500
FXUS65 KRIW 161041
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
441 AM MDT TUE JUN 16 2026
KEY MESSAGES
- WARM, DRY, AND BREEZY CONDITIONS WILL CONTINUE THROUGH THE
WEEK. CHANCES FOR RAIN WILL BE LOW (5 TO 10 PERCENT), MAINLY
LIMITED TO THE MOUNTAINS.
- WIND GUSTS OF 30 TO 40 MPH AND HUMIDITY OF 10 TO 20 PERCENT
WILL LEAD TO WIDESPREAD ELEVATED TO CRITICAL FIRE WEATHER
CONDITIONS ON TUESDAY AND WEDNESDAY.
- A DRY COLD FRONT QUICKLY MOVES THROUGH AREAS EAST OF THE
DIVIDE EARLY WEDNESDAY MORNING, REACHING THE DIVIDE SHORTLY
AFTER SUNRISE. HIGHS WILL BE 5 TO 15 DEGREES COOLER AS A
RESULT.
- CHANCES FOR PRECIPITATION RETURN FOR THE WEEKEND, WITH THE
NORTHERN HALF OF THE FORECAST AREA HAVING THE BEST CHANCES.
DISCUSSION
ISSUED AT 253 AM MDT TUE JUN 16 2026
A SUBTLE RIDGE IS BUILDING IN FROM THE WEST CURRENTLY, AHEAD OF AN
APPROACHING TROUGH AND COLD FRONT. THIS WILL LEAD TO HIGH
TEMPERATURES IN THE UPPER 80S TO LOWER 90S IN THE WIND RIVER AND
BIGHORN BASINS AND PORTIONS OF NATRONA COUNTY. NORTHWEST WINDS WILL
INCREASE THROUGH THE MORNING, WITH GUSTS OF 25 TO 30 MPH EXPECTED
FOR MOST AREAS BETWEEN 16Z AND 18Z (10AM AND 12PM). THESE WINDS WILL
CONTINUE TO INCREASE WITH GUSTS 30 TO 40 MPH EXPECTED AFTER 20Z
ACROSS MUCH OF THE CWA. THESE WINDS, COMBINED WITH RH VALUES BELOW
15% AND ABOVE NORMAL TEMPERATURES, WILL LEAD TO WIDESPREAD CRITICAL
FIRE WEATHER CONDITIONS. A RED FLAG WARNING IS NOW IN EFFECT FOR
PORTIONS OF NATRONA COUNTY, DUE TO THE CRITICAL FUELS IN THIS ZONE.
CONDITIONS WILL REMAIN DRY, WITH A 10% CHANCE FOR VIRGA SHOWERS/DRY
THUNDERSTORMS OVER EASTERN PORTIONS OF THE BIGHORN BASIN UP AGAINST
THE WEST SLOPES OF THE BIGHORNS AND CROSSING OVER JOHNSON COUNTY
BETWEEN 00Z AND 06Z WEDNESDAY.
THE AFOREMENTIONED COLD FRONT WILL QUICKLY MOVE THROUGH AREAS EAST
OF THE DIVIDE LATE TONIGHT/EARLY WEDNESDAY MORNING, REACHING THE
DIVIDE A FEW HOURS AFTER SUNRISE. THIS WILL KEEP WINDS NORTH-
NORTHEASTERLY IN THIS AREA THROUGH THE DAY, AS WELL AS DROPPING HIGH
TEMPERATURES 5 TO 15 DEGREES COOLER FROM TUESDAY. WIND GUSTS OF 35
TO 45 MPH WILL BE IN PLACE OVER NORTHERN PORTIONS IN THE WAKE OF THE
FRONT, AND SOUTHERN PORTIONS AS THE FRONT LOOKS TO REMAIN STATIONARY
ALONG THE DIVIDE THROUGH THE REST OF THE DAY. ELEVATED TO CRITICAL
FIRE WEATHER CONDITIONS WILL REMAIN WIDESPREAD, ESPECIALLY CENTRAL
AND SOUTHERN PORTIONS OF THE CWA, AS WELL AS THE WESTERN VALLEYS.
