105
FXUS65 KCYS 100150
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
750 PM MDT THU APR 9 2026
KEY MESSAGES
- MULTIPLE, WEAKER COLD FRONT WILL PUSH THROUGH OVER THE NEXT
COUPLE OF DAYS, LEADING TO SLIGHTLY COOLER TEMPERATURES AND
INCREASING PRECIPITATION CHANCES HEADING INTO THE WEEKEND.
- THE FIRST STRONG THUNDERSTORMS COULD ARRIVE AS EARLY AS
SATURDAY AFTERNOON TO THE WESTERN NEBRASKA PANHANDLE.
UPDATE
ISSUED AT 749 PM MDT THU APR 9 2026
RED FLAG WARNING FOR SOUTHEAST WYOMING AND THE NE PANHANDLE HAS
BEEN EXPIRED. HUMIDITY VALUES HAVE RISEN ABOVE RED FLAG
THRESHOLDS AS A COLD FRONT HAS MOVED SOUTH THROUGH THE HIGH
PLAINS.
SHORT TERM /THROUGH SATURDAY NIGHT/
ISSUED AT 317 PM MDT THU APR 9 2026
A LAGGING COLD FRONT IS NOW PROGGED TO TRANSIT THROUGH THE FORECAST
AREA THURSDAY EVENING INTO THE OVERNIGHT HOURS. THE CURRENT COLD
FRONT IS ROUGHLY CROSSING THE NORTHERN PORTION OF OUR CWA NEAR
CHADRON. A LAST MINUTE RED FLAG WARNING WAS ISSUED FOR THE SOUTHERN
HALF OF THE NEBRASKA PANHANDLE AND PORTIONS OF PLATTE, GOSHEN, AND
LARAMIE COUNTY THROUGH 8PM AS RH VALUES BELOW 15 PERCENT AND GUSTY
WINDS ARE NOW EXPECTED TO REACH THAT MINIMUM 3 HOUR THRESHOLD. THE
WINDS WILL GRADUALLY DIE DOWN THROUGH THE EVENING AND INTO THE
OVERNIGHT PERIOD ROTATING IN A CLOCKWISE FASHION. BY FRIDAY MORNING
THE WINDS SHOULD BE SOUTHEASTERLY AND PUSHING SOUTHERLY BY THE
AFTERNOON. IN THE MID TO UPPER LEVELS, A TRANSIENT RIDGE MOVES OVER
THE INTERMOUNTAIN WEST. THIS RIDGE WILL TRANSITION THE UPPER LEVELS
TO A SOUTHERLY FLOW EFFECTIVELY DRAWING IN MORE MOISTURE INTO THE
MID-LEVELS AND INCREASE SATURATION ABOVE US TO HELP INCREASE THE
MUCH NEEDED PRECIPITATION CHANCES THROUGH SUNDAY. SATURDAY IS
CONTINUING TO BE A DAY TO WATCH FOR THE POTENTIAL FOR A FEW STRONG
THUNDERSTORMS. THE RIDGE AXIS WILL PEAK OVERHEAD ON SATURDAY BEFORE
STARTING TO SHIFT EASTWARD LATER IN THE PERIOD. 700-MB TEMPERATURES
PEAK AROUND +6 TO +8C. LOOK FOR SATURDAY TO BE THE WARMEST DAY OF
THE PERIOD AS A RESULT, WITH WIDESPREAD UPPER 60S TO 70S EXPECTED. A
FEW LOW 80S COULD SHOW UP IN THE LOWEST ELEVATIONS TOO. AT THE
SURFACE, WE WILL OPEN UP SATURDAY WITH SOUTH TO SOUTHEAST FLOW OVER
THE HIGH PLAINS AROUND THE PERIPHERY OF A VERY LARGE SURFACE HIGH
PRESSURE SYSTEM POSITIONED WELL TO THE EAST. GULF MOISTURE ADVECTION
LOOKS TO BE EXCELLENT FOR THIS TIME OF YEAR, WITH DEWPOINTS EXPECTED
TO REACH INTO THE LOW 40S FOR ALL ALONG AND EAST OF I-25. MORNING
LOW CLOUDS AND/OR FOG LOOK LIKE A GOOD BET, BUT FOG WAS NOT ADDED TO
THE FORECAST YET SINCE WE ARE STILL A FEW DAYS OUT. FORECAST
SOUNDINGS SHOW A FAIRLY POTENT SUBSIDENT DRY LAYER ON TOP OF THE
SHALLOW SURFACE MOISTURE, WHICH WILL PLAY A ROLE IN THE POTENTIAL
FOR AFTERNOON CONVECTION. BROAD SOUTHWEST FLOW ALOFT WILL SUPPORT
LEE CYCLOGENESIS ACROSS CENTRAL WYOMING DURING THE DAY ON SATURDAY.
AS THIS ADVANCES EASTWARD, WE SHOULD SEE THE DRYLINE WHICH WILL BE
POSITIONED ALONG THE LARAMIE RANGE MOVE EASTWARD THROUGH THE DAY.
HOW FAR THE MOISTURE RETREATS TO THE EAST WILL BE THE MAIN
UNCERTAINTY CONCERNING THUNDERSTORM POTENTIAL. AN APPROACHING VORT-
MAX WILL ENHANCE SYNOPTIC LIFT DURING THE AFTERNOON AND EVENING
HOURS, WHICH SHOULD KICK OFF SOME SCATTERED PM SHOWERS AND ISOLATED
THUNDERSTORMS. THE RIGHT BALANCE BETWEEN THE CAPPING INVERSION
WEAKENING, AND THE BOUNDARY LAYER NOT DRYING OUT TOO MUCH WILL NEED
TO BE STRUCK IN ORDER TO GET MORE ORGANIZED THUNDERSTORM POTENTIAL.
