764
FXUS65 KCYS 081120
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
420 AM MST THU JAN 8 2026
KEY MESSAGES
- A COLD FRONT WILL MOVE THROUGH BRINGING LIGHT SNOWFALL, TODAY
INTO FRIDAY MORNING.
- COLDER TEMPERATURES RETURN TO THE REGION THROUGH FRIDAY NIGHT.
- WARMER TEMPERATURES MOVE BACK IN OVER THE WEEKEND AND INTO
NEXT WEEK.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 121 AM MST THU JAN 8 2026
WITH A NICE REPRIEVE FROM THE HIGH WINDS THAT SEEMED LIKE THEY MAY
NEVER END, LETS SHIFT OUR FOCUS IN THE MEANTIME BACK TO WINTER AND
TALK ABOUT PRECIPITATION CHANCES AND TEMPERATURES. AN UPPER LEVEL
TROUGH AT 500MB COMES TOGETHER AND SLIDES ACROSS THE REGION THROUGH
FRIDAY. EMBEDDED VORTICITY MAXIMA MOVES INTO OUR CWA AND WILL
BE ONE OF A FEW FEATURES THAT WILL BE THE CATALYST FOR THE
SNOWFALL TO COME, THE OTHER WILL BE A COLD FRONT THAT PLUNGES
SOUTHWARD. SO, LIGHT SNOW WILL CONTINUE TO OVERSPREAD THE REGION
THIS MORNING AND CONTINUE THROUGH THURSDAY NIGHT. AS THE UPPER
LEVEL TROUGH EXITS EAST AND THE COLD FRONT PUSHES FURTHER SOUTH,
SNOWFALL WILL BE TAPERING OFF FRIDAY MORNING BEFORE COMING TO
AN END DURING THE AFTERNOON HOURS. SO, A LOT OF YOU MAY BE
WONDERING, HOW MUCH SNOW CAN WE EXPECT? IF YOU WERE TO DRAW A
LINE FROM GLENROCK TO SCOTTSBLUFF, POINTS SOUTH CAN EXPECT
GENERALLY 1-3 INCHES, HIGHER ELEVATIONS 2-4 INCHES, AND A HALF
INCH ACROSS THE NEBRASKA PANHANDLE. WHAT ABOUT HERE IN CHEYENNE,
WELL, WHEN IT IS ALL SAID AND DONE, CHEYENNE WILL RECEIVE 1-2
INCHES BY FRIDAY AFTERNOON. NOW LETS TAKE A LOOK AT
TEMPERATURES, WITH THE AFOREMENTIONED COLD FRONT, UPPER LEVEL
AND SURFACE WINDS WILL BECOME NORTHERLY, USHERING IN AN ARCTIC
AIR MASS. HIGHS WILL TOP OUT IN THE 30S TO NEAR 40 TODAY WITH
LOWS THURSDAY NIGHT DIPPING INTO THE TEENS TO LOW 20S. WITH
CONTINUED NORTHERLY FLOW, FRIDAY'S HIGHS WILL BE A TAD COOLER,
IN THE MID 20S WEST OF I-25 AND MID 30S EAST OF THE CORRIDOR.
FRIDAY NIGHT WILL CONTINUE THAT COOLER TREND AS LOWS TANK INTO
THE LOW TEENS, WITH SOME AREAS SEEING SINGLE DIGITS.
AND YOU THOUGHT THERE WOULD BE NO MENTION OF WINDS IN THE SHORT
TERM, YOU'D BE WRONG. WELL, WITH NOT MUCH SUPPORT ALOFT, WINDS
WILL START OFF LIGHT, PEAKING THIS AFTERNOON INTO THE 10 TO 20
MPH RANGE, STRONGER WINDS ACROSS OUR WESTERN FORECAST ZONES,
INCLUDING RAWLINS. THEN DECREASE THURSDAY NIGHT BEFORE PICKING
RIGHT BACK UP BY FRIDAY AFTERNOON AS THE PRESSURE GRADIENT
TIGHTENS. SO, WINDS WILL CONTINUE TO STRENGTHEN THROUGH FRIDAY
NIGHT, BECOMING SUSTAINED UP TO 40 MPH MAINLY FOR OUR WIND
PRONES ACROSS SOUTHEAST WYOMING, GUSTS AS HIGH AS 55 MPH ARE NOT
OUT OF THE QUESTION BY SATURDAY MORNING.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 303 PM MST WED JAN 7 2026
THE AXIS OF A SPLIT TROUGH WILL MOVE ACROSS THE AREA ON FRIDAY.
