445
FXUS65 KCYS 161911
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
111 PM MDT TUE JUN 16 2026
KEY MESSAGES
- A RED FLAG WARNING IS IN EFFECT FOR ALL AREAS ALONG AND EAST
OF INTERSTATE 25 FROM NOON TUESDAY THROUGH 10 PM WEDNESDAY.
- THE HIGH WIND WATCH FOR THE TYPICAL WIND PRONE REGIONS OF
SOUTHEAST WYOMING HAS BEEN UPGRADED TO A HIGH WIND WARNING
FROM 6 PM TUESDAY THROUGH 3 PM WEDNESDAY.
- FIRE WEATHER CONCERNS CONTINUE THROUGH THE END OF THE WORK
WEEK WITH DRY CONDITIONS AND MINIMAL CHANCES OF PRECIPITATION.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED AT 108 PM MDT TUE JUN 16 2026
A HOT AND BREEZY DAY CONTINUES ACROSS THE AREA THIS AFTERNOON.
CURRENT OBSERVATIONS SHOW TEMPERATURES IN THE 80S AND 90S ACROSS A
MAJORITY OF THE FORECAST AREA WITH GUSTS OF 25 TO 45 MPH. WINDS WILL
EASE BRIEFLY THIS EVENING EAST OF THE LARAMIE RANGE, BUT WILL PICK
UP WEST OF THE LARAMIE RANGE. AN INCOMING COLD FRONT WILL CAUSE MSLP
GRADIENTS TO TIGHTEN, AS WELL AS 850 AND 700 MB CAG TO CPR HEIGHT
GRADIENTS. THIS STEEPENING OF GRADIENTS WILL CAUSE WINDS ALOFT TO
INCREASE TO ABOUT 60 KTS OVER THE TYPICAL SOUTHEAST WYOMING WIND
PRONE AREAS. STRONG SUBSIDENCE WILL LIKELY HELP FACILITATE GETTING
THESE WINDS DOWN TO THE SURFACE. HIGH WIND WARNINGS ARE IN EFFECT
FOR THE WIND PRONES STARTING THIS EVENING AND CONTINUING
THROUGH PART OF THE DAY WEDNESDAY. THE STRONGEST WINDS ARE
EXPECTED EARLY WEDNESDAY MORNING WITH GUSTS OF 60 TO 70 MPH
POSSIBLE. IN-HOUSE GUIDANCE IS ALSO FAIRLY CONFIDENT IN HIGH
WINDS OCCURRING, SUGGESTING A 50 TO 60 PERCENT CHANCE. WINDS
WILL BEGIN TO GRADUALLY PICK UP EAST OF THE LARAMIE RANGE
SOMETIME AFTER MIDNIGHT WITH THE PASSAGE OF A COLD FRONT. AHEAD
OF THIS COLD FRONT, HI-RES GUIDANCE SHOWS THE POTENTIAL FOR SOME
SCATTERED SHOWERS AND STORMS AROUND MIDNIGHT. MODEL SOUNDINGS
FROM THE GFS SHOW VERY WEAK INSTABILITY AROUND THIS TIME, BUT IT
COULD BE ENOUGH TO PRODUCE A FEW LIGHTNING STRIKES IF SHOWERS
CAN MAKE IT INTO THE EXTREME NORTHERN NEBRASKA PANHANDLE. GIVEN
FAIRLY POOR OVERNIGHT HUMIDITY RECOVERIES IN THAT AREA, OPTED
TO ADD SLIGHT CHANCE POPS AS WELL AS DRY LIGHTNING SINCE THE RED
FLAG WARNING IN EFFECT CONTINUES THROUGH WEDNESDAY EVENING.
AS EXPECTED, TEMPERATURES ON WEDNESDAY WILL BE COOLER BEHIND THE
FRONT, WITH THE NORTHERN ZONES OF THE CWA SEEING THE BIGGEST CHANGE
IN HIGH TEMPERATURES. AREAS NORTH OF THE NORTH PLATTE RIVER VALLEY
WILL SEE HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN
TUESDAY. MOST OTHER AREAS WILL SEE ABOUT A 5 TO 10 DEGREE REDUCTION
IN HIGH TEMPERATURES WEDNESDAY. FOR THE MOST PART, THIS WILL
PUT A MAJORITY OF CITIES AT NEAR AVERAGE HIGH TEMPERATURES.
CRITICAL FIRE WEATHER CONDITONS CONTINUE FOR ONE MORE DAY,
MAINLY DUE TO THE STRONG/HIGH WINDS. DOWNSLOPING WINDS WILL
CONTRIBUTE TO KEEPING THE SURFACE DRY WITH RELATIVE HUMIDITY AT
20 PERCENT AND LOWER. WINDS OUTSIDE OF THE WIND PRONES,
ESPECIALLY IN THE NORTHERN ZONES AND THE NEBRASKA PANHANDLE WILL
ALSO BE EXCEPTIONALLY STRONG. A LOW-LEVEL JET WILL PARK ITSELF
OVER THE NORTHEAST CORNER OF THE CWA ON WEDNESDAY, LEADING TO
WIND GUSTS OF 40 TO 50 MPH. WINDS WILL EVENTUALLY EASE ACROSS
THE CWA AROUND SUNSET, LEADING TO A QUIET OVERNIGHT.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED AT 108 PM MDT TUE JUN 16 2026
WE START THURSDAY OFF A LITTLE CHILLIER THAN THE LAST FEW DAYS DUE
TO THE COLD FRONT PASSAGE ON WEDNESDAY. LOWS IN THE 40S TO LOW 50S
ARE EXPECTED AREA WIDE IN THE MORNING BEFORE RISING TO THE 70S WITH
A FEW 80S IN VALLEY AREAS. OVERHEAD WE HAVE AN IMPRESSIVELY LONG JET
STREAK EXTENDING FROM COAST TO COAST ON THE SOUTHERN AMBIT OF A
TROUGH IN CANADA. THIS WILL GIVE WAY TO A RIDGING PATTERN FRIDAY.
