003
FXUS65 KCYS 072206
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
306 PM MST WED JAN 7 2026
KEY MESSAGES
- HIGH WINDS WILL CONTINUE THROUGH THIS MORNING IN THE WIND
PRONE AREAS, INTERMITTENTLY SPILLING INTO ADJACENT ZONES.
- ELEVATED GRASSLAND FIRE DANGER IS EXPECTED TODAY OVER THE
HIGH PLAINS.
- THE NEXT STORM SYSTEM WILL BRING A CHANCE FOR SNOW SHOWERS AND
A RETURN TO BELOW AVERAGE TEMPERATURES THIS EVENING INTO
FRIDAY.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 304 PM MST WED JAN 7 2026
THE WINDS SHOULD START DIEING OFF BY 00Z AS THE UPPER LEVEL SUPPORT
MOVES WITH THIS INCOMING TROUGH. RIGHT NOW RH VALUES ARE KIND OF LOW
WITH VALUES IN THE MID TO UPPER 20'S. IT WILL TAKE A LITTLE BIT FOR
THE LOWER ELEVATIONS EAST OF I-25 DUE TO THE DOWNSLOPING WINDS
TODAY. FORCING ALSO ISN'T THE GREATEST AS WE HAVE ISENTROPIC DESCENT
LATER TONIGHT COUPLED WITH THE STRONGER FGEN MOVING OFF TO THE EAST
CREATING A LITTLE BIT OF A TIMING ISSUE WITH THE MOISTURE
AVAILABILITY AND THE FORCING NEEDED TO CREATE THE LARGER SNOW
AMOUNTS. THE QPF TOTALS AND SNOW TOTALS WERE CUT DOWN FROM NBM
GUIDANCE DUE TO THIS MISMATCH IN TIMING. HOWEVER, THERE IS SOME
CONVERGENCE IN THE NEBRASKA PANHANDLE TO HELP LIFT THE MOISTURE
PARCELS FOR THE DEVELOPMENT OF SOME POSSIBLE SNOW. THE RECENT RUNS
OF THE HRRR ALSO CUT SNOW TOTALS COMPARED TO PREVIOUS ONES LIKELY
PICKING UP ON THE LACK OF SIGNIFICANT SUPPORT. CHEYENNE MAY SEE
BETWEEN 1-2 INCHES ON THURSDAY AS THE TROUGH PUSHES THROUGH BUT
SIDNEY MAY ONLY SEE HALF AN INCH. IF THE ENVIRONMENT WERE TO
SATURATE IN TIME TO UTILIZE THE STRONGER FORCING THEN WE COULD SEE
SNOW TOTALS FOR THE LOWER ELEVATIONS INCREASE BY 1-2 INCHES. BY
THURSDAY EVENING THE TROUGH IS EXPECTED TO PUSH EAST INTO THE PLAINS
AREA BUT ANOTHER WEAK SHORTWAVE IS EXPECTED TO PUSH THROUGH THE
INTERMOUNTAIN WEST THURSDAY EVENING INTO FRIDAY MORNING. THIS
SHORTWAVE SHOULD PROVIDE ENOUGH FORCING TO PRODUCE ANOTHER COUPLE
TENTHS OF SNOW.
THE GOOD NEWS IS THAT AN ARCTIC AIRMASS FOLLOWS THE TROUGH TONIGHT
LEADING TO MORE SEASONABLE TEMPERATURES THURSDAY. OVERNIGHT
TEMPERATURES WILL DROP INTO THE TEENS THURSDAY NIGHT INTO FRIDAY. SO
THE SNOW THAT FALLS SHOULD STAY AROUND A LITTLE BIT LONGER THAN
PREVIOUS TIMES TO HOPEFULLY HAVE SNOW ON THE GROUND THURSDAY THROUGH
FRIDAY MORNING.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
ISSUED AT 304 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 /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1046 AM MST WED JAN 7 2026
ANOTHER ROUND OF GUSTY WINDS IS ON TRACK FOR THIS AFTERNOON, BUT
GUSTS WILL BE LIGHTER THAN THE LAST FEW DAYS. LOOK FOR
CONSISTENT GUSTS OF 20 TO 30 KNOTS AT ALL TERMINALS, AND TO
AROUND 35 KNOTS AT KRWL AND KLAR. CIGS WILL DROP THROUGH THE
EVENING AND OVERNIGHT HOURS AS THE NEXT STORM SYSTEM APPROACHES.
SNOW SHOWERS WILL ARRIVE AT KRWL FIRST THIS EVENING, WITH
PERIODS OF IFR CONDITIONS LIKELY. HEADING TOWARDS THURSDAY
MORNING, SNOW SHOWERS WILL FILL IN FURTHER EAST. CONFIDENCE IN
IFR IS HIGHEST AT WYOMING TERMINALS (70% CHANCE). CIGS AND VIS
MAY FALL AT NEBRASKA TERMINALS AFTER DAYBREAK, WITH MVFR LIKELY
(70%) AND IFR POSSIBLE (30%).
CYS WATCHES/WARNINGS/ADVISORIES
WY...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ106-107-
110.
NE...NONE.
SHORT TERM...MM
LONG TERM...MN
AVIATION...MN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page