789
FXUS65 KCYS 232325
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
525 PM MDT SAT MAY 23 2026
KEY MESSAGES
- A WARMING TREND WILL CARRY THROUGH MEMORIAL DAY WEEKEND, WITH
NEAR RECORD HIGH TEMPERATURES POSSIBLE BY MONDAY.
- ISOLATED HIGH-BASED SHOWERS AND STORMS WILL BE POSSIBLE EACH
AFTERNOON OVER THE LONG WEEKEND, BUT RAINFALL WILL BE
LIMITED.
- POTENTIAL FOR THUNDERSTORMS AND RAINFALL WILL INCREASE TUESDAY
AND CONTINUE THROUGH MUCH OF NEXT WEEK.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 145 PM MDT SAT MAY 23 2026
WE ARE ENJOYING A PLEASANT DAY ACROSS THE REGION TODAY AS WE
TRANSITION FROM THE COOL AND UNSETTLED WEATHER PATTERN THAT HAS
DOMINATE THE LAST SEVERAL DAYS INTO A WARMER PATTERN THAT WILL
PREVAIL FOR THE NEXT SEVERAL. ALOFT, THE BROAD TROUGH IS MOVING OUT
AS APPARENT ON GOES SATELLITE IMAGERY, AND RIDGING IS STARTING TO
BUILD IN OVER THE WESTERN CONUS. A VERY DISORGANIZED SERIES OF VORT-
MAXES CONTINUES TO PROGRESS THROUGH THE AREA, PROVIDING SOME
VERY WEAK ASCENT IN PLACE OF MINIMAL INSTABILITY. SBCAPE RANGES
FROM ABOUT 100 TO ABOUT 500 J/KG ACROSS THE AREA, WITH THE
HIGHER VALUES PRESENT FURTHER EAST. THIS WILL SUPPORT A FEW
WIDELY SCATTERED HIGH- BASED SHOWERS, WHICH ARE ALREADY SHOWING
UP ON RADAR AND SATELLITE, CONTINUING THROUGH THE EARLY EVENING.
EXPECT A FEW RUMBLES OF THUNDER AND GUSTY AND ERRATIC WINDS
NEAR THIS ACTIVITY, BUT RAINFALL WILL BE MINIMAL.
RIDGING WILL START TO TAKE OVER ON SUNDAY, PUSHING HIGH TEMPERATURES
ABOVE 10 DEGREES ABOVE TODAY'S VALUES. A JUMBLED MESS OF 500-MB
VORTICITY WILL PUSH IN FROM THE WEST DURING THE AFTERNOON HOURS. AT
THE SAME TIME, A WEAK TAP OF PACIFIC MOISTURE WILL ALLOW MID TO
UPPER LEVEL MOISTURE TO BEGIN TO RECOVER. THIS WILL LEAD TO ANOTHER
ROUND OF HIGH BASED SHOWERS AND THUNDERSTORMS, WITH OVERALL COVERAGE
EXPECTED TO BE GREATER THAN TODAY. RAINFALL WILL ALSO BE MORE LIKELY
TO REACH THE GROUND SUNDAY WITH THE HIGHER MOISTURE CONTENT ALOFT.
THIS ACTIVITY WILL BE CONCENTRATED FURTHER WESTWARD, BEGINNING IN
CARBON COUNTY IN THE EARLY AFTERNOON AND SPREADING EASTWARD LATER IN
THE AFTERNOON AND THROUGH THE EVENING. THIS ACTIVITY WILL START TO
RUN OUT OF STEAM HEADING EAST OF THE I-25 CORRIDOR, BUT EXPECT A FEW
ISOLATED SHOWERS WITH SOME RUMBLES OF THUNDER TO SURVIVE. WITH THE
VORTICITY ALOFT MAINTAINING FORCING INTO THE EVENING, WE COULD SEE A
FEW EVENING HEAT BURSTS AFTER THE SURFACE DECOUPLES FROM THE DEEP,
MIXED BOUNDARY LAYER JUST ABOVE.
