052
FXUS65 KCYS 140837
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
237 AM MDT FRI AUG 14 2026
KEY MESSAGES
- TEMPERATURES WARM A FEW DEGREES ON FRIDAY WITH ISOLATED TO
SCATTERED THUNDERSTORMS EXPECTED ALONGSIDE A MARGINAL RISK OF
SEVERE WEATHER AND A SLIGHT RISK OF EXCESSIVE RAINFALL.
- UNSETTLED WEATHER CONTINUES THROUGH AT LEAST SUNDAY, BRINGING
COOLER THAN AVERAGE TEMPERATURES AND DAILY CHANCES FOR SHOWERS
AND THUNDERSTORMS.
- ISOLATED STRONG TO SEVERE STORMS AND LOCALIZED FLASH FLOODING
WILL REMAIN POSSIBLE THROUGH SUNDAY.
- DRIER WEATHER AND TEMPERATURES CLOSE TO SEASONAL AVERAGES WILL
RETURN EARLY NEXT WEEK.
SHORT TERM /THROUGH SATURDAY NIGHT/
ISSUED AT 230 AM MDT FRI AUG 14 2026
SCATTERED SHOWERS AND WEAKENING THUNDERSTORMS ARE ONGOING ACROSS
THE CWA THIS MORNING, LEFTOVERS FROM YESTERDAY'S ACTIVITY. THESE
SHOWERS SHOULD CONTINUE TO WEAKEN THROUGH SUNRISE, WITH
PRECIPITATION AND CLOUD COVER THEN EXPECTED TO BEGIN CLEARING
OUT THROUGH THE AFTERNOON IN RESPONSE TO DRIER WESTERLY FLOW AT
THE SURFACE, ALLOWING FOR A BIT MORE DAYTIME HEATING THAN
YESTERDAY. TEMPERATURES WILL RISE BACK UP IN RESPONSE TO THIS,
WITH LOCATIONS WEST OF THE LARAMIE RANGE GENERALLY STILL UNDER
ENOUGH CLOUD COVER THAT HIGHS WILL ONLY MAX IN THE UPPER 70'S
FOR THE DAY. EAST OF THE LARAMIE RANGE, WE'LL SEE THE RETURN OF
THE 80'S, WITH A FEW SPOTS IN THE NEBRASKA PANHANDLE POSSIBLY
EVEN ACHIEVING THE VERY LOW 90'S AGAIN. AS FOR OUR THUNDERSTORM
CHANCES, WHILE NOT AS WIDESPREAD AND HEAVY AS THE PAST COUPLE OF
DAYS, WE SHOULD SEE ANOTHER ROUND OF ACTIVITY FORM DURING THE
EARLY AFTERNOON AND CONTINUE INTO THE EVENING, THE STRONGEST OF
WHICH SHOULD FIRE OFF OF THE HIGH TERRAIN AND MOVE ACROSS THE
HIGH PLAINS INTO THE EVENING. THERE WILL BE SOME LIMITATIONS TO
THE STRENGTH OF THIS THOUGH, WITH THE BEST INSTABILITY ALONG THE
BORDER OF AND INTO COLORADO OR FURTHER EAST INTO NEBRASKA. BUT
SOME GUIDANCE STILL PRODUCES DECENT LOW TO MID LEVEL LAPSE
RATES IN THE 8-9 C/KM RANGE, AND BULK 0-6 KM SHEAR HAS POCKETS
IN THE 30-40 KNOT RANGE, SO A FEW STORMS ALONG THE I-80 CORRIDOR
FROM CHEYENNE THROUGH THE PANHANDLE COULD BE STRONG TO SEVERE.
