Heavy rain brought isolated flash flooding to parts of northern Utah.
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The episode as NWS SLC wrote it up.
Heavy rain brought isolated flash flooding to parts of northern Utah.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Salt Lake City, UT wrote its last area forecast discussion before the first event at Oct 4, 2:41 PM MST, 1 hour 19 minutes earlier.
Area Forecast Discussion National Weather Service Salt Lake City UT 341 PM MDT Thu Oct 4 2018 .SYNOPSIS...One weather system will exit the region this afternoon, however a secondary system will quickly follow, pushing a cold front through the region tonight. An active pattern is expected to continue into the upcoming weekend. && .SHORT TERM (Through 00Z Sunday)...A weak shortwave over northeast Nevada that is moving northeast ahead of the cold front over western Nevada will keep the scattered showers and isolated thunderstorms going this evening over northern Utah. The cold front will arrive across extreme northwest Utah this evening and to the SLC areas by about 1100pm to midnight. Numerous showers and isolated thunderstorms will occur over the Wasatch Front and Wasatch Mountains with and behind the cold front and associated 700 mb baroclinic zone. Snow levels will drop to between 7000 and 8000 ft by Friday morning with 1 to 5 inches possible above 8000 ft and 0.30 to 0.80 of an inch in the valleys. This storm system will be much weaker as you move farther south with scattered showers and 0.05 to 0.30 of an inch expected. The storm should clear the CWA by early Friday afternoon as the 500mb vorticity advection shifts eastward into far eastern Utah. Have backed off on the PoPs for eastern Utah as the 700mb baroclinic zone weakens in addition to downsloping winds drying the air mass. Increased the westerly winds over this area as well for early Friday. A second storm system will be arriving Saturday. However, both the GFS and EC indicate a disturbance out running the next storm system on Friday night bringing a threat of showers to western and northern Utah. Otherwise, this second storm system will move in Saturday bringing another round of showers and possible thunderstorms, although the LIs are mainly positive across all but southern Utah in the afternoon. The 700mb baroclinc zone is ill defined with this second system as energy digs down the back side of the trough and 700mb trough axis doesn't reach Utah until Saturday evening. However, 500mb vorticity advection and some weak jet dynamics should be sufficient to have likely showers across much of the CWA by afternoon. .LONG TERM (After 00Z Sunday)...A longwave trough will remain in place across the region through the long term period, maintaining a cool and active pattern across the forecast area. Two main features rotating through the flow will bring the greatest threat for precip to the area...the first deepening upper low Sunday into Monday, with a secondary trough digging into the region during the midweek period. 700mb temperatures fall to near -2C with the initial low, which should bring snow levels down into the 7500-8000 range, while the midweek wave is expected to drop snow levels into the 6500-7000 foot range across northern and central Utah. && .FIRE WEATHER...Scattered showers and isolated thunderstorms over northern Utah this afternoon will transition into widespread showers and isolated thunderstorms tonight as a cold front moves into the region. Numerous showers will occur with this front across the north but less showers are expected with the southern end of the front over southern Utah Friday. A short break in the precip will occur Friday afternoon and evening. Another storm system with slightly colder air will arrive Friday night and remain across the area through Sunday. Snow levels will lower to between 7000 and 8000 ft. A third storm will impact the region Tuesday into Wednesday before a possible pattern change to warmer and drier weather end of next week. && .AVIATION...Showers and the occasional thunderstorm will pass in the vicinity of SLC through the afternoon/evening. The main impact from these storms would be erratic outflow winds although brief cigs <7K ft and lightning are also possible. Outside of storms strong southerly winds should prevail before a cold front arrives around 05-07Z. Winds wills shift to the northwest at this time with steadier precipitation and MVFR vsbys likely. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && SHORT TERM...Struthwolf LONG TERM...Seaman FIRE WEATHER...Struthwolf AVIATION...Carr For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity For frequently asked questions about the Area Forecast Discussion visit... http://weather.gov/saltlakecity/general/afd_faqs.php
Hazardous Weather Outlook National Weather Service Salt Lake City UT 631 AM MDT Thu Oct 4 2018 UTZ001>016-019>021-517-518-WYZ021-051300- Cache Valley/Utah Portion-Northern Wasatch Front- Salt Lake and Tooele Valleys-Southern Wasatch Front- Great Salt Lake Desert and Mountains-Wasatch Mountain Valleys- Wasatch Mountains I-80 North-Wasatch Mountains South of I-80- Western Uinta Mountains-Wasatch Plateau/Book Cliffs- Western Uinta Basin-Castle Country-San Rafael Swell- Sanpete/Sevier Valleys-West Central Utah-Southwest Utah- Utahs Dixie and Zion National Park-South Central Utah- Glen Canyon Recreation Area/Lake Powell-Central Mountains- Southern Mountains-Southwest Wyoming- 631 AM MDT Thu Oct 4 2018 This Hazardous Weather Outlook is for the western two thirds of Utah and southwest Wyoming. .DAY ONE...Today and Tonight Scattered showers and thunderstorms will gradually diminish today. The next storm system will push a cold front into northern and central Utah tonight. Precipitation is expected along the front and may be locally heavy at times. Accumulating snow can be expected over the higher terrain. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Precipitation will continue along the cold front Friday morning before diminishing. Much colder temperatures are expected Friday behind the front. Cool and wet weather will then continue for the weekend, with a potential for heavy rain across southern and eastern Utah. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures. For more information from NOAA/s National Weather Service visit... http://weather.gov/saltlakecity For information on potential road travel impacts visit... http://www.udottraffic.utah.gov/roadweatherforecast.aspx
Special Weather Statement National Weather Service Salt Lake City UT 332 PM MDT THU OCT 4 2018 UTZ001-002-006-007-042215- Wasatch Mountain Valleys UT-Cache Valley/Utah Portion UT- Wasatch Mountains I-80 North UT-Northern Wasatch Front UT- 332 PM MDT THU OCT 4 2018 ...SIGNIFICANT WEATHER ADVISORY FOR WEBER...SOUTH CENTRAL CACHE... EASTERN BOX ELDER...NORTHERN DAVIS AND WEST CENTRAL MORGAN COUNTIES UNTIL 415 PM MDT... At 331 PM MDT, National Weather Service Doppler radar indicated a strong thunderstorm near Hooper, or near Ogden...moving northeast at 35 mph. Winds in excess of 40 mph will be possible. Locations impacted include... Ogden, Layton, Farmington, Brigham City, Morgan, Roy, Clearfield, Kaysville, Syracuse, Clinton, North Ogden, South Ogden, Washington Terrace, Riverdale, Hooper, South Weber, Perry, Willard, Marriott-Slaterville and Uintah. PRECAUTIONARY/PREPAREDNESS ACTIONS... If threatening weather approaches, take shelter in a sturdy building. Heavy rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4097 11236 4149 11233 4151 11174 4100 11159 TIME...MOT...LOC 2131Z 239DEG 29KT 4121 11207 NC
The Salt Lake City radar (KMTX), 109 km away, was scanning. The volume nearest the first event began at 22:58 UTC.
1 flash flood. Local standard time, as filed.
Heavy rain over the Quail Fire burn scar produced flash flooding, with the basements of two homes in Highland flooded.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2018Every state in 2018This day in weather historyWarnings in Utah, October 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 785232.