477
FXUS65 KCYS 131737
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1037 AM MST SAT DEC 13 2025
KEY MESSAGES
- STRONG GUSTY WINDS CONTINUE OVER THE WIND PRONE AREAS OF
SOUTHEAST WYOMING THIS MORNING. A HIGH WIND WARNING REMAINS IN
EFFECT.
- ARCTIC COLD FRONT WILL BRUSH EASTERN WYOMING AND THE NEBRASKA
PANHANDLE SATURDAY AND SATURDAY NIGHT. MUCH COLDER
TEMPERATURES EXPECTED ALONG AND EAST OF INTERSTATE 25. A FEW
FLURRIES ARE ALSO POSSIBLE.
- WARMING TREND EXPECTED SUNDAY THROUGH EARLY NEXT WEEK WITH
STRONG WINDS POSSIBLY RETURNING TO SOUTHEAST WYOMING ON
TUESDAY AND WEDNESDAY.
SHORT TERM /THROUGH MONDAY/
ISSUED AT 315 AM MST SAT DEC 13 2025
A BIT MORE ACTIVE ACROSS THE REGION THAN PREVIOUSLY EXPECTED
WITH A SHARP CONTRAST BETWEEN STRONG WINDS ALONG AND WEST OF
I-25, AND FOG NEAR THE WYOMING/NEBRASKA BORDER INCLUDING WESTERN
NEBRASKA. THE FOG SHOWS THE GENERAL LOCATION OF THE LEADING
EDGE OF THE STATIONARY ARCTIC FRONT, CURRENTLY ALONG A LINE
JUST EAST OF DOUGLAS WYOMING EXTENDING SOUTHEAST TO PINE BLUFFS
WYOMING, 35 MILES EAST OF CHEYENNE. PINE BLUFFS IS CURRENTLY AT
25 DEGREES IN FOG WHILE CHEYENNE IS AT 45 DEGREES WITH GUSTY
WESTERLY WINDS. THE FOG WAS A BIT OF A SURPRISE, SO WILL
CONTINUE THE DENSE FOG ADVISORY UNTIL 500 AM. VISIBILITY HAS
COME UP COMPARED TO EARLIER, SO WILL LIKELY EXPIRE THE ADVISORY
ON TIME SHORTLY. OTHERWISE, HIGH WIND WARNING LOOKS GOOD FOR THE
WIND PRONE AREAS. THERE HAVE BEEN A FEW SURPRISES, WITH SOME
MOUNTAIN WAVE ACTIVITY AND LOCALLY STRONGER SUBSIDENCE PRODUCING
BRIEF GUSTS OF 60 MPH ACROSS PORTIONS OF CARBON COUNTY EARLY
THIS MORNING. THESE LOCALLY STRONG GUSTS HAVE BEEN IMMEDIATELY
FOLLOWED BY MUCH LIGHTER WINDS 30 MINUTES LATER. WILL MONITOR
THIS ACTIVITY THROUGH SUNRISE, BUT NOT EXPECTED TO EXTEND THE
HIGH WIND WARNING TO THE OTHER LOWER ELEVATIONS OF CARBON AND
ALBANY COUNTIES AT THIS TIME DUE TO LOW CONFIDENCE OF CRITERIA
BEING MET AGAIN, AND THE VERY SHORT DURATION OF THE EVENT(S).
OTHERWISE, PEAK GUSTS SO FAR HAVE BEEN AROUND 73 MPH AT BOTH
BORDEAUX AND NEAR AREAS NEAR ARLINGTON, WITH VEDAUWOO NOT FAR
BEHIND AT 66 MPH.
FOR SATURDAY, HIGH TEMPERATURES WILL REMAIN COLD JUST EAST OF
THE ARCTIC FRONT ACROSS EAST CENTRAL WYOMING AND NORTHERN AND
CENTRAL NEBRASKA PANHANDLE...WITH TEMPERATURES IN THE TEENS AND
20S NORTH AND EAST OF THE NORTH PLATTE RIVER VALLEY. COULD SEE A
FEW BANDS OF SNOW OR SNOW FLURRIES DEVELOP OVER THIS AREA AS
THE ARCTIC FRONT MAKES ONCE LAST SURGE SOUTHWARD ACROSS THE HIGH
PLAINS, INCLUDING THE I-25 AND I-80 CORRIDOR BY THIS EVENING.
THIS WILL BRING AN END TO THE CONSTANT STRONG WIND THREAT OVER
SOUTHEAST WYOMING FOR THE NEXT FEW DAYS AS LOW LEVEL PRESSURE
TENDENCIES REVERSE JUST EAST OF THE MOUNTAINS. ALTHOUGH
SOUTHEAST WYOMING WILL SEE HIGHS IN THE UPPER 40S TO AROUND 50
SATURDAY AFTERNOON, EXPECT THE LEADING EDGE OF THE ARCTIC FRONT
TO SHIFT WINDS INTO THE NORTH WITH FALLING TEMPERATURES THROUGH
THE AFTERNOON. COULD SEE MOST OF THE I-25 CORRIDOR BELOW
FREEZING BY SUNSET BASED ON CURRENT MODEL TRENDS. EITHER WAY,
EXPECT A SEASONABLY COLD NIGHT SATURDAY NIGHT WITH LOWS IN THE
TEENS TO LOW 20S FOR MOST LOCATIONS...AND EVEN A FEW SINGLE
DIGITS NEAR CHADRON AND ALLIANCE NEBRASKA.
