Alert archive / Wyoming / Red Flag Warnings in 2026

Red Flag Warning 41, NWS Cheyenne, WY

September 8, 20266 counties in Wyoming

NWS Cheyenne, WY issued this red flag warning at Sep 8, 2026, 8:06 PM MDT for 6 counties in Wyoming. It took effect at Sep 9, 2026, 11:00 AM MDT. It was in force for 33 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 8, 2026, 8:06 PM MDT (02:06 UTC)
In effect from
Sep 9, 2026, 11:00 AM MDT
Expired
Sep 10, 2026, 8:00 PM MDT
In force
33 hr
Issued by
NWS Cheyenne, WY

Counties Albany County, WY, Carbon County, WY, Converse County, WY, Goshen County, WY, Laramie County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 103 km from the middle of the area, began a volume at 02:10 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 2.1 hours before the alert went out and 308 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Rapid City, SD at 00:00Z on 2026-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 39 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 00:00Z on 2026-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
39 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
2288 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

525 
WWUS85 KCYS 090206
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
806 PM MDT Tue Sep 8 2026


WYZ419>422-425-427-091015-
/O.NEW.KCYS.FW.W.0041.260909T1700Z-260911T0200Z/
North Laramie Range and Adjacent High Plains-
North Laramie Valley/Shirley Basin-
Ferris/Seminoe/Shirley Mountains-Central and West Carbon-
Upper North Platte River Basin-North Snowy Range Foothills-
806 PM MDT Tue Sep 8 2026

...RED FLAG WARNING IN EFFECT FROM 11 AM WEDNESDAY TO 8 PM MDT
THURSDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY...

The National Weather Service in Cheyenne has issued a Red Flag
Warning, which is in effect from 11 AM Wednesday to 8 PM MDT
Thursday. 

* AFFECTED AREA...Fire weather zone 419, 410, 421, 422, 455, and
  427.

* WIND...Westerly 15 to 30 MPH with occasional gusts up to 40 MPH.
  The strongest winds will occur Thursday afternoon. 

* HUMIDITY...10% to 15% Wednesday afternoon and as low as 5%
  Thursday afternoon. Poor humidity recoveries Wednesday night
  with recoveries as low as 20% over Albany and Carbon Counties. 

* IMPACTS...any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$
5 follow-up statements
910 
WWUS85 KCYS 090821
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
221 AM MDT Wed Sep 9 2026

WYZ419>422-425-427-100000-
/O.CON.KCYS.FW.W.0041.260909T1700Z-260911T0200Z/
North Laramie Range and Adjacent High Plains-
North Laramie Valley/Shirley Basin-
Ferris/Seminoe/Shirley Mountains-Central and West Carbon-
Upper North Platte River Basin-North Snowy Range Foothills-
221 AM MDT Wed Sep 9 2026

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
8 PM MDT THURSDAY FOR GUSTY WINDS AND LOW RH FOR FIRE WEATHER 
ZONES 419, 420, 421, 422, 425, AND 427...

* AFFECTED AREA...Fire weather zones 419, 420, 421, 422, 425, and
  427. 

* WIND...Westerly 15 to 30 MPH with occasional gusts up to 40 
  MPH. The strongest winds will occur Thursday afternoon. 

* HUMIDITY...10 to 15% Wednesday afternoon and as low as 5%
  Thursday afternoon. Poor overnight recoveries Wednesday night,
  as low as 20% to 30%.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$
198 
WWUS85 KCYS 091801
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
1201 PM MDT Wed Sep 9 2026

WYZ419>422-425-427-101215-
/O.CON.KCYS.FW.W.0041.000000T0000Z-260911T0200Z/
North Laramie Range and Adjacent High Plains-
North Laramie Valley/Shirley Basin-
Ferris/Seminoe/Shirley Mountains-Central and West Carbon-
Upper North Platte River Basin-North Snowy Range Foothills-
1201 PM MDT Wed Sep 9 2026

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THURSDAY FOR
GUSTY WINDS AND LOW RH FOR FIRE WEATHER ZONES 419, 420, 421, 422,
425, AND 427...

* AFFECTED AREA...Fire weather zones 419, 420, 421, 422, 425, 
  and 427. 

* WIND...Westerly 15 to 30 MPH with occasional gusts up to 40 
  MPH. The strongest winds will occur Thursday afternoon.

