637
FXUS65 KCYS 161043
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
343 AM MST TUE DEC 16 2025
KEY MESSAGES
- HIGH WIND WARNINGS ONGOING FOR THE USUAL WIND PRONE LOCATIONS
OF WYOMING, WITH HIGH WIND WATCHES ISSUED FOR WYOMING AND A
SMALL PORTION OF THE NEBRASKA.
- FURTHER WINDY CONDITIONS EXPECTED THURSDAY INTO FRIDAY WITH
ADDITIONAL WIND PRODUCTS LIKELY AT THAT TIME.
- WARM WEATHER EXPECTED TO CONTINUE THROUGH WEDNESDAY WITH A
COLD FRONT BRIEFLY DROPPING OUR TEMPERATURES ON THURSDAY
BEFORE WARMING BACK UP ON FRIDAY.
- NEXT CHANCE FOR PRECIPITATION ON WEDNESDAY EVENING WITH
PERIODS OF SNOW AND RAIN POSSIBLE.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED AT 154 AM MST TUE DEC 16 2025
HIGH WIND WARNINGS CURRENTLY ONGOING ACROSS THE REGION THIS
MORNING AS BREEZY WINDS FROM A FAIRLY POTENT LOW LEVEL JET ARE
FUELING THE HIGHLIGHTS FOR OUR USUAL WIND PRONE LOCATIONS. THIS
FEATURE SHOULD CONTINUE THROUGH THE EARLY AFTERNOON WITH WINDS
LESSENING INTO THE LATE AFTERNOON AND EARLY EVENING HOURS. BUT
THIS WILL BE A BRIEF RESPITE AS A MUCH MORE POTENT JET DEVELOPS
TONIGHT INTO TOMORROW, BRINGING A MORE WIDESPREAD HIGH WIND
EVENT TO MOST OF OUR WYOMING ZONES AND POTENTIALLY OVERSPREADING
INTO THE NEBRASKA PANHANDLE AS WELL. THIS NEXT EVENT WILL BE
CAUSED BY A STOUT UPPER LEVEL TROUGH AND LOW THAT WILL MOVE
ACROSS THE REGION AND FLATTEN OUT THE RIDGE THAT HAS BEEN IN
CONTROL, HELPING TO BRIEFLY BRING OUR TEMPERATURES BACK DOWN AS
WELL JUST BEYOND THE SHORT TERM. AT THE 700MB LEVEL, THE LOW
LEVEL JET WILL BE HOWLING ON WEDNESDAY, WITH SPEEDS IN THE 70-90
KNOT RANGE AND VERY FAVORABLE DOWNWARD OMEGA VALUES BRINGING
THESE WINDS TO THE SURFACE. PRESSURE GRADIENTS FROM CRAIG TO
CASPER IN EXCESS OF 80-90 METERS WILL ALSO ENSURE SURFACE WINDS
WILL BE QUITE BREEZY, LEADING TO THIS LIKELY HIGH WIND EVENT FOR
OUR REGION. FOR THIS MORNING'S UPDATE WE HAVE ISSUED WATCHES
ACROSS THE REGION IN TANDEM WITH OUR NEIGHBORING OFFICES, WITH
THESE LIKELY TO BE UPGRADED LATER THIS AFTERNOON AS THE ONGOING
WARNINGS EXPIRE LATER TODAY. THERE IS A CHANCE WE COULD SEE
THESE WATCHES/WARNINGS EXPAND FURTHER INTO THE NEBRASKA
PANHANDLE AS WELL, OR ADDITIONAL WATCHES/WARNINGS MAY BE NEEDED
JUST BEYOND THE SHORT TERM AS THE JET FLARES AGAIN INTO NEBRASKA
AS THE SYSTEM MOVES ACROSS THE REGION INTO THURSDAY.
OTHERWISE, TEMPERATURES WILL REMAIN ELEVATED AND SEASONABLY VERY
WARM TO NEAR RECORD, WITH THE APPROACHING SYSTEM BRINGING A
QUICK SHOT OF PRECIPITATION ON WEDNESDAY WITH WIDESPREAD RAIN
AND MOUNTAIN SNOW INCLUDING SEVERAL INCHES OF NEW SNOWFALL FOR
THE SNOWY AND SIERRA-MADRE RANGES. WINTER WEATHER ADVISORIES ARE
LIKELY FOR OUR MOUNTAINS, BUT SNOW RATIOS HAVE BEEN RUNNING A
BIT AGGRESSIVE IN THE NBM SO THESE AMOUNTS SHOULD BE ON THE
LOW-END FOR AN ADVISORY AND THE OVERALL PRECIPITATION WILL BE A
QUICK SHOT BEFORE EXITING.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED AT 200 PM MST MON DEC 15 2025
WITH A GENERALLY LOW AMPLITUDE UPPER AIR PATTERN THROUGH THE NEXT
WEEK THERE IS GOOD SYNOPTIC AGREEMENT UPON HOW THE PATTERN UNFOLDS.
