779
FXUS65 KRIW 230731
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
131 AM MDT FRI OCT 23 2026
KEY MESSAGES
- LIGHT SHOWERS WILL CONTINUE ACROSS EASTERN FREMONT TO NATRONA
COUNTIES OVERNIGHT, DISSIPATING BY SUNRISE.
- THE MAIN ROUND OF SHOWER ACTIVITY WILL PUSH INTO THE WEST FROM
IDAHO/NORTHERN UTAH BY EARLY FRIDAY MORNING, EXTENDING TO THE
DIVIDE THE REMAINDER OF THE DAY (60-80% COVERAGE).
- STRONG GUSTY SOUTHWEST WINDS OF 40 TO 55 MPH FRIDAY AFTERNOON
AND EARLY EVENING EAST OF THE DIVIDE AHEAD OF FRONTAL PASSAGE
FROM MID AFTERNOON IN THE NORTHWEST THROUGH MUCH OF THE AREA
BY MIDNIGHT. WINDS TURN MORE NORTHWESTERLY AND QUICKLY
DIMINISH THEREAFTER.
- LOW RELATIVE HUMIDITY VALUES AROUND 20 PERCENT, GUSTY WINDS,
AND A WIND SHIFT WILL RESULT IN NEAR-CRITICAL FIRE WEATHER
CONDITIONS ACROSS JOHNSON COUNTY ON FRIDAY.
- MUCH COOLER TEMPERATURES ARE FORECAST THIS WEEKEND BEHIND THIS
WEATHER SYSTEM WITH NEAR SEASONABLE TO BELOW AVERAGE FOR THIS
TIME OF YEAR.
DISCUSSION
ISSUED AT 130 AM MDT FRI OCT 23 2026
IR SHOWS COOLING CLOUD TOPS ACROSS THE CWA AS THE TROPICAL
MOISTURE HAS BEGUN TO INTERACT WITH THE OPEN WAVE PUSHING UP
FROM THE SOUTHWEST NEARING THE CWA. WV IMAGERY SHOWS A
DISJOINTED PFJ DIPPING AROUND THE TROUGH TO THE WEST BUT MAINLY
TO THE NORTH INTO SOUTHERN CANADA WITH A 120-130KT JET MAX
HELPING TO AID THE AFOREMENTIONED SYSTEM THAT WILL AFFECT THE
CWA THROUGHOUT FRIDAY AND LINGERING INTO SATURDAY. RADAR SHOWS A
FEW SCATTERED LIGHT SHOWERS PUSHING ACROSS NATRONA COUNTY THAT
WILL DIMINISH BEFORE SUNRISE FRIDAY MORNING. THE MAIN PUSH OF
PRECIPITATION WILL COME FROM EASTERN IDAHO AND NORTHERN UTAH
LATER THROUGH THE OVERNIGHT HOURS THAT WILL EVENTUALLY SPREAD
EAST TO THE DIVIDE LATER IN THE MORNING. SOME RUMBLES OF THUNDER
ARE POSSIBLE WITH INSTABILITY VALUES IN THE 100-200 J/KG RANGE
INTO THE AFTERNOON. PVA ANOMALIES LOOK TO BE MORE CONSTRAINED
OVER IDAHO AND INTO SOUTHERN MONTANA, LIMITING ANY SIGNIFICANT
ACCUMULATIONS BUT LIMITED MOUNTAIN SNOW IS LIKELY FOR THE HIGHER
ELEVATIONS OF THE WESTERN MOUNTAINS. MORE PROMINENT FOR THE
TETONS AND INTO YELLOWSTONE, 3 TO 5 INCHES ARE POSSIBLE BUT WITH
LOWER CONFIDENCE AT THIS TIME (30-40%). FREEZING LEVELS WILL
REMAIN ABOVE 10KFT AHEAD OF THE COLD FRONT LATER IN THE
AFTERNOON WITH LIMITED PRECIPITATION AT THAT TIME OF FROPA.
