Strong winds were reported across southwest Carbon County on 5 April.
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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 CYS wrote it up.
Strong winds were reported across southwest Carbon County on 5 April.
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 Cheyenne, WY wrote its last area forecast discussion before the first event at Apr 5, 10:42 AM MST, 2 hours 1 minute earlier. Its key messages:
Area Forecast Discussion
National Weather Service Cheyenne WY
1142 AM MDT Fri Apr 5 2024
.KEY MESSAGES...
1) Elevated to marginally critical fire weather conditions
Friday afternoon with warm temperatures, dry conditions, and
gusty winds, especially for Laramie and Kimball Counties.
2) Thunderstorms are possible Saturday afternoon in portions of
the Nebraska panhandle. Severe weather is not expected at this
time.
3) Strong winds are increasingly likely for the wind prone
areas, and much of the I-80 corridor from Cheyenne to Kimball
Saturday night. Wind gusts up to 75 MPH are possible.
4) Confidence is increasing in a significant winter storm
impacting portions of the area Saturday through early Monday.
The Pine Ridge (US-20 corridor) and northern Laramie Range have
the highest probability of significant impacts.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 354 AM MDT Fri Apr 5 2024
Friday will be the final day of upper level ridging as a strong
low pressure system approaches western Wyoming. The tightening
pressure gradient between the developing low over the western
CONUS and the ridge over the central plains will increase the
potential for stronger winds today. The dry conditions due to
the ridge paired with the strong winds will result in critical
fire weather conditions across far east Wyoming and the southern
Nebraska panhandle.
Friday night into Saturday, as the cold front is pushing east
and cyclogenesis is beginning to occur along the Front Range,
strong south to southeast winds are possible, mainly across the
High Plains. The best combination of strong winds aloft and
enough subsidence to mix it down to the surface is portions of
the Nebraska panhandle north of the Platte River Valley where
there are High Wind Watches currently issued. Along the Pine
Ridge, the HREF has 80 to 100% probability of wind gusts greater
than 55 mph with 50 to 70% probabilities in surrounding
valleys. These strong wind gusts will likely hit in a very short
time period, mainly between 9 PM Friday and 3 AM Saturday. As
the low continues to develop on the lee side of the mountains
Saturday morning, the probability of high winds spreads across
more of southeast Wyoming, starting in wind prone areas,
ridgetops, and higher elevations before spilling over into
the Cheyenne Ridge and eastward. The probability for wind gusts
greater than 70 mph increases through the afternoon Saturday
into Saturday evening, especially along and just east of the
southern Laramie Range and near Arlington.
In terms of precipitation, while a brief shower or rumble of
thunder cannot be ruled out Friday afternoon, the better
moisture, instability, and dynamics enter southeast Wyoming and
western Nebraska following the cold front Friday night into
Saturday. Once the lee troughing develops further along the
Front Range Saturday late morning into afternoon, the chances
for precipitation drastically increase, especially across the
High Plains where the better moisture and dynamics are located.
For more details on the developing system, refer to the long
term forecast discussion.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 354 AM MDT Fri Apr 5 2024
Models continue to trend towards better agreement regarding the
second part of the storm system, forecast to develop and
quickly occlude as it moves northeast across northeast Colorado
and into central Nebraska Saturday night. 00z models and
ensemble spreads are in much better agreement, especially with
the 00z GFS trending closer towards the ECMWF. The 00z and 06z
NAM continues to trend drier for the I-80 corridor, but more
windy through Sunday afternoon. Ensemble members are also
showing locations near the Colorado border (Laramie, Cheyenne,
Sidney, etc) struggling to see any persistent snowfall with this
event due to westerly downslope winds. With this in mind,
trended the forecast towards higher snowfall amounts well north
of I-80, with drier weather but very windy across the I-80
corridor from Rawlins and Laramie to Cheyenne and further east
into the southern Nebraska Panhandle. Models have also trended
slightly colder with somewhat lower snowlevels across the area,
probably due to some additional dynamic cooling and/or the more
progressive solution as the surface and 700mb low move eastward
a little faster compared to model solutions 24 to 48 hours ago.
For the bulk of the event: Saturday night and Sunday...all models
show rapid, but brief, intensification of the surface and 700mb
low across far northeast Colorado and into central Nebraska.
Dynamic forcing will peak between late Saturday afternoon until
mid Sunday morning with high Omega values, strong low level
convergence, and frontogenesis across east central Wyoming and
most of the western Nebraska Panhandle. Tweaked snowfall and QPF
to align with the areas of best forcing in addition to best
orographic lift around and along the Pine Ridge. Expect the
highest precip amounts and snowfall to be between the I-25
corridor and Sioux County across northwest Nebraska if current
model solutions stay the same, with a well defined TROWAL
signature and a clear 700mb convergence axis aligned from
northwest to southeast. Thankfully, this period of rapid
cyclogenesis should be short-lived as the upper level jet max
weakens and the main jet stream translates to the southeast too
quickly...limiting upper level diffluence to only a short
duration. Therefore, by early to mid Sunday morning, expect the
occluded storm system to start weakening. Snow levels are
starting to become a little more clear, with snowlevels lowering
to 3600 to 4100 feet Saturday night. This will lead to some
snow for Torrington, Scottsbluff and Kimball. Chadron and
Alliance may escape the bulk of the accumulating snowfall, but
will need to keep a close eye on how much colder air wraps
around the strong storm system. Most models show a warm nose
advecting westward through Saturday evening, which may greatly
limit accumulating snow below 4000 feet for most of the event.
