200
FXUS65 KCYS 071808
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1208 PM MDT TUE JUL 7 2026
KEY MESSAGES
- STRONG TO MARGINALLY SEVERE THUNDERSTORMS EXPECTED TUESDAY
THROUGH THURSDAY FOR MOST LOCATIONS.
- SLIGHT RISK OF SEVERE THUNDERSTORMS WEDNESDAY AFTERNOON AND
EVENING WITH VERY HEAVY RAINFALL, HAIL, AND STRONG GUSTY WINDS
POSSIBLE.
- A RIDGE BUILDS LATE IN THE LONG TERM, DRYING THE AREA OUT AND
PERHAPS BREAKING HEAT RECORDS.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED AT 255 AM MDT TUE JUL 7 2026
SURFACE OBSERVATIONS ACROSS THE REGION SHOW RELATIVELY MILD
TEMPERATURES EARLY THIS MORNING WITH READINGS IN THE UPPER 60S
TO UPPER 70S IN A FEW SPOTS, MAINLY OVER THE WESTERN NEBRASKA
PANHANDLE. SOUTH TO SOUTHEASTERLY WINDS CONTINUE TO RESULT IN
GOOD LOW LEVEL MOISTURE ADVECTION WITH DEWPOINTS IN THE 50S FOR
EASTERN WYOMING AND WESTERN NEBRASKA. WITH DECENT LOW LEVEL
MOISTURE REMAINING OVER THE REGION TODAY...AND SIMILAR
CONVECTIVE PARAMETERS AS YESTERDAY (MONDAY), EXPECT TUESDAY TO
BE NEARLY A CARBON COPY OF YESTERDAY WITH SCATTERED SHOWERS AND
THUNDERSTORMS BY MID TO LATE AFTERNOON. HIGH RESOLUTION CAMS
HAVE BEEN VERY CONSISTENT WITH THIS ACTIVITY DEVELOPING AROUND
NOON ACROSS THE MOUNTAINS AND PUSHING EAST ACROSS THE PLAINS.
SLIGHTLY MORE FAVORABLE SHEAR PROFILES AND SBCAPE/MLCAPE VALUES
AROUND 1500 J/KG/1000 J/KG RESPECTIVELY SHOULD RESULT IN MORE
THAN JUST ISOLATED STRONG TO MARGINALLY SEVERE THUNDERSTORMS.
SPC HAS EXTENDED THE SLIGHT RISK AREA TO INCLUDE EXTREME EAST
CENTRAL WYOMING AND THE FAR NORTHERN NEBRASKA PANHANDLE THIS
AFTERNOON AND THIS EVENING. OVERALL, IT LOOKS LIKE THE PRIMARY
THREAT WILL BE STRONG GUSTY WINDS, AS IT WAS YESTERDAY.
MARGINALLY LARGE HAIL (1.00 TO 1.50 INCH DIAMETER) LOOKS
SLIGHTLY MORE FAVORABLE TODAY ALSO, BUT SHOULD BE VERY ISOLATED
DUE TO THE RELATIVELY WEAK SHEAR...WHICH REALLY DOESN'T INCREASE
UNTIL LATER IN THE DAY. THUNDERSTORM AND/OR SHOWER ACTIVITY MAY
ACTUALLY LINGER WELL INTO THE LATE EVENING HOURS AND AFTER
MIDNIGHT TONIGHT SINCE MODELS NOW SHOW ANOTHER UPPER LEVEL
SHORTWAVE AXIS MOVING INTO CENTRAL WYOMING AND EVENTUALLY EAST
ACROSS THE HIGH PLAINS AFTER MIDNIGHT. HAVE TO KEEP AN EYE ON
THE CONVECTIVE ENVIRONMENT AS THIS FEATURE TRACKS EAST LATER
TONIGHT. NAM AND GFS SOUNDINGS SHOW ELEVATED MUCAPE OF 1000 TO
1500 J/KG NORTH OF I-80. CONFIDENCE IS VERY LOW AT THIS TIME
WITH ALL HIGH RES GUIDANCE SHOWING WEAK AND VERY ISOLATED
ACTIVITY, SO KEPT POP AROUND 20 PERCENT UP UNTIL 3 AM WEDNESDAY
FOR NOW. HIGH TEMPERATURES TODAY MAY BE A FEW DEGREES COOLER
COMPARED TO THE LAST FEW DAYS, BUT HIGHS IN THE MID 80S TO MID
90S ARE EXPECTED FOR A BULK OF THE AREA...WITH HIGHS NEAR THE
CENTURY MARK ACROSS THE NORTHERN AND CENTRAL NEBRASKA PANHANDLE.