* HUMIDITY...10 to 15% Wednesday afternoon and as low as 5%
  Thursday afternoon. Poor overnight recoveries Wednesday and
  Thursday night, as low as 20% to 30%.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$
944 
WWUS85 KCYS 100618
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
1218 AM MDT Thu Sep 10 2026


WYZ423-424-426-428-429-432-110200-
/O.EXA.KCYS.FW.W.0041.000000T0000Z-260911T0200Z/
Southwest Carbon County-Sierra Madre Range/Medicine Bow NF-
Snowy Range/Medicine Bow NF-Southern Laramie Valley-
Southern Laramie Range-Bordeaux/Chugwater/Wheatland-
1218 AM MDT Thu Sep 10 2026

...RED FLAG WARNING IN EFFECT UNTIL 8 PM MDT THIS EVENING FOR
GUSTY WINDS AND LOW RH FOR FIRE WEATHER ZONES 423, 424, 426, 428,
429, AND 432...

The National Weather Service in Cheyenne has issued a Red Flag
Warning, which is in effect until 8 PM MDT this evening. 

* AFFECTED AREA...Fire weather zones 423, 424, 426, 428, 429, and
  432...

* WIND...Westerly winds 15 to 30 MPH with gusts up to 40 MPH.

* HUMIDITY...Between 5 to 13%.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$

WYZ419>422-425-427-110200-
/O.CON.KCYS.FW.W.0041.000000T0000Z-260911T0200Z/
North Laramie Range and Adjacent High Plains-
North Laramie Valley/Shirley Basin-
Ferris/Seminoe/Shirley Mountains-Central and West Carbon-
Upper North Platte River Basin-North Snowy Range Foothills-
1218 AM MDT Thu Sep 10 2026

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR GUSTY WINDS AND LOW RH FOR FIRE WEATHER ZONES 419, 420, 421, 
422, 425, AND 427...

* AFFECTED AREA...Fire weather zones 419, 420, 421, 422, 425, 
  and 427. 

* WIND...Westerly winds 15 to 30 MPH with gusts up to 40 MPH.

* HUMIDITY...Between 5 to 10%.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$
487 
WWUS85 KCYS 101812
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
1212 PM MDT Thu Sep 10 2026

NEZ434>437-WYZ433-111200-
/O.NEW.KCYS.FW.W.0042.260911T1700Z-260912T0100Z/
Pine Ridge/Nebraska National Forest-
Box Butte/South Sioux/Niobrara River-
Lower North Platte River Basin/Scottsbluff National Monument-
Lodgepole Creek/Southern Nebraska Panhandle-Goshen/Middle-
Lower North Platte River Basin-
1212 PM MDT Thu Sep 10 2026

...RED FLAG WARNING IN EFFECT FROM 11 AM TO 7 PM MDT FRIDAY FOR
DRY AND BREEZY CONDITIONS...

The National Weather Service in Cheyenne has issued a Red Flag
Warning, which is in effect from 11 AM to 7 PM MDT Friday. 

* AFFECTED AREA...Fire weather zones 433 through 437. 

* WIND...West to northwest winds with gusts of 25 to 35 MPH.

* HUMIDITY...12 to 15 percent.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$

WYZ419>429-432-110200-
/O.CON.KCYS.FW.W.0041.000000T0000Z-260911T0200Z/
North Laramie Range and Adjacent High Plains-
North Laramie Valley/Shirley Basin-
Ferris/Seminoe/Shirley Mountains-Central and West Carbon-
Southwest Carbon County-Sierra Madre Range/Medicine Bow NF-
Upper North Platte River Basin-Snowy Range/Medicine Bow NF-
North Snowy Range Foothills-Southern Laramie Valley-
Southern Laramie Range-Bordeaux/Chugwater/Wheatland-
1212 PM MDT Thu Sep 10 2026

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR GUSTY WINDS AND LOW RH FOR FIRE WEATHER ZONES 419, 420, 421,
422, 425, AND 427...

* AFFECTED AREA...Fire weather zones 419 through 422, 425, and 
  427.
 
* WIND...Westerly winds with gusts up to 40 MPH.

* HUMIDITY...5 to 10 percent during the afternoon. Poor humidity
  recovery is expected Thursday night.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$
576 
WWUS85 KCYS 110133
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
733 PM MDT Thu Sep 10 2026

WYZ419>429-432-110245-
/O.EXP.KCYS.FW.W.0041.000000T0000Z-260911T0200Z/
North Laramie Range and Adjacent High Plains-
North Laramie Valley/Shirley Basin-
Ferris/Seminoe/Shirley Mountains-Central and West Carbon-
Southwest Carbon County-Sierra Madre Range/Medicine Bow NF-
Upper North Platte River Basin-Snowy Range/Medicine Bow NF-
North Snowy Range Foothills-Southern Laramie Valley-
Southern Laramie Range-Bordeaux/Chugwater/Wheatland-
733 PM MDT Thu Sep 10 2026

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR GUSTY
WINDS AND LOW RH FOR FIRE WEATHER ZONES 419, 420, 421, 422, 423, 
424, 425, 426, 427, 428, 429, AND 432...

Humidity values are slowly recovering across the region with 
winds slowly decreasing. Therefore, the Red Flag Warning will 
expire on time. Elevated fire conditions expected to continue 
overnight with very poor humidity recovery expected.

$$

NEZ434>437-WYZ433-110945-
/O.CON.KCYS.FW.W.0042.260911T1700Z-260912T0100Z/
Pine Ridge/Nebraska National Forest-
Box Butte/South Sioux/Niobrara River-
Lower North Platte River Basin/Scottsbluff National Monument-
Lodgepole Creek/Southern Nebraska Panhandle-Goshen/Middle-
Lower North Platte River Basin-
733 PM MDT Thu Sep 10 2026

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 7 PM MDT
FRIDAY FOR DRY AND BREEZY CONDITIONS FOR FIRE WEATHER ZONES 433, 
434, 435, 436, AND 437...

* AFFECTED AREA...Fire weather zones 433 through 437.

* WIND...West to northwest winds with gusts of 25 to 35 MPH.

* HUMIDITY...12 to 15 percent.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$

What forecasters said that day

The local office's own words before this red flag warning went out, 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 this red flag warning went out at Sep 8, 5:23 PM MDT, 2 hours 43 minutes earlier. Its key messages:

  • Chances for light and brief showers with temporary strong wind gusts possible this evening.
  • A temporary drying trend begins Tuesday and possibly continuing through the end of the week.
Area forecast discussion, Sep 8, 5:23 PM MDT, 2 hours 43 minutes before
Area Forecast Discussion
National Weather Service Cheyenne WY
523 PM MDT Tue Sep 8 2026

.KEY MESSAGES...

- Chances for light and brief showers with temporary strong wind
  gusts possible this evening.

- A temporary drying trend begins Tuesday and possibly
  continuing through the end of the week.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 1213 PM MDT Tue Sep 8 2026

A slightly cooler, but much drier day today as the longwave ridge to
our south begins to elongate, transitioning the flow regime to more
zonal. This will shunt off our main supply of monsoonal moisture
from the southwest, which was responsible for providing us with the
scattered showers and thunderstorms that we saw yesterday afternoon
and evening. These managed to squeeze out anywhere from a quarter to
four tenths of an inch of rainfall, however they were moving fast
enough to limit any flooding threat. We will take what we can get
before we begin the stretch of mostly dry weather through the work
week.

Mid-level water vapor imagery shows another disturbance digging
south and east across Eastern Oregon and Western Idaho, which is
expected to lift north and east, well to the north of our area. As a
result, the bulk of the forcing for ascent is anticipated to remain
over Montana and the Dakotas. A much drier air mass is in place
today behind a weak, stalled front that has essentially washed out
somewhere in the vicinity of NE Colorado, as denoted by a surface
pressure trough based on current mesoanalysis. With the lack of any
synoptic-scale forcing, any convection will be driven by
differential heating of the higher terrain. PWAT is well under an
inch across all of SE Wyoming and Western Nebraska, with surface
dewpoints in the 30s and 40s across the region. Any showers and
thunderstorms that do manage to drift off the higher terrain will
produce far more wind than rain (in other words, the Wyoming Special
aka gusty showers). CAMs and high-resolution ensemble guidance are
hinting at widely isolated high-based showers later this afternoon
and evening mainly along and south of I-80, however confidence isn't
high enough at this time to increase PoPs beyond 20% given such a
dry air mass in a relatively stagnant pattern. Temperatures today
are expected to peak in the low to mid 80s east of the I-25
corridor, with mid to upper 70s further west.

Red flag conditions are also in place today mainly across northern
and western portions of our Wyoming counties as median minimum RH
values are expected to range from 10-15%, with winds gusts peaking
from 20-25 mph out of the west. Dry lightning from showers that
produce little to no rain, but gusty and erratic winds will
exacerbate our fire concerns, hence the Red Flag Warning that is in
effect until 8PM this evening.