EXPECT SNOW SHOWERS TO LINGER OVER THE AREA, ESPECIALLY IN THE
MOUNTAINS, INTO FRIDAY, BUT OUR AREA IS POSITIONED SOMEWHAT
UNFAVORABLY (FOR SIGNIFICANT PRECIPITATION) BETWEEN TWO UPPER LEVEL
LOWS BOTH TO OUR NORTH AND TO OUR SOUTH. AN ELONGATED BAND OF
ELEVATED VORTICITY ALOFT WILL MOVE THROUGH FRIDAY, AND SINCE WE WILL
CONTINUE TO HAVE STEEP LOW-LEVEL LAPSE RATES IN PLACE, WE SHOULD SEE
SOME LIMITED CONVECTIVE-TYPE SNOW SHOWER ACTIVITY CONTINUE INTO
FRIDAY. A STRONG REINFORCING SURFACE COLD FRONT WILL RIDE ALONG THE
UPPER LEVEL TROUGH AXIS, PUSHING THROUGH THE AREA BY DAYBREAK
FRIDAY. EXPECT FAIRLY RAPID PRESSURE RISES THROUGH THE DAY AS A
SURFACE HIGH PRESSURE SETTLES IN OVER THE NORTHERN ROCKIES. THIS
WILL KEEP A POTENT PRESSURE GRADIENT OVER MUCH OF THE AREA, AND
RETURN GUSTY WINDS INTO THE FORECAST FOR FRIDAY. THE PROBABILITY FOR
HIGH WINDS IS FAIRLY LOW (20%) BUT FAIRLY WIDESPREAD GUSTS OF 30 TO
45 MPH ARE ANTICIPATED. TEMPERATURES WILL BE CONSIDERABLY COLDER
TOO, AS 700-MB TEMPERATURES BOTTOM OUT AROUND -15C BEHIND THE COLD
FRONT. THIS WILL SUPPORT HIGHS MAINLY IN THE 20S TO LOW 30S, WITH
THE WINDS KEEPING APPARENT TEMPERATURES IN THE SINGLE DIGITS WEST OF
THE LARAMIE RANGE AND IN THE TEENS TO LOWER 20S TO THE EAST.
DEPENDING ON HOW MUCH SNOW FALLS TONIGHT AND THURSDAY, BLOWING SNOW
MAY BE A CONCERN ON FRIDAY, EVEN OUTSIDE OF THE TYPICAL WIND PRONE
AREAS.
THIS STORM WILL HELP COMPLETE A PATTERN SHIFT INTO A DRY NORTHWEST
FLOW PATTERN THAT WILL DOMINATE MUCH OF NEXT WEEK. THE SYNOPTIC
PATTERN LOOKS TO BE DOMINATED BY A STRONG WEST COAST RIDGE, AND
BROAD CENTRAL/EASTERN CONUS TROUGH. THE MAIN WEATHER MAKERS FOR OUR
AREA DURING THIS PERIOD WILL BE A SERIES OF CLIPPER SYSTEMS DIVING
DOWN THE WESTERN FLANK OF THE TROUGH. THE FIRST OF THESE IS EXPECTED
AROUND THE SATURDAY TIME PERIOD AS A SUBTLE VORT-MAX DIVES DOWN FROM
THE NORTH AND GETS WRAPPED INTO THE STRENGTHENING UPPER LEVEL LOW
OVER THE NORTHERN PLAINS. AT THE SAME TIME, THE WESTERN RIDGE WILL
TRY TO ADVANCE EASTWARD, LIKELY PRODUCING SOME OVERRUNNING ON TOP OF
THE RETREATING ARCTIC FRONTAL BOUNDARY. AS A RESULT, WE HAVE A
CHANCE FOR SNOW SHOWERS MAINLY OVER OUR NORTHERN AND EASTERN ZONES
(AND IN THE MOUNTAINS) SATURDAY AS THIS DISTURBANCE MOVES THROUGH.
