817
FXUS65 KCYS 010608
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1208 AM MDT FRI MAY 1 2026
KEY MESSAGES
- CHANCES FOR SCATTERED RAIN AND SNOW SHOWERS WILL CONTINUE FOR
PORTIONS OF SOUTHEAST WYOMING THROUGH THIS EVENING. ISOLATED
THUNDER REMAINS POSSIBLE.
- WARMER AND DRIER CONDITIONS ARE EXPECTED TO RETURN FOR FRIDAY
INTO THE WEEKEND WITH ELEVATED FIRE WEATHER CONCERNS POSSIBLE
FRIDAY AND SATURDAY.
- COOLER WEATHER RETURNS BY EARLY NEXT WEEK AS A MESSY AND
SOMEWHAT PROGRESSIVE PATTERN RETURNS.
SHORT TERM /THROUGH SATURDAY/
ISSUED AT 230 PM MDT THU APR 30 2026
SENSIBLE WEATHER CONCERNS ARE ON THE DECLINE THROUGH THE START
OF THE WEEKEND AS TROUGHING BEGINS TO EXIT WITH RIDGING
BUILDING IN. FOR THE REST OF TODAY, THE LIMITED PRECIPITATION WE
HAVE SEEN WILL BEGIN DECLINING, EXITING TO OUR SOUTH AS THE
SHORTWAVE THAT PRODUCED THIS MOVES SOUTHWARDS AS WELL AND
RIDGING FROM THE WEST TRIES TO BUILD IN. FOR TONIGHT EXPECT
SKIES TO CLEAR FROM NORTH TO SOUTH WITH DRY AIR BUILDING IN, AND
CLEAR CONDITIONS BY FRIDAY MORNING.
BEYOND THIS, THE BUILDING RIDGE WILL THEN BE OUR PRIMARY WEATHER
FEATURE THROUGH THE START OF THE WEEKEND. SPRING WARMTH WILL
REBOUND, WITH HIGHS ON FRIDAY IN THE 50'S AND 60'S, AND THEN UP
INTO THE 60'S TO 70'S BY SATURDAY, AROUND 5 TO 10 DEGREES ABOVE
NORMAL. OUTSIDE OF THIS, THE PRESSURE GRADIENT SHOULD REMAIN
WEAK FOR THE MOST PART, KEEPING WINDS FAIRLY LOW TO CALM, AND
CONDITIONS REMAINING DRY. THAT BEING SAID, THE RETURN OF
ELEVATED FIRE WEATHER CONCERNS IS EXPECTED AS RH VALUES DROP
INTO THE 20'S TO TEENS ON FRIDAY, AND THEN BOTTOM OUT IN THE LOW
TEENS ON SATURDAY. WINDS MAY PEAK AROUND 15 TO 20 MPH GUSTS, BUT
CURRENT FORECAST REASONING KEEPS STRONGER WINDS THAT WOULD BRING
CRITICAL FIRE DANGER CONCERNS OUT OF THE AREA, BUT SOMETHING TO
KEEP AN EYE ON IN CASE PRESSURE GRADIENTS STRENGTHEN EARLY AS
RIDGING BEGINS TO FLATTEN INTO THE LONG TERM PERIOD.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
ISSUED AT 230 PM MDT THU APR 30 2026
- COOL AND UNSETTLED WEATHER WILL PREVAIL FOR SUNDAY THROUGH
TUESDAY, WITH A RIDGE ALOFT HELPING TO PRODUCE DRIER AND WARMER
WEATHER FOR WEDNESDAY AND THURSDAY.
SUNDAY...NORTHWEST FLOW ALOFT CONTINUES, AND WITH A WEAK SHORTWAVE
TROUGH ALOFT MOVING ACROSS EASTERN WYOMING IN THE AFTERNOON, WE
EXPECT TO SEE ISOLATED SHOWERS AND THUNDERSTORMS NORTH OF A LUSK TO
CHADRON LINE, WITH DRY CONDITIONS ELSEWHERE. 700 MB TEMPERATURES
NEAR 5 CELSIUS WILL YIELD MAXIMUM TEMPERATURES IN THE MID 60S TO
LOWER 70S.
MONDAY...ANOTHER SHORTWAVE TROUGH ALOFT MOVES NEARBY, AND WITH
ADEQUATE LOW AND MID LEVEL MOISTURE, WE ANTICIPATE SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS MAINLY SOUTH OF A
DOUGLAS TO ALLIANCE LINE. TEMPERATURES SLIGHTLY COOLER WITH MORE
CLOUD COVER AND PRECIPITATION COVERAGE.
TUESDAY...MOIST NORTHWEST FLOW ALOFT WILL HELP PRODUCE ANOTHER ROUND
OF SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. WITH
700 MB TEMPERATURES ONLY NEAR 2 CELSIUS, MAXIMUM TEMPERATURES WILL
RISE ONLY INTO THE 50S TO NEAR 60 DEGREES.
WEDNESDAY...ALTHOUGH THE FLOW ALOFT REMAINS NORTH NORTHWEST, 500 MB
HEIGHTS RISE FROM 5640 METERS TO 5720 METERS AS THE RIDGE OVER THE
PACIFIC NORTHWEST BEGINS TO BULGE ACROSS THE NORTHERN ROCKIES. THIS
WILL EFFECTIVELY DECREASE THE AREAL COVERAGE OF LATE DAY SHOWERS AND
THUNDERSTORMS TO A MORE ISOLATED VARIETY.
THURSDAY...AS THE RIDGE ALOFT OVER THE GREAT BASIN STATES EXERTS ITS
INFLUENCE OVER OUR COUNTIES, WITH 500 MB HEIGHTS RISING FROM 5720
METERS TO 5760 METERS, WARMER TEMPERATURES ALOFT WILL LIMIT SHOWER
AND THUNDERSTORM CHANCES AND LIKELY KEEP IT DRY. TEMPERATURES WILL
CORRESPONDINGLY WARM INTO THE MID 60S TO MID 70S.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1207 AM MDT FRI MAY 1 2026
AVIATION CONCERNS REMAIN MINIMAL OVERNIGHT AS HIGH PRESSURE MOVING
INTO THE AREA CLEARS CLOUDS OUT OF SOUTHEAST WYOMING AND WESTERN
NEBRASKA. SOME LINGERING MID TO LOW-LEVEL CLOUD COVER WILL BE
POSSIBLE FOR THE REMAINDER OF THE NIGHT, BUT SHOULD BE MOSTLY CLEAR
BY FRIDAY MORNING. LIGHT WINDS ARE ALSO EXPECTED OVERNIGHT, WHICH
HAS CONTRIBUTED TO THE FOG DEVELOPING IN THE LARAMIE VALLEY.
INCREASED MOISTURE FROM SNOW SHOWERS DURING THE AFTERNOON
COMBINED WITH CLEARING SKIES AND CALM WINDS WILL LEAD TO FOG,
DENSE AT TIMES AT KLAR THROUGH ABOUT 14Z.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...CG
LONG TERM...RUBIN
AVIATION...SF
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page