914
FXUS65 KRIW 180001
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
601 PM MDT SAT OCT 17 2026
KEY MESSAGES
- BREEZY WINDS IN CENTRAL WYOMING WILL CONTINUE OVERNIGHT, BUT
WILL SLOWLY WANE IN INTENSITY, BECOMING LIGHT AFTER SUNRISE
SUNDAY.
- MOSTLY CLEAR CONDITIONS CONTINUE INTO EARLY NEXT WEEK, WITH A
SLIGHT COOLDOWN SUNDAY (COMPARED TO SATURDAY), AS LIGHT NORTH
WINDS PUSH COOLER AIR SOUTHWARD FROM MONTANA.
- HIGH CLOUDS WITH A FEW ISOLATED VIRGA SHOWERS (LIGHT RAIN
EVAPORATING BEFORE THE GROUND) ACROSS FAR SOUTHERN WYOMING
SUNDAY AFTERNOON AND EVENING.
- SCATTERED SHOWERS POSSIBLE (60% CHANCE) FOR THE MOUNTAINS OF
WESTERN WYOMING ON TUESDAY AFTERNOON AND EVENING, BUT ANY
PRECIPITATION ACCUMULATIONS WILL BE MINIMAL.
- A LARGE AND WET WEATHER SYSTEM IS FORECAST FOR FRIDAY INTO
NEXT WEEKEND. A LOT OF UNCERTAINTY ON DETAILS THIS FAR OUT,
BUT THIS SEEMS TO BE THE NEXT CHANCE FOR WIDESPREAD RAIN/SNOW.
UPDATE
ISSUED AT 1231 PM MDT SAT OCT 17 2026
HIGH PRESSURE CONTINUES OVER THE AREA, WITH WARM AND DRY CONDITIONS
REMAINING. CURRENT WATER VAPOR IMAGERY SHOWS THE DRY AIR OVER THE
STATE, WITH A LITTLE MOISTURE BRINGING HIGH CLOUDS ACROSS FAR
NORTHERN WYOMING. NO NOTABLE CHANGES MADE TO THE FORECAST WITH THIS
UPDATE, AS A SUBTLE TROUGH IS STILL EXPECTED TO BRING COOLER (BUT
SEASONAL) TEMPERATURES FOR SUNDAY, AS WELL AS LIGHTER WINDS.
DISCUSSION
ISSUED AT 207 AM MDT SAT OCT 17 2026
H5 RIDGING DOMINATES THE WEATHER TODAY, BRINGING MUCH WARMER
TEMPERATURES ACROSS WESTERN AND CENTRAL WYOMING. THIS WILL
BRING A BEAUTIFUL AUTUMN AFTERNOON ACROSS WYOMING, WITH HIGHS
REACHING THE 60S FOR MOST AREAS. A WEAK TROUGH SWEEPING BY WELL
TO THE NORTH ALONG THE CANADIAN BORDER WILL TIGHTEN THE LOCAL
GRADIENT ENOUGH TO RAMP UP WINDS THIS AFTERNOON, GENERALLY FROM
SOUTH PASS EAST ACROSS NATRONA AND JOHNSON COUNTIES. GUSTS IN
THESE AREAS WILL REACH 30 TO 40 MPH. THIS GUSTY WIND WILL ALSO
TAP SOME DRIER AIR ACROSS JOHNSON COUNTY, PUSHING TEMPERATURES
THERE EVEN HIGHER, REACHING THE MID TO UPPER 70S.
THE SYSTEM TO THE NORTH WILL BRING A WEAK COLD FRONT DOWN ALONG
THE I-25 CORRIDOR AFTER SUNSET, BRINGING LIGHTER NORTH WINDS,
AND DRAWING TEMPERATURES BACK DOWN CLOSER TO NORMAL INTO THE
DAY SUNDAY. HIGHS WILL DRAW BACK DOWN TO THE LOW 60S, SIMILAR TO
THE REMAINDER OF WESTERN AND CENTRAL WYOMING.
MODELS ARE GETTING MORE CONSISTENT ON THE LARGER TROUGH THAT
WILL BE DROPPING SOUTHWARD ALONG THE WEST COAST THIS WEEK. THIS
WILL PUT WYOMING IN SOUTHWESTERLY FLOW BETWEEN THE TROUGH AND
THE AMPLIFYING RIDGE ACROSS THE GREAT PLAINS. A DECAYING CUTOFF
TROUGH WILL WRAP AHEAD OF THE DIVING COASTAL TROUGH AND ZIP
NORTHWARD TUESDAY ACROSS WESTERN WY. MOISTURE WITH THIS
DECREASING SYSTEM IS LIMITED, SO A FEW SHOWERS ARE POSSIBLE
TUESDAY AFTERNOON, BUT ANY ACCUMULATIONS WILL BE MINIMAL AT
BEST. THE TROUGH HOLDS IN PLACE FOR A COUPLE DAYS ACROSS CENTRAL
CALIFORNIA BEFORE EJECTING TO THE NORTHEAST LATE IN THE WEEK.
WHERE THIS TROUGH MOVES NORTHEAST WILL HAVE BEARING ON
PRECIPITATION CHANCES AND AMOUNTS WHEN IT MOVES THROUGH
THURSDAY AND FRIDAY.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 555 PM MDT SAT OCT 17 2026
VFR CONDITIONS PREVAIL OVER THE NEXT 24 HOURS, WITH NO
PRECIPITATION FORECAST. LOCATIONS ACROSS CENTRAL WYOMING,
INCLUDING CPR, WILL CONTINUE TO SEE BREEZY SOUTHWEST WINDS INTO
THE OVERNIGHT HOURS, BUT GUSTS WILL BEGIN TO WANE AFTER
18/0300Z, AND ULTIMATELY BECOME LIGHT AROUND SUNRISE SUNDAY. AT
COD, SURFACE WINDS WILL QUICKLY BECOME LIGHT AFTER SUNSET, BUT
BREEZY WEST WINDS LINGER A COUPLE THOUSAND FEET OFF THE GROUND
UNTIL AFTER MIDNIGHT. LIGHTER WINDS ARE FORECAST FOR SUNDAY,
WITH A SUBTLE SHIFT TO NORTHERLY FOR BASINS EAST OF THE
CONTINENTAL DIVIDE.
RIW WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...WITTMANN
DISCUSSION...STRAUB
AVIATION...VANDENBOOGART
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