539
FXUS65 KCYS 282109
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
209 PM MST WED JAN 28 2026
KEY MESSAGES
- MOUNTAIN SNOWFALL EXPECTED TONIGHT THROUGH THURSDAY WITH SNOW
ACCUMULATIONS LESS THAN 6 INCHES.
- MILD WEATHER COOLING OFF LATER IN THE WEEK TO NEAR AVERAGE AS
A FRONTAL SYSTEM PASSES THROUGH THE HIGH PLAINS. VERY LOW
CHANCES OF LIGHT SNOW IN THE NE PANHANDLE ON FRIDAY.
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 1224 PM MST WED JAN 28 2026
NORTHWEST FLOW WILL DOMINATE THE SHORT-TERM FORECAST PERIOD FROM
THIS EVENING THROUGH FRIDAY. TWO SYSTEMS WILL AFFECT OUR WEATHER
THROUGH THIS PERIOD, WITH THE FIRST MOVING THROUGH TONIGHT INTO
THURSDAY MORNING. THIS FIRST SYSTEM COMES IN THE FORM OF A WEAK
SHORTWAVE/VORT MAX RIDING EASTWARD ALONG THE MAIN RIDGE AXIS
OVER THE SOUTHWESTERN CONUS. WHILE THIS SYSTEM WILL LACK ANY
APPRECIABLE SURFACE MOISTURE TO WORK WITH, FORECAST SOUNDINGS IN
THE MID AND UPPER LEVELS DO SUPPORT A PERIOD OF LIGHT TO BRIEFLY
MODERATE SNOW IN THE SIERRA MADRE AND SNOWY RANGES OVERNIGHT
WITH THE BEST CHANCES OF SNOW AROUND DAYBREAK ON THURSDAY.
SHORT-TERM HREF ENSEMBLE MEAN QPF SUPPORTS A LIGHT, SUB-ADVISORY
SNOW EVENT WITH TOTALS RUNNING AROUND 3-6 INCHES ABOVE 9000
FEET. SOME LIGHT SNOW MAY MAKE IT DOWN INTO THE LOWER VALLEYS OF
CARBON AND ALBANY COUNTIES AS WELL, HOWEVER ACCUMULATIONS FOR
RAWLINS OR LARAMIE WILL ONLY REACH AROUND A DUSTING. THIS SYSTEM
QUICKLY EXITS TO THE EAST ON THURSDAY AFTERNOON WITH A BROAD
COLD FRONT PASSAGE REDUCING AFTERNOON HIGHS AREA-WIDE BY AROUND
10 DEGREES COMPARED TO WEDNESDAY.
AFTER A PARTLY CLOUDY EVENING AND OVERNIGHT ON THURSDAY INTO
FRIDAY, ATTENTION TURNS TO A POWERFUL UPPER-LEVEL LOW PRESSURE
SYSTEM AND ARCTIC COLD FRONT LOCATED OVER THE NORTHERN GREAT
PLAINS AND MIDWEST. THIS SYSTEM WILL DIVE SOUTHWARD THROUGH THE
PLAINS ON FRIDAY, WITH AN EXTREMELY POTENT HEIGHT GRADIENT AND
VERY LOW MID-LEVEL TEMPERATURES SETTING UP JUST EAST OF OUR CWA
IN CENTRAL NEBRASKA. THE SURFACE COLD FRONT ASSOCIATED WITH
THIS SYSTEM WILL GRADUALLY BACK WESTWARD THROUGH THE DAY,
PERHAPS SNEAKING INTO THE NEBRASKA PANHANDLE COUNTIES BY SUNSET.