CURRENTLY THERE IS HIGH CONFIDENCE IN A STRONG WAVE WEDNESDAY DIVES
A BIT FURTHER SOUTH INTO THE NORTHERN TIER US STATES WITH SUBTLE
TIMING AND STRENGTH DIFFERENCES AMONG GLOBAL ENSEMBLES. THINGS
CONTINUE TO COME INTO BETTER AGREEMENT AND MAINLY DIFFER ON TRACK
TIMING. YET ANOTHER CHANCE FOR HIGH WINDS LOOKS APPARENT BEYOND THE
MIDWEEK AS WE HEAD INTO THE WEEKEND BUT LETS TAKE IT ONE WINDY DAY
AT A TIME.
LOOKING AT WEDNESDAY WE SEE 700MB FLOW TICKS UP OVER 60KTS WITH HIGH
CONFIDENCE AND THE 85TH PERCENTILE SHOWING AS HIGH AS 70KTS FOR A
REASONABLE HIGH END. THIS WILL BRING MORE WIDESPREAD HIGH WINDS TO
THE REGION WITH AVAILABLE GUIDANCE SHOWING THIS TO BE A MORE
WIDESPREAD EVENT LIKELY BLEEDING OUTSIDE THE WIND PRONES AND INTO
THE ADJACENT HIGH PLAINS. THIS WEDNESDAY EVENT LOOKS TO BE A QUICK
HITTER AND NOT LONG LASTING THANKFULLY (<24 HOURS). THE PRESSURE
GRADIENT THEN LOOKS TO REVERSE FOR THURSDAY BEHIND THE PACIFIC FRONT
SHUTTING OFF THE WIND MACHINE FOR A SHORT TIME BEFORE ANOTHER SURGE
IN WINDS ALOFT BRINGS SIMILAR STRENGTH FLOW ALOFT TO WEDNESDAY
EVENT. THIS WOULD BEGIN THURSDAY EVENING FOR THE WIND PRONES AND
FRIDAY MORNING FOR AREAS EAST THE LARAMIE RANGE LASTING THROUGH
FRIDAY FOR ALL AND POSSIBLY EARLY SATURDAY FOR THE WIND PRONES. FLOW
THEN LOOKS TO TURN MORE ZONAL WITH LESSER CHANCES FOR SHORTWAVE
ACTIVITY TO BRING IMPACTFUL WINDS THE REGION.
ALONG WITH THE WINDS SHOULD COME SOME LIGHT SHOTS OF MOISTURE
WED/THUR AND AGAIN NEXT WEEKEND. THIS WOULD BE MOST IMPACTFUL FOR
THE HIGH TERRAIN (ABOVE 8000FT) WHERE A FEW INCHES OF SNOW WOULD BE
EXPECTED THOUGH CAN'T RULE OUT A FEW HUNDREDTHS OF RAIN OR A DUSTING
OF SNOW IN THE LOW ELEVATIONS. LOOKING AT TEMPS QUICKLY WE ARE QUITE
A BIT ABOVE AVERAGE (37-42F ALONG AND EAST OF I25) WITH HIGHS LIKELY
TO REACH WELL INTO THE 50S FOR AREAS BELOW 7000FT WEDNESDAY AND THEN
FRIDAY THROUGH THE WEEKEND. THURSDAY WILL BE SLIGHTLY COOLER IN THE
40S BEHIND THE COLD FRONT. LOW TO MID 60S EVEN APPEAR PROBABLE
WEDNESDAY AND FRIDAY WITH HIGH TEMPERATURE RECORDS VERY MUCH IN
DANGER FOR MOST LOCATIONS ON FRIDAY. THERE IS ABOUT A 30% CHANCE
CURRENTLY WITHIN THE NORTH PLATTE RIVER VALLEY FRIDAY FOR TEMPS OVER
70. DIGGER EVEN DEEPER INTO THE STATS IF LOOKS LIKE MOST SITES IN
THE PANHANDLE HAVE DECEMBER ALL TIME RECORD HIGHS IN THE MID TO
UPPER 70S SO WE LIKELY COME UP JUST A BIT SHORT OF THAT BUT CERTAINLY
NEARING THE VERY UPPER END OF WHAT IS POSSIBLE IN TERMS OF TEMPS
THIS TIME OF YEAR.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 1020 PM MST MON DEC 15 2025
VFR CONDITIONS WILL DOMINATE FOR THE DURATION OF THIS TAF PERIOD
ACROSS ALL TERMINALS. HOWEVER, WINDS WILL BEGIN TO RAMP UP TONIGHT
INTO TUESDAY MORNING WITH GUSTS TOPPING OUT NEAR 40 KNOTS FOR THE
WYOMING TERMINALS AND NEAR 30 KNOTS A BIT LATER ACROSS THE NEBRASKA
PANHANDLE. LLWS MAY AFFECT KLAR AND KCDR, POSSIBLY OTHER NE
TERMINALS, BETWEEN 10Z AND 16Z TUESDAY.
CYS WATCHES/WARNINGS/ADVISORIES
WY...HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY EVENING
FOR WYZ101-103>105-109.
HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR WYZ102-107-108-115-118-119.
HIGH WIND WARNING UNTIL NOON MST TODAY FOR WYZ106.
HIGH WIND WATCH FROM LATE TONIGHT THROUGH LATE WEDNESDAY NIGHT
FOR WYZ106-110-116-117.
HIGH WIND WARNING UNTIL 3 PM MST THIS AFTERNOON FOR WYZ110.
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ116-117.
NE...HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR NEZ095.
SHORT TERM...CG
LONG TERM...WFOCYS
AVIATION...RZ
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page