421
FXUS65 KCYS 091729
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1129 AM MDT THU JUL 9 2026
KEY MESSAGES
- SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON WITH HEAVY
RAINFALL, HAIL, AND STRONG GUSTY WINDS POSSIBLE.
- AN UPPER LEVEL RIDGE IS MAY BRING RED FLAG CONDITIONS AND
POTENTIAL HEAT ADVISORY HEADLINES STARTING THIS WEEKEND.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 223 AM MDT THU JUL 9 2026
TODAY WILL BE ALMOST A WASH, RINSE, AND REPEAT OF YESTERDAY. MODELS
HAVE SHOWERS MOVING INTO OUR AREA AROUND 18Z WITH THUNDERSTORM
DEVELOPMENT OCCURRING AROUND 21Z. CONVECTION LOOKS TO FOLLOW THE
DIURNAL TREND ONCE MORE WITH SEVERE THUNDERSTORMS COINCIDING WITH
PRIME HEATING AND THEN WANING OFF AROUND 04Z. MOST OF OUR FORCING
LOOKS TO EXIT OUR AREA AROUND 03Z SO THERE MAY BE SOME LINGERING
SHOWERS GOING UNTIL ABOUT 06Z OR MIDNIGHT. BULK SHEAR LOOKS TO BE
AROUND 30-40KTS WITH A TEMPORARY INCREASE IN INTENSITY OF 50KTS NEAR
THE WY/NE BORDER AROUND 00Z THEN PUSHING EAST INTO CENTRAL NEBRASKA.
THE THUNDERSTORMS WILL PROBABLY BE PULSY UNTIL THAT BETTER SHEAR
OCCURS TO REALLY ORGANIZE AND SUSTAIN THE THUNDERSTORMS. MAIN
THREATS WILL BE GUSTY WINDS ESPECIALLY WHEN THE STORMS ARE PULSY.
BUT ONCE THE STORMS START TO ORGANIZE THE HAIL THREAT WILL INCREASE
WITH HAIL STONES POTENTIALLY UP TO GOLF BALLS BUT THE WINDOW FOR
THAT LARGE OF HAIL IS GOING TO BE PRETTY LIMITED AS THE FORCING
STARTS TO DEPART THE AREA. TORRENTIAL RAINFALL LOOKS LIKELY AGAIN AS
PWAT VALUES CREEP TOWARDS THE 1.0 TO 1.25 INCH MARK. URBAN FLOODING
MAY BE A FACTOR TO CONSIDER FOR TODAY ESPECIALLY IF THE STORMS ARE
SLOW MOVING SINCE THE UPPER LEVELS WINDS LOOK PRETTY LACKLUSTER FOR
TODAY.
FRIDAY, THE INTERMOUNTAIN WEST STARTS DRYING OUT AS THE UPPER LEVEL
RIDGE STARTS BUILD OVER THE REGION. MIN RH VALUES LOOK TO RANGE FROM
15 TO 25 IN SOUTHEASTERN WYOMING AND 25 TO 35 PERCENT IN THE
PANHANDLE FOR ELEVATED FIRE WEATHER CONCERNS. IN THE AFTERNOON THERE
IS SMALL/ISOLATED CHANCE OF SHOWERS MAINLY NEAR THE COLORADO WITH
SOME MODELS HAVING A FEW SHOWERS MOVE IN FROM COLORADO AND DISSIPATE
IN OUR FORECAST AREA. LOW POPS WERE KEPT TO CONVEY THIS POSSIBLE
OUTCOME.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED AT 223 AM MDT WED JUL 8 2026
UPDATE:
SUNDAY THROUGH TUESDAY LOOKS LIKE WIDESPREAD RED FLAG
CONDITIONS AS SYNOPTIC WINDS INCREASE WITH DAILY RH VALUES
DROPPING BELOW 15 PERCENT. THIS COMBUSTIBLE ENVIRONMENT MAY
UNDUE ALL THE WORK THE BENEFICIAL RAIN DID THE PAST COUPLE DAYS.
COMBINED WITH THE WARMER TEMPERATURES ANY FINE FUELS WILL
PROBABLY CURE TO CARRY A WILDFIRE IF ONE DEVELOPS.
PREVIOUS DISCUSSION.
SATURDAY THROUGH WEDNESDAY...RIDGING ALOFT DOMINATES OUR REGION,
WITH QUITE DRY AIR AT LOW AND MID LEVELS, ACCOMPANIED BY 700 MB
TEMPERATURES FROM 14 TO 21 CELSIUS, THUS CHANCES FOR LATE DAY
SHOWERS AND THUNDERSTORMS WILL BE NEARLY NIL AND NON EXISTENT, AND
DRY WEATHER WILL PREVAIL. THE 700 MB TEMPERATURES WILL YIELD MAXIMUM
TEMPERATURES IN THE 90 TO 105 DEGREE RANGE. A WEAK PERTURBATION AND
A SLIGHT INCREASE IN MID LEVEL MOISTURE MAY SPARK ISOLATED
THUNDERSTORMS ON TUESDAY, AND MORESO ON WEDNESDAY, ALONG THE
CONVECTIVE INHIBITION ALOFT GRADIENT ALONG THE I-25 CORRIDOR AND
FURTHER TO THE WEST.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1118 AM MDT THU JUL 9 2026
STORM ACTIVITY WILL BEGIN INCREASING ACROSS THE REGION OVER THE
NEXT COUPLE OF HOURS. ANY STORMS COULD PRODUCE MVFR OR WORSE
CONDITIONS AND GUSTY, VARIABLE WINDS, ALL SITES EXCEPT KRWL
WHERE ONLY WEAK ACTIVITY IS EXPECTED. CLOUD BANKS THIS AFTERNOON
WILL GENERALLY BE AROUND 10K FEET AT BKN, WITH LOWERED CIGS
UNDER ANY STORM ACTIVITY. AFTER STORMS MOVE OUT LATER THIS
EVENING, EXPECT CIGS TO BEGIN LIFTING AND CLEARING, WITH CLEAR
SKIES INTO TOMORROW MORNING. WINDS ARE MESSY THANKS TO SHIFTING
BOUNDARIES ACROSS THE REGION AND THE EXPECTED STORM ACTIVITY,
BUT LOOK FOR PREVAILING WINDS TO GENERALLY BE AROUND 10-20
KNOTS, VARIABLE ACROSS OUR ENTIRE FORECAST AREA, BECOMING LIGHT
AND VARIABLE OVERNIGHT INTO TOMORROW MORNING AS STRONG PRESSURE
GRADIENTS EXIT THE REGION.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...MM
LONG TERM...RUBIN
AVIATION...CG
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page