782
FXUS65 KCYS 081809
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1209 PM MDT WED JUL 8 2026
KEY MESSAGES
- SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND THURSDAY
WITH HEAVY RAINFALL, HAIL, AND STRONG GUSTY WINDS POSSIBLE.
- A RIDGE BUILDS LATE IN THE LONG TERM, DRYING THE AREA OUT AND
DEVELOPING RED FLAG AND POTENTIAL HEAT ADVISORY CONDITIONS
THROUGH NEXT WEEK.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 405 AM MDT WED JUL 8 2026
A SMALL PLUME OF SHOWERS IS SLOWLY WEAKENING AS IT MOVES EASTWARD
ALONG I-80 THIS MORNING. ONLY A TRACE TO COUPLE HUNDREDTHS IS
EXPECTED FROM THIS SHOWER, SO NO BENEFICIAL RAIN IS EXPECTED
UNFORTUNATELY. ANOTHER SHORTWAVE IS EXPECTED TO PUSH ACROSS THE
REGION THIS AFTERNOON. HI-RES MODELS HAVE INITIATION STARTING
AROUND 20Z BUT THE MAJORITY OF THE FORCING WON'T ARRIVE UNTIL
ABOUT 00Z IN THE FORM OF LOBES OF STRONG VORTICITY. RAP HAS
3CAPE AROUND 5-600 JOULES WITH MUCAPE AROUND 1100 JOULES. THE
MODELS MAINTAIN A RATHER STRAIGHT HODOGRAPH FOR THE MID-LEVELS
WHILE THE SOUNDING INDICATES A RATHER DRY LOWER LEVEL. THIS
ENVIRONMENT BEST SUITS GUSTY WINDS AND LARGE SIZED HAIL. WITH
0-6 BULK SHEAR AROUND 50-60 KTS IN THE PANHANDLE THERE'S ENOUGH
SHEAR TO SEPARATE THE STORMS UPDRAFT AND DOWNDRAFT FOR SUSTAINED
INTENSITY. GIVEN THE SETUP OF A SHORTWAVE WITH ACCOMPANYING
VORTMAXES THE HRRR AND NAM-NEST ARE PROBABLY THE MOST RELIABLE
GIVEN THEIR HISTORY WITH THIS SETUP. BOTH MODELS HAVE
THUNDERSTORMS OCCURRING IN TWO PHASES WITH THE WEAKER SET OF
THUNDERSTORMS HAPPENING FIRST. THE TWO MODELS DIVERGE IN THE
SECOND PHASE AS THE HRRR HAS ALL THE STRONGER STORMS DEVELOPING
NORTH OF OUR FORECAST AREA THEN DROPPING SOUTH INTO THE
PANHANDLE FROM SOUTH DAKOTA FOR A CLASSIC DAWES COUNTY CLIPPER
SCENARIO. THE NAM-NEST HAS ALL THE FORCING STAYING OVER OUR AREA
FROM 00Z TO 06Z AND THE PANHANDLE GETTING ALL THE STORMS. SO IT
WILL BE INTERESTING TO SEE WHERE THE FORCING SETS UP FOR OUR
THUNDERSTORMS TO UTILIZE. SPC HAS THE FAR-EASTERN PORTION OF
WYOMING AND THE ALL OF THE PANHANDLE IN A SLIGHT RISK FOR THIS
AFTERNOON WITH HAIL AND HIGH WINDS AS THE MAIN THREAT. THE
MODELS HAVE THE STORMS ENDING BETWEEN 06Z TO 08Z HOWEVER THE
INTERMOUNTAIN WEST LOOKS TO LOSE THE SHEAR CLOSER TO 04Z SO OUR
SEVERE POTENTIAL WINDOW LOOKS TO BE FROM 22Z TO 04Z OR 2PM TO
10PM TOMORROW. THURSDAY LOOKS TO BE A WASH RINSE REPEAT OF
TODAY. THE SAME INGREDIENTS ARE PRESENT HOWEVER THE BULK SHEAR
LOOKS TO BE A TINY BIT WEAKER THURSDAY AFTERNOON. HOWEVER, THE
PANHANDLE DOES RECEIVE MORE A LITTLE BIT MORE MOISTURE AT THE
SURFACE THURSDAY COMPARED TO TODAY. THIS MEANS THE STORMS WILL
HAVE A MORE ENERGY TO UTILIZE BUT WITH WEAKER SHEAR.