FOR WEDNESDAY, ALL MODELS SHOW THE UPPER LEVEL RIDGE FLATTENING
AS NEAR-ZONAL FLOW DEVELOPS OVER THE FORECAST AREA. A POTENT AND
BROAD UPPER LEVEL SHORTWAVE IS FORECAST TO QUICKLY PUSH EAST-
SOUTHEAST ACROSS THE PLAINS. EXPECT WEDNESDAY AFTERNOON AND EVENING
TO BE THE BEST CHANCE SO FAR FOR SEVERE THUNDERSTORMS. INCREASING
MIDLEVEL UNIDIRECTIONAL FLOW WILL RESULT IN NEARLY STRAIGHT
HODOGRAPHS WITH PLENTY OF SPEED SHEAR. THIS SET UP TENDS TO FAVOR
UPSCALE GROWTH AND SQUALL LINES FOR MOST LOCATIONS. A QUICK LOOK AT
THE MODEL SOUNDINGS SHOW CAPE VALUES INCREASING TO 2000 TO 3000 J/KG
WITH PWATS NEAR THE 90TH PERCENTILE. COULD SEE SOME VERY HEAVY RAIN
AND STRONG GUSTY WINDS, WITH THE POTENTIAL FOR MULTIPLE BANDS OF
THUNDERSTORMS AS THE SHORTWAVE MOVES OVERHEAD. NOT SURPRISED TO SEE
SPC INTRODUCE A SLIGHT RISK OF SEVERE THUNDERSTORMS TO MOST OF THE
HIGH PLAINS, INCLUDING THE I-25 CORRIDOR. THIS SLIGHT RISK WILL
FAVOR STRONG GUSTY WINDS, BUT CAN'T RULE OUT SOME LARGE HAIL IN THIS
ENVIRONMENT ALSO. SEVERAL PLACES MAY SEE SOME GOOD RAINFALL AMOUNTS
IN THIS SET UP (FINGERS CROSSED). KEPT POP ON THE HIGH SIDE, BETWEEN
50 TO 70 PERCENT ACROSS A LARGE PORTION OF THE FORECAST AREA.
NOTICEABLY COOLER WITH HIGHS IN THE 80S, BUT COOLING OFF RAPIDLY
WITH ANY NEARBY RAINFALL.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED AT 152 PM MDT MON JUL 6 2026
AFTERNOON THUNDERSTORMS SHOULD BE ONGOING THROUGH THE FIRST COUPLE
OF HOURS OF WEDNESDAY NIGHT. THIS ACTIVITY SHOULD TAPPER OFF BEFORE
MIDNIGHT LEAVING FOR A CLOUD FILLED AND MUGGY NIGHT. SOME FOG COULD
BE POSSIBLE IN PORTIONS OF THE NEBRASKA PANHANDLE.
THURSDAY WILL BE THE LAST DAY IN A STRETCH FOR MILD AFTERNOON
TEMPERATURES. THE REMAINDER OF THE MONSOON MOISTURE AND UPPER LEVEL
LIFTING WILL KEEP THE WEATHER INTERESTING, SOMETHING THAT CANNOT BE
SAID FOR LATER ON. AFTERNOON HIGHS ARE LIKELY TO STAY BELOW 90. WE
WILL NEED TO WATCH THE WESTERN MOST COUNTIES FOR ELEVATED FIRE
CONDITIONS. MINIMUM RELATIVE HUMIDITY VALUES WILL BOTTOM OUT IN THE
MID TO LOWER TEENS FOR PORTIONS OF CARBON, ALBANY, AND CONVERSE
COUNTIES. WINDS LOOK TO BE JUST BELOW RED FLAG CRITERIA AT THIS TIME
HOWEVER. AFTERNOON THUNDERSTORMS ARE ANTICIPATED ALONG I-25 WHERE
MUCAPE VALUES OF AROUND 2000 J/KG AND BULK WIND SHEAR OF 30-40 KNOTS
COULD SUPPORT SOME ORGANIZED THUNDERSTORMS. THE SUB CLOUD LAYER MAY
NOT BE AS DRY AS IT HAS BEEN DURING THE PREVIOUS DAYS ALLOWING FOR
MORE RAINFALL FROM STORMS ALONG WITH SEVERE WEATHER POTENTIAL.
