482
FXUS65 KCYS 042043
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
243 PM MDT THU JUN 4 2026
KEY MESSAGES
- SEVERE WEATHER CHANCES WRAP UP THURSDAY NIGHT WITH A SLIGHT
RISK PRIMARILY FOR OUR NORTHEASTERN ZONES.
- NEAR RECORD HIGH TEMPERATURES AND NEAR CRITICAL FIRE WEATHER
CONDITIONS ARE ANTICIPATED THIS WEEKEND.
- EXPECT A QUICK COOL DOWN ON MONDAY BEFORE HEAT BUILDS BACK INTO
THE AREA TOWARDS THE MIDDLE OF NEXT WEEK.
- THERE IS POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS
ON TUESDAY AND WEDNESDAY.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 239 PM MDT THU JUN 4 2026
CURRENT OBSERVATIONS FROM ACROSS THE AREA POSITION THE DRYLINE
ROUGHLY ALONG THE WYOMING/NEBRASKA BORDER. A CUMULUS FIELD WITH A
FEW SPOTTY SHOWERS HAVE DEVELOPED BEHIND THE DRYLINE AS MODEL
SOUNDINGS STILL SHOW A WEAKLY CAPPED ENVIRONMENT IN THE NEBRASKA
PANHANDLE EARLY THIS AFTERNOON. THIS CAP SHOULD ERODE AWAY SOON AND
AS THESE SHOWERS TREK EASTWARD INTO A MORE FAVORABLE ENVIRONMENT,
A FEW ISOLATED THUNDERSTORMS COULD DEVELOP. CANNOT RULE OUT
THESE STORMS BEING SEVERE, WITH MESO ANALYSIS SHOWING ABOUT 1500
J/KG OF CAPE IN THE PANHANDLE ALONG WITH PRETTY GOOD EFFECTIVE
SHEAR. BOTH LARGE HAIL AND SEVERE WIND GUSTS COULD BE POSSIBLE
GIVEN THE MUCAPE AND DCAPE VALUES ACROSS THE NEBRASKA PANHANDLE.
FOR AREAS BEHIND THE DRYLINE, STRONG INVERTED-V SOUNDING
PROFILES POINT TO GUSTY SHOWERS THIS AFTERNOON. WITH HOW DRY THE
LOW AND MID-LEVELS ARE, ITS LIKELY NOT MUCH, IF ANY,
PRECIPITATION WILL MAKE IT THE GROUND. INSTEAD, ROGUE SEVERE
WIND GUSTS WILL BE POSSIBLE IN THESE DRY MICROBURSTS. HEADING
INTO THE OVERNIGHT HOURS, MODEL SOUNDINGS FROM THE GFS SHOW
PRETTY GOOD ELEVATED CONVECTION WILL EXIST AS WELL AS A SURGE OF
LOW-LEVEL MOISTURE INTO THE NORTHERN NEBRASKA PANHANDLE AND
NIOBRARA COUNTY. AS A RESULT, SOME STRONG STORMS WILL BE
POSSIBLE OVERNIGHT IN THE AFOREMENTIONED AREAS.
MUCH QUIETER WEATHER IS EXPECTED FOR FRIDAY AS ZONAL FLOW DOMINATES
THE UPPER-LEVELS OF THE ROCKIES. DRY AIR ALOFT WILL STAY IN PLACE,
LEADING TO A MOSTLY SUNNY DAY ACROSS THE AREA. TEMPERATURES WILL
REMAIN ON THE WARM SIDE WITH HIGHS IN THE 80S ACROSS THE CWA.
LUCKILY A BREEZE THROUGHOUT THE DAY WILL HELP THE WARM AIR FROM
FEELING STAGNANT.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 239 PM MDT THU JUN 4 2026
HOT TEMPERATURES WILL PREVAIL THIS WEEKEND. A STRONG UPPER LEVEL LOW
PUSHING INTO THE PACIFIC NORTHWEST WILL AMPLIFY A POWERFUL RIDGE
OVER THE ROCKIES AND PLAINS OVER THE WEEKEND. WARM AIR WILL SURGE
NORTHWARD, SENDING TEMPERATURES WELL ABOVE SEASONAL AVERAGES.
SATURDAY WILL BE THE HOTTEST DAY OF THE PERIOD, AND ENSEMBLE MEMBERS
HAVE CONTINUED TO TREND MORE AGGRESSIVE ON THE HOT TEMPERATURES.
