Prayers Sorta Answered

Utahn's prayers have finally been answered... somewhat. The storm that impacted the state the first half of this past weekend (10/3-10/4) is one that will go down in the record books. The KMTX radar loop from the morning of 10/4 reveals a cyclonically spinning precipitation field over northern Utah. Much of the higher radar reflectivities are skewed by "bright banding" - higher reflectivities from melting snow within the cloud - but in general the level 2 scan identifies a broad area of moderate to heavy rainfall with lower correlation coefficient values indicating the melting layer (bright banding). As far as some metrics go, this storm was not the "strongest" October system Utah has seen, but it was the most moisture rich. The storm track aligned in such a way a prolonged and consistent rain event played out in northern Utah valley areas.

Right: KMTX level 2 scan reflectivity 10/4/2025 0821-0848 MDT; Left: Level 2 correlation coefficient

To get straight to the point, on 10/4/2025 Salt Lake City observed the 2nd greatest daily total precipitation (2.47") since records began in 1874. A table of the top 10 daily total precipitation accumulations for SLC is given below. The only date to out-rain this past Saturday (10/4/2025) was back on 5/3/1901. Even then, the observations were taken in downtown SLC in 1901 and not at Salt Lake City International Airport (KSLC), so there could be an argument whether or not 10/4/2025 is the first. 

I think we all can agree - vegetation and people alike - that the record amount of rain this past weekend was much enjoyed and appreciated. It's been such a lackluster year for precipitation in Utah. We just ended the water year on Oct. 1 - water year spans a year starting and ending on Oct. 1 - at 10.48". This is the 8th driest water year on record as shown in the table below.   

As far as yearly precipitation (Jan. 1 - Dec. 31), prior to this storm, SLC was 4.04" below normal for year to date precipitation. After the storm, SLC is now only 1.51" below normal or 1.56" depending on if you compare against 10/5 or 10/6. This comeback is all thanks to the event/storm total of 2.62" between 10/3-10/5. 

This Week's Outlook:

Now that the storm and rain is behind us, conditions will be dry with temperature moderating a bit each day going late into this workweek as a ridge builds back over Utah. The Salt Lake City Valley may actually kiss 80 F by Thursday. It is looking to be a beautiful few days of mild fall weather so enjoy. 

Things look to deteriorate again by the end of the week/weekend as a Pacific tropical system and fairly deep trough off the U.S Pacific coast interact. Definitely lots of uncertainty as to what will occur, but models are still trending on bringing remnants of the tropical system into Utah combined with impacts from the trough and associated cold front. 

ECMWF 00Z 10/6 four-panel forecast for 10/11/2025 @ 00Z: (Top left to bottom right) MSLP/precip and 1000-500 mb thickness; 300 mb gph and winds; 500 mb gph, vorticity, and winds; 700 mb gph, RH, temp, and winds 

It could be a one two punch this Fri-Sun, with more active and cool and wet weather on the way for Utah. Flooding will be a large threat for areas of the state as the extra-tropical nature of this weekends storm and precipitation enhancement from topography could produce extended heavy rainfall. Details are likely to change, but this could be another big rainmaker for Utah and early season mountain snowmaker depending on the storm track.