241
FXUS65 KCYS 170802
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
202 AM MDT WED JUN 17 2026
KEY MESSAGES
- A RED FLAG WARNING IS IN EFFECT FOR ALL AREAS ALONG AND EAST
OF INTERSTATE 25 THROUGH 10 PM WEDNESDAY.
- HIGH WIND WARNINGS REMAIN IN EFFECT FOR THE TYPICAL WIND PRONE
REGIONS OF SOUTHEAST WYOMING 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 THURSDAY NIGHT/
ISSUED AT 202 AM MDT WED JUN 17 2026
A COLD FRONT WILL SAG SOUTH ACROSS THE CWA OVER THE NEXT SEVERAL
HOURS, BRINGING COOLER AIR ALONG WITH TIGHTER SURFACE GRADIENTS.
THIS COUPLED WITH A MODEST LOW-LEVEL JET UP AROUND 60 KNOTS AND
ENOUGH SUBSIDENCE, NEGATIVE OMEGA (GFS), WILL BRING THESE WINDS DOWN
TO THE SURFACE. THEREFORE, THE STRONGEST WINDS ARE EXPECTED IN OUR
KNOWN WIND PRONES ACROSS SOUTHEAST WYOMING NOW THROUGH THIS
AFTERNOON. HENCE, THE HIGH WIND WARNINGS THAT WERE ISSUED YESTERDAY
REMAIN IN EFFECT UNTIL 3PM THIS AFTERNOON. THE APEX OF THIS EVENT
WILL BE A BIT LATER THIS MORNING WITH POSSIBLE GUSTS UP TO 70 MPH,
THIS IS IN AGREEMENT WITH OUR IN-HOUSE GUIDANCE THAT SUGGESTS A 50-
60 PERCENT CHANCE OF HIGH WINDS, MAINLY FOR THE WINDIER LOCATION
ALONG I-25 AND I-80. CURRENT SURFACE OBSERVATIONS ARE SHOWING WINDS
PICKING UP ALONG I-25 NORTH OF CHEYENNE AND I-80 WEST OF THE LARAMIE
RANGE. AS THE AFOREMENTIONED COLD FRONT SAGS SOUTH, PRECIPITATION
CHANCES WILL BE A MEAGER WITH AMPLE DRY AIR IN PLACE AT THE LOWER
LEVELS, WITH NORTHERN PORTIONS OF THE NEBRASKA PANHANDLE HAVING THE
BEST CHANCES, ALBEIT SLIM, OF SEEING PRECIPITATION. THERE MAY BE
ENOUGH INSTABILITY TO PRODUCE LIGHTNING, OF WHICH WILL BE DRY, AND
MAY EXACERBATE THE ONGOING FIRE WEATHER CONCERNS ACROSS THE REGION.
WITH THIS SAID, WE WILL CONTINUE THE RED FLAG WARNING THAT HAS BEEN
OUT FOR MANY LOCATIONS EAST OF I-25 UNTIL 10PM THIS EVENING
PRIMARILY FOR WINDS AND ONGOING DRY FUELS. ELSEWHERE, WINDS ACROSS
OUR NORTHERN ZONES, INCLUDING THE NEBRASKA PANHANDLE, WILL BE
EXCEPTIONALLY STRONG THIS AFTERNOON WITH A STRENGTHENING LOW-LEVEL
JET OVER THE AREA, THIS WILL LEAD TO WIND GUSTS UP TO 50 MPH. THIS
IS SHORT-LIVED AS WINDS WILL QUICKLY DIE DOWN THIS
AFTERNOON/EVENING, LEADING TO A RELATIVELY QUIET OVERNIGHT. HEADING
INTO THURSDAY, NOT MUCH TO TALK ABOUT AS WE WILL GET A REPRIEVE FROM
WINDS AND FIRE WEATHER AS WEAK RIDGING BUILDS IN FROM THE SOUTH.
WITH THE PASSAGE OF THE COLD FRONT LATER THIS MORNING, COOLER HIGHS
ARE FORECAST TODAY AND THURSDAY, WITH HIGHS ONLY TOPPING OUT INTO
THE LOW TO MID 80S FOR MANY LOCATIONS ACROSS THE CWA.