MONDAY WILL BE THE WARMEST DAY OF THE PERIOD TO ROUND OUT THE
HOLIDAY WEEKEND. THE RIDGE AXIS WILL SHIFT EAST OF OUR AREA AND
AMPLIFY SIGNIFICANTLY AS A STRONG UPPER LEVEL LOW BEGINS TO DIVE
INTO THE PACIFIC NORTHWEST. ANOTHER MORE SUBTLE UPPER LEVEL LOW OVER
THE DESERT SOUTHWEST STATES WILL SET UP SOUTHERLY FLOW ALOFT AND
INITIATE A PSEUDO-MONSOONAL PATTERN FOR A DAY OR TWO. EXPECT ANOTHER
ROUND OF SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
MONDAY. NBM POPS REMAIN CONSISTENTLY TOO LOW FOR ALL THREE DAYS OF
THE HOLIDAY WEEKEND, BUT SLIGHT CHANCE (20%) POPS FROM THE PREVIOUS
FORECAST WERE MAINTAINED AND SLIGHTLY EXPANDED BETWEEN 18Z AND 06Z
EACH DAY. IN ADDITION, MONDAY WILL BRING A CHANCE FOR RECORD HIGHS.
HIGHS WILL BE AT OR ABOVE THE CLIMATOLOGICAL 90TH PERCENTILE ACROSS
THE AREA, BUT THE GREATEST CHANCE FOR RECORDS IS IN THE NEBRASKA
PANHANDLE, WHERE FORECAST HIGHS ARE GENERALLY WITHIN 1-3 DEGREES OF
THE DAILY RECORD.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED AT 145 PM MDT SAT MAY 23 2026
THE GLOBAL MODELS CONTINUE THE TREND OF A DEEP REINFORCED
TROUGH FROM THE LOW OVER THE ALASKAN BAY AND PUSHING INTO THE
PACIFIC NORTHWEST. THIS WILL STILL PUSH US INTO A SOUTHWEST
ADVECTING IN SOME MOISTURE FROM THE PACIFIC ON TUESDAY. BY
TUESDAY AFTERNOON THE LOW PRESSURE SYSTEM GETS CLOSE ENOUGH TO
SEND A SHORTWAVE AS A CATALYST TO ANOTHER WET PATTERN. THANKS TO
OUR SUMMER SUN, THE SYNOPTIC SET UP OF THIS DEEP TROUGH WILL
LEAD TO DECENT DESTABILIZATION OF THE ATMOSPHERE AND PRODUCE
SCATTERED THUNDERSTORMS FOR THE AFTERNOON AND EVENING. THIS
BOWLING BALL OF A LOW GETS TEMPORARILY CUT OFF FROM THE SYNOPTIC
AS AN OMEGA BLOCK BEGINS TO SETUP OVER THE CONUS REGION. AN
AREA OF HIGH PRESSURE APPEARS TO SIT OVER THE NORTHERN PLAINS
REGION WHILE LOWS SIT AND SPIN OVER THE NOVA SCOTIA REGION AND
THE WEST COAST. WHILE THE LOW FROM THE WEST COAST PARKS ITSELF
OVER NEVADA IT WILL SEND WITH CORRESPONDING SHORTWAVES THROUGH
THE INTERMOUNTAIN WEST FOR ALMOST DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS TO FINISH OUT THE MONTH OF MAY. THE GLOBAL MODELS
STILL SHOW A SORT OF A WET START TO JUNE BUT THE MODELS HAVE
DIVERGED ON THE DETAILS. BUT ANY MOISTURE TO HAVE PUT A DENT IN
THE DROUGHT IS MORE THAN WELCOME FOR SOUTHEAST WYOMING AND THE
NEBRASKA PANHANDLE.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 525 PM MDT SAT MAY 23 2026
CUMULUS CLOUDS ARE ROLLING THROUGH THE REGION BRINGING SOME ISOLATED
TO SCATTERED SHOWERS ACROSS THE NEBRASKA PANHANDLE, NORTH OF A LINE
FROM KBFF TO KAIA. DUE TO DRY CONDITIONS AT THE LOWER LEVELS, THIS
PRECIPITATION MAY HAVE A HARD TIME HITTING THE GROUND. IN
ADDITION, THERE HAS BEEN NO LIGHTNING OBSERVED RECENTLY IN THIS
ACTIVITY. GUSTY WINDS WILL DIE DOWN OVER THE NEXT FEW HOURS FOR
ALL THE TERMINALS, GENERALLY LESS THAN 10 KNOTS. WINDS WILL PICK
RIGHT BACK UP BETWEEN 13Z AND 17Z SUNDAY, FOR MANY OF THE
SITES, WITH WESTERLY GUSTS 15 TO 25 KNOTS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...MN
LONG TERM...MM
AVIATION...RZ
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