Dense fog formed as low level moisture from showers the previous day remained trapped in the mountain valley.
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The episode as NWS GJT wrote it up.
Dense fog formed as low level moisture from showers the previous day remained trapped in the mountain valley.
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 Grand Junction, CO wrote its last area forecast discussion before the first event at May 17, 9:57 PM MST, 3 hours 3 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 1057 PM MDT TUE MAY 17 2016 .SHORT TERM...(Tonight through Wednesday night) Issued at 403 PM MDT Tue May 17 2016 Southerly flow continues to pump in moisture thanks to the low pressure that is to our west. Instability wasn't as strong today so the intensity of the showers and storms was weaker than seen yesterday though a few heavier showers have popped. Most of the precipitation will end a few hours after sunset though some showers, generally south, will continue overnight. Some snow can be expected above 10,000 feet tonight but expect minimal impacts on roadways so held off on issuing any advisories. By Wednesday morning, the low will have shifted to southern Arizona but moisture will continue to stream into the area. Once again, afternoon showers and storms will form mid-morning onwards. H7 winds remain light so gusty winds not too much of a concern with storms that fire though some small hail is possible along with heavier rain at times. .LONG TERM...(Thursday through Tuesday) Issued at 403 PM MDT Tue May 17 2016 By Thursday morning, finally, the low pressure center will open up, become an open wave, and shift to eastern Colorado. A ridge will build in but plenty of moisture will remain in the atmosphere allowing the more usual afternoon showers and storms to form. As this occurs, a very deep area of low pressure will drop down into the Pacific northwest and become somewhat stationary. Model runs have changed where the low will set up so confidence a bit shaky in that regard. One thing that has remained constant though is that this low will tighten the pressure gradient considerably causing gusty winds across much of the Great Basin. Our area can expect to see winds picking up Friday and continue each afternoon through Sunday. Best upper level support for this system looks to stay to our north so expect some showers at times through Tuesday but nothing too widespread. Temperatures will jump to near or above normals Friday and Saturday before dropping a few degrees below Sunday onwards thanks to increased clouds. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1057 PM MDT Tue May 17 2016 Low pressure to the west continues to pump moisture on southerly winds into eastern Utah and western Colorado late this evening. This moisture advection will stay focused over southern portions of CO/UT over the next 24 hours as the low drops into Arizona then lifts into southeast Colorado. Therefor showers and thunderstorms will continue across the region and could impact flight operation over a majority of the forecast terminals. MVFR/IFR ceilings and visibility from passing showers will be a temporary threat along with the threat of lightning and small hail tomorrow afternoon. Widespread terrain obscuration will also continue into tomorrow evening before drier air infiltrates the region as this storm finally departs. && .HYDROLOGY... Issued at 400 AM MDT Tue May 17 2016 Wet weather through midweek combined with rising temperatures toward the end of the week are expected to drive river levels gradually higher. In fact, over the next few weeks increased flows will primarily be the result of melting snowpack. This will cause rivers and streams to swell causing some streams to reach bankfull. Use caution in and near swift currents. && .GJT Watches/Warnings/Advisories... CO...None. UT...None. && SHORT TERM...TGR LONG TERM...TGR AVIATION...TGJT HYDROLOGY...NL
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
The national radar mosaic for the moment the first event began.
1 dense fog. Local standard time, as filed.
Dense fog occurred in some mountain valley locations in the northwestern San Juan Mountains. The visibility at the Telluride Regional Airport down to a quarter mile at times.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2016Every state in 2016This day in weather historyWarnings in Colorado, May 2016
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: 668790.