121
FXUS65 KCYS 061120
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
420 AM MST TUE JAN 6 2026
KEY MESSAGES
- HIGH WINDS WILL CONTINUE INTERMITTENTLY THROUGH WEDNESDAY IN
THE WIND PRONE AREAS OF SOUTHEAST WYOMING AND MAY SPREAD INTO
ADJACENT POPULATED AREAS.
- ELEVATED GRASSLAND FIRE DANGER IS EXPECTED TODAY AND WEDNESDAY
OVER THE HIGH PLAINS.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED AT 245 AM MST TUE JAN 6 2026
WIND WIND GO AWAY, COME BACK ANOTHER DAY, NOT SO FAST. ITS
GONNA BE WINDY ACROSS SOUTHEAST WYOMING FOR A MAJORITY OF THE
SHORT TERM PERIOD, ESPECIALLY FOR OUR WIND PRONES AND PRONE
ADJACENTS. WE HAVE A FEW FACTORS AT WORK, ONE BEING THE
STRENGTHENING OF WINDS AT 700MB UP TO 80 KNOTS BY THIS EVENING
ALONG WITH AMPLE SUBSIDENCE TO MIX THESE WINDS DOWN TO THE
SURFACE. WITH A TIGHT PRESSURE GRADIENT AT THE SURFACE, GUSTS
AS HIGH AS 70 MPH ARE POSSIBLE THROUGH WEDNESDAY MORNING. IN-
HOUSE GUIDANCE HAVE PROBABILITIES IN THE 40-60% RANGE FOR HIGH
WINDS ALONG I-25 FROM THE WYOMING/COLORADO BORDER TO GLENROCK.
THE HIGH WINDS WILL NOT BE CONTINUOUS, THERE WILL BE LULLS,
WITH SOME UNCERTAINTY OF WHEN OR HOW LONG THESE LULLS WILL
OCCUR, HIGH WIND WARNINGS HAVE BEEN ISSUE FOR THE ENTIRE
DURATION OF THIS EVENT, THROUGH WEDNESDAY AFTERNOON. ALONG I-80
FROM CHEYENNE TO RAWLINS, ESPECIALLY IN AND AROUND ARLINGTON,
PROBABILITIES FOR WINDS EXCEEDING 60 MPH IS IN THE RANGE OF
40%-60% IN GENERAL, WITH ARLINGTON NEAR 80%. BY WEDNESDAY
EVENING, MID-LEVEL WINDS WEAKEN ALONG WITH THE SURFACE GRADIENT
LAXING, THUS THE HIGH WINDS WILL DIMINISH RELATIVELY QUICK AFTER
3PM.
NOW WITH ALL THAT WIND TALK OUT OF THE WAY, WHAT WILL THE
TEMPERATURES BE DOING AND HOW ABOUT OUR PRECIPITATION CHANCES IN THE
SHORT TERM? LETS FIRST TALK ABOUT TEMPERATURES, WE ARE NOT EXPECTING
THAT MAJOR COOL DOWN THAT YOU MAY BE WANTING WITH HIGHS TOPPING OUT
IN THE 40S WEST OF I-25 AND LOW TO MID 50S FOR FAR EASTERN WYOMING
INTO THE NEBRASKA PANHANDLE. LOWS, NOT ALL THAT COLD FOR THIS TIME
OF YEAR, WILL DIP INTO THE 20S ACROSS THE HIGHER TERRAIN WEST OF I-
25 AND ONLY INTO THE MID 20S/30S EAST OF THE CORRIDOR. CHANCES OF
PRECIPITATION, RAIN/SNOW, REMAIN VERY LOW THROUGH WEDNESDAY
MORNING. AND AS SUCH, ELEVATED GRASSLAND FIRE DANGER IS
EXPECTED TODAY AND WEDNESDAY OVER THE HIGH PLAINS. HOWEVER, IN-
HOUSE GUIDANCE IS INDICATING AN INCREASE IN CHANCES ACROSS OUR
WESTERN FORECAST ZONES BY WEDNESDAY AFTERNOON, ESPECIALLY ACROSS
THE SIERRA MADRE AND SNOWY RANGES WHERE THEY COULD SEE SEVERAL
INCHES OF NEW POWDER.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED AT 330 PM MST MON JAN 5 2026
WESTERLY FLOW DOES CONTINUE ON WEDNESDAY THROUGH THURSDAY
MORNING. WINDS WILL GRADUALLY START TO DECREASE WEDNESDAY
EVENING AND INTO THE OVERNIGHT PERIOD. THE PREVIOUS HIGH WIND
WARNINGS THAT STARTED AT THE BEGINNING OF THE WEEK WITH END BY
WEDNESDAY EVENING. THE WINDS WILL STILL BE GUSTY ON THURSDAY
HOWEVER THEY CURRENTLY DON'T LOOK TO WARRANT ANY HEADLINES AND
BE DIURNAL IN TREND. THURSDAY ALSO LOOKS TO BE A TEMPORARY BREAK
IN THIS DRY PATTERN. THERE IS A SHORT DISTURBANCE THAT MOVES
THROUGH THE INTERMOUNTAIN WEST THURSDAY INTO FRIDAY. THIS
SHORTWAVE LOOKS TO DEVELOP SOME LEEWARD CYCLOGENESIS TO WHICH
SOME OVER-RUNNING MOISTURE COULD PROVIDE A LIGHT DUSTING OF SNOW
EAST OF I-25 INTO THE SOUTHERN NEBRASKA PANHANDLE. THE PATTERN
MOVES FROM WESTERLY FLOW TO A MORE NORTHERLY FLOW AS THE
SHORTWAVE PUSHES THROUGH. A HIGHLY AMPLIFIED RIDGE STARTS TO
BUILD OVER THE WEST COAST KEEPING THE INTERMOUNTAIN WEST IN A
NORTHERLY FLOW. A WEAK SHORTWAVE DOES PUSH THROUGH THE
INTERMOUNTAIN WEST ON SATURDAY BUT AREAS OUTSIDE OUR MOUNTAINS
LOOK TO REMAIN DRY DURING THIS TIME. SATURDAY EVENING THE RIDGE
LOOKS TO SHIFT EAST AND START TO PUSH INTO THE INTERMOUNTAIN
WEST. SUNDAY AND MONDAY LOOKS TO REMAIN DRY AS THIS RIDGE MOVES
OVER THE INTERMOUNTAIN WEST.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 420 AM MST TUE JAN 6 2026
VFR CONDITIONS WILL PREVAIL ACROSS ALL TERMINALS FOR THE DURATION OF
THIS TAF PERIOD. WINDS WILL BE THE PRIMARY AVIATION CONCERN WITH
GUSTY WINDS AFFECTING ALL TERMINALS AT VARYING TIMES AND MAGNITUDE.
IN GENERAL, EXPECT GUSTS IN THE 30-45 KNOT RANGE, HIGHER END FOR
KRWL, KLAR, AND KCYS. THERE WILL BE BRIEF LULLS IN THE STRONGEST
WINDS AND LLWS IS POSSIBLE BETWEEN NOW AND 17Z FOR ALL TERMINALS
EXCEPT KLAR AND KRWL.
CYS WATCHES/WARNINGS/ADVISORIES
WY...HIGH WIND WARNING UNTIL 5 PM MST WEDNESDAY FOR WYZ106-110-116-
117.
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ107-118.
NE...NONE.
SHORT TERM...RZ
LONG TERM...MN
AVIATION...RZ
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