NAEFS MEAN 700-MB TEMPERATURES CLIMB TO AROUND +15 TO +17C ACROSS
THE AREA, WHICH WILL RANGE FROM THE CLIMATOLOGICAL 90TH TO 99TH
PERCENTILE ACROSS THE AREA. OVER MOST OF THE AREA, HIGHS WILL EASILY
BE 15 TO 20F ABOVE SEASONAL AVERAGES, WITH THE LARGEST ANOMALIES
AROUND THE CHADRON AREA. MOST LOCATIONS WILL BE WITHIN A FEW DEGREES
OF DAILY RECORD HIGHS, BUT NO RECORDS ARE CURRENTLY FORECAST. THE
RAWLINS TO CHEYENNE CORRIDOR CAN EXPECT HIGHS IN THE MID 80S TO
CLOSE TO 90 DEGREES, WHILE EVEN HOTTER TEMPERATURES WILL SHOW UP IN
THE LOWER ELEVATIONS NORTH AND EAST OF CHEYENNE. PROBABILITIES FOR
100 DEGREE TEMPERATURES ARE AROUND 50 TO 60% IN TORRINGTON,
SCOTTSBLUFF, AND CHADRON, AND AROUND 20 TO 30% IN SIDNEY AND
ALLIANCE. DESPITE A DRY AIRMASS IN PLACE, THE HEAT SHOULD BE
SUFFICIENT TO KICK OFF HIGH-BASED SHOWER AND THUNDERSTORM ACTIVITY.
THERE IS SOME UNCERTAINTY ON THE LOCATION OF THE DRYLINE SATURDAY
AFTERNOON, WHICH WILL DETERMINE WHETHER THIS ACTIVITY WILL BE ABLE
TO PRODUCE NOTABLE RAINFALL, OR IF IT WILL JUST BE THE TYPICAL DRY
MICROBURST THREAT. SUNDAY WILL BE SIMILAR TO SATURDAY. TEMPERATURES
WILL BE NOT QUITE AS HOT AS THE PACIFIC TROUGH APPROACHES FROM THE
WEST, BUT EXPECT HIGHS WELL ABOVE SEASONAL AVERAGES ONCE AGAIN. THE
CONVECTIVE THREAT WILL AGAIN BE DETERMINED BY THE EXACT POSITION OF
THE DRYLINE, WHICH COULD VARY SOMEWHERE BETWEEN ENTIRELY EAST OF OUR
AREA, AND CLOSER TO THE WY/NE STATE LINE.
EXPECT A MODEST COOL DOWN ON MONDAY AS THE SHORTWAVE TROUGH EJECTS
TO OUR NORTH. HOWEVER, MODEL GUIDANCE HAS TRENDED WEAKER AND FURTHER
NORTH WITH THIS COLD FRONT. AS A RESULT, HIGHS MAY ACTUALLY REMAIN
ABOVE SEASONAL AVERAGES ON MONDAY, BUT JUST BY PERHAPS 5 OR SO
DEGREES. THE POWERFUL RIDGE WILL AMPLIFY ONCE AGAIN TUESDAY THROUGH
THE MIDDLE OF NEXT WEEK AS YET ANOTHER TROUGH DIVES INTO THE WEST
COAST. THEREFORE, EXPECT HIGHS TO SURGE TO NEAR RECORD HIGH VALUES
YET AGAIN FOR TUESDAY, WEDNESDAY, AND POSSIBLY BEYOND. ENSEMBLES ARE
NOT VERY OPTIMISTIC FOR WIDESPREAD PRECIPITATION AT ANY POINT DURING
THE FORECAST PERIOD. FIRE WEATHER CONCERNS WILL BE ELEVATED TO NEAR
CRITICAL FOR MOST OF THE NEXT WEEK THANKS TO THE HOT TEMPERATURES
AND DRY AIRMASS EXPECTED TO REMAIN IN PLACE. TUESDAY AND WEDNESDAY
HAVE THE POTENTIAL TO BE PARTICULARLY CONCERNING FIRE WEATHER DAYS
DUE TO INCREASING SOUTHWEST WINDS ALOFT IN BETWEEN THE WEST COAST
TROUGH AND THE POWERFUL RIDGE OVER THE CENTRAL PLAINS.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1139 AM MDT THU JUN 4 2026
THUNDERSTORMS WILL BE THE PRIMARY HAZARD ONCE AGAIN TODAY. LOOK
FOR ACTIVITY TO KICK UP SHORTLY, MAINLY AS HIGH BASED SHOWERS
WITH A FEW RUMBLES OF THUNDER IN SOUTHEAST WYOMING. THERE WILL
BE POTENTIAL FOR GUSTY AND ERRATIC WINDS AT WY TERMINALS THIS
AFTERNOON. ONCE STORMS ENCOUNTER HIGHER MOISTURE IN WESTERN
NEBRASKA, EXPECT THEM TO START PRODUCING LOCALLY HEAVY RAINFALL
AND ISOLATED HAIL IN ADDITION TO THE WIND. THUNDERSTORM ACTIVITY
SHOULD WIND DOWN AROUND 01-02Z.
A FRONTAL BOUNDARY WILL PASS THROUGH LATE THIS EVENING OR EARLY
FRIDAY MORNING. EXPECT A WIND SHIFT TO THE NORTHWEST, NORTH, OR
NORTHEAST FOR THE HIGH PLAINS TERMINALS. WINDS MAY BE GUSTY AT
TIMES. THIS MAY ALSO COME WITH A FEW HOURS OF LOWERED CIGS.
PROBABILITIES FOR MVFR CIGS RANGE FROM 30 TO 60%, SO THIS WAS
HINTED AT IN THE LATEST TAF.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...SF
LONG TERM...MN
AVIATION...MN
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