AN AREA OF FRONTOGENETIC FORCING DRIVEN BY THE STRONG GRADIENT
SETTING UP TO OUR EAST MAY RESULT IN A BAND OF LIGHT SNOW
STRETCHING FROM EAST-CENTRAL WYOMING THROUGH THE NEBRASKA
PANHANDLE ON FRIDAY EVENING. THIS FEATURE IS MOST NOTABLY
SUPPORTED IN GFS ENSEMBLE GUIDANCE, WHERE ENOUGH QPF IS FORECAST
TO GIVE THESE LOCATIONS AROUND A COATING TO PERHAPS AN INCH OF
SNOW ON FRIDAY EVENING. FORECAST CONFIDENCE IN THIS LIGHT SNOW
EVENT IS LOW FOR NOW, GIVEN LARGE ENSEMBLE SPREAD IN THE
LOCATION OF THE BEST FORCING AS THIS LOW PRESSURE SYSTEM AND
FRONT RAPIDLY MOVE SOUTHWARD. TOMORROW'S GUIDANCE CYCLES WILL
CERTAINLY BRING THIS POTENTIAL LIGHT WINTER EVENT INTO BETTER
FOCUS.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
ISSUED AT 1224 PM MST WED JAN 28 2026
A RATHER BENIGN PATTERN FEATURING WESTERN US RIDGING AND
EASTERN TOUGHING WILL CONTINUE THROUGH THE LONG-TERM PERIOD. A
WEAK VORT-MAX MOVING UP AND OVER THE WESTERN RIDGE WILL SKIRT
THE SOUTHEAST WYOMING/WESTERN NEBRASKA AREA ON SATURDAY, PERHAPS
BRINGING ANOTHER PERIOD OF LIGHT SNOW TO THE MOUNTAINS. BEHIND
THIS SYSTEM, THE WESTERN RIDGE BUILDS EASTWARD RESULTING IN
HEIGHT-RISES AND WEAK DOWNSLOPE FLOW OVER OUR REGION. EXPECT
AFTERNOON HIGHS TO WARM INCREMENTALLY EACH DAY FROM SATURDAY
THROUGH MONDAY, WITH AFTERNOON HIGHS RUNNING AROUND 15 DEGREES
ABOVE AVERAGE ON BOTH SUNDAY AND MONDAY. AS HAS BEEN THE CASE IN
THE PAST SEVERAL GUIDANCE CYCLES, ENSEMBLES BEGIN TO DIVERGE BY
TUESDAY WITH SOME CLUSTERS SHOWING A SERIES OF WEAK PASSING
TROUGHS AND LIGHT SNOW CHANCES BY THE MIDDLE AND END OF NEXT
WEEK, AND OTHERS KEEPING THE POTENT RIDGE OF HIGH PRESSURE IN
PLACE. SOME MODEL RUNS EVEN SUPPORT A STRONG REX-BLOCK PATTERN
(VERY FAVORABLE FOR DRY AND WARM WEATHER HERE) WITH A LARGE
RIDGE OVER THE PNW AND CUTOFF LOW PRESSURE SYSTEM OVER SOUTHERN
ARIZONA. GIVEN THE PATTERN TRENDS THROUGHOUT MUCH OF THIS
WINTER, WE WILL FAVOR THE DRIER, WARMER SOLUTIONS FOR NOW.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 952 AM MST WED JAN 28 2026
HIGH CLOUDS WILL CONTINUE TO DRIFT FROM THE WEST TO THE EAST
OVER ALL TERMINALS THIS AFTERNOON WITH VFR CONDITIONS AREA WIDE.
OVERNIGHT EXPECT SOME THICKENING AND LOWERING CEILING HEIGHTS AT
RWL AND LAR HOWEVER MVFR THRESHOLDS WILL LIKELY NOT BE BREACHED.
ISOLATED SNOW SHOWERS ARE POSSIBLE AT RWL AS A WEAK SYSTEM MOVES
THROUGH HOWEVER PREVAILING MVFR TO IFR IS NOT EXPECTED TO LAST
MORE THAN 15 MINUTES. CONDITIONS WILL IMPROVE BY SUNRISE ON
THURSDAY WITH VFR EXPECTED AT ALL TERMINALS THROUGH THE DAY.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...MAC
LONG TERM...MAC
AVIATION...MAC
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