MUCH LIKE THURSDAY, FRIDAY IS EXPECTED TO BE MILD AND SUNNY WITH
AFTERNOON TEMPERATURES 10 DEGREES WARMER AT MOST SPOTS. GIVEN THE
LOW HUMIDITY VALUES IN THE EARLY PART OF THE LONG TERM WE DO HAVE
LINGERING ELEVATED FIRE WEATHER CONCERNS, THOUGH WINDS SHOULD HAVE
CALMED QUITE A BIT BY THEN.
A TROUGH WILL BE POSITIONING ITSELF TO OUR WEST TO IMPACT
OUR STORM CHANCES SATURDAY. IN RESPONSE TO THE UPPER LEVEL SYSTEM,
SURFACE FLOW OUT OF THE SOUTHEAST WILL AMPLIFY. HIGHER QUALITY
MOISTURE WILL BE ADVECTED IN AND WILL BE SUFFICIENT IN ALLOWING
THUNDERSTORMS TO DEVELOP. A GOOD AMOUNT OF MACHINE LEARNING MODELS
ARE HIGHLIGHTING SEVERE WEATHER POTENTIAL FOR OUR AREA,
PARTICULARLY THE NEBRASKA PANHANDLE. INSPECTING THE 12Z GFS DOES
SHOW AN ENVIRONMENT CHARACTERIZED BY UNCAPPED SBCAPE VALUES OVER
2000 J/KG, EBWD VALUES AROUND 50 KNOTS, AND STEP LAPSE RATES. SUCH
PARAMETERS ARE SUPPORTIVE OF SUPERCELLS WITH AN ELEVATED LARGE HAIL
RISK. IN ADDITION TO SEVERE WEATHER THE FLOODING RISK MAY BE
ELEVATED GIVEN THE HIGH PERCEPTIBLE WATER VALUES NEARING AN INCH OR
GREATER FOR THE EASTERN PORTIONS OF OUR AREA. IN ADDITION STORM
MOTIONS DO NOT APPEAR TO BE PARTICULARLY FAST, GENERALLY BELOW 15 TO
20 KNOTS. THE WPC HAS INTRODUCED A MARGINAL RISK FOR FLOODING IN THE
NORTHEASTERN PORTIONS OF OUR CWA GIVEN THE ABOVE CONDITIONS.
SUNDAY THROUGH MONDAY KEEPS OUR STORMY PATTERN GOING. THE GREATER
SHEAR MAY BE DISPLACED TO OUR SOUTH AND EAST TO REDUCE SEVERE
WEATHER ODDS, BUT THE MOISTURE AND INSTABILITY WILL BE PRESENT TO
KEEP STORM POTENTIAL AROUND UNTIL OUR NEXT DRY OUT.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1133 AM MDT TUE JUN 16 2026
WIND WILL BE THE MAIN AVIATION CONCERN OVER THE NEXT 24 HOURS. GUSTY
WINDS WILL CONTINUE THIS AFTERNOON WITH GUSTS OVER 30 KTS LIKELY AT
TERMINALS WEST OF THE LARAMIE RANGE. GUSTS OF 20 TO 30 KTS CAN BE
EXPECTED AT TERMINALS EAST OF THE LARAMIE RANGE. WINDS WILL BRIEFLY
EASE THIS EVENING AROUND SUNSET, HOWEVER THEY WILL INCREASE AGAIN AS
A COLD FRONT MOVES ACROSS THE AREA OVERNIGHT. LLWS WILL BE POSSIBLE
AS WINDS ALOFT INCREASE BEFORE SURFACE WINDS DO. STRONG WINDS WILL
CONTINUE INTO THE DAY WEDNESDAY.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING UNTIL 10 PM MDT WEDNESDAY FOR WYZ417-418-
430>433.
HIGH WIND WARNING FROM 9 PM THIS EVENING TO 9 AM MDT WEDNESDAY
FOR WYZ106.
HIGH WIND WARNING FROM 6 PM THIS EVENING TO NOON MDT WEDNESDAY
FOR WYZ110.
HIGH WIND WARNING FROM 9 PM THIS EVENING TO 3 PM MDT WEDNESDAY
FOR WYZ116-117.
NE...RED FLAG WARNING UNTIL 10 PM MDT WEDNESDAY FOR NEZ434>437.
SHORT TERM...SF
LONG TERM...RV
AVIATION...SF
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