Layton, Utah 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

497
FXUS65 KSLC 181012
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
312 AM MST Sat Jan 18 2025

.SYNOPSIS...Light snow across northern Utah tapers off today
leaving a very cold airmass in its wake. Northerly flow will
persist across the region through most of the week keeping
conditions mostly dry and cold. A gradual warmup begins towards
the end of the week.

&&

.SHORT TERM (THROUGH 12Z Monday)...As of 3am, light valley snow
is spread across the Salt Lake and Cache Valleys with some heavier
snow in the mountains that are favored in northwest flow.
Elsewhere, conditions are mainly dry and cold. The post-frontal
environment has led to cold temperatures aloft and northwest flow
inducing some upslope snow showers. Lake induced instability has
also contributed to periods of more focused banding across the
Salt Lake Valley, but this banding has been short lived giving way
to more unorganized showers. Given cold surface temperatures, snow
is quickly adhering to most surfaces leading to slick roads in
areas that experience more prolonged periods of snow. This
confined precipitation will continue through the mid morning hours
before snow tapers off in the afternoon.

In addition to the snow, strong downsloping winds across the
leeward side of the terrain down in Castle Country and The Swell
have been ongoing since the front passed through earlier in the
evening. These winds have mainly stayed confined to the terrain,
but some gusts in the 30s to low 40s have managed to make it into
some valley locations. But these winds should be peaking with a
gradual decrease throughout the day.

A cold day is in store for the CWA with highs struggling to get
above freezing for areas outside of the lower elevations of
southern Utah. These lower elevation areas will also remain below
normal with temperatures in the mid 40s.

A trailing shortwave will move through the area this evening, but
it will only bring some reinforcing cold air with some isolated
light snow showers to the mountains. This will help to maintain a
cold northerly flow that will lead to very cold overnight
temperatures tonight and Sunday night. Most locations will be in
the single digits and teens. This will create hazardous
conditions for vulnerable populations and pets exposed to the
elements.

.LONG TERM (AFTER 12Z MONDAY)...The long term forecast period
continues to feature the maintenance of the general pattern of a
ridge near the West Coast and mean longwave trough over the
central/eastern CONUS into late week. For Utah, this means the
continuation of a cold north to northwesterly flow aloft. Model
trends then show the pattern shifting for the end of the week and
into next weekend.

Monday morning, models are in fairly good agreement with a trough
carving south through the Great Basin and into the desert southwest.
Moisture remains fairly limited, with the main impact with this
system being cold temperatures. Model H7 temperatures over SLC range
from -20 to -17C at the 25th and 75th percentile by its coldest
point around midday Monday. This will translate to surface
temperatures well below climatological normals and should be the
coldest day for most of the forecast area during this 7-day forecast
period. One other thing to watch will be the potential for gap winds
in Washington County Monday night into Tuesday morning given
northeasterly gradient and H7 cold advection.

Temperatures will moderate a bit on Tuesday as a shortwave ridge
builds into the area briefly. However, with decreasing mixing and
the low sun angles, the cold air in place would be difficult to
displace, so would not be surprised if temperatures end up a bit
cooler than forecast, at least in the northern valleys.

The shortwave ridge will quickly yield to the next trough carving
into the area for Wednesday. While models are generally on board
with the idea of this trough, there is still some model spread
regarding how far west it will carve. Most ensemble members are
going for more of a glancing blow of northeast Utah and southwest
Wyoming, similar to the deterministic 00z GFS and Canadian. However,
around 28% of members do show the trough carving farther back into
Utah, more in line with the 00z deterministic EC. Moisture remains
very limited any way you look at it, but the EC-like solution would
result in cooler temperatures.

Towards the end of the week, the ridge over the western CONUS is
progged to continues building inland while flattening, allowing
storm activity from the northwest. However, there remains much
uncertainty as to how this next trough will impact Utah, as some
solutions are favoring an eventual cutoff low.


&&

.AVIATION...KSLC...Snow showers are likely to remain at least in the
vicinity of the SLC terminal through around 15-16z, with periods of
snow at the terminal itself from lake-effect showers off the Great
Salt Lake. These showers could bring occasional IFR conditions to
the terminal. The snow is expected to wind down by late morning,
although CIGS below 6kft may remain in place through midday or early
afternoon. Otherwise, northerly winds are likely to prevail into
this evening before light southerly winds return around 03-04z.

.REST OF UTAH AND SOUTHWEST WYOMING...Mountain top obscurations can
be expected across the northern and central Utah mountains through
mid/late morning as snow showers continue behind a cold front.
Periods of IFR conditions can be expected in heavier showers at some
northern Utah/southwest Wyoming terminals, especially SLC, SVR, LGU,
and EVW, though the chances will gradually decrease from north to
south after 12z. Snow is expected to wind down by late morning to
midday, although some lower CIGS may remain in place over/near
the mountains into early afternoon.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

$$

SHORT TERM...Mahan
LONG TERM...Cheng
AVIATION...Cheng

For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity