344
FXUS65 KCYS 102353
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
553 PM MDT MON AUG 10 2026
KEY MESSAGES
- MARGINAL RISK OF SEVERE THUNDERSTORMS THROUGH EARLY THIS
EVENING FOR THE WESTERN HALF OF THE NEBRASKA PANHANDLE, WITH A
SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE EASTERN HALF OF
THE NEBRASKA PANHANDLE IN OUR FORECAST AREA.
- RED FLAG WARNING HAS BEEN ISSUED FOR PORTIONS OF SOUTHEAST
WYOMING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITIES STARTING
TUESDAY AT NOON THROUGH 9PM TUESDAY NIGHT.
- COOLER ON WEDNESDAY AND ESPECIALLY FOR THURSDAY THROUGH
SATURDAY, WITH INCREASING CHANCES FOR AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS.
SHORT TERM /THROUGH TUESDAY NIGHT/
ISSUED AT 211 PM MDT MON AUG 10 2026
TONIGHT...CHALLENGES TONIGHT WILL BE POSSIBILITIES OF ISOLATED TO
SCATTERED THUNDERSTORMS THROUGH EARLY EVENING, ALONG WITH THE
POSSIBLE FEW STRONG TO SEVERE THUNDERSTORMS OVER THE NEBRASKA
PANHANDLE THROUGH EARLY EVENING. THE STORM PREDICTION CENTER IN
NORMAN, OKLAHOMA HAS TRIMMED BACK THE MARGINAL RISK OF SEVERE
THUNDERSTORMS TO THE EASTERN HALF OF THE NEBRASKA PANHANDLE, WITH A
SLIGHT RISK OF SEVERE THUNDERSTORMS THAT INCLUDES OUR CHEYENNE
COUNTY OF THE SOUTHERN NEBRASKA PANHANDLE, INCLUDING SIDNEY.
THE 16Z HRRR RUN SHOWS ISOLATED TO WIDELY SCATTERED THUNDERSTORMS
DEVELOPING AROUND 20Z, ROUGHLY TO THE RIGHT OF A LINE FROM LARAMIE
TO TORRINGTON TO SCOTTSBLUFF, WITH ISOLATED STRONG TO SEVERE
THUNDERSTORMS DEVELOPING ACROSS THE SOUTHERN PANHANDLE COUNTIES OF
KIMBALL AND CHEYENNE, INCLUDING SIDNEY THROUGH LATE AFTERNOON. THIS
SEEMS QUITE PLAUSIBLE CONSIDERING THE IMPRESSIVE 850/700 MB THETA-E
RIDGE AXIS DEVELOPING ACROSS THE SOUTHERN NEBRASKA PANHANDLE, ALONG
WITH CAPE VALUES FROM 600 J/KG OVER EASTERN KIMBALL COUNTY UP TO
2800 J/KG OVER EASTERN CHEYENNE COUNTY, COMBINED WITH BULK SHEAR
VALUES NEAR 35 KNOTS. AS PER THE SPC DISCUSSION, THE PRIMARY THREATS
FROM ANY SEVERE STORMS WILL BE WIND GUSTS IN EXCESS OF 60 MPH, WITH
A SMALLER THREAT FOR HAIL. MOST THUNDERSTORMS SHOULD END BY 01Z
ACCORDING TO THE LATEST HRRR RUN. OUTSIDE OF THE SOUTHERN NEBRASKA
PANHANDLE, THUNDERSTORMS WILL BE CAPABLE OF PRODUCING GUSTY WINDS
DUE TO THE STEEP ADIABATIC LAPSE RATES. EXPECTING CLOUDS TO CLEAR
OUT AFTER EARLY EVENING WITH A QUIET NIGHT ON TAP.
SECONDARILY, THE RED FLAG WARNING LOOKS ON TRACK UNTIL MID EVENING
FOR MUCH OF SOUTHEAST WYOMING EXCEPT FOR THE FAR SOUTHEAST.
TUESDAY...RELATIVELY WEAK WESTERLY FLOW ALOFT PREVAILS, WITH A
SHORTWAVE TROUGH ALOFT MOVING ACROSS OUR COUNTIES NEAR PEAK HEATING.
WITH THE NAM INDICATING A DECENT PLUME OF LOW AND MID LEVEL MOISTURE
BY LATE AFTERNOON STRETCHING FROM SOUTHERN ALBANY COUNTY INTO THE
SOUTHERN NEBRASKA PANHANDLE, EXPECTING ISOLATED TO WIDELY SCATTERED
THUNDERSTORMS TO FORM NEAR THE CAP WEAKNESS OVER AND NEAR OUR SNOWY,
SIERRA MADRE AND SOUTHERN LARAMIE RANGES, INCLUDING THE LARAMIE
VALLEY AND WESTERN AND CENTRAL LARAMIE COUNTY INCLUDING CHEYENNE.
USED A BLEND OF THE MET MOS AND AVN MOS FOR MAXIMUM TEMPERATURES
WHICH WILL RANGE FROM THE UPPER 80S TO LOWER 90S WEST OF I-25, WITH
MID 90S TO NEAR 105 EAST OF I-25, WITH THE HOTTEST TEMPERATURES OVER
THE NORTHERN AND CENTRAL NEBRASKA PANHANDLE.
WILL NEED TO KEEP AN EYE ON THE NECESSITY OF ANOTHER RED FLAG
WARNING FOR LATE MORNING INTO THE EARLY EVENING HOURS PRIMARILY
WHERE DECENT WINDS AND LOW RELATIVE HUMIDITIES WILL COINCIDE OVER
MUCH OF THE NORTHERN LARAMIE RANGE AND CONVERSE COUNTY.
