333
FXUS65 KCYS 111135
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
535 AM MDT TUE AUG 11 2026
KEY MESSAGES
- RED FLAG WARNING FOR PORTIONS OF SOUTHEAST WYOMING FOR GUSTY
WINDS, LOW RELATIVE HUMIDITIES, AND DRY LIGHTNING FROM 12 PM
THROUGH 9 PM TUESDAY NIGHT.
- SEVERE WEATHER CHANCES SHOULD MOSTLY REMAIN JUST NORTHEAST OF
OUR AREA ON TUESDAY, THOUGH GUSTY SHOWERS OR VIRGA WILL BE
POSSIBLE STILL, WITH A MORE WIDESPREAD SEVERE THREAT EXPECTED
ON WEDNESDAY AS WE UNDERGO A PATTERN CHANGE.
- COOLER ON WEDNESDAY AND ESPECIALLY FOR THURSDAY THROUGH
SATURDAY, WITH INCREASING CHANCES FOR AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS EACH DAY AND A RISING EXCESSIVE
RAINFALL THREAT.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED AT 300 AM MDT TUE AUG 11 2026
FOR THE SHORT TERM, TUESDAY WILL MARK THE LAST DAY WE SHOULD SEE
LARGELY SIMILAR CONDITIONS AS WE'VE EXPERIENCED OVER THE PAST
SEVERAL DAYS, WITH WARMER THAN AVERAGE TEMPERATURES AND ANOTHER
ROUND OF DRY THUNDERSTORMS WITH STRONGER ACTIVITY POSSIBLE
MOVING INTO THE NEBRASKA PANHANDLE. BUT ON WEDNESDAY WE'LL BEGIN
TO UNDERGO A PATTERN CHANGE AS MONSOONAL MOISTURE RETURNS TO THE
REGION, BRINGING HEIGHTENED SHOWER AND THUNDERSTORM CHANCES
ALONG WITH A RE-IGNITED SEVERE WEATHER THREAT.
TODAY, EXPECT ONE FINAL HIT OF SUPER WARM CONDITIONS AS WE
REMAIN AROUND 10-12 DEGREES ABOVE NORMAL WITH WIDESPREAD HIGHS
IN THE UPPER 80'S TO VERY LOW 100'S. A DRY SURFACE WILL BRING A
TWOFOLD OF THREATS TODAY HOWEVER - A CRITICAL FIRE WEATHER
ENVIRONMENT AND DRY, GUSTY THUNDERSTORMS. A RED FLAG WARNING HAS
ONCE AGAIN BEEN ISSUED FOR MOST OF SOUTHEAST WYOMING DUE TO
BREEZY CONDITIONS, RELATIVE HUMIDITY VALUES INTO THE TEENS, AND
THE AFOREMENTIONED DRY THUNDERSTORMS. WHILE PORTIONS OF THE
REGION, MAINLY THE MOUNTAINOUS ZONES, MAY NOT HIT LOW ENOUGH RH
VALUES, THE DRY LIGHTNING THREAT WILL CONTINUE TO PROMOTE A
CRITICAL ENVIRONMENT. ON THE NOTE OF THESE THUNDERSTORMS, A DRY
SURFACE LAYER WILL CONTINUE TO PRODUCE AN INVERTED V SOUNDING
PROFILE, WITH DCAPE VALUES IN THE 1000-1500 J/KG RANGE.
EXPECTING ANOTHER RISK OF GUSTY VIRGA SHOWERS WITH LITTLE TO NO
RAIN AND NEAR SEVERE LEVEL WIND GUSTS. INTO THE NEBRASKA
PANHANDLE THE ENVIRONMENT SHOULD BE SLIGHTLY MORE IMPRESSIVE AS
MUCAPE VALUES DURING THE START OF THE AFTERNOON WILL BE SIMILAR
TO THE EXPECTED DCAPE, BUT WILL BEGIN RETREATING NORTHEASTWARDS
INTO THE LATER AFTERNOON AND EVENING WITH THE STALLED BOUNDARY
THAT WILL ALSO MOVE JUST OUT OF OUR AREA. THAT BEING SAID, SOME
CAMS ARE STILL DEVELOPING A STRONGER STORM OR TWO FOR OUR
NORTHEASTERN ZONES IN THE PANHANDLE, AND WITH HOW THE PAST
SEVERAL DAYS HAVE GONE IT WOULDN'T BE SURPRISING IF WE HAD
ANOTHER SEVERE WARNING OR TWO TONIGHT FOR THIS AREA.