WINDS WILL BE OF CONCERN TODAY REMAINING ELEVATED IN MANY AREAS
INTO FRIDAY MORNING ALREADY, WITH A POSSIBLE WEAK MOUNTAIN WAVE
OFF THE SOUTHERN WINDS INTO THE EASTERN PARTS OF THE WIND RIVER
BASIN. GUSTS UP TO 30 TO 35 MPH ARE POSSIBLE WITH THIS BUT NOT
OF HIGH CONCERN AT THIS TIME. WINDS WILL INCREASE THROUGH THE
LATE FRIDAY MORNING HOURS AS THE GRADIENT CONTINUES TO TIGHTEN
AHEAD OF FROPA. SOUTHWEST GUSTS UP TO 40 TO 55 MPH ARE LIKELY
FOR MUCH OF THE AREA, STRONGEST EAST OF THE DIVIDE. HIRES MODELS
INDICATE THE FRONT TO PUSH INTO YELLOWSTONE BY AROUND 4PM AND
PUSHING SOUTHEAST THROUGH THE EVENING HOURS, REACHING EAST OF
THE BIGHORNS BY 6-7PM WHERE THE HIGHEST OF FIRE WEATHER CONCERNS
WILL BE. MOISTURE WILL BE LIMITED EAST OF THE DIVIDE, BUT AREAS
AROUND THE CODY FOOTHILLS OFF THE ABSAROKAS WILL HAVE THE BEST
CHANCE FOR PRECIPITATION WITH FRONTAL PASSAGE, OUTSIDE OF THE
UPSLOPE FLOW OF THE BIGHORNS TO OWL CREEKS/BRIDGERS. MINIMAL
HIGH ELEVATION SNOW AND LIMITED IN THE VALLEY RAIN OF
SIGNIFICANCE BUT AROUND A 20 PERCENT COVERAGE ON THIS OCCURRENCE
HEADING TOWARDS SUNSET FRIDAY EVENING. BY SUNRISE SATURDAY
MORNING, ANY SHOWER ACTIVITY WILL HAVE DIMINISH IN WAKE OF THE
COLD FRONT AS THIS SYSTEM HAS CONTINUED TO UNDER PERFORM WITH
THE MODELS WITH ITS WEAKER TRAJECTORY OVER TIME THIS PAST WEEK.
BEING INDICATIVE OF THE WINTER TO COME IN THE STRONGER EL NINO
PATTERN, IT COULD BE A RECURRING THEME GOING FORWARD AND
ESPECIALLY EAST OF THE DIVIDE.
BEYOND THAT, TEMPERATURES FRIDAY AFTERNOON WILL PUSH 10 TO 20
DEGREE ABOVE AVERAGE DUE TO THE SUPPRESIONAL HEATING AHEAD OF
THE AFOREMENTIONED COLD FRONT. BEHIND IT, EXPECT MORE SEASONABLE
TO JUST BELOW AVERAGE TEMPERATURES OVER THE WEEKEND INTO EARLY
NEXT WEEK TO FEEL MORE FALL-LIKE HEADING INTO THE LAST WEEK OF
OCTOBER IN WYOMING. BEHIND THIS QUICK PUSHING SYSTEM INTO THE
NORTHERN GREAT PLAINS, EXPECT INDUCE RIDGING FOR THE LATER HALF
OF THE WEEKEND AHEAD OF THE NEXT BOWLING BALL OF A LOW COMING
FROM THE GULF OF ALASKA. BY MONDAY MORNING, EXPECT IT TO REACH
THE PACIFIC NORTHWEST REMAINING A CLOSED LOW THAT WILL BEGIN TO
AFFECT THE CWA AND IN PARTICULAR FOR THE WEST BY TUESDAY. THIS
WILL BE MORE INCLINED FOR WESTERN MOUNTAIN SNOW AND REINFORCING
THE COOLER AIR TO ALLOW FOR EVEN SOME VALLEY SNOW WEST OF THE
DIVIDE. TIME WILL TELL, BUT MODELS SHOW A DISJOINTED SYSTEM WITH
MUCH DISAGREEMENT STILL TO COME. STAY TUNED FOR UPDATED
FORECASTS BEYOND THIS SYSTEM FOR FRIDAY IN THE COMING DAYS.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1045 PM MDT THU OCT 22 2026
WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS TERMINALS
A FEW TERMINALS REMAIN VFR TO START THE PERIOD BUT CONDITIONS WILL