THUNDERSTORMS LOOK TO INITIATE AROUND 21Z AGAIN AND LAST UNTIL
04Z. GIVEN THE WEAKER SHEAR THESE THUNDERSTORMS ARE MORE LIKELY
TO BE PULSY IN NATURE WITH DECENT MICROBURST POTENTIAL BUT ALSO
ABLE TO PRODUCE SOME SEVERE HAIL WHEN THEY PULSE UP. GIVEN THE
HISTORY WITH THIS SECTION OF THE INTERMOUNTAIN WEST, SEVERE
WINDS WILL BE POSSIBLE WITH COLLAPSING CORES AND IN THE
STRATIFORM REGION OF THE STORMS WITH ACCUMULATING HAIL WITH A
COUPLE QUARTERS THROWN IN THERE.
LONG TERM /FRIDAY THROUGH TUESDAY/
ISSUED AT 405 AM MDT WED JUL 8 2026
FRIDAY, THE UPPER LEVEL PATTERN STARTS TO CHANGE AS AN UPPER
LEVEL RIDGE STARTS TO BUILD AROUND THE INTERMOUNTAIN WEST AND
EXPAND INTO THE CENTRAL PLAINS. THE GLOBAL MODELS HAVE COME INTO
AN AGREEMENT ABOUT THE RIDGE BECOMING PRETTY STOUT AND WILL DRY
US OUT POSSIBLE THROUGH THE START OF THE NEXT WORK WEEK. NAEFS
HAS MOST OF WYOMING AND THE PANHANDLE IN THE 90TH AND ABOVE
PERCENTILE THROUGH THE END OF NEXT WEEK. IT WILL BE HOT AND DRY
IN THE LONG TERM FOR A POSSIBLE EXTENDED RED FLAG WARNING FOR
OUR ENTIRE CWA DUE TO THE ALREADY DRY FUELS AND LOW RH'S.
HOWEVER, THE IMPORTANT WIND COMPONENT MAY NOT SHOW UP WHILE
UNDER THIS BROAD RIDGE UNTIL SUNDAY AS A SHORTWAVE LOOKS TO GIVE
US SOME BREEZY CONDITIONS WORTHY OF A RED FLAG. TEMPERATURES
WILL RISE INTO THE 80'S AND 90'S THIS WEEKEND WITH POTENTIAL
90'S AND 100'S BY THE START OF THE NEXT WORK WEEK. STAYING COOL
WILL BE A MUST AND IF YOU HAVE TO WORK OUTSIDE MAY SURE TO TAKE
PLENTY OF BREAKS AND SNACK BETWEEN MEALS SO YOUR BODY CAN RETAIN
SOME ELECTROLYTES THAT WILL BE LOST FROM SWEATING.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1128 AM MDT WED JUL 8 2026
A RELATIVELY ACTIVE DAY FOR THUNDERSTORM DEVELOPMENT IS EXPECTED
THIS AFTERNOON AND EVENING, AS THE STORM PREDICTION CENTER IN
NORMAN, OKLAHOMA HAS A SLIGHT RISK FOR SEVERE THUNDERSTORMS THIS
AFTERNOON AND EVENING, TO THE EAST OF A LUSK TO CHEYENNE LINE,
INCLUDING FAR SOUTHEAST WYOMING AND THE NEBRASKA PANHANDLE. A
MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THIS AFTERNOON EXISTS
ELSEWHERE TO THE WEST OF A LUSK TO CHEYENNE LINE.
SYNOPTICALLY, A NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT WILL
MOVE INTO WESTERN NEBRASKA THIS EVENING, WHILE A LOW LEVEL
CONVERGENCE AXIS DEVELOPS ALONG THE INTERSTATE 25 CORRIDOR, THEN
STORMS WILL DEVELOP AND STRENGTHEN AS THEY DEVELOP AND
PROPAGATE ACROSS FAR SOUTHEAST WYOMING, AND ESPECIALLY THE
NEBRASKA PANHANDLE, WHERE SCATTERED THUNDERSTORMS MAY
CONGLOMERATE AND DEVELOP INTO A MESOSCALE CONVECTIVE COMPLEX, OR
MCC, SOMEWHERE OVER THE NORTHERN OR CENTRAL NEBRASKA PANHANDLE
THIS EVENING, THUNDERSTORMS WILL LIKELY END ACROSS THE NEBRASKA
PANHANDLE IN THE 03Z TIMEFRAME.
