059
FXUS65 KCYS 231136
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
536 AM MDT THU JUL 23 2026
KEY MESSAGES
- SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THURSDAY EVENING. LOCALIZED FLASH FLOODING REMAINS
POSSIBLE.
- WARMER AIR WILL RETURN TO THE AREA FRIDAY INTO EARLY NEXT
WEEK. NEAR RECORD HIGH TEMPERATURES ARE POSSIBLE SATURDAY
THROUGH MONDAY.
- DRY WEATHER IS EXPECTED FRIDAY WITH A FEW ISOLATED STORMS
SATURDAY AND SUNDAY. MONSOON MOISTURE WILL RETURN MONDAY AND
INCREASE THUNDERSTORM CHANCES THEREAFTER.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 300 AM MDT THU JUL 23 2026
ABUNDANT MOISTURE CONTINUES TO STREAM THROUGH THE AREA THIS MORNING
THANKS TO AN UPPER LEVEL SHORTWAVE INTERACTING WITH MONSOON
MOISTURE. HEAVY RAINFALL HAS BEEN FAIRLY ISOLATED SO FAR, BUT
SHOWERS WITH ISOLATED EMBEDDED THUNDER ARE PRODUCING LOCALLY
MODERATE HEAVY RAINFALL EARLY THIS MORNING, WHICH WILL CONTINUE FOR
SEVERAL MORE HOURS. WE SHOULD SEE COVERAGE DECREASE A LITTLE BIT
AROUND SUNRISE, BUT SOME SHOWER ACTIVITY IS EXPECTED TO CONTINUE
ACROSS THE AREA FOR MOST OF THE NEXT 24 HOURS. WITH THE SHORTWAVE
TROUGH AXIS MOVING THROUGH TODAY, WE WILL ENJOY THE COOLEST DAY OF
THE WEEK TODAY WITH HIGHS GENERALLY IN THE MID 70S TO MID 80S UNDER
PARTLY SUNNY SKIES. COVERAGE OF SHOWERS AND THUNDERSTORMS WILL KICK
UP QUICKLY AFTER NOON ONCE AGAIN TODAY WITH SCATTERED TO NUMEROUS
STORMS EXPECTED THROUGH THE EVENING HOURS. WE ARE NOT EXPECTING
WIDESPREAD RAINFALL ACROSS THE ENTIRE AREA, BUT LOCALLY HEAVY
THUNDERSTORM RAINFALL REMAINS POSSIBLE. PRECIPITABLE WATER WILL
REMAIN FAIRLY STEADY THROUGH THE DAY TODAY, AROUND 1" IN THE
MOUNTAINS OF SOUTHERN WYOMING, INCREASING TO NEAR 1.75" IN
PORTIONS OF THE NEBRASKA PANHANDLE. THIS REMAINS EASILY OVER THE
99TH PERCENTILE OF CLIMATOLOGY FOR MOST OF THE AREA, AND
POTENTIALLY PUSHING CLIMATOLOGICAL MAXIMUMS. AS IS TYPICAL IN
THESE MONSOON PATTERNS, INSTABILITY LOOKS SOMEWHAT LIMITED DUE
TO UNIMPRESSIVE LAPSE RATES. THE ORGANIZED SEVERE WEATHER THREAT
LOOKS LIMITED TODAY, BUT GUSTY OUTFLOW WINDS EXCEEDING 60 MPH
CAN HARDLY EVER BE RULED OUT WHEN THUNDERSTORMS ARE IN THE
FORECAST IN OUR AREA. THE PRIMARY CONCERN REMAINS FREQUENT
LIGHTNING AND LOCALLY HEAVY RAINFALL / FLASH FLOODING. WHILE
CONFIDENCE IN WIDESPREAD FLASH FLOODING IS PRETTY LOW AT THIS
TIME, LOCALIZED FLASH FLOODING CERTAINLY REMAINS POSSIBLE. IT IS
DIFFICULT TO PINPOINT AN AREA OF MAXIMUM CONCERN TODAY, AND IT
WILL DEPEND ON WHERE THUNDERSTORMS MANAGE TO DEVELOP. THEREFORE,
THE FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL MIDNIGHT TONIGHT,
BUT IT IS WORTH EMPHASIZING AGAIN THAT THIS IS FOR LOCALIZED
HEAVY THUNDERSTORM RAINFALL, NOT WIDESPREAD STEADY EXCESSIVE
RAINFALL. DRIER AIR ABOVE 500-MB WILL MOVE IN FROM THE WEST THIS
EVENING AS THE MONSOON SURGE COMES TO ITS CONCLUSION. EXPECT
SHOWER AND THUNDERSTORM ACTIVITY TO WIND DOWN QUICKLY AFTER
MIDNIGHT.
THE RIDGE ALOFT WILL AMPLIFY ACROSS THE ROCKIES ON FRIDAY INTO THE
WEEKEND, LEADING TO ANOTHER ROUND OF HEAT. TEMPERATURES WILL CLIMB
CONSIDERABLY ON FRIDAY, REACHING THE MID TO UPPER 80S AROUND LARAMIE
AND RAWLINS, AND UPPER 80S TO 90S EAST OF I-25. TEMPERATURES ALOFT
WILL SURGE MUCH FASTER THAN IN THE BOUNDARY LAYER. 500-MB
TEMPERATURES ARE EXPECTED TO BE NEAR OR EVEN EXCEEDING
CLIMATOLOGICAL MAXIMUMS OVER MUCH OF THE AREA FRIDAY AFTERNOON
DESPITE 700-MB TEMPERATURES "ONLY" AROUND THE 90TH PERCENTILE. THIS
WILL RESULT IN A ROBUST CAPPING INVERSION AROUND 550-MB PER FORECAST
SOUNDINGS, WHICH WILL PUT A STRONG CAP ON THUNDERSTORM ACTIVITY.