LONG TERM /FRIDAY THROUGH TUESDAY/
ISSUED AT 202 AM MDT WED JUN 17 2026
RIDGING WILL PUSH INTO FRIDAY, CONTINUING TO BRING SUNNY SKIES AND
HIGHS THAT WILL SOAR A FEW DEGREES WARMER, AS MUCH AS 10 DEGREES
WARMER THEN THURSDAY FOR MANY LOCATIONS. DUE TO THE ONGOING DRY
CONDITIONS, ELEVATED FIRE WEATHER CONCERNS WILL MAKE A RETURN
FRIDAY, THOUGH WINDS WILL BE CALMER. A DISORGANIZED TROUGH PUSHES
EAST JUST TO OUR WEST, BRINGING THE BEST CHANCES OF PRECIPITATION
FOR SATURDAY. WITH SOUTHEAST FLOW AT THE SURFACE, MOISTURE WILL
SURGE IN AND BE SUFFICIENT ENOUGH TO BRING INCREASED CHANCES OF
PRECIPITATION AND THE THREAT OF THUNDERSTORMS, WITH THE GREATEST
THREAT OF SEVERE WEATHER ACROSS THE NEBRASKA PANHANDLE. INSTABILITY
PARAMETERS, RIGHT NOW, ARE SUFFICIENT ENOUGH TO SUPPORT POSSIBLE
SUPERCELL ACTIVITY ALONG WITH LARGE HAIL. THIS MAY NOT BE THE ONLY
CONCERN FOR SATURDAY, BUT THE FLOODING RISK IS ELEVATED WITH HIGH
PWAT VALUES AND SLOW STORM MOTION. THEREFORE, WPC HAS A MARGINAL
RISK FOR EXCESSIVE RAINFALL ACROSS NORTHEASTERN PORTIONS OF OUR CWA,
STAY TUNED TO THE FORECAST FOR FUTURE UPDATES. THE WEATHER PATTERN
INTO NEXT WEEK LOOKS TO BE RELATIVELY ACTIVE WITH MODELS SHOWING
AMPLE MOISTURE AND INSTABILITY ACROSS OUR CWA TO KEEP PRECIPITATION
AND STORM CHANCES AROUND THROUGH AT LEAST MID-WEEK NEXT WEEK.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1133 PM MDT TUE JUN 16 2026
VFR CONDITIONS EXPECTED FOR THE FORECAST PERIOD. THE MAIN
AVIATION HAZARD WILL BE STRONG WINDS. OVERNIGHT, LOOK FOR
SIGNIFICANT LLWS ESPECIALLY AT TERMINALS ALONG THE I-80
CORRIDOR. SURFACE WINDS GUSTS WILL BE INTERMITTENT (EXCEPT RWL
WHERE WINDS WILL BE FAIRLY STEADY) AND MAY PRODUCE SUDDEN
CHANGES IN WIND SPEED AT CYS, LAR, AND SNY.
WINDS WILL SHIFT MORE NORTHWEST DURING THE EARLY MORNING HOURS
AS A BOUNDARY MOVES THROUGH THE AREA, BUT EXPECT CONSISTENTLY
STRONG WINDS AT ALL TERMINALS FROM MID MORNING ONWARD. GUSTS OF
35 TO 45 KNOTS ARE EXPECTED IN WYOMING AND AT CDR, WITH GUSTS
OF 30 TO 40 KNOTS AT BFF, AIA, AND SNY. WINDS WILL SHIFT NORTH
TO SLIGHTLY NORTHEAST WEDNESDAY EVENING, AND THEN FINALLY DIE
OFF TOWARDS THE END OF THE TAF PERIOD.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING FOR WYZ417-418-
430>433.
HIGH WIND WARNING UNTIL 9 AM MDT THIS MORNING FOR WYZ106.
HIGH WIND WARNING UNTIL NOON MDT TODAY FOR WYZ110.
HIGH WIND WARNING UNTIL 3 PM MDT THIS AFTERNOON FOR WYZ116-117.
NE...RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING FOR NEZ434>437.
SHORT TERM...RZ
LONG TERM...RZ
AVIATION...MN
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