Precipitation remained below normal for many areas, even with some late season winter storms that moved through the region during the month of April. The most notable monthly deficit occurred in southwestern Colorado where precipitation was almost an inch below normal.
Every event with a place to put it; 11 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.
Precipitation remained below normal for many areas, even with some late season winter storms that moved through the region during the month of April. The most notable monthly deficit occurred in southwestern Colorado where precipitation was almost an inch below normal.
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 31, 10:45 PM MST, 1 hour 15 minutes earlier.
Area Forecast Discussion National Weather Service GRAND JUNCTION CO 1145 PM MDT Sat Mar 31 2018 .SHORT TERM...(Tonight through Sunday night) Issued at 329 PM MDT Sat Mar 31 2018 A disturbance is dropping down into Wyoming and the very northern reaches of Colorado tonight from the northwest. The general flow will shift from northwesterly to westerly tonight and pick up some Pacific moisture. Clouds will increase across the region, especially across northeastern UT and northwest CO, and some short term models indicate a band of snow developing around 3 to 4 am dropping into the Craig eastward to Hayden and Steamboat corridor. Have adjusted precipitation forecast to account for this, but there is a possibility that this band won't set up very far south past the Wyoming/Colorado border. Unseasonably cold air to our north in Wyoming is expected to slosh into northern Colorado bringing a tight gradient with differing snow levels along a north to south gradient. Some snow showers are anticipated to drop into the Vail Pass corridor around daybreak Sunday, which could produce short bursts of snow along I-70. Conditions are expected to clear out around noon or shortly thereafter on Sunday. .LONG TERM...(Monday through Saturday) Issued at 329 PM MDT Sat Mar 31 2018 Dry and windy conditions will start the work week across SE Utah and SW Colorado with moisture increasing across NE Utah and NW Colorado throughout the afternoon Monday. A weak disturbance looks to drop down into western Colorado again during the day on Monday, bringing scattered showers to the higher terrain. This possibility of precipitation will be short-lived as extremely dry air advects into the region from the northwest early Tuesday morning. This dry airmass will persist through midweek when moisture begins to increase from the west again. Unsettled conditions will begin again on Thursday, though widespread precipitation is not possible until at least Friday. A weak atmospheric river (AR) event will move onshore California and entrain into the westerly flow reaching Utah and Colorado next weekend, providing the possibility for an active and wet weekend across much of the forecast area depending on how far south the trough materializes. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1145 PM MDT Sat Mar 31 2018 Mid and high level moisture continues to stream into the central Rockies on very strong westerlies aloft. This will eventually equate to some snow showers over the northern and central divide mountains with a more widespread area of obscured terrain. For the most part weather will be limited at the TAF sites though some ILS conditions along with sprinkles or flurries can not be ruled out at KHDN and less probable KASE. The main concern will again be windy conditions aloft mixing some stronger gusts into the valleys where gusts over 25 mph will be possible...especially near showers. Mountain wave and ridgetop turbulence can also be expected. Northwest winds into KASE may also lead to scheduling issues associated with approaches. && .FIRE WEATHER... Issued at 329 PM MDT Sat Mar 31 2018 It's getting to be that time of year again when relative humidity values plummet and winds increase between air masses. Monday is looking to be a marginal critical day for fire weather across SE Utah and SW Colorado, however fuels at this time have not been deemed critical for extreme fire threat. Winds across these areas may get into the 30-35 mph range with relative humidity below 15 percent for a few hours during the afternoon. Winds subside quite a bit on Tuesday erasing the threat for red flag non-existent thereafter. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...JAM LONG TERM...JAM AVIATION...TGJT FIRE WEATHER...TGJT
Hazardous Weather Outlook National Weather Service GRAND JUNCTION CO 529 AM MDT Sat Mar 31 2018 COZ001>014-017>023-UTZ022>025-027>029-011200- 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- 529 AM MDT Sat Mar 31 2018 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight A few snow showers are possible over the Park Range today though accumulations will remain light. A few gusty winds are expected today across the region but they'll only reach between 20 to 25 MPH. .DAYS TWO THROUGH SEVEN...Sunday through Friday Some light snow is possible over the northern mountains for much of the period though amounts will be very light. The first push of widespread precipitation looks to be Monday afternoon and evening. The next chance after that looks to be next weekend. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
The national radar mosaic for the moment the first event began.
11 drought. Local standard time, as filed.
Extreme (D3) drought conditions worsened to exceptional (D4) drought conditions in mid April. This situation persisted through the end of the month.
Extreme (D3) drought conditions worsened to exceptional (D4) drought conditions in mid April for the majority of the forecast zone. This situation persisted through the end of the month.
Extreme (D3) drought conditions persisted through the end of the month. However, exceptional (D4) drought conditions inched into the far western portion of the zone in mid April where it persisted through the end of the month.
Extreme (D3) drought conditions worsened to exceptional (D4) drought conditions in mid April for much of the forecast zone. This situation persisted through the end of the month.
Extreme (D3) drought conditions persisted through the end of the month.
Extreme (D3) drought conditions persisted through the end of the month. However, exceptional (D4) drought conditions inched into the far southern portion of the zone in mid April and persisted through the end of the month.
Extreme (D3) drought conditions persisted across the southern portion of the zone while severe (D2) drought conditions remained across the northern portion of the zone through the end of the month.
Extreme (D3) drought conditions persisted through the end of the month.
Extreme (D3) drought conditions persisted across the southern portion of the zone while severe (D2) drought conditions remained across the northern portion of the zone through the end of the month.
Extreme (D3) drought conditions persisted across the far western portion of the zone through the end of the month.
Extreme (D3) drought conditions persisted across the far southwestern and far northwestern portions of the zone through the end of the month.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2018Every state in 2018This day in weather historyWarnings in Colorado, April 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: 743194, 743195, 743196, 743197, 743198, 743199, 743200, 743201, 743202, 757879, 757880.