ALSO, OUR PWATS DEFINITELY AREN'T SHABBY, IN THE 1.2-1.4 INCHES
RANGE, AND A FEW POCKETS NEARING 1.5 INCHES ARE SHOWING UP, SO
ANY SHOWERS AND STORMS COULD ONCE AGAIN PRODUCE MODERATE TO
HEAVY RAINFALL. AND WITH SOILS NOW AT LEAST MOIST FROM MULTIPLE
ROUNDS OF PRECIPITATION, IT MAY BE EASIER AGAIN FOR LOCALIZED
FLOODING TO OCCUR.
SATURDAY WE WILL COOL BACK DOWN BY A FEW DEGREES INTO THE
WIDESPREAD 70'S AND LOW 80'S AS A MODEST COLD FRONT DROPS ACROSS
THE REGION, POSSIBLY AIDED BY POCKETS OF CLOUD COVER LINGERING
FROM FRIDAY'S ACTIVITY. BUT WE ARE ANTICIPATING SOME FAIRLY
DECENT DESTABILIZATION ON SATURDAY ACROSS THE HIGH PLAINS, WITH
MORE WIDESPREAD AND FAVORABLE CAPE IN THE 1000-2000 J/KG RANGE,
STEEP LAPSE RATES, AND MORE READILY AVAILABLE BULK SHEAR.
BECAUSE OF THIS, A SLIGHT RISK OF SEVERE WEATHER IS EXPECTED
FROM CHEYENNE EASTWARDS AND ACROSS MOST OF THE NEBRASKA
PANHANDLE, WITH LARGE HAIL AND DAMAGING WIND GUSTS THE MOST
LIKELY HAZARDS. PWAT VALUES WILL GENERALLY MIRROR FRIDAY'S AS
WELL, SO ANY STRONG OR TRAINING STORMS COULD EASILY PRODUCE
EXCESSIVE RAINFALL ONCE AGAIN. LIKELY SCENARIO FOR THIS ACTIVITY
WILL BE STORMS CONSOLIDATED INTO CLUSTERS OR A LINEAR SEGMENT
AS THEY START MOVING OUT OF THE CWA TOWARDS THE EARLY EVENING,
WITH A FEW STRAGGLERS POSSIBLE OUTSIDE OF THIS, BUT OTHERWISE
NOT THE WIDESPREAD LINGERING PRECIPITATION FROM THE LAST COUPLE
OF DAYS.
LONG TERM /SUNDAY THROUGH THURSDAY/
ISSUED AT 1150 AM MDT THU AUG 13 2026
SATURDAY...MOIST WESTERLY FLOW ALOFT AND A WEAK SHORTWAVE TROUGH
ALOFT NEAR PEAK HEATING WILL COMBINE WITH DEEP ATMOSPHERIC MOISTURE
SUPPLY TO PRODUCE SCATTERED TO NUMEROUS SHOWERS AND SCATTERED
THUNDERSTORMS IN THE AFTERNOON AND EVENING, WITH THE GREATEST AREAL
COVERAGE EAST OF INTERSTATE 25. AIDING IN THE LIFT WILL BE LOW LEVEL
SOUTHEAST WINDS ADDING THE MECHANICAL LIFT IN ADDITION TO DIURNAL
HEATING. PWAT, PRECIPITABLE WATER VALUES LOOK DECENT FOR BENEFICIAL
RAINFALL. 700 MB TEMPERATURES YIELD HIGHS IN THE 70S TO LOWER 80S.
SUNDAY...RIDGING BECOMES A BIT MORE PRONOUNCED OVER WYOMING,
PRODUCING WARMER TEMPERATURES ALOFT WHICH WILL TEND TO LIMIT AREAL
COVERAGE OF SHOWERS AND THUNDERSTORMS, COMPARED TO SATURDAY.
NEVERTHELESS THOUGH, THE MONSOONAL MOISTURE WILL STRETCH FROM
CENTRAL COLORADO THROUGH FAR EASTERN WYOMING AND WESTERN NEBRASKA,
WHERE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR IN
THE AFTERNOON AND EVENING. SLIGHTLY WARMER, BUT COMFORTABLE,
TEMPERATURES FOR THIS TIME IN AUGUST.