Overnight tonight, a secondary front will slide down across the area
bringing another surge of cooler and drier air. We may actually wake
up to some more "fall-like" temperatures tomorrow morning,
especially in the typical cool spots such as Laramie, where HREF
guidance has median low temperatures in the low to mid 40s, and
Cheyenne dipping to around 50 degrees by sunrise. Perhaps the most
notable change overnight into the morning will be the increase in
our winds (it is getting to be that time of year again!), mainly for
our Nebraksa counties, which should begin to wind down by the lunch
hour.

Attention then shifts to more fire weather concerns tomorrow
afternoon over areas along and west of I-25, with westerly winds
increasing to 15-20 knots during the day, and minimum RH values
ranging from 10-15%. Tomorrow will also feature cooler temperatures
behind the front, with temperatures primarily in the 70s tomorrow
afternoon and dry conditions as the zonal flow shunts off any
moisture from the south and west. Can expect another seasonably cool
night tomorrow across the region with light and variable winds and
lack of cloud cover, allowing for efficient radiative cooling.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 1213 PM MDT Tue Sep 8 2026

Heading towards the end of the work week, a warming trend will take
place as flow remains primarily out of the west, resulting in
downsloping. High temperatures on Thursday and Friday are expected
to peak in the mid 80s to around 90 degrees east of the Laramie
Range, with mid 70s to the west. With the gusty, downslope flow and
minimum RH values of 10-20%, fire weather will again be a concern
given the lack of any moisture, especially as much of our area is
currently in severe to extreme drought. A cold front is expected to
move through sometime late Friday into Saturday as lee cyclogenesis
occurs over the Dakotas. This will drop high temperatures by 5-10
degrees heading into the weekend, with the potential for some more
active weather after a dry and breezy week.

On Saturday and Sunday, a vigorous closed low is expected to dig
across the Pacific Northwest, shifting our mid-level flow to more
southwesterly, thus allowing for another influx of monsoonal
moisture. Long range ensemble guidance has PWAT above the 75th
percentile over Southeastern Wyoming and Western Nebraska during
this time, which provides some optimism in terms of beneficial
moisture. With the main bulk of the forcing lifting off to the north
and east over Montana and Dakotas, widespread precipitation isn't
expected at this time. Thus, most shower and thunderstorm coverage
will likely be highest over the higher terrain and activity over
lower elevations will be dependent on if these storms can survive
with rather poor low-level moisture expected (dewpoints in the low
to mid 40s). Temperatures will also be cooler over the weekend with
increased cloud cover thanks to increasing mid and upper-level
moisture and the post-frontal air mass. The flow again becomes more
zonal on Monday, with a lobe of vorticity moving through the area,
continuing the chance for scattered showers and thunderstorms,
though nothing appears to be widespread at this time.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 522 PM MDT Tue Sep 8 2026

Some evening showers are possible over KBFF and KSNY this evening.
These showers are expected to bring gusty winds up to 20 knots. KCYS
and KRWL are expected to have gusty winds, up to 30 knots. Generally
for the other terminals, winds are expected to be under 15 knots.
VFR conditions are expected to prevail for this TAF period.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 8 PM MDT this evening for WYZ417>423-
     427-428.
NE...None.

&&

SHORT TERM...NB
LONG TERM...NB
AVIATION...ML

In the hours before

Special weather statement, Sep 8, 6:39 PM MDT, 1 hour 27 minutes before
Special Weather Statement
National Weather Service Cheyenne WY
639 PM MDT Tue Sep 8 2026

WYZ106>108-090115-
East Platte County WY-
Central Laramie Range and Southwest Platte County WY-
Goshen County WY-
639 PM MDT Tue Sep 8 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN GOSHEN AND
SOUTHEASTERN PLATTE COUNTIES THROUGH 715 PM MDT...

At 638 PM MDT, Doppler radar was tracking a strong thunderstorm over
Chugwater, or 19 miles south of Wheatland, moving northeast at 25
mph.

HAZARD...Wind gusts up to 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Chugwater and Slater.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4170 10490 4178 10498 4197 10472 4180 10450
TIME...MOT...LOC 0038Z 238DEG 23KT 4179 10484

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Brauer

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 8, 6:39 PM MDTSpecial Weather StatementCYSPlatte36 min

Nearby

Red Flag Warnings in Wyoming, 2026Every red flag warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.