FXUS65 KSLC 201855

AFDSLC



Area Forecast Discussion

National Weather Service Salt Lake City UT

1255 PM MDT Sun Sep 20 2026



.KEY MESSAGES, Issued 1001 PM MDT Sat Sep 19 2026...





- High pressure will bring dry conditions through Monday with

  temperatures near or just below seasonal normals. 



- Moisture and instability will return to the area beginning late

  Monday, bringing an increasing potential of showers and

  thunderstorms. The unsettled pattern is most likely to continue

  for much of the remainder of the upcoming week. 



&&



.DISCUSSION, Issued 1001 PM MDT Sat Sep 19 2026...

The Pacific Northwest low that has been moving

across northern Utah is now centered over central Wyoming this

evening. Isolated showers and thunderstorms continued into the

early evening for northeastern portions of the forecast area, but

given the loss of daytime heating and the eastward movement of the

low, showers have dissipated and skies are mostly clear for the

vast majority of the area. Northern Utah and southwest Wyoming

locations saw much cooler temperatures today, with maxes averaging

10F below seasonal normals. Over southern Utah, there was much

less cooling, keeping temperatures near normal for this time of

year. 



High pressure is expected to move overhead tomorrow afternoon,

with Utah and southwest Wyoming sandwiched in between the exiting

low and another one approaching the California coast. As the ridge

builds, maxes for northern portions of the area will increase by a

few degrees, running 5-7F above seasonal normals, with little

change over southern Utah. By Monday afternoon, the ridge axis is

on track to move into Colorado, with the resultant southerly flow

bringing temperatures back to near normals across the entire area. 



Southerly flow over the area is expected to increase by Monday

night as the California low makes its way into the Great Basin. In

this flow, monsoonal moisture is expected to advect back northward

into the area, with PWs expected to be in the 0.6 to 0.8 inch

range across much of the area by early Tuesday. Though confidence

is high that there will be less moisture coming up with this push

than what was seen last week, it will still increase the potential

of showers and thunderstorms across the area. There remains some

spread in the guidance with regard to the system's track after it

moves into the Great Basin and how much it weakens while onshore.

However, the majority of guidance is now indicating it will take a

turn into southern Utah Monday night, moving across the remainder

of the area in a weakened state during the day Tuesday. With this

extra instability, the forecast for coverage of convection on

Tuesday is definitely trending upward. 



Ensemble spread increases further for the latter part of the

upcoming week. Guidance is generally favoring a continued

unsettled pattern for much of the remainder of the week, keeping

temperatures near normal with occasional chances of showers and

thunderstorms. It should be noted that a minority of guidance,

including the latest deterministic EC, show strong high pressure

returning by late in the upcoming week, bringing a warming and

drying trend. 











&&



.AVIATION, Issued 509 AM MDT Sun Sep 20 2026...





KSLC...VFR conditions will persist across the KSLC airspace through 

the TAF period with diurnal wind shifts. The next wind shift to 

northwesterly can be expected around 18z. 





REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected to 

persist across all terminals through the TAF period with diurnal 

wind shifts. Low clouds are expected through the morning at KEVW 

with brief instances of IFR CIGs possible, though length remains 

uncertain enough to leave out of the TAF at this time.  



&&



.FIRE WEATHER...Cool, dry, and stable conditions will continue areawide until Monday

evening when showers and storms move into southern Utah thanks to

an area of low pressure moving into the Great Basin. These storms

will be moving from south to north, arriving in northern Utah on 

Tuesday. These storms will be fast moving, but rainfall rates will

be high enough to quickly produce wetting rains. Some strong 

storms will be embedded within the complex which will be capable 

of strong and erratic winds, frequent lightning, and some hail. 

Conditions become mostly dry and stable by Wednesday, except for

areas of eastern Utah that hold on to moisture, with near normal 

conditions persisting through the remainder of the week.



&&



.SLC WATCHES/WARNINGS/ADVISORIES...

UT...None.

WY...None.

&&



$$



PUBLIC...Traphagan

AVIATION...Worster

FIRE WEATHER...Mahan



For more information from NOAA's National Weather Service visit...

http://weather.gov/saltlakecity