Moisture wrapped around an upper level low centered near the Four Corners area led to a quick shot of moderate snow for the southwest San Juan Mountains.
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The episode as NWS GJT wrote it up.
Moisture wrapped around an upper level low centered near the Four Corners area led to a quick shot of moderate snow for the southwest San Juan Mountains.
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 Mar 3, 10:43 PM MST, 1 hour 17 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 1043 PM MST Wed Mar 3 2021 .SHORT TERM...(Tonight through Thursday night) Issued at 217 PM MST Wed Mar 3 2021 Another sunny day across eastern Utah and western Colorado with warm temperatures being the rule. Flow around an upper level low to our southwest remains southerly and with all the sunshine, temperatures have run about 10 degrees above normal. Speaking of, this same closed low has just come ashore over southern California bringing some rain and clouds to portions of Cali and Nevada. Upper level support for this feature continues to be a 120+kt jet that will continue to lift the low northeastward at a fairly brisk pace. Accompanying the low is some decent QG forcing which remains in place as all models indicate large scale lift starting over our area from about now, reaching a maximum overnight into Thursday morning. Latest forecast PWATs also continue to bump us up so all the ingredients are in place for some precip to move in with rain for the valleys and snow for the higher elevations. The trajectory of the low pressure and flow favors the San Juans with accumulating snow of about 6 to 10 inches there. Expect precip to start around midnight with the heaviest occurring from about 2AM through 6AM when the strongest lift moves overhead. The current advisories look good and will remain in place. Snow will also fall over the central and northern mountains during the day Thursday but expect most snow to melt on roadways so not much of an impact expected...Vail and Rabbit Ears Pass may get a bit dicey but widespread impacts are not anticipated. Remaining areas will see the best chances of precip overnight and then favoring the Divide from daybreak onwards. By noon tomorrow, the center of the low will have already shifted to the Front Range as our flow becomes more west to northwesterly. Cold air aloft will create some minor instability in the wake of the passing low so some showers will likely continue through the day Thursday...favoring the higher elevations. Valleys will likely see virga or an odd, quick passing shower. Height rises then kick in Thursday evening as another ridge begins to build in. Clouds and precip will preclude much in the way of heating tomorrow so expect a cool day with high temps running about 5 to 10 degrees below climo. Not to worry though as the weekend looks to bring in another round of warmer temperatures. .LONG TERM...(Friday through Wednesday) Issued at 217 PM MST Wed Mar 3 2021 Mostly sunny skies will return Friday as drier air moves in behind the departing low pressure trough from Thursday. A ridge of high pressure building across the Great Basin will exert its influence over the Western Slope as temperatures return towards normal levels Friday, before another warm up takes place this weekend. As the ridge of high pressure slides overhead and slightly east Saturday, the flow will turn southwest and increase, allowing for decent mixing and warm air advection to take place. Temperatures will rise to 10 or so degrees above climatological norms for the period Saturday through at least Monday. A weak shortwave looks to clip the north Saturday evening through Sunday morning, bringing potential for showers over the eastern Uintas and Park Range, however some models keep this shortwave north of us with drier conditions. Regardless, this shortwave will have little influence on temperatures and is only expected to produce a few tenths of an inch of snow at best in the high elevations. As mentioned earlier though, the big story this weekend into early next week is the well above normal temperatures and mild, spring-like weather so enjoy it while it lasts as cooler unsettled weather looks to be on tap for the rest of next week. Models are not in the best agreement on how to handle a trough moving onto the west coast once it tracks inland next week. The GFS shows a few fast moving shortwaves moving across beginning Monday with colder air arriving Tuesday, while the ECMWF holds off on the precipitation and cooler weather until Tuesday evening and Wednesday. Still a ways out but temperatures do look to drop back to near normal by Tuesday and perhaps below normal in spots Wednesday. Really all depends on the timing of this colder air and precipitation as well as how amplified or deep the trough gets. If the ECMWF timing is correct, temperatures on Tuesday could still remain above normal for one more day before the cooler, unsettled weather arrives by mid week. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1037 PM MST Wed Mar 3 2021 Clouds will continue to spread northeastward across the region, with showers increasing in coverage overnight. Lower valleys should see rain with snow at higher elevations and a mix in rain and snow for southern valleys. Anticipate ILS breakpoints to be met with low CIGS in any showers and brief periods of MVRF/IFR conditions at the higher elevation sites and southern valleys. Showers will decrease in coverage Thursday evening, as cold and dry air works its way in from west to east. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Winter Weather Advisory until 5 PM MST Thursday for COZ019. UT...None. && SHORT TERM...TGR LONG TERM...MDA AVIATION...TGJT
Hazardous Weather Outlook National Weather Service Grand Junction CO 904 AM MST Wed Mar 3 2021 COZ001>014-017>023-UTZ022>025-027>029-041615- Lower Yampa River Basin-Central Yampa River Basin- Roan and Tavaputs Plateaus-Elkhead and Park Mountains- Upper Yampa River Basin-Grand Valley-Debeque to Silt Corridor- Central Colorado River Basin-Grand and Battlement Mesas- Gore and Elk Mountains/Central Mountain Valleys- Central Gunnison and Uncompahgre River Basin- West Elk and Sawatch Mountains-Flat Tops- Upper Gunnison River Valley-Uncompahgre Plateau and Dallas Divide- Northwest San Juan Mountains-Southwest San Juan Mountains- Paradox Valley/Lower Dolores River- Four Corners/Upper Dolores River-Animas River Basin- San Juan River Basin-Southeast Utah-Eastern Uinta Mountains- Eastern Uinta Basin-Tavaputs Plateau-Arches/Grand Flat- La Sal and Abajo Mountains-Canyonlands/Natural Bridges- 904 AM MST Wed Mar 3 2021 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Mostly sunny and spring like weather in store for today. A winter storm brings valley rain and mountain snow into the region later tonight. 5 to 10 inches of snow is expected for the San Juans and thus, a winter weather advisory has been issued. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Valley rain and mountain snow continues through Thursday before high pressure builds in on Friday. A weak wave will move through northern portions of the CWA on Sunday but little precip expected. The next system to affect the area will move in on Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected today or tonight, however spotters are encouraged to report snowfall amounts to the National Weather Service in Grand Junction.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
802 PM MST WED MAR 3 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0742 PM NON-TSTM WND GST 4 SW CORTEZ 37.31N 108.63W
03/03/2021 M47 MPH MONTEZUMA CO ASOS
&&
NLThe national radar mosaic for the moment the first event began.
1 winter weather. Local standard time, as filed.
Generally 4 to 10 inches of snow fell across the area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2021Every state in 2021This day in weather historyWarnings in Colorado, March 2021
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: 936464.