Expect the higher ridges to do quite well with forecast snow
accumulations between 8 to 14 inches around Lusk, Harrison
Nebraska, and just north of Douglas. The Winter Storm Watches
look good in these areas. Again, models have trended slightly
cooler for the lower elevations, so nudged snow totals up a bit
around Torrington and Scottsbluff. Snow forecasts in this
general area will be tricky because as the rain or rain/snow mix
finally changes over to all snow, the storm system will in the
weakening phase early Sunday morning.
Further south, closer to the I-80 corridor, the primary focus
will be very strong winds on the backside of the storm. Models
continue to show strong downslope winds around Arlington
eastward to Cheyenne and even Kimball and Sidney. Ensemble
spreads continue to show gusts as high as 70 to 75 MPH in these
areas. Kept winds as is but included Cheyenne County (Sidney) to
the High Wind Watch. Will have to watch where the wrap around
snow is located since it will not take much falling snow to
produce very low visibilities in this environment.
For next week, models show the cool and unsettled weather
lingering into early Tuesday with persistent northerly flow
aloft and periods of rain/snow showers on the backside of the
upper level low. Models have trended a little more progressive
with the remnant storm, and now position it over the Great Lakes
Region later on Tuesday. A gradual, but slow, warming up is
expected by the middle of next week with temperatures trending
close to average for this time of the year by Wednesday and
Thursday.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1140 AM MDT Fri Apr 5 2024
A broad mountain wave cloud should generally thin and dissipate
this afternoon. Expect VFR conditions for all terminals today.
However, afternoon wind gusts will be quite strong, especially
at RWL, LAR and CYS. Overnight, strong surface winds will
overspread western Nebraska terminals as well. Winds could gust
in the 40 to 50 knot range at times.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 7 PM MDT this evening for WYZ430-431.
High Wind Watch from Saturday afternoon through Sunday
afternoon for WYZ118-119.
Winter Storm Watch from Saturday afternoon through late Sunday
night for WYZ101-102.
Winter Storm Watch from Saturday morning through late Sunday
night for WYZ103.
High Wind Watch from Saturday morning through Sunday afternoon
for WYZ106-110-116-117.
High Wind Warning until 8 PM MDT this evening for WYZ111.
NE...High Wind Watch from 8 PM MDT this evening through Saturday
morning for NEZ002-003-095.
Red Flag Warning until 7 PM MDT this evening for NEZ437.
High Wind Watch from Saturday afternoon through Sunday
afternoon for NEZ054.
High Wind Watch from Saturday afternoon through Sunday
afternoon for NEZ055.
Winter Storm Watch from Saturday afternoon through late Sunday
night for NEZ095.
&&
SHORT TERM...LEG
LONG TERM...TJT
AVIATION...MACHazardous Weather Outlook National Weather Service Cheyenne WY 437 AM MDT Fri Apr 5 2024 NEZ002-003-019>021-054-055-095-096-WYZ101>119-061045- Dawes County-Box Butte County-Scotts Bluff County-Banner County- Morrill County-Kimball County-Cheyenne County- Northern Sioux County-Southern Sioux County- Converse County Lower Elevations-Niobrara County- North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-Central Laramie Range and Southwest Platte County- East Platte County-Goshen County-Central Carbon County- North Snowy Range Foothills-Southwest Carbon County- Sierra Madre Range-Upper North Platte River Basin-Snowy Range- Laramie Valley-South Laramie Range-South Laramie Range Foothills- Central Laramie County-East Laramie County- 437 AM MDT Fri Apr 5 2024 This hazardous weather outlook is for portions of panhandle Nebraska...east central Wyoming...south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Elevated to marginally critical fire weather conditions Friday afternoon with warm temperatures, dry conditions, and gusty winds, especially for Laramie and Kimball Counties. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY Thunderstorms are possible Saturday afternoon in portions of the Nebraska panhandle. Severe weather is not expected at this time. Strong winds are increasingly likely for the wind prone areas, and much of the Interstate 80 corridor from Cheyenne to Kimball Saturday night. Wind gusts up to 75 MPH are possible. Confidence is increasing in a significant winter storm impacting portions of the area Saturday through early Monday. The Pine Ridge (US 20 corridor) and northern Laramie Range have the highest probability of significant impacts. .Spotter information statement... Spotter activation will not be needed. Please report any wind damage and snowfall amounts to the National Weather Service in Cheyenne.
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Cow Creek RAWS, 19 miles north of Dixon reported this peak wind gust.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2024Every state in 2024This day in weather historyWarnings in Wyoming, April 2024
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: 1161631.