GRADUALLY DETEORIATE SHORTLY AFTER THE START OF THE PERIOD BECOMING
WIDELY MVFR. SHOWERS WILL MOVE INTO THE AREA AROUND 09Z FRIDAY WITH
PROB30 GROUPS AT KPNA, KBPI, AND KJAC. MVFR TO POSSIBLY IFR
CONDITIONS MAY BE POSSIBLE THROUGH MUCH OF FRIDAY MORNING. KRKS
LIKELY SEES SHOWERS JUST MISS THE TERMINAL BUT A STRAY LIGHT SHOWER
CANNOT BE RULED OUT BETWEEN 09Z-12Z FRIDAY. CEILINGS AT KPNA AND
KBPI MAY FLIRT WITH MVFR CONDITIONS FOR THE REMAINDER OF THE
MORNING EVEN AFTER SHOWERS DISSIPATE. KRKS SHOULD SEE IMPROVING
CEILINGS FOR THE REST OF THE PERIOD. PREVAILING LIGHT RAIN IS
EXPECTED TO MOVE INTO KJAC BY 19Z AND PERSISTING NEAR THE END OF
THE TAF PERIOD. WINDS WILL INCREASE IN THE MORNING ACROSS ALL
TERMINALS WITH GUSTS OF 20 TO 30 KNOTS AT TIMES DURING THE LATE
MORNING AND THROUGH MUCH OF THE AFTERNOON. WINDS SHOULD DECREASE
A FEW HOURS BEFORE THE END OF THE TAF PERIOD FOR ALL TERMINALS.
MOUNTAINS WILL BE OBSCURED THROUGHOUT MUCH OF THE TAF PERIOD.
EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL TERMINALS
MOSTLY DRY WITH VFR CONDITIONS ACROSS ALL TERMINALS THROUGH THE TAF
PERIOD WITH THE ONE EXCEPTION BEING KCOD. KCOD MAY SEE A FEW CHANCES
FOR SHOWERS DURING THE MORNING HOURS FRIDAY AND ONCE AGAIN BY THE
EVENING INTO THE END OF THE PERIOD FRIDAY. WINDS WILL BE THE MAIN
FOCUS WITH WIDESPREAD STRONG GUSTY WINDS OF 30 TO 45 KNOTS ACROSS
KLND, KRIW AND KCPR STARTING AROUND 12Z FRIDAY. WEAKER WINDS OF 20
TO 35 KNOTS WILL BE POSSIBLE AT THE OTHER TERMINALS. WINDS GRADUALLY
DECREASE BY THE LATE EVENING ON FRIDAY BEFORE THE END OF THE TAF
PERIOD. MOUNTAINS WILL BE OBSCURED THROUGHOUT MUCH OF THE TAF PERIOD.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND ZLC FOR
THE LATEST INFORMATION ON SMOKE, ICING, AND TURBULENCE FORECASTS.
FIRE WEATHER
ISSUED AT 130 AM MDT FRI OCT 23 2026
NEAR CRITICAL FIRE WEATHER CONDITIONS EXPECTED THIS AFTERNOON
AND EARLY EVENING THROUGH SUNSET. GUSTY SOUTHWEST WINDS UP TO 40
TO 55 MPH WIDESPREAD EAST OF THE DIVIDE. HUMIDITY VALUES WILL
DROP TO 20 TO 25 PERCENT WITH THE UNSEASONABLE TEMPERATURES IN
THE AFTERNOON, LOWEST ACROSS JOHNSON COUNTY WHERE A RED FLAG
WARNING IS IN EFFECT FROM NOON THROUGH 8PM THIS EVENING. A COLD
FRONT WILL PUSH THROUGH FROM NORTHWEST TO SOUTHEAST FROM MID
AFTERNOON THROUGH SUNSET TURNING WINDS OUT OF THE NORTHWEST BUT
DIMINISH THEREAFTER BECOMING 10 TO 20 MPH BY MIDNIGHT,
LINGERING IN EASTERN COUNTIES THROUGH SATURDAY SUNRISE. SHOWER
ACTIVITY WEST OF THE DIVIDE WILL DIMINISH THE FIRE WEATHER
CONCERN SOMEWHAT BUT STILL ELEVATED DUE TO THE STRONG WINDS.
RIW WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
WYZ281.
DISCUSSION...LOWE
AVIATION...DZIEWALTOWSKI
FIRE WEATHER...LOWE
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