WYOMING TAFS...USING THE 16Z HRRR, WHICH HAS CONSISTENTLY BEEN
FAIRLY ACCURATE WITH RESPECT TO TIMING, HIGH CONFIDENCE, AND EXPECT
THUNDERSTORM INITIATION BETWEEN 18Z AND 20Z FROM A DOUGLAS TO
LARAMIE LINE, WITH STORMS STRENGTHENING ALONG THE I-25 CORRIDOR
NEAR 22Z, AND MOSTLY MOVING INTO WESTERN NEBRASKA AROUND 00Z TO
02Z.
EXPECT TEMPO FOR THUNDERSTORMS AT RAWLINS AND LARAMIE FOR MUCH
OF THE AFTERNOON AND INTO THE EARLY EVENING HOURS, AND SOME
STORMS WILL PRODUCE LOW LEVEL TURBULENCE, STRONG DOWNDRAFTS, AS
WELL AS GUSTY AND ERRATIC WINDS UP TO 45 KNOTS, ALONG WITH BRIEF
MVFR VISIBILITY RESTRICTIONS. VFR PREVAILS HOWEVER, WITH CLOUDS
CLEARING OUT LATE THIS EVENING AND OVERNIGHT. AS IS TYPICAL,
EXPECT GUSTY GRADIENT AND MIX DOWN WINDS UNTIL SUNSET.
AT CHEYENNE, BEST CHANCE FOR THUNDERSTORMS, AND HIGH CONFIDENCE,
ACCORDING TO THE LIKELY ACCURATE 16Z RUN OF THE HRRR, WILL BE
FROM 20Z TO 02Z, WITH STORM INITIATION AROUND 20Z, AND STORMS
INCREASING IN COVERAGE AND INTENSITY FROM 22Z TO 01Z. SOME
STORMS WILL PRODUCE LOW LEVEL TURBULENCE, STRONG DOWNDRAFTS, AS
WELL AS GUSTY AND ERRATIC WINDS UP NEAR 50 KNOTS, ALONG WITH
BRIEF MVFR VISIBILITY RESTRICTIONS. VFR PREVAILS HOWEVER, WITH
CLOUDS CLEARING OUT LATE THIS EVENING AND OVERNIGHT. AS IS
TYPICAL, EXPECT GUSTY GRADIENT AND MIX DOWN WINDS UNTIL SUNSET.
NEBRASKA TAFS...HIGH CONFIDENCE IN THE 16Z HRRR RUN, WHICH HAS
CONSISTENTLY SHOWN THUNDERSTORMS DEVELOPING AND/OR PROPAGATING
ALONG THE WYOMING AND NEBRASKA STATE LINE AROUND 23Z, AND
CROSSING THE PANHANDLE DURING THE 00Z TO 03Z TIME FRAME, WITH
CLUSTERS OF THUNDERSTORMS AND A POSSIBLE MCC, MESOSCALE
CONVECTIVE COMPLEX, FORMING THIS EVENING, SOMEWHERE OVER THE
NORTHERN OR CENTRAL NEBRASKA PANHANDLE AND PROPAGATING
SOUTHEASTWARD. THE STRONGEST STORMS WILL BE CAPABLE OF
PRODUCING ONE INCH DIAMETER HAIL OR LARGER, WIND GUSTS IN EXCESS
OF 60 MPH AND LOCALLY HEAVY RAINFALL, ALONG WITH LOW LEVEL
TURBULENCE, AND STRONG DOWNDRAFTS. BRIEF MVFR WILL BE LIKELY
DURING THE THUNDERSTORMS THIS EVENING, WITH SKIES CLEARING OUT
LATE THIS EVENING AND LATE TONIGHT. AS IS TYPICAL, EXPECT GUSTY
GRADIENT WINDS AND MIX DOWN WINDS UNTIL SUNSET.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...MM
LONG TERM...MM
AVIATION...RUBIN
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