A strong upper level low pressure system moved across Western Colorado bringing heavy snow to the mountains.
Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 strong upper level low pressure system moved across Western Colorado bringing heavy snow to the 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 Apr 30, 10:44 PM MST, 1 hour 16 minutes earlier.
Area Forecast Discussion
National Weather Service Grand Junction CO
1144 PM MDT Tue Apr 30 2019
.SHORT TERM...(Tonight through Wednesday night)
Issued at 307 PM MDT Tue Apr 30 2019
The first midlevel trough is currently crossing the Divide this
afternoon leaving pockets of showers and isolated storms along the
western slopes. A midlevel dry slot in the wake of the trough has
allowed sun to heat things up in portions of the forecast area. With
low-level moisture in place the atmosphere will begin to destabilize
across northeast Utah and northwest Colorado over the next few hours.
The latest guidance is suggesting 250-500 J/kg of MLCAPE, which
seems somewhat bullish since morning and early afternoon
precipitation has limited boundary layer heating and mixing. The
next midlevel trough is tracking southeastward over the Great
Basin causing the deep layer shear to increase across the area.
So if a decent updraft is able to form then the unidirectional
shear profile could favor mechanical mixing of stronger winds to
the surface near these storms and outflows. The sub-cloud evaporation
may not contribute much to the wind potential with the lower
cloud bases than previously thought. The best area for strong
convection is in far northeast Utah and far northwest Colorado
through about 8 pm. Most of the precipitation this afternoon will
be generally terrain and cold pool driven until the front arrives
around 00Z. The coverage of storms should increase along this
front as it slides southeastward through the evening especially
with the additional ascent provided by the trough passing just
north of the area.
The other side of this storm is winter and the tricky snow levels.
Given the convective nature snow levels could drop locally within
heavy precipitation, but overall the levels lower from northwest to
southeast. By sunrise tomorrow morning the Uintas will be around
4500 feet and San Juans around 8500 feet. The sun has been keeping
the roads clear during the day time only to becomes slick overnight.
Elevations above 8500 feet could receive an additional 6-12 inches
through mid day tomorrow. Given these amounts the Winter Weather
Advisory has been extended in the San Juan mountains until noon
tomorrow.
Rainfall amounts in the past 36 hours have ranged from 0.50 to
1.50 inches so small creeks and rivers are beginning to fill up.
Therefore the potential for localized flooding increases tonight
as the cold front moves through the area. Showers could continue
along the Divide late tomorrow morning with the system exiting to
the east. Although lingering moisture could result in convective
terrain-driven showers and storms tomorrow afternoon mainly in the
central and southern mountains of Colorado. The cold air mass in
the wake of the departing trough will pose a risk for freezing
temperatures in some of the higher valleys. A few zones are still
not susceptible to a damaging freeze, but the upper Colorado,
Yampa and Green river valleys are and could have lows in the 20s
and lower 30s tomorrow night. This is where confidence is high
enough for a Freeze Watch although lows in other valleys will need
to be closely monitored for the freeze potential.
.LONG TERM...(Thursday through Tuesday)
Issued at 307 PM MDT Tue Apr 30 2019
Persistent convergence and a few embedded shortwaves in the west-
northwesterly flow aloft will continue to support diurnal terrain-
driven convection in the higher elevations through the weekend. With
that being said the coverage appears minimal, but highest during
the afternoon. Ridging aloft looks to be limited so temperatures
should only run 5-10 degrees above normal before cooling down next
week hopefully keeping the snow melt under control. A closed low
pressure will reach the coast of California by late weekend, but
the model solutions diverge on the evolution into early next week.
Another strong trough could drop southward out western Canada,
which is helping the western trough kick out over the Four
Corners. Where exactly these troughs track is uncertain especially
given the fact that the ECMWF keeps the low cut off from the main
flow off the coast of California.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1144 PM MDT Tue Apr 30 2019
The tail end of a Pacific storm will continue to bring rain and
snow to the region overnight and into Wednesday morning.
Conditions improve Wednesday afternoon. Before then, expect
widespread showers which will result in MVFR conditions for a time
at most TAF sites. In addition, CIGS will be below ILS breakpoints
for the remainder of the night and well into Wednesday morning.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...Freeze Watch from late Wednesday night through Thursday morning
for COZ001-007-008.
Winter Weather Advisory until noon MDT Wednesday for COZ018-019.
Winter Storm Warning until noon MDT Wednesday for COZ004-009-010-
012-013.
UT...Freeze Watch from late Wednesday night through Thursday morning
for UTZ024.