MONDAY...A DRIER PATTERN ENSUES AND IS ON TAP AS THE FLOW ALOFT
TURNS WEST NORTHWEST AND THE PRECIPITABLE WATER VALUES DECREASE, DUE
TO DRYING AT LOW AND MID LEVELS AND DOWNSLOPE SOUTHWEST WINDS NEAR
THE SURFACE. THUS, A MUCH DRIER DAY WHEN COMPARED TO THE WEEKEND. A
WARMING TREND BEGINS WITH MORE SUNSHINE AND WARMER MID LEVEL
TEMPERATURES.
TUESDAY...BRISK WESTERLY FLOW ALOFT PREVAILS, AND WITH A DECENT
AMOUNT OF LOW AND MID LEVEL MOISTURE AVAILABILITY, EXPECT ISOLATED
TO WIDELY SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS, MAINLY EAST
OF INTERSTATE 25 AND THE LARAMIE RANGE. SIMILAR MAXIMUM TEMPERATURES
TO MONDAY BASED ON 700 MB TEMPERATURES.
WEDNESDAY...THE SYNOPTIC PATTERN LOOKS MORE LIKE SEPTEMBER AND EARLY
AUTUMN WITH A DEEP SHORTWAVE TROUGH ALOFT SWEEPING ACROSS WESTERN
MONTANA AND IDAHO, WITH WEST SOUTHWEST FLOW ALOFT OVER OUR COUNTIES.
RIGHT NOW, WE HAVE SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS IN
OUR GRIDDED FORECASTS, THOUGH WITH A DECENT INCREASE IN PRECIPITABLE
WATER VALUES, THE MOIST FLOW ALOFT, AND LOW LEVEL UPSLOPE, ALONG
WITH PATTERN RECOGNITION, BELIEVE OUR POPS AND CONVECTIVE COVERAGE
WILL LIKELY NEED TO BE INCREASED IN THE NEXT FEW DAYS.
THURSDAY...THE HIGH AMPLITUDE AND PROGRESSIVE SHORTWAVE TROUGH ALOFT
MOVES EASTWARD FROM WESTERN MONTANA, TO THE DAKOTAS AND WESTERN
NEBRASKA BY EVENING, SENDING A DECENT PACIFIC ORIGIN COLD FRONT
ACROSS OUR COUNTIES. THERE MAY BE ENOUGH MOISTURE AT LOW AND MID
LEVELS FOR ISOLATED TO WIDELY SCATTERED CONVECTIVE COVERAGE, THOUGH
THE BIGGEST CHANGE WILL LIKELY BE A RETURN TO COOLER TEMPERATURES
AND WINDY DOWNSLOPE WEST WINDS, WHICH WILL LIKELY NEED TO BE
ADJUSTED IN THE NEXT FEW DAYS, IF MODEL CONSISTENCY REMAINS FOR DAY
7. IF YOU ARE LOOKING FOR AN EARLY TASTE OF FALL WEATHER, THIS MAY
BE YOUR DAY.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1122 PM MDT THU AUG 13 2026
A TRICKY TAF FORECAST ONCE AGAIN DUE TO LOW CIGS, FG/BR, SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO CAUSE AVIATION IMPACTS THROUGH THE
FIRST PART OF THE OVERNIGHT HOURS. THE PRIMARY HAZARD WILL BE VERY
HEAVY RAINFALL PRODUCING IFR TO LIFR VIS, BUT THERE IS ALSO THE
POSSIBILITY FOR FREQUENT LIGHTNING, GUSTY WINDS, AND SMALL HAIL. BE
ALERT FOR POSSIBLE AMDS THROUGH THIS FORECAST PERIOD. EXPECT
CONDITIONS TO TREND TOWARDS VFR SOMETIME AFTER 14Z FRIDAY DUE TO
DRIER AIR MOVING IN.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...CG
LONG TERM...RUBIN
AVIATION...RZ
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