THIS IS POSSIBLE, BUT FAR FROM A GUARANTEE. WITH GOOD VERTICAL WIND
SHEAR IN PLACE, A FEW STRONG THUNDERSTORMS WILL BE POSSIBLE, BUT
UNCERTAINTY IS CONSIDERABLE AT THIS LEAD TIME.
LONG TERM /SUNDAY THROUGH THURSDAY/
ISSUED AT 317 PM MDT THU APR 9 2026
WHILE THE STORM TRACK LOOKS TO REMAIN ACTIVE INTO THE EARLY PART OF
NEXT WEEK, THE PROBABILITIES FOR NOTABLE MOISTURE CONTINUE TO
DECREASE. PICKING UP ON SUNDAY, WE WILL BE BEHIND A COMPACT VORT-MAX
MOVING OUT OF OUR AREA TO THE NORTHEAST. THE UPPER LEVEL SYSTEM WILL
DRAW THE ASSOCIATED SURFACE TROUGH OFF TO THE NORTHEAST AS WELL,
WHICH WILL NUDGE THE LOW-LEVEL MOISTURE PLUME OUT OF OUR AREA AND
ALLOW FOR DRY SOUTHWEST FLOW TO OVERSPREAD SOUTHEAST WYOMING AND
WESTERN NEBRASKA. THIS WILL INCREASE THE CHANCE FOR CRITICAL FIRE
WEATHER CONDITIONS RETURNING ON SUNDAY AS 700-MB TEMPERATURES CLIMB
BACK UP TO AROUND +6C. WITH A MUCH DRIER BOUNDARY LAYER AND
TEMPERATURES FAIRLY CLOSE TO SATURDAY'S HIGHS, WE WILL SEE RH
DIPPING INTO CRITICAL TERRITORY. THE WIND IS A LITTLE MORE
UNCERTAIN, BUT THE CURRENT MODEL CONSENSUS WOULD SUPPORT CRITICAL
WIND GUSTS. THESE CONDITIONS MAY CONTINUE INTO MONDAY, BUT CURRENTLY
WINDS LOOK A LITTLE WEAKER AND HUMIDITY A LITTLE HIGHER COMPARED TO
SUNDAY. BOTH SUNDAY AND MONDAY WILL ALSO FEATURE A FEW ISOLATED TO
SCATTERED VIRGA SHOWERS (MORESO ON MONDAY), BUT THE CHANCE FOR
WETTING RAINFALL IS VERY LOW.
UNSETTLED WEATHER WILL RETURN TUESDAY INTO WEDNESDAY AS THE BROAD
TROUGH OVER THE WEST COAST PROGRESSES INLAND. RECENT MODEL GUIDANCE
HAS BEGUN TO COALESCE AROUND A SOLUTION SHOWING A BROAD,
DISORGANIZED SPLIT TROUGH EJECTING ACROSS THE ROCKIES.
UNFORTUNATELY, THIS HAS RESULTED IN QPF TRENDING SHARPLY DOWNWARD
ACROSS THE ENTIRE AREA. WHILE WE SHOULD STILL SEE SOME RAIN AND SNOW
SHOWERS ACROSS THE AREA, THE PROBABILITY OF ORGANIZED, WIDESPREAD
STRATIFORM PRECIPITATION IS LESS THAN 10% AT THIS TIME. NBM POPS AND
QPF HAVE BEEN SLOW TO RESPOND TO THIS CHANGE, AND ARE LIKELY TOO
HIGH AS OF THIS WRITING. MORE PLAUSIBLE IS THE LREF, WHICH HAS
WIDESPREAD PROBABILITIES OF 0.25" OR MORE OF RAINFALL AROUND 10 TO
20%, WITH ABOUT A 40% CHANCE FOR 0.10" OR MORE. HIGHS ON TUESDAY
WILL BE GENERALLY NEAR SEASONAL AVERAGES BEFORE ANOTHER WARMING
TREND COMMENCES ON WEDNESDAY. THE DEPARTING TROUGH (AND/OR ANOTHER
UPPER LEVEL LOW PASSING TO OUR NORTH) MAY HELP TO ACCELERATE WIND
SPEEDS ACROSS THE AREA WEDNESDAY OR THURSDAY. WHILE THE TIMING IS
UNCERTAIN, PROBABILITIES FOR HIGH WINDS RETURNING TO OUR WIND PRONE
AREAS ALONG I-80 AND I-25 CLIMB BACK TO AROUND 50% TOWARDS THE END
OF THE FORECAST PERIOD.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 514 PM MDT THU APR 9 2026
ISOLATED SHOWERS WILL COME TO AN END AFTER 0Z THIS EVENING WITH
ONLY A LESS THAN 20% CHANCE OF SHOWERS AT LAR AND CYS.
OVERNIGHT, EXPECT EASTERLY TO SOUTHEASTERLY UPSLOPE FLOW TO
RETURN TO THE NE PANHANDLE AND POSSIBLY CYS, BRINGING LOWER
CELINGS AT ALL OF THESE TERMINALS. MVFR WILL LIKELY BE THE THE
LIMIT TO CEILINGS AT OR AROUND 2000 FEET OR MORE, HOWEVER THERE
IS AT LEAST A 40% CHANCE OF 1000 FOOT OR LOWER CEILINGS AT CYS
PER THE HREF ENSEMBLE FORECAST. LOW CLOUDS SHOULD LAST
THROUGHOUT THE MORNING ON FRIDAY BEFORE EVENTUALLY SCATTERING IN
THE 21-0Z TIMEFRAME AT ALL TERMINALS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR WYZ431>433.
NE...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NEZ436-437.
UPDATE...MAC
SHORT TERM...MM
LONG TERM...MN
AVIATION...MAC
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page