&&
SHORT TERM...KJS
LONG TERM...KJS
AVIATION...NL/MDAHazardous Weather Outlook National Weather Service Grand Junction CO 836 AM MDT Tue Apr 30 2019 COZ001>014-017>023-UTZ022>025-027>029-011445- 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- 836 AM MDT Tue Apr 30 2019 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Showers and thunderstorms, with high mountain snowfall, will continue today. Snow will accumulate mainly above 8500 feet with heaviest accumulation above 10,000 feet. Only the highest mountain passes will be impacted by several inches of snow accumulation with light accumulations and wet roads affecting other lower elevation roadways through the mountains. There is a marginal risk for severe weather this afternoon for portions of eastern Utah and west-central Colorado with strong gusty outflow winds the main concern in addition to heavy rain and small hail. A colder system will move through tonight bringing additional snow to the mountains. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Storms will decrease from west to east Wednesday with drier and warmer conditions Thursday through the weekend. Isolated afternoon showers and thunderstorms are possible over the mountains each afternoon Thursday through Monday. SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
Special Weather Statement National Weather Service Grand Junction CO 716 PM MDT Tue Apr 30 2019 COZ003-007-009-010200- Roan and Tavaputs Plateaus CO-Grand and Battlement Mesas CO- Debeque to Silt Corridor CO- 716 PM MDT Tue Apr 30 2019 ...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL MESA AND SOUTH CENTRAL GARFIELD COUNTIES UNTIL 800 PM MDT... At 716 PM MDT, Doppler radar was tracking a strong thunderstorm over De Beque, or 24 miles northeast of Grand Junction, moving east at 30 mph. Half inch hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Parachute, De Beque and Battlement Mesa. This includes Interstate 70 in Colorado between mile markers 53 and 75, between mile markers 78 and 80, and between mile markers 83 and 86. PRECAUTIONARY/PREPAREDNESS ACTIONS... Heavy rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3922 10827 3938 10834 3952 10785 3929 10775 TIME...MOT...LOC 0116Z 253DEG 27KT 3932 10821 15
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
955 PM MDT TUE APR 30 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0932 PM TSTM WND GST 17 NW MOAB 38.77N 109.75W
04/30/2019 M47 MPH GRAND UT ASOS
ASOS STATION KCNY CANYONLANDS FIELD AIRPORT.
&&
NLSpecial Weather Statement National Weather Service Grand Junction CO 1028 PM MDT Tue Apr 30 2019 COZ003-006-007-009-011-017-010515- Roan and Tavaputs Plateaus CO-Grand and Battlement Mesas CO- Uncompahgre Plateau/Dallas Divide CO-Debeque to Silt Corridor CO- Grand Valley CO-Central Gunnison and Uncompahgre River Basin CO- 1028 PM MDT Tue Apr 30 2019 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL DELTA...NORTHWESTERN MESA AND SOUTH CENTRAL GARFIELD COUNTIES UNTIL 1115 PM MDT... At 1028 PM MDT, Doppler radar was tracking strong thunderstorms along a line extending from 7 miles north of Fruita to 13 miles southwest of Grand Junction. Movement was east at 40 mph. Wind gusts up to 50 mph will be possible with these storms. Locations impacted include... Grand Junction, Fruita, Palisade, Parachute, Collbran, De Beque, Mesa, Battlement Mesa, Cameo, Fruitvale, Molina, Clifton, Whitewater, Glade Park, Redlands, Skyway, Plateau City and Orchard Mesa. This includes the following highways... Interstate 70 in Colorado between mile markers 17 and 75. U.S. Highway 50 in Colorado between mile markers 32 and 47. Colorado 65 between mile markers 23 and 61. Colorado 141 between mile markers 148 and 162. LAT...LON 3948 10795 3891 10797 3891 10880 3933 10878 TIME...MOT...LOC 0428Z 263DEG 36KT 3927 10875 3899 10877 NL
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1054 PM MDT TUE APR 30 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1048 PM TSTM WND GST 3 NW FRUITVALE 39.12N 108.52W
04/30/2019 M47 MPH MESA CO ASOS
ASOS STATION KGJT GRAND JUNCTION RGNL AP.
&&
NLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1059 PM MDT TUE APR 30 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0935 PM TSTM WND GST MOAB CANYONLANDS AIRPOR 38.76N 109.74W
04/30/2019 M52 MPH GRAND UT ASOS
ASOS STATION KCNY CANYONLANDS FIELD.
&&
NLThe national radar mosaic for the moment the first event began.
6 heavy snow, 1 winter weather. Local standard time, as filed.
Snowfall amounts ranged from 15 to 25 inches with up to 37 inches estimated at the Tower SNOTEL. This storm started on April 29, 2019.
Estimated snowfall amounts ranged from 10 to 20 inches with up to 26 inches at the Overland Reservoir SNOTEL site. This storm started on April 29, 2019.
Estimated snowfall ranged from 8 to 14 inches. Significant impacts to travel were reported by the Colorado Department of Transportation over Vail Pass with Interstate 70 shutdown for periods of time to clear accidents. This storm started on April 29, 2019.
An estimated 10 to 20 inches of snow fell with the greatest amounts recorded at the Bison Lake SNOTEL and the Ripple Creek SNOTEL sites. This storm started on April 29, 2019.
Estimated snowfall amounts ranged from 1 to 2 feet with up to 40 inches recorded at the Schofield Pass SNOTEL site. This storm started on April 29, 2019.
Estimated snowfall amounts ranged from 6 to 12 inches. This storm started on April 29, 2019.
Estimated snowfall amounts ranged from 10 to 20 inches with up to 22 inches recorded at the Black Mesa SNOTEL Site. This storm started on April 29, 2019.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2019Every state in 2019This day in weather historyWarnings in Colorado, May 2019
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: 814914, 814917, 814919, 814921, 814923, 814926, 814928.