MORE SEASONAL CONDITIONS RETURN FOR THURSDAY, WITH WINDS NOT BEING
SO STRONG. GUSTS UP TO 25 MPH LOOK TO BE CONFINED OVER AREAS WEST OF
THE DIVIDE IN THE AFTERNOON. A RIDGE LOOKS TO BUILD OVER THE REGION
FROM THE WEST FRIDAY, MARKING A RETURN FOR TEMPERATURES IN THE UPPER
80S AND LOWER 90S. FIRE WEATHER CONDITIONS WILL BE ELEVATED TO
CRITICAL ON THESE DAYS AS WELL, WITH RH VALUES DROPPING INTO THE
SINGLE DIGITS ACROSS THE SOUTH AND POSSIBLY INTO CENTRAL PORTIONS.
CHANCES FOR PRECIPITATION RETURN FOR THE WEEKEND, AS THE REMNANTS OF
A PACIFIC LOW MOVE OVER THE REGION. FOR NOW, THE NORTHERN HALF OF
THE CWA LOOKS TO HAVE THE BEST CHANCES TO RECEIVE ANY PRECIPITATION.
LOCALLY HEAVY RAIN COULD OCCUR FROM THESE STORMS, AS PRECIPITABLE
WATER VALUES OF 0.75" TO 1" ARE FORECASTED.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 435 AM MDT TUE JUN 16 2026
VFR CONDITIONS PREVAIL AT ALL TERMINALS THROUGH THE FORECAST PERIOD.
THE PRESSURE GRADIENT WITHIN NORTHWEST FLOW ALOFT TIGHTENS AS A
SYSTEM MOVES INTO THE NORTHERN ROCKIES LATE TUESDAY. THIS
RESULTS IN GUSTY WEST TO NORTHWEST SURFACE WIND AT ALL
TERMINALS, WHICH DEVELOPS BETWEEN 16Z AND 21Z. WIND GUSTS
25-35KT WILL BE COMMON AFTER 20Z AND THESE SPEEDS CONTINUE
THROUGH AROUND 03Z BEFORE DIMINISHING BY 10-15KT. SHORTWAVE
ENERGY MOVING ACROSS MONTANA THIS EVENING NUDGES A COLD FRONT
INTO NORTHERN WYOMING AROUND 06Z AND CONTINUES SOUTHWARD TOWARD
KRIW, KLND AND KCPR TOWARD THE END OF THE PERIOD. THIS LEADS TO
A NORTHERLY WIND 10-14KT AT KCOD AND KWRL JUST PRIOR TO
06Z AND AT KRIW AROUND 09Z. CURRENT INDICATIONS HAVE THE FRONT
REACHING KCPR AND KLND AFTER 12Z WEDNESDAY.
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 253 AM MDT TUE JUN 16 2026
ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS EXPECTED THROUGH
THE WEEK THIS WEEK. CONDITIONS WILL BE THE MOST CRITICAL TODAY,
WITH WIND GUSTS OF 30 TO 40 MPH EXPECTED ACROSS MUCH OF THE
FORECAST AREA. ABOVE NORMAL TEMPERATURES AND WIDESPREAD CRITICAL
RH VALUES WILL COINCIDE WITH THE WINDS. THUS, A RED FLAG WARNING
IS IN EFFECT FOR ZONE 280 WHERE FUELS ARE CRITICAL AT THIS
TIME.
A DRY COLD FRONT WILL QUICKLY MOVE OVER AREAS EAST OF THE DIVIDE
LATE TONIGHT/EARLY WEDNESDAY MORNING, TURNING WINDS MORE
NORTHERLY IN THIS AREA. GUSTS OF 30 TO 40 MPH WILL RETURN FOR
NORTHERN PORTIONS OF THE FORECAST AREA IN THE WAKE OF THE FRONT,
WHILE SOUTHERN PORTIONS (ZONES 277/278/279) ALSO HAVE NORTHWEST
WINDS GUSTING 30 TO 40 MPH. RH VALUES WILL BE CRITICAL ACROSS
THE SOUTH, AND PORTIONS OF THE WIND RIVER BASIN, AS THE FRONT
IS EXPECTED TO BE STATIONARY ALONG THE DIVIDE THROUGH THE DAY
WEDNESDAY.
RIW WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
WYZ280.
DISCUSSION...LAVOIE
AVIATION...LAVOIE/CNJ
FIRE WEATHER...LAVOIE
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