A severe thunderstorm moving right of the mean flow brought large hail to portions of Moffat County.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS GJT wrote it up.
A severe thunderstorm moving right of the mean flow brought large hail to portions of Moffat County.
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 7, 10:21 AM MST, 3 hours 9 minutes earlier.
Area Forecast Discussion National Weather Service GRAND JUNCTION CO 1121 AM MDT Sun May 7 2017 .SHORT TERM...(Today through Monday) Issued at 238 AM MDT Sun May 7 2017 The strong closed low near San Diego will meander over southern CA today and eventually move south to the northern Baja peninsula tonight. A strong ridge will remain over the midwest. This configuration places western CO and eastern UT beneath and area of moderate divergence aloft within a moist southerly flow. The uplift and precipitation production seen Saturday was enhanced by a weak shortwave riding north across the area which will exit to the north this morning. An area of subsidence behind this shortwave will suppress convective development a bit this afternoon, heating should overcome the convective inhibition and enough instability and upper support remain for convective redevelopment, especially over SW CO and SE UT, causing scattered showers and a few thunderstorms this afternoon. On Monday the old cold front wrapping around the low pressure system, far from the low center, will rotate over SE UT and SW CO Monday morning and afternoon, but makes little progress to the east and north and as the upper low wobbles over southern AZ. .LONG TERM...(Monday night through Sunday) Issued at 345 PM MDT Sat May 6 2017 Monday night ought to remain cloudy but relatively dry as most of the precipitation slides east of the area and the AZ storms dry slot rest of the forecast area. On Tuesday the upper low center will still reside over AZ, but the cold front will rotate north and over the forecast area. This will bring the best day for precipitation. Wednesday the low finally begins to fill and slide north and east over CO and NM. By Thursday morning the upper low center should be over SE CO and western Kansas, with plenty of moisture and precipitation wrapping around the low and covering much of western CO. Thursday evening the moisture and precipitation will be pulling out of the area with a ridge and drying conditions spreading over eastern UT. Friday through Saturday, dry ridging should be in place. As the ridge line passes east of the area, southwest flow ahead of the next Pacific system along with drier air will spread over the area. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 1112 AM MDT Sun May 7 2017 Relatively moist southerly flow continues to move through the area. The atmosphere will become unstable this afternoon supporting showers and thunderstorms into the evening hours. Expect gusty winds, hail and frequent lightning will accompany these storms. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...CJC LONG TERM....CJC AVIATION...Larry
Hazardous Weather Outlook National Weather Service GRAND JUNCTION CO 237 AM MDT Sun May 7 2017 COZ001>014-017>023-UTZ022>025-027>029-080845- 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- 237 AM MDT Sun May 7 2017 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Breezy with scattered to numerous showers and a few thunderstorms, decreasing this evening, then increasing again late tonight. .DAYS TWO THROUGH SEVEN...Monday through Saturday Monday through Thursday: Breezy and slightly cooler with a chance of afternoon and evening showers and a few thunderstorms. Friday and Saturday: a slight chance of afternoon showers and thunderstorms mainly near the Continent Divide. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. CJC
Special Weather Statement
National Weather Service Grand Junction CO
119 PM MDT SUN MAY 7 2017
COZ003-007>010-013-072000-
Central Colorado River Basin CO-Roan and Tavaputs Plateaus CO-
Grand and Battlement Mesas CO-Debeque to Silt Corridor CO-
Flattops CO-Gore and Elk Mountains/Central Mountain Valleys CO-
119 PM MDT SUN MAY 7 2017
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN GARFIELD COUNTY
UNTIL 200 PM MDT...
At 118 PM MDT, Doppler radar was tracking a strong thunderstorm over
Silt, or 17 miles west of Glenwood Springs, moving north at 20 mph.
Half inch hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Rifle, New Castle and Silt.
This includes the following highways...
Interstate 70 in Colorado between mile markers 89 and 107 .
Colorado 13 between mile markers 1 and 8 .