PAST THURSDAY AND THROUGH AT LEAST MONDAY THE UPPER LEVEL RIDGE
BUILDS WITH FORCE AND SUBSIDING AIR STARTS DRYING AND HEATING THE
AREA. A LARGE PORTION OF THE NEBRASKA PANHANDLE WILL SEE +100 DEGREE
AFTERNOONS WHILE THE INNER BASINS SEE 90S. THE GFS HAS BEEN SHOWING
SOME RATHER HOT TEMPERATURES THE LAST FEW DAYS, HOWEVER RUNS
RECENTLY ARE TRENDING DOWN THANKFULLY. THE GFS DOES HAVE A WARM BIAS
AT LONGER RANGES. THAT BEING SAID MODEL BLENDS ARE STILL HOT AND IF
THE RIDGE CENTER SLIDES EAST OF OUR AREA, DOWNSLOPING EFFECTS CAN
CAUSE TEMPERATURES LEE SIDE OF RIDGES TO HEAT A FEW DEGREES ON TOP
OF EXPECTED TEMPERATURES.
LETS TALK ABOUT THE FIRE WEATHER OUTLOOK. NATURALLY THIS SUBSIDING
AIR ALSO DRIES THE ENVIRONMENT EFFICIENTLY AND FORECASTS HAVE
AFTERNOON MINIMUM RELATIVE HUMIDITIES IN THE TEENS AND SINGLE
DIGITS. BEING DIRECTLY UNDERNEATH OF SUCH A STRONG RIDGE DOES HAVE A
PERK, THE WINDS ARE TYPICALLY LESSENED. WE WILL LIKELY STILL SEE 25-
35 MPH WIND GUST DURING THIS PERIOD, BUT CONSISTENT WINDS ABOVE 25
MPH MAY BE DIFFICULT TO ACHIEVE. REGARDLESS, THE ANTECEDENT
CONDITIONS AND CRITICAL FUELS COULD LEAD TO US HAVING AFTERNOON
CRITICAL FIRE CONDITIONS THROUGH MUCH OF THE RIDGING PATTERN
DAYS.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1139 AM MDT TUE JUL 7 2026
A SHORTWAVE TROUGH WILL MOVE TO THE WYOMING AND NEBRASKA STATE
LINE THIS AFTERNOON, WHILE A LOW LEVEL CONVERGENCE AXIS
DEVELOPS FROM DOUGLAS TO CHEYENNE, SPARKING ISOLATED TO
SCATTERED THUNDERSTORMS THIS AFTERNOON AND THIS EVENING, WITH
ISOLATED TO SCATTERED THUNDERSTORMS CONTINUING FROM DOUGLAS TO
CHADRON INTO THE LATE EVENING HOURS.
WYOMING TAFS...VFR PREVAILS. HIGH CONFIDENCE IN ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS FROM 21Z TO 01Z AT RAWLINS,
18Z TO 00Z AT LARAMIE,AND 20Z TO 02Z AT CHEYENNE, WITH SOME
STORMS PRODUCING GUSTY AND ERRATIC WIND GUSTS TO 45 KNOTS ALONG
WITH LOCALIZED MVFR VISIBILITIES. CLEARING SKIES THIS EVENING.
GUSTY USUAL GRADIENTS WINDS UNTIL SUNSET, THEN AGAIN AFTER MID
MORNING WEDNESDAY.
NEBRASKA TAFS...VFR CONTINUES. HIGH CONFIDENCE IN ISOLATED TO
SCATTERED THUNDERSTORMS, WITH THE MOST AREAL COVERAGE AT CHADRON
AND ALLIANCE, AND LESSER SO AT SCOTTSBLUFF AND SIDNEY, WITH
SCATTERED THUNDERSTORMS AT CHADRON AND ALLIANCE FROM 21Z TO 03Z,
WITH SOME STORMS PRODUCING WIND GUSTS OF 45 TO 50 KNOTS ALONG
WITH BRIEF MVFR VISIBILITIES. EXPECT MVFR CEILINGS AND
VISIBILITIES IN LOW CLOUDS AND FOG AT ALLIANCE AND CHADRON FROM
09Z TO 13Z. SKIES WILL BECOME MOSTLY CLEAR WEDNESDAY MORNING.
GUSTY GRADIENT WINDS WILL OCCUR UNTIL SUNSET, AND AGAIN AFTER
15Z WEDNESDAY.
AT SCOTTSBLUFF AND SIDNEY, STORMS SHOULD BE LESS COVERAGE THAN
FURTHER NORTH, THOUGH OCCUR FROM 20Z TO 00Z AT SCOTTSBLUFF, AND
22Z TO 03Z AT SIDNEY, WITH THE STRONGEST STORMS PRODUCING WIND
GUSTS NEAR 45 KNOTS, ALONG WITH BRIEF MVFR VISIBILITIES. SKIES
WILL CLEAR OUT LATE THIS EVENING AND OVERNIGHT. GUSTY GRADIENT
WINDS WILL OCCUR UNTIL SUNSET, AND AGAIN AFTER 15Z WEDNESDAY.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...TJT
LONG TERM...RV
AVIATION...RUBIN
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