INTO WEDNESDAY THE HIGH THAT HAS BEEN CONTROLLING OUR WEATHER
PATTERN WILL SHIFT EASTWARDS, ALLOWING MONSOONAL FLOW TO RETURN
AND FUELING MOISTURE AND COOLER TEMPERATURES. WHILE WE WON'T SEE
A WILD SWING OF HIGHS, OVERALL TEMPERATURES WILL DROP BY AROUND
5 TO 8 DEGREES, BRINGING AFTERNOON TEMPERATURES INTO THE 80'S TO
LOW 90'S AND CLOSER TO NORMAL. MEANWHILE THE INCREASE OF
MOISTURE WILL MEAN AN INCREASE TO BOTH PRECIPITATION AND
THUNDERSTORM CHANCES. PWAT VALUES WILL BE AROUND 130-160% OF
NORMAL, ROUGHLY AROUND 1-1.5 INCHES. AT THE SURFACE, A BACKDOOR
COLD FRONT WILL DESCEND DOWN AND STALL OUT ACROSS OUR REGION,
WHILE AN UPPER LEVEL SHORTWAVE IS EXPECTED TO RIDE THE PERIPHERY
OF THE RIDGE ACROSS THE AREA WITH THIS COMBINATION FUELING SOME
VEERING WIND PROFILES AND BULK SHEAR IN THE 30-50 KNOT RANGE.
CAM'S INDICATE TWO ROUNDS OF PRECIPITATION OFF OF THIS - AN
INITIAL ROUND AS THE FIRST BATCH OF MOISTURE ARRIVES DURING THE
VERY BEGINNING OF THE AFTERNOON, WITH MORE DEVELOPMENT FORMING
OFF OF THE HIGH TERRAIN TO OUR SOUTHWEST IN COLORADO AND THEN
LIFTING UP DURING THE LATE AFTERNOON AND BEGINNING OF THE
EVENING AS A LARGE COMPLEX OF RAIN AND THUNDERSTORMS. ANY
THUNDERSTORMS WILL BE CAPABLE OF LARGE HAIL AND DAMAGING WIND
GUSTS, AND WITH MULTIPLE ROUNDS OF PRECIPITATION EXPECTED, ANY
TRAINING THUNDERSTORMS COULD BRING A MARGINAL RISK OF FLOODING
(PARTICULARLY FROM DRY AND POSSIBLY HYDROPHOBIC GROUND). THE NBM
HAS A 20-60% PROBABILITY OF GREATER THAN OR EQUAL TO A HALF
INCH OF NEW PRECIPITATION FROM JUST ALONG THE WYOMING BORDER
THROUGH THE NEBRASKA PANHANDLE, AND WHILE NOT AN ABSOLUTE
DRENCHING, WITH HOW LITTLE WE'VE SEEN OVER THE PAST SEVERAL
WEEKS THAT RAINFALL WILL BE BENEFICIAL TO SAY THE LEAST, AS LONG
AS IT DOESN'T FALL TOO QUICKLY.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED AT 211 PM MDT MON AUG 10 2026
THURSDAY EVENING STARTS OFF 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 WEDNESDAY/
ISSUED AT 530 AM MDT TUE AUG 11 2026
VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS, WITH CIGS AT MID
TO HIGH LEVELS OR SKC THROUGH THE PERIOD. WINDS FOR WY TERMINALS
GENERALLY WESTERLY, WITH A NORTHWESTERLY TURN EXPECTED INTO THE
AFTERNOON, AND THEN KRWL/KLAR MAY SEE A SHIFT BACK TO
SOUTHWESTERLY BY THE EVENING HOURS. WINDS FOR NE TERMINALS A BIT
MORE VARIABLE DUE TO NEARBY BOUNDARIES, THOUGH A PUSH FROM THE
WEST TO NORTHWEST DURING THE AFTERNOON IS EXPECTED. ONCE AGAIN
CHANCE OF THUNDERSTORMS NEAR TERMINALS WITH GUSTY WINDS, ERRATIC
WINDS POSSIBLE, AND DRY WITH LITTLE RAIN. STRONGER STORMS MAY BE
POSSIBLE NEAR KCDR, WITH LOW CONFIDENCE IN STORMS REACHING KBFF
OR KAIA, THEREFORE NOT LISTED IN TAF AT THIS TIME.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
WYZ417>430.
NE...NONE.
SHORT TERM...CG
LONG TERM...ML
AVIATION...CG
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