TUESDAY NIGHT...WITH THE LOSS OF DAYTIME HEATING, AND LACK OF
SIGNIFICANT LIFTING MECHANISMS, IT LOOKS LIKE ISOLATED TO WIDELY
SCATTERED THUNDERSTORMS/CONVECTION SHOULD DISSIPATE AROUND SUNSET,
WITH A TRANQUIL, QUIESCENT OVERNIGHT EXPECTED THEREAFTER.
LONG TERM /WEDNESDAY THROUGH MONDAY/
ISSUED AT 211 PM MDT MON AUG 10 2026
THURSDAY EVENING STARTS OF THIS LONG TERM PERIOD WITH MONSOONAL
MOISTURE MOVING IN, AND A SHORTWAVE MOVING THROUGH THE AREA. WITH
PRECIPITABLE WATER VALUES IN THE 1-1.5 RANGE, RH VALUES 60-90%, AND
THE SHORTWAVE, ITS SAFE TO SAY OUR AREA WILL BE GETTING SOME MUCH
NEEDED MOISTURE. THIS MOISTURE STICKS AROUND THROUGH MONDAY,
BRINGING DAILY AFTERNOON CHANCES OF PRECIPITATION. THIS
PRECIPITATION LOOKS TO MAINLY BE SHOWERS, BUT AN ISOLATED
THUNDERSTORM CANNOT BE RULED OUT ESPECIALLY NEAR THE NE PANHANDLE
WITH CAPE VALUES NEAR 1000J/KG. WINDS DO NOT APPEAR TO BE OUT OF THE
ORDINARY, STAYING BELOW 15 KNOTS MOST OF THE TIME. TEMPERATURES COOL
OFF AS A COLD FRONT MOVES OVER THE AREA THURSDAY. 700MB TEMPERATURES
STAY NEAR 12C DURING THE DAYTIME THURSDAY-SUNDAY, WITH NIGHTTIME
TEMPERATURES GETTING NEAR 10C. THIS MEANS TEMPERATURES WILL COOL OFF
NEARLY 20F FROM WHAT WE HAVE BEEN EXPERIENCING. TYPICALLY OUR AREA
HAS DAYTIME TEMPERATURES NEAR 83F THIS TIME OF YEAR. THIS IS A
WELCOMED BREAK FROM OUR HOT TEMPERATURES THE LAST FEW WEEKS. WITH
ALL OF THIS MONSOONAL MOISTURE COMING IN, FIRE WEATHER IS NOT A
CONCERN THROUGH THIS LONG TERM PERIOD.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 525 AM MDT MON AUG 10 2026
THIS TAF PERIOD BRINGS CHANCES OF SHOWERS/THUNDERSTORMS TO ALL
TERMINALS THIS AFTERNOON. THESE SHOWERS/STORMS WILL BRING VARIABLE,
GUSTY WINDS BETWEEN 35-40 KNOTS. THE WY TERMINALS WILL MOSTLY SEE
WESTERLY TO NORTHWESTERLY WINDS, AND THE NE TERMINALS WILL SEE
MAINLY VARIABLE WINDS EARLY IN THE AFTERNOON, WITH GUSTS OUT OF THE
WEST IN AFTERNOON STORMS. WY TERMINALS CAN EXPECT TO SEE GUSTY
SHOWERS WITH LITTLE RAIN AND THE SNY AND AIA TERMINALS HAVE
CHANCES FOR STRONGER THUNDERSTORMS. ONCE THE SHOWERS/STORMS MOVE
OUT OF THE AREA, WINDS ARE EXPECTED TO RETURN TO AROUND 10
KNOTS ACROSS MOST TERMINALS, AND CLOUDS WILL MAINLY BE SCATTERED
TO BROKEN. VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD
HOWEVER, VISIBILITY MAY DROP BELOW 3SM UNDER THE STRONGEST
STORMS BUT MOST OF THE TIME SHOULD STAY AROUND 5 TO 6SM.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 553 PM MDT MON AUG 10 2026
ISOLATED TO SCATTERED SHOWERS AND WEAK THUNDERSTORMS ARE TO BE
FOR ALL TERMINALS THROUGH 06Z. BESIDES THE THUNDERSTORM THAT
JUST WENT THROUGH KSNY, THERE IS ANOTHER HEADING TOWARDS KLAR
WITHIN THE NEXT HOUR. AFTER 02Z THE CONFIDENCE IN PRECIPITATION
MAKING IT TO THE GROUND DWINDLES BUT MICROBURST LIKE GUSTY
SHOWERS WITH ERRATIC GUSTS BETWEEN 50 AND 60 MPH WILL POSSIBLE
THROUGH 06Z. SOME LOWER CLOUDS MAY BE POSSIBLE IN THE MORNING
AROUND THE SOUTHERN PANHANDLE BUT SHOULD STAY VFR. ANOTHER ROUND
OF HIGH BASED SHOWERS STARTS AROUND 21Z FOR THE WYOMING
TERMINALS AND AROUND 23/00Z FOR THE NEBRASKA TERMINALS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR WYZ417>427.
RED FLAG WARNING FROM NOON TO 9 PM MDT TUESDAY FOR WYZ417>430.
NE...NONE.
SHORT TERM...RUBIN
LONG TERM...ML
AVIATION...MM
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