ALL MODELS IN GOOD AGREEMENT FOR SUNDAY AND MONDAY AND SHOW
PRETTY PLEASANT AND BENIGN WEATHER FOR MID DECEMBER. MODELS AND
ALL ENSEMBLE GUIDANCE SHOWS THE ARCTIC COLD FRONT RETREATING
EASTWARD BY EARLY TO MID SUNDAY MORNING. THIS WILL ALLOW SUNDAY
TO BE A PRETTY NICE DAY WITH HIGHS RETURNING TO THE 50S
EVERYWHERE, INCLUDING WESTERN NEBRASKA. A FEW LOCATIONS ALONG
I-25 MAY SEE LOW 60S IN THE AFTERNOON DUE TO LIGHT WESTERLY
WINDS. SIMILAR WEATHER EXPECTED FOR MONDAY AS 700MB TEMPERATURES
REMAIN BETWEEN 4C TO 7C...RESULTING IN AFTERNOON HIGHS A FEW
DEGREES WARMER COMPARED TO SUNDAY. WINDS WILL START TO INCREASE
OVER THE WIND PRONE AREAS OF SOUTHEAST WYOMING, BUT HIGH WIND
CRITERIA IS NOT EXPECTED AT THIS TIME.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
ISSUED AT 119 PM MST FRI DEC 12 2025
THERE REMAINS STRONG AGREEMENT FROM GLOBAL ENSEMBLE BASED CLUSTERS
REGARDING THE EVOLUTION OF THE RIDGE CURRENTLY OVER THE WESTERN HALF
OF CONUS. THE MAIN DIFFERENCES BETWEEN ENSEMBLES WOULD BE IN THE
AMPLITUDE OF ANY SHORTWAVE ACTIVITY TRAVERSING THE WEAKENING RIDGE
EARLY NEXT WEEK WITH MORE SOUTHERLY TRACKING WAVES BRINGING STRONGER
LOW LEVEL PRESSURE GRADIENTS TO THE FORECAST REGION AND HIGH
POTENTIAL FOR STRONG WINDS IN THE WIND PRONES AREAS EARLY IN THE
WEEK (TUESDAY). LOOKING TOWARDS THE MID WEEK THE IS SIGNAL EVEN
IN THE ENSEMBLES FOR A STRONG HYBRID TYPE LOW TO TRACK ACROSS
THE CANADA/US BORDER WITH A ZONAL FLOW IN THE CENTRAL/NORTHERN
ROCKIES ALLOWING STRONG LOW TO MID LEVEL FLOW TO PUSH SOUTH INTO
OUR AREA BRINGING STRONG WINDS TO THE WIND PRONES AND ADJACENT
AREAS. CURRENTLY THIS EVENT DOES NOT LOOK TO HAVE THE CEILING AS
THE EVENT WE JUST CONCLUDED BUT 70KT 700MB FLOW IS CERTAINLY IN
THE CARDS WHICH WHEN PAIRED WITH FAVORABLE NEGATIVE OMEGA IN
THE LEE OF THE HIGHER TERRAIN AND AN INCREASING SFC PRESSURE
GRADIENT ALONG THE FRONT RANGE AS THE ATTENDANT COLD FRONT
PUSHES SOUTH THROUGH THE HIGH PLAINS THE CEILING REMAINS HIGHER
SOMEWHERE BETWEEN SATURDAY'S HIGH WINDS IN THE WIND PRONES AND
LAST TUESDAY'S PEAK GUSTS WHICH WERE WIDELY 60-80MPH EVEN
OUTSIDE THE WIND PRONES.
ASIDE FROM THE TYPICAL THREAT OF WIND THIS TRANSIENT EARLY WEEK
SHORTWAVE ACTIVITY DOES LOOK TO BRING A CHANCE FOR HIGH ELEVATION
SNOW (LIKELY BELOW ADVISORY THRESHOLDS) AND WILL PREVAIL THE
DOWNSLOPE AIRMASS THROUGH THE MID WEEK PERIOD WHEN THAT REINFORCING
COLD FRONT MOVES SOUTH ALONG THE FRONT RANGE DROPPING HIGHS FROM THE
EARLY WEEK 50S AND 60S TO LATE WEEK 40S AND 50S BEHIND THE
FRONT.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1037 AM MST SAT DEC 13 2025
AN ARCTIC COLD FRONT DRAPED ACROSS FAR EASTERN WYO AND THE NEB
PANHANDLE IS CAUSING SOME HAZARDOUS AVIATION WEATHER TODAY. A
LOW STRATUS DECK WITH EMBEDDED FOG AND LIGHT SNOW SHOWERS WILL
CONTINUE TO RESULT IN IFR FOR THE PANHANDLE TERMINALS, ALONG
WITH BREEZY NORTH WINDS THIS AFTERNOON. CEILINGS GRADUALLY LIFT
AND WINDS TAPER EARLY EVENING WITH A RETURN TO VFR EXPECTED BY
14/00Z. OVER WYO, BREEZY WEST WINDS WILL CONTINUE THROUGH ABOUT
SUNSET WITH PRIMARILY VFR EXPECTED OVER THE COURSE OF THE
FORECAST PERIOD.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...TJT
LONG TERM...WFOCYS
AVIATION...DS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page