IN ADDITION, THIS SYSTEM WILL TIGHTEN THE PRESSURE GRADIENT ACROSS
OUR GAP AREAS ONCE AGAIN, INCREASING WIND SPEEDS. THIS EVENT LOOKS
FAIRLY MARGINAL AT THIS TIME, WITH OVERALL WIND PARAMETERS NEAR
TYPICAL THRESHOLDS FOR HIGH WIND WARNING ISSUANCE. AT THIS TIME, THE
PROBABILITY FOR WINDS REACHING HIGH WIND CRITERIA IS ABOUT 60% IN
THE I-80 WIND PRONE AREAS, AND 20 TO 40% FOR THE I-25 CORRIDOR.
THE RIDGE WILL EVENTUALLY WIN BY SUNDAY, PUSHING THE ARCTIC AIR OFF
TO THE EAST. 700-MB TEMPERATURES WILL RECOVER TO AROUND -2C BY THE
END OF THE DAY SUNDAY, WHICH WILL PUT HIGHS BACK AROUND 10F ABOVE
AVERAGE FOR THIS TIME OF YEAR. EXPECT MILD TEMPERATURES WITH LITTLE
TO NO CHANCE FOR PRECIPITATION SUNDAY THROUGH MONDAY NIGHT AND
POSSIBLY LONGER. WE SHOULD GET A BREAK FROM THE WIND ON SUNDAY, AND
ENSEMBLE MEMBERS DIFFER IN HOW QUICKLY THEY RETURN. LOOK FOR AT
LEAST ELEVATED WINDS TO RETURN BY AROUND TUESDAY. THE NEXT CHANCE
FOR PRECIPITATION WILL BE WITH A WEAK CLIPPER SYSTEM TUESDAY NIGHT.
ENSEMBLE MEMBERS ARE FAIRLY EVENLY SPLIT, WITH ABOUT HALF OF LREF
MEMBERS (MAINLY FROM THE ECMWF ENSEMBLE) SHOWING THE CLIPPER TAKING
A MORE WESTWARD TRACK THAT BRINGS COLDER TEMPERATURES AND A CHANCE
FOR SNOW TUESDAY INTO WEDNESDAY, WHILE THE OTHER HALF (MAINLY FROM
THE GEFS) KEEP THE SYSTEM JUST TO OUR EAST, WHICH WOULD MEAN
CONTINUED MILD AND DRY CONDITIONS.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 420 AM MST THU JAN 8 2026
LIGHT SNOW HAS BEEN FALLING AT KRWL THRU THE NIGHT, REDUCING VIS AT
TIME TO LESS THAN 2SM AND THEN JUMPING BACK UP TO 5SM OR MORE. THIS
WILL CONTINUE AND THE REMAINING TERMINALS ACROSS THE CWA, EXCEPT
KCDR AND KSNY, WILL BE GETTING LIGHT SNOW AT SOME POINT. KLAR AND
KCYS HAVE THE GREATEST CHANCES TO SEE WHAT KRWL HAS, VIS DOWN TO 2SM
AND CIGS LESS THAN 800 FEET. HOWEVER, CONFIDENCE REMAINS LOW
RELATING TO COVERAGE, TIMING, AND INTENSITY. DUE TO LOW
CONFIDENCE, KEPT VCSH FOR KBFF AND KAIA AS HI-RES GUIDANCE
CONTINUES TO BACK OFF ON THE SNOWFALL AND ASSOCIATED RATES.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...RZ
LONG TERM...MN
AVIATION...RZ
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page