHERN VALLEYS, ANY LINGERING STRATUS HAS LARGELY DIMINISHED.
THIS WILL INCREASE THE THREAT OF VALLEY FOG AFTER SUNSET. LOOKING
AT THE HREF AND NBM VISIBILITY FORECASTS, THERE IS AROUND A 40%
CHANCE OF DENSE FOG IN THE CACHE VALLEY AND BEAR RIVER VALLEY
BETWEEN 09Z-16Z. WITH VERY COLD TEMPERATURES, PATCHY FREEZING FOG
IS ALSO A THREAT IN THE CACHE AND BEAR RIVER VALLEY, WITH THE
POTENTIAL FOR SLICK ROADS, OVERPASSES, AND OTHER ELEVATED
SURFACES. FOR NOW, GIVEN THE PROBABILITY OF DENSE FOG DEVELOPMENT
IS LESS THAN 50%, DID NOT ISSUE A DENSE FOG OR FREEZING FOG
ADVISORY WITH THIS PACKAGE...BUT THIS WILL NEED TO BE MONITORED
MOVING FORWARD OVER THE EVENING SHIFT.
OTHER LOCATIONS THAT HAVE A 20% CHANCE OF DENSE FOG DEVELOPMENT
INCLUDE AREAS NEAR THE GREAT SALT LAKE IN WEBER AND DAVIS COUNTY,
AND HEBER CITY NEAR THE RESERVOIR.
AS THE INVERSIONS STRENGTHEN AND PARTICULATE CONCENTRATIONS
INCREASE, THE THREAT OF DENSE FOG AND/OR VISIBILITY RESTRICTIONS
IN HAZE WILL INCREASE SUNDAY THROUGH MOST OF THE NEXT WEEK.
CURRENTLY, THE UTAH DEPARTMENT OF AIR QUALITY IS FORECASTING
MODERATE/YELLOW AIR QUALITY CONDITIONS TO DEVELOP SUNDAY ACROSS
MOST MONITORED NORTHERN UTAH VALLEYS. THOSE IN SENSITIVE GROUPS
SHOULD CONTINUE TO MONITOR AIR QUALITY FORECASTS AND CONSIDER
PRECAUTIONS ONCE CONDITIONS ARE FORECAST TO SHIFT TO
ORANGE/UNHEALTHY FOR SENSITIVE GROUPS.
LOOKING AT THE LATEST GUIDANCE, A PORTION OF THE ENSEMBLE MEMBERS
SUGGEST THE POTENTIAL FOR A BACKDOOR COLD FRONT WITH MID-LEVEL
COLD AIR ADVECTION SUFFICIENT FOR MOST NORTHERN VALLEYS TO
VENTILATE THURSDAY INTO FRIDAY. THE MEAN FROM THE LREF (INCLUDING
EPS, GEFS AND CANADIAN ENSEMBLE MEMBERS) FOR 700MB TEMPERATURES
LESS THAN -2C IS THURSDAY NIGHT. THIS IS OUR NEXT HOPE FOR
IMPROVEMENT IN NORTHERN VALLEY INVERSION. SOMETHING TO MONITOR
MOVING FORWARD BUT GIVEN BROAD AND SIGNIFICANT VARIATIONS ACROSS
THE ENSEMBLE SUITE, CONFIDENCE IS LOW. EITHER WAY, THIS WILL BE A
PROLONGED PERIOD OF INVERSION CONDITIONS.
AVIATION...KSLC
VFR CONDITIONS TO PREVAIL AT THE TERMINAL
THROUGH THE PERIOD. LIGHT NORTHERLY WINDS CONTINUE THROUGH AROUND
04-05Z BEFORE SWITCHING TO SOUTHEASTERLY. CLEAR SKIES TODAY GIVE
WAY TO INCREASING MID-TO-HIGH LEVEL CLOUD COVERAGE OVERNIGHT.
REST OF UTAH AND SOUTHWEST WYOMING
LIGHT, TERRAIN DRIVEN WINDS
PREVAIL FOR ALL REGIONAL TERMINALS TODAY. CLEAR SKIES ACROSS THE
AIRSPACE CONTINUE FOR THE REMAINDER OF THE DAY, WITH MID-TO-HIGH
LEVEL CLOUDS INCREASING ACROSS THE NORTHERN HALF OF THE AIRSPACE
OVERNIGHT INTO SUNDAY MORNING. THERE IS A CHANCE FOR FOG OR LOW
STRATUS TO DEVELOP ACROSS THE CACHE VALLEY BETWEEN 07Z-16Z, WITH A
~30% CHANCE TO IMPACT KLGU WITH IFR/LIFR CIGS/VIS THROUGH THIS
PERIOD.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
KRUSE/WHITLAM
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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