OVERALL, EXPECT LITTLE TO NO AFTERNOON SHOWERS AND THUNDERSTORMS
FRIDAY.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 300 AM MDT THU JUL 23 2026
ANOTHER ROUND OF HEAT WILL BE THE MAIN STORY THIS WEEKEND INTO EARLY
NEXT WEEK. 700-MB TEMPERATURES ARE EXPECTED TO CLIMB TO AROUND +17C
TO +20C ACROSS THE AREA BY SATURDAY AFTERNOON AND REMAIN THERE
THROUGH MONDAY. THIS VALUES ARE AROUND THE CLIMATOLOGICAL 99TH
PERCENTILE (AND THIS IS THE HOTTEST TIME OF THE YEAR TOO). LARAMIE
AND RAWLINS CAN EXPECTED HIGHS NEAR 90 DEGREES EACH OF THESE DAYS
SATURDAY THROUGH MONDAY, WHILE THOSE TO THE EAST OF I-25 WILL BE IN
THE MID 90S TO MID 100S. SUNDAY LOOKS LIKE THE HOTTEST DAY OF THE
PERIOD, WITH DAILY RECORD HIGHS EXPLICITLY FORECAST AT ALLIANCE,
CHADRON, AND SIDNEY. TIED RECORDS ARE IN THE FORECAST FOR CHEYENNE
AND LARAMIE. WHILE WIDESPREAD THUNDERSTORM ACTIVITY IS NOT EXPECTED
OVER THE WEEKEND, WE WILL LOSE THE UPPER LEVEL INVERSION AS THE
BOUNDARY LAYER WARMS AND 500-MB TEMPERATURES DROP EVER SO SLIGHTLY.
WE SHOULD REACH CONVECTIVE TEMPERATURES AND PRODUCE A FEW
ISOLATED HIGH-BASED SHOWERS AND THUNDERSTORMS BOTH SATURDAY AND
SUNDAY AFTERNOONS. GUSTY WINDS WILL BE THE PRIMARY CONCERN WITH
DEEP INVERTED-V BOUNDARY LAYERS.
ANOTHER SURGE IN MONSOON MOISTURE IS EXPECTED TO BEGIN MONDAY AS THE
POWERFUL UPPER LEVEL RIDGE SHIFTS SLIGHTLY TO THE EAST. NAEFS MEAN
PRECIPITABLE WATER VALUES EXCEED THE CLIMATOLOGICAL 90TH PERCENTILE
AGAIN BY MONDAY AND REMAIN THERE THROUGH AT LEAST WEDNESDAY.
THEREFORE, EXPECT SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS TO INCREASE IN COVERAGE THESE DAYS. MONDAY WILL BRING
NEAR RECORD HEAT ONCE AGAIN, BUT EXPECT TEMPERATURES TO MODERATE A
LITTLE CLOSER TO SEASONAL AVERAGES AFTER THAT AS MOISTURE
IMPROVES.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 533 AM MDT THU JUL 23 2026
OVERNIGHT SHOWERS ARE BEGINNING TO CLEAR OUT OF THE AREA, BUT
EXPECT SOME IN THE VICINITY OF SNY, AIA, AND CDR FOR THE NEXT
FEW HOURS. IN ADDITION, FOG AND LOW CIGS MAY IMPACT FLIGHT
CONDITIONS AT THESE TERMINALS FOR THE NEXT FEW HOURS, THOUGH
CONFIDENCE IS QUITE LOW IN TIMING AND EXTENT OF THIS REGION OF
LOW CLOUDS.
EXPECT LIMITED SHOWER COVERAGE THROUGH THE MORNING HOURS, WHICH
WILL INCREASE AGAIN AFTERNOON. THUNDER WILL ALSO BE MORE LIKELY
THIS AFTERNOON THROUGH THE EVENING. CONFIDENCE IS LOW IN THE
EXACT TIMING AND LOCATION OF PM THUNDERSTORMS, SO THE LATEST TAF
UPDATE RETAINS THE PROB30 GROUPS AT MOST TERMINALS. TODAY'S
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING FREQUENT LIGHTNING,
TORRENTIAL RAINFALL, AND GUSTY WINDS. ISOLATED SMALL HAIL IS
ALSO POSSIBLE. EXPECT SHOWERS AND STORMS TO COME TO AN END
BETWEEN 03Z AND 06Z WITH SKIES TRENDING CLEAR INTO FRIDAY
MORNING.
CYS WATCHES/WARNINGS/ADVISORIES
WY...FLOOD WATCH THROUGH THIS EVENING FOR WYZ101>119.
NE...FLOOD WATCH THROUGH THIS EVENING FOR NEZ002-003-019>021-054-
055-095-096.
SHORT TERM...MN
LONG TERM...MN
AVIATION...MN
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