LAT...LON 3940 10752 3941 10780 3979 10785 3982 10763
3979 10741
TIME...MOT...LOC 1918Z 181DEG 18KT 3951 10765
CharnickSpecial Weather Statement
National Weather Service Grand Junction CO
123 PM MDT SUN MAY 7 2017
COZ006-017-072015-
Uncompahgre Plateau/Dallas Divide CO-Grand Valley CO-
123 PM MDT SUN MAY 7 2017
...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL MESA COUNTY UNTIL
215 PM MDT...
At 122 PM MDT, Doppler radar was tracking a strong thunderstorm 14
miles south of Grand Junction, moving northwest at 25 mph.
Half inch hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Orchard Mesa and Redlands.
This includes the following highways...
U.S. Highway 50 in Colorado between mile markers 32 and 36 .
Colorado 141 between mile markers 140 and 150 .
LAT...LON 3882 10843 3878 10853 3900 10871 3907 10864
3906 10852
TIME...MOT...LOC 1922Z 156DEG 24KT 3888 10853
CharnickSpecial Weather Statement
National Weather Service Grand Junction CO
154 PM MDT SUN MAY 7 2017
COZ006-017-072045-
Uncompahgre Plateau/Dallas Divide CO-Grand Valley CO-
154 PM MDT SUN MAY 7 2017
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MESA COUNTY UNTIL
245 PM MDT...
At 154 PM MDT, Doppler radar was tracking a strong thunderstorm 11
miles southwest of Grand Junction, moving north at 30 mph.
Dime size hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Grand Junction, Fruita, Redlands, Glade Park and Orchard Mesa.
This includes the following highways...
Interstate 70 in Colorado between mile markers 16 and 30 .
U.S. Highway 50 in Colorado between mile markers 32 and 33 .
LAT...LON 3888 10858 3887 10868 3916 10884 3922 10870
3918 10854
TIME...MOT...LOC 1954Z 170DEG 25KT 3894 10864
CharnickPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
203 PM MDT SUN MAY 7 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0150 PM HAIL 3 SSE REDLANDS 39.04N 108.63W
05/07/2017 E0.25 INCH MESA CO TRAINED SPOTTER
REPORTED AT LEAST PEA SIZE HAIL.
&&
LARRYPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
204 PM MDT SUN MAY 7 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0155 PM HAIL 1 ENE REDLANDS 39.09N 108.63W
05/07/2017 M0.50 INCH MESA CO NWS EMPLOYEE
SPOTTER REPORTED 0.50 INCH HAIL.
&&
LARRYSpecial Weather Statement
National Weather Service Grand Junction CO
205 PM MDT SUN MAY 7 2017
COZ001-072030-
Lower Yampa River Basin CO-
205 PM MDT SUN MAY 7 2017
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN MOFFAT AND
NORTHWESTERN RIO BLANCO COUNTIES UNTIL 230 PM MDT...
At 205 PM MDT, Doppler radar was tracking a strong thunderstorm near
Dinosaur, or 37 miles southeast of Vernal, moving northeast at 25
mph.
Dime size hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Massadona and Blue Mountain.
This includes the following highways...
U.S. Highway 40 in Colorado between mile markers 6 and 26 .
U.S. Highway 84 in Colorado Colorado 64 between mile markers 3 and
13 .
LAT...LON 4009 10895 4016 10904 4042 10882 4036 10866
4023 10858
TIME...MOT...LOC 2005Z 224DEG 21KT 4017 10892
CharnickThe Grand Junction radar (KGJX), 143 km away, was scanning. The volume nearest the first event began at 20:30 UTC.
1 hail. Local standard time, as filed.
A strong thunderstorm that traveled from southwest to northeast dropped hail up to the size of quarters along with pea-sized hail up to 1 inch in depth on U.S. Highway 40 near Blue Mountain.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2017Every state in 2017This day in weather historyWarnings in